EX-96.2 22 fs42021ex96-2_sustainable.htm TECHNICAL REPORT SUMMARY - INITIAL ASSESSMENT OF THE TOML MINERAL RESOURCE, CLARION-CLIPPERTON ZONE, PACIFIC OCEAN, FOR DEEP GREEN METALS INC., EFFECTIVE AS OF MARCH 17, 2021, BY AMC CONSULTANTS PTY LTD AND OTHER QUALIFIED PERSONS

Exhibit 96.2

 

AMC Consultants Pty Ltd

ABN 58 008 129 164

 

Level 21, 179 Turbot Street

Brisbane Qld 4000

Australia

 

T      +61 7 3230 9000

E       brisbane@amcconsultants.com

W     amcconsultants.com

 

 

 

 

 

 

Technical Report Summary

 

TOML Mineral Resource, Clarion Clipperton Zone, Pacific Ocean

DeepGreen Metals Inc.

 

In accordance with the requirements of SEC Regulation S-K (subpart 1300)

 

 

AMC Project 321012

26 March 2021

 

Unearth a smarter way

 

 

TOML Mineral Resource, Clarion Clipperton Zone, Pacific Ocean
DeepGreen Metals Inc. 321012
  

 

1Executive summary

 

A large deposit of polymetallic nodules is located in the Clarion Clipperton Zone (CCZ) of the northern central Pacific Ocean. Despite the nodules being located at great depths (4000 to 6000 m), they were explored with considerable success between the mid-1960s to the present day using a variety of increasingly sophisticated deep-sea technologies. In early 2012, Tonga Offshore Mining Limited (TOML), then a 100% owned subsidiary of Nautilus Minerals Inc., acquired an Exploration Area of 74 713 km2 of the CCZ. In line with the requirements of the relevant oversight body (International Seabed Authority or ISA) TOML is sponsored by the government of the Kingdom of Tonga. The contract for exploration of polymetallic nodules was approved in July 2011, and then formalised on 11 January 2012. The Exploration area consists of six separate areas (termed Areas A to F) scattered across the CCZ (Figure 1.1).

 

TOML commissioned AMC Consultants Pty Ltd (AMC) to prepare a Technical Report in accordance with the Canadian National Instrument 43-101 reporting standards (NI43-101) and
Form 43-101F1. The Report presented the results of exploration and related studies carried out between 2013 and 2016 and an updated Mineral Resource estimate (AMC, 2016). The Mineral Resource statement was prepared in accordance with the SEC Regulation S-K (subpart 1300).

 

In 2020, DeepGreen Minerals Inc (DeepGreen) acquired the polymetallic nodule exploration contract awarded by the ISA to TOML. DeepGreen commissioned AMC Consultants Pty Ltd (AMC) to recompile the NI43-101 Technical Report (AMC, 2016) as a Technical Report Summary in accordance with SEC Regulation S-K (subpart 1300). AMC understands that DeepGreen may file this Technical Report Summary with the Securities Exchange Commission as part of an S-4 filing to support the merger between Sustainable Opportunities Acquisition Corporation and DeepGreen Metals Inc.

 

Exploration and development efforts in the CCZ started in the 1960s by state sponsored groups from Russia, France, Japan, Eastern Europe, China, Korea and Germany. Several commercial consortia also explored between the 1960s and the 1980s and in some instances their descendants are still involved to the present day. No commercial mining operations have yet been established in the CCZ. However, a variety of collectors, pick-up systems, and metallurgical processing flow sheets were tested, and several integrated “demonstration scale” systems operated in the CCZ for several months in the late 1970s. Processing test-work has encompassed a variety of hydrometallurgical and pyrometallurgical flow sheets, usually with good results.

 

The climate is largely warm, and equatorial surface currents vary by season but are not generally very strong. Wave heights and frequencies are relatively moderate (for the open ocean). Storms are significant for part of the year as a major tropical cyclone belt covers the southern side of the CCZ, approximately one cyclone traverses any given area each year. The deposit is distal from major sea routes used by commercial transport vessels and is marginal to tuna fisheries. No communication cables cross the region.

 

The worldwide occurrence of polymetallic nodules has been known since the late 1800s. They form by the precipitation of metals either directly from ocean waters or via decomposing microorganisms and/or their waste matter in the benthic sediments. The specific conditions of the CCZ (water depth, latitude and seafloor sediment type) are believed to be the key controls on the formation of the CCZ nodule deposit, which is believed to be the largest and highest Ni-Cu-Co grade deposit of this type in the world. Nodules are typically 4 to 6 cm and up to 10 cm in diameter.

 

Unlike most land deposits, seafloor nodule deposits are characterized in terms of abundance, measured in units of wet kg/m2. This is because both the primary exploration method (surface sampling) and likely recovery method (surface collectors or rakes) are unlikely to work at any significant depth below the seafloor (i.e., 0 to 30 cm). Abundances are typically reported as wet weights due to the practicalities of handling the nodule samples, the wet density of studied nodules is around 2 t/m3 irrespective of the nodule size. Studies show nodules to contain around 29% free water and 16% water of crystallisation (incorporated into the complex manganese and iron oxy-hydroxide minerals of formation).

 

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In 2012, Golder Associates Pty Ltd estimated an Inferred Mineral Resource for the entire TOML tenement Area. Part of this data was collected by previous explorers including pioneer contractors representing Japan, Russia and France. This data was obtained directly from the ISA and was not supplied with quality assurance or quality control data. However, verification was possible by cross comparison between all of the six pioneer contractors (also Korea, Germany and an eastern European consortium) who have so far supplied the ISA with data across what is effectively a single large deposit.

 

Figure 1.1Location of the Clarion Clipperton Zone

 

Source: https://www.isa.org.jm/map/clarion-clipperton-fracture-zone, downloaded 18 February 2021

 

Data collected by TOML in 2013 and 2015 supports the historical data but also is of sufficient quantity and quality to allow estimation of an Indicated Mineral Resource for five sub areas within TOML Areas B, C, D and F called B1, C1, D1, D2 and F1. More detailed data collected by TOML has also allowed estimation of a Measured Mineral Resource for a single sub area within TOML Area B. Chain of custody, sample security, Quality Assurance and Quality Control were documented in detail for the TOML data.

 

The key data sets behind the Inferred Mineral Resource estimate for TOML Areas A through E are surface samples obtained by free fall grab samplers, although a few results from box-corers were also included. Free fall grab samplers are the standard sampling method as they are the most productive tool available. They are believed to underestimate the actual abundance, as smaller nodules may escape some grabs during ascent and larger nodules around the edge of the sampler may be knocked or fall out during the sampling process. This may introduce some conservatism to the Inferred Mineral Resource estimates.

 

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The key data behind the Inferred Mineral Resource estimate for TOML Area F and the Indicated and Measured Mineral Resources are box-corers and measured photographs. Box-corers take longer to collect than free fall grab samplers, but they are believed to have less bias. Photos cover a much greater area than either free fall grabs or box-cores. The weight of individual nodules can be accurately estimated from the length of their long or major axis; a relationship first discovered in the 1970s. Using the box-core samples as calibration devices, TOML was able to measure the size of nodules on several hundred photographs in Areas B and C. Abundance is shown to be related both to nodule coverage in photos and to acoustic response (backscatter) from regional survey. These data thus provide very detailed indications of nodule abundance and continuity.

 

Many of the records of the sampling procedures used by the pioneer contractors were not available to the Qualified Persons, but it is likely that all of the pioneer contractors followed similar procedures to that used by TOML. Nodule abundance (wet kg/m2) was derived by dividing the weight of recovered nodules by the surface area covered by the open jaws of the sampler or corer (typically 0.25 to 0.75 m2). A split of the nodules was dried, crushed and ground to enable grade determination via standard analytical methods (typically atomic absorption spectrometry, X-ray fluorescence or inductively coupled plasma methods), either on the vessel or back on shore. Specific nodule chemical standards were used for instrument calibration. TOML also present the results of field, submitted and laboratory duplicates of nodule samples.

 

Analysis of the data reveals that, as a consequence of their origin, nodule grades vary only slightly across the CCZ, with spatial continuity of the abundance, Mn, Ni, Co, and Cu grades often ranging from the order of several kilometres up to several tens of kilometres. Nodule abundance is sometimes less continuous than grade, as it is also subject to local changes in net sedimentation (a consequence of seafloor slope, slumping, erosion and local currents).

 

The TOML Exploration Area has been split into two domains: areas with polymetallic nodules; and areas predominately without polymetallic nodules. The multibeam bathymetry and the backscatter data was used to interpret the parts of TOML Area B to F with no polymetallic nodules.

 

Estimation of tonnage and grade for the TOML Exploration Area within the CCZ was undertaken using only sample data within the TOML Exploration Area. Six block models were constructed using the programs Gstat 1.1-3 and R 3.2.5, one for each TOML Exploration Area (A to F), in three passes. The first pass used a parent block dimension of 1.75 km by 1.75 km and filled the areas defined as Measured Mineral Resource. The second pass for Indicated Mineral Resource used a parent block size of 3.5 km by 3.5 km while the third pass for Inferred used a parent block size of 7.0 km by 7.0 km.

 

The modelling methodology used for estimating the Mineral Resource was determined through careful consideration of the scale of deposit, mechanism of nodule formation, geological controls and nature of the sampling method. The approach involved estimating nodule abundance and grades into a two-dimensional block model with abundance used for calculating tonnage. Abundance and grades were estimated using Ordinary Kriging (OK) with comparison (not reported) estimates using Inverse Distance Weighting (IDW) and nearest neighbour (NN). The modelling methodology is similar to the method applied by the ISA (2010) for its global estimate which was produced by a multi-disciplinary effort that involved recognised subject matter experts.

 

The Mineral Resource estimate, with an effective date of 31 December 2020, is presented in Table 1.1. The Mineral Resource estimate at an abundance cut-off of 4 wet kg/m2 is the selected base case scenario considering a non-selective bulk mining operation.

 

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Table 1.1Mineral resource Estimate for the TOML exploration area within the CCZ at a 4 kg/m2 nodule abundance cut-off

 

Mineral
Resource
Classification
Tonnes
(x106 wet t)*
Abundance
(wet kg/m2)
Ni
(%)
Cu
(%)
Co
(%)
Mn
(%)
Measured 2.6 11.8 1.33 1.05 0.23 27.6
Indicated 69.6 11.8 1.35 1.18 0.21 30.3
Measured + Indicated 72.2 11.8 1.35 1.18 0.21 30.2
Inferred 696 11.3 1.29 1.14 0.20 29.0

 

* Variations in totals are due to rounding of individual values. Mn, Ni, Cu and Co assays on samples dried at 105˚C

 

The TOML Mineral Resource estimates are supported by an Initial Assessment carried out on behalf of DeepGreen for the neighbouring NORI Property (AMC, 2021). The polymetallic nodule deposits in NORI Area D are very similar to those in TOML Areas A to F and the QPs consider that the proposed development of NORI Area D is a reasonable analogue for future development in the TOML Areas. The NORI Property IA is directly relevant and applicable to the TOML Property for the reasons set out below:

 

This polymetallic nodule mineral field within the CCZ is essentially a single mineral deposit almost 5,000 km in length and up to 600 km wide. The size and level of uniformity of mineralization is unmatched by any mineral deposit of similar value on land.

 

The mechanism of formation of the nodules is interpreted to be essentially identical across the entire CCZ, with only minor local variations. Consequently, there is relatively little difference between the size, shape or metal content of the nodules from one area to another.

 

The morphological features of the seafloor are similar in the TOML and the NORI Areas

 

All Areas are administered under a common legal framework.

 

There are no physical or logistical barriers between the Areas. Their location may simply influence shipping costs.

 

The commonality between the polymetallic nodule deposits in NORI Area D and the TOML Areas indicates that the methods proposed for the development of NORI Area D can reasonably be assumed to be equally relevant for future development in the TOML Areas. The Technical Report Summary for NORI Area D assessed the following mining development scenario:

 

The IA proposes that nodules will be collected from the seafloor by self-propelled, tracked, collector vehicles. No rock cutting, digging, drill-and-blast, or other breakage will be required at the point of collection. The collectors will be remotely controlled and supplied with electric power via umbilical cables from production support vessel (PSV). Suction dredge heads on each collector will recover a dilute slurry of nodules, sediment, and water from the seafloor. A hopper on each vehicle will separate sediment and excess water, which will pass out of the hopper overflow, from the nodules, which will be pumped as a higher concentration slurry via flexible hoses to a riser. The riser is a steel pipe through which nodules will be transferred to the surface by means of an airlift.

 

The PSV will support a riser and lift system (RALS) and its handling equipment, and will house the airlift compressors, collector vehicle control stations, and material handling equipment. All power for off-shore equipment, including the nodule collecting vehicles, will be generated on the PSV. The PSVs will be equipped with controllable thrusters and will be capable of dynamic positioning (DP), which will allow the vessels and risers to track the collectors. Nodules will be discharged from the RALS to the PSVs, where they will be dewatered and temporarily stored or transferred directly to a transport vessel.”

 

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A combined pyrometallurgical and hydrometallurgical mineral processing scenario is envisaged. The first part of the pyrometallurgical process is the Rotary Kiln Electric Furnace (RKEF) process that is widely used in the nickel laterite industry. The second pyrometallurgical step (sulphidisation of the alloy produced in the first step to form a matte and then partially conversion in a Peirce-Smith converter to remove iron), while not widely practiced, also has commercial precedent at the Doniambo plant of Societe Le Nickel in New Caledonia.

 

Sulphuric acid leaching of matte from the pyrometallurgical process has precedent in the platinum group minerals (PGM) industry. Although copper producers typically have a solvent extraction step before electrowinning of their copper, direct copper electrowinning is done in most PGM refineries, where nickel and cobalt are also significant pay-metals. This is to maximise nickel recovery and minimise operating expenses. The nickel and cobalt are purified using solvent extraction, ion exchange and precipitation, which are all commercially proven hydrometallurgical processes. Battery grade nickel and cobalt sulphate are then crystallised from the purified solutions.

 

The pyrometallurgical process forms two by-products as well as the matte for the hydrometallurgical refinery:

 

Electric furnace slag containing silica and 53% MnO that is intended to be sold as feed to the Si-Mn industry.

 

A converter aisle slag that could be used for aggregate in road construction or other applications.

 

The hydrometallurgical refinery generates iron residues that would, for a stand-alone plant, require disposal. However, these streams can be recycled back to the pyrometallurgical plant for re-treatment and recovery of entrained pay metals.

 

Selection of ammonia as a principal reagent in the hydrometallurgical refinery means that an additional by-product—ammonium sulphate—is generated. This could be sold into the fertiliser industry.

 

The copper cathode quality from direct electrowinning, without a solvent extraction step, is expected to be ≥99.9% Cu. Quality of the matte produced in the pyrometallurgical plant will have an impact on this, including the potential carryover of impurities beyond values assumed for the purpose of the IA.

 

The production of battery-grade nickel and cobalt sulphates is targeted instead of nickel or cobalt cathodes or other intermediate products.

 

In summary:

 

All parts of the proposed process have commercial precedents in similar or analogous industries, however not as a whole continuous flowsheet.

 

Pay-metals are recovered in the following forms:

 

Copper cathodes with an expected quality of ≥99.9% Cu.

 

Battery-grade nickel sulphate.

 

Battery-grade cobalt sulphate.

 

Rather than generating large waste streams, the process produces by-products including high manganese content furnace slag and ammonium sulphate.

 

The process assumptions used in this study will need to be verified as the project proceeds.

 

The QP considers that this IA supports the view that there are reasonable prospects of economic extraction of polymetallic nodule Mineral Resources in the TOML Areas.

 

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The infrastructure requirements for the development of commercial production in the TOML Areas, apart from the minerals processing facility, will be modest compared to terrestrial resources projects of similar production capacities.

 

The site and host country for the minerals processing facility has not yet been confirmed. The site must be serviced by grid power, reticulated water, and natural gas. A location will be selected that is close to an industrial port, and near an existing municipality from which labour can be sourced.

 

A preliminary assessment of the transportation fleet for transfer of nodules from the CCZ to an existing deep-water industrial port equipped with bulk offloading facilities was examined (AMC, 2021). The IA assumed that chartered vessels would be used to transport the dewatered nodules to the port of Lazaro Cardenas, Michoacan, Mexico, 960 nm from the NORI Area D reference site. The vessels would be converted bulk mineral carriers with dynamic positioning (DP) to allow tracking behind the production support vessels during operations. The method of offloading, known as tandem offloading, is well established for offloading of oil production vessels in remote areas of the world.

 

AMC has considered the market for the nickel, copper, cobalt and manganese products that might be recovered from the polymetallic nodules in the TOML Areas.

 

CRU International Limited (CRU) was commissioned by NORI to provide market overviews for the four main products from the NORI Area D Project: nickel sulphate (NiSO4), cobalt sulphate (CoSO4), copper, and a manganese product (CRU, 2020). CRU expects growth in these markets.

 

CRU expects copper and NiSO4 prices to rise in real terms by 2035, while manganese ore and CoSO4 prices are forecast to remain flat, due to current prices being at or near a high point in the cycle, recent fall in prices, and expected modest growth in the global steel industry after the COVID 19 epidemic. The long-term cost of production is expected to rise for both copper and NiSO4, helping to support prices.

 

The QPs consider that the proposed development of NORI Area D is a reasonable analogue for future development in the TOML Areas and the IA completed for the NORI Property is directly relevant and applicable to the TOML Property. The QPs consider that this IA supports the view that there are reasonable prospects of economic extraction of polymetallic nodule Mineral Resources in the TOML Areas.

 

Recommended future work on the TOML Exploration Area will focus on:

 

Further exploration to raise the Inferred Mineral Resources to Indicated and Measured status. The proximity of TOML Area F to NORI Area D suggests that TOML Area F should be a priority.

 

Detailed studies to develop key modifying factors to a point where a Mineral Reserve may potentially be estimated;

 

Environmental baseline work to support an EIS;

 

Concept study work on engineering and commercial aspects leading to trial mining;

 

Trial mining.

 

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Contents

 

1 Executive summary i
2 Introduction 1
  2.1 Purpose of the Technical Report Summary 1
  2.2 Sources of information and data 1
    2.2.1 International Seabed Authority data 1
    2.2.2 TOML exploration data 2
  2.3 Field involvement 2
  2.4 Personnel 2
  2.5 Reliance on other experts 3
3 Property Description and Location 4
  3.1 Tenements and Permits 4
    3.1.1 United Nations Convention on the Law of the Sea 5
    3.1.2 International Seabed Authority 7
  3.2 TOML Obligations 8
    3.2.1 Work Programme 8
    3.2.2 Royalties and Taxes 8
4 Accessibility, Climate, Local Resources, Infrastructure and Physiography 9
  4.1 Accessibility and infrastructure 9
  4.2 Climate 9
5 History 10
  5.1 1875–1969: Discovery of the Clarion Clipperton Zone 10
    5.1.1 First Samples 10
    5.1.2 Commercial Recognition 11
    5.1.3 USSR 11
    5.1.4 Kennecott 11
    5.1.5 Deepsea Ventures Inc 12
  5.2 1970–1981: The International Decade of Ocean Exploration 12
    5.2.1 USSR 13
    5.2.2 Japan 13
    5.2.3 Kennecott Consortium (KCON) 14
    5.2.4 Ocean Mining Associates (OMA) 16
    5.2.5 AFERNOD 17
    5.2.6 Ocean Mining INC. (OMI) 18
    5.2.7 Ocean Minerals Company (OMCO) 22
    5.2.8 DOMES 23
  5.3 1982–1995: The Reciprocating States Regime and the Pioneer Investors 24
    5.3.1 Deep Ocean Resources Development 26
    5.3.2 China and COMRA 27
    5.3.3 GEMONOD 28
    5.3.4 USSR and Russia 29
    5.3.5 Interoceanmetal Joint Organisation 30
    5.3.6 Benthic Impact Experiments 31
  5.4 1996 onwards: The International Seabed Authority 34
    5.4.1 Korean Research Groups 34
    5.4.2 The new developed nation contractors 34
    5.4.3 The new developing sponsored nation contractors 35
6 Geological Setting and Mineralisation 37
  6.1 Global distribution of nodules 37
  6.2 Tectonic setting and topographic features 37
    6.2.1 Seamounts, knolls, and other volcanic features 39
    6.2.2 Sediment drifts 40
  6.3 Polymetallic mineralisation 42
    6.3.1 Sedimentation and nodule formation 42

 

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    6.3.2 Nodule grades 43
    6.3.3 Grades of other metals 44
    6.3.4 Nodule abundance and estimation of tonnages 45
    6.3.5 Nodule abundance 45
  6.4 Nodule Density and Moisture Content 46
    6.4.1 Nodule density 46
    6.4.2 Nodule water content 47
  6.5 Diagenetic Crusts 51
  6.6 Deposit Types 52
  6.7 TOML Nodule Types 52
  6.8 Variation in TOML Nodule Grades 54
  6.9 Nodule Distribution 55
    6.9.1 Importance of buried nodules 57
7 Exploration 58
  7.1 Historical Data 58
    7.1.1 Nodule Sample Data Supplied to TOML 58
    7.1.2 Historical Sampling Method 63
  7.2 TOML Work Programmes 65
  7.3 TOML Sampling Methods 66
    7.3.1 Multibeam Bathymetry 66
    7.3.2 Box-coring 67
    7.3.3 Box-coring Overview 68
    7.3.4 Box-corer Equipment 69
    7.3.5 Nodule sampling 72
    7.3.6 Buried Nodules 75
    7.3.7 Vane Shear Readings 75
    7.3.8 Biological-Sediment sampling 76
    7.3.9 Sediment residue sampling 80
    7.3.10 Water sampling 80
    7.3.11 Water column profiling 81
    7.3.12 Photo-Profiling Programme 82
    7.3.13 Deep Towed Sonar Programme 84
    7.3.14 Dredging Programmes 86
      7.3.14.1 CCZ13 Epibenthic sled 86
      7.3.14.2 CCZ15 Galatea dredge 87
    7.3.15 Marine Survey 89
    7.3.16 Other Programmes 89
      7.3.16.1 Long Term Moorings 89
      7.3.16.2 Other Environmental Data 90
  7.4 TOML Exploration Results 91
    7.4.1 TOML MBES results 91
    7.4.2 TOML Box-core results 93
    7.4.3 TOML Photo-profile results 101
    7.4.4 TOML Photo-profile based habitat mapping trial 111
      7.4.4.1 BRT Results 112
      7.4.4.2 Cluster Analysis Results 113
      7.4.4.3 Conclusions of Preliminary Habitat Mapping 114
    7.4.5 Other results 114
      7.4.5.1 Dredging 114
      7.4.5.2 Towed Sonar - Side Scan 115
      7.4.5.3 Towed Sonar – Sub-bottom Profiler 116
      7.4.5.4 Relationship with backscatter 119
8 Sample preparation, analyses and security 121
  8.1 Historical preparation, analysis and security 121
    8.1.1 Historical sample preparation 121
      8.1.1.1 OMCO procedures 121

 

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      8.1.1.2 Yuzhmorgeologiya procedures 122
      8.1.1.3 DORD procedures 124
      8.1.1.4 BGR procedures 124
    8.1.2 Historical Quality Assurance and Quality Control procedures 124
    8.1.3 Historical adequacy of sample preparation, security and analytical 125
8.2 TOML preparation, analysis and security 125
    8.2.1 Sample Chain of Custody 125
    8.2.2 Laboratory analysis methods 127
      8.2.2.1 ALS 127
      8.2.2.2 Jacobs 128
    8.2.3 TOML Quality Assurance and Quality Control procedures 129
    8.2.4 Blanks, Laboratory Duplicates and Standards 133
    8.2.5 TOML photo abundance estimates Chain of Custody 135
    8.2.6 TOML adequacy of sample preparation security and analytical procedures 136
9 Data Verification 137
  9.1 Historical data 137
    9.1.1 Data independence 137
    9.1.2 Historical data integrity 137
    9.1.3 Data comparisons for the entire reserved areas 138
    9.1.4 Comparison with non-ISA sourced data 138
  9.2 TOML data 139
    9.2.1 Comparison of historical and TOML data 139
    9.2.2 Nodule variation test work 139
    9.2.3 Nodule long-axis estimate validation 140
      9.2.3.1 Photo-based estimates in the TOML Area 142
      9.2.3.2 Confirmation Study 147
  9.3 Adequacy of data 149
10 Mineral Processing and Metallurgical Testing 150
11 Mineral Resources 152
  11.1 Mineral Resource domains 152
  11.2 Manganese Nodule Data used for the Mineral Resource Estimate 156
    11.2.1 Description of data 156
    11.2.2 Sample statistics 157
    11.2.3 Representativeness of sampling 164
  11.3 Geostatistics 170
    11.3.1 Nodule sample variography 170
    11.3.2 Variography of nodule coverage estimated from photo profiles 174
    11.3.3 Variography of the estimated nodule abundance from the photo profile 174
    11.3.4 Variography of the backscatter data 175
  11.4 Geological block model 176
  11.5 Mineral Resource estimation 176
  11.6 Cut-off grade 177
  11.7 Mineral Resource classification 177
  11.8 Comparison with previous Mineral Resource estimate 184
  11.9 Initial Assessment 187
    11.9.1 Geological setting and mineralisation 187
    11.9.2 Exploration methods 187
    11.9.3 Sample preparation analysis and security 187
    11.9.4 Mineral Resources 187
    11.9.5 Mining methods 188
    11.9.6 Mineral Processing and metallurgical testing 189
    11.9.7 Infrastructure 190
    11.9.8 Market studies 191
    11.9.9 Environmental compliance and permitting 191

 

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12 Mineral Reserve Estimates 194
13 Mining Methods 195
14 Recovery Methods 196
15 Project Infrastructure 197
16 Market Studies and Contracts 198
17 Environmental Studies, Permitting, and Social or Community Impact 199
18 Capital and Operating Cost 201
19 Economic Analysis 202
20 Adjacent Properties 203
21 Other Relevant Data and Information 204
22 Interpretation and Conclusions 205
23 Recommendations 209
24 References 210
25 Reliance on information provided by the registrant 223

 

Tables

 

Table 1.1 Mineral resource Estimate for the TOML exploration area within the CCZ at a 4 kg/m2 nodule abundance cut-off iv
Table 2.1 List of Qualified Persons responsible for each section 3
Table 2.2 Reliance on other experts 3
Table 3.1 TOML exploration area in the CCZ 5
Table 3.2 TOML area extents 5
Table 6.1 Summary of Global Nodule Grades 37
Table 6.2 Nodule Density measurements TOML Area B, C, D and F 46
Table 6.3 Comparison with published moisture contents 48
Table 6.4 TOML CCZ15 Nodule classification and proportions seen in logging during CCZ15 52
Table 6.5 MBES mapped seabed classification and proportions 56
Table 7.1 Summary of Historical Grab Samples Area A 59
Table 7.2 Summary of Historical Grab Samples Area B 60
Table 7.3 Summary of Historical Grab Samples Area C 60
Table 7.4 Summary of Historical Grab Samples Area D 60
Table 7.5 Summary Historical Grab Samples Area E 60
Table 7.6 Summary of Historical Samples from the Reserved Areas outside the TOML tenement area 61
Table 7.7 TOML datasets by area and by campaign 65
Table 7.8 CCZ15 Environmental Data Matrix 93
Table 8.1 Half Relative Difference Submitted Portions and Submitted Duplicates 131
Table 8.2 Half Relative Difference Submitted Portions and Field Duplicates 132
Table 8.3 Blanks Laboratory Duplicates and Standards 133
Table 9.1 Mean Grades of the CCZ Nodules from Various Sources 139
Table 9.2 Coefficients of variation for historical and TOML nodule samples 140
Table 9.3 Summary statistics of abundance between box-cores and LAE 146

 

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Table 11.1 Minimum and maximum UTM coordinates for each TOML Exploration Area 157
Table 11.2 Statistics of all samples within the TOML Exploration Areas 157
Table 11.3 Declustered statistics of all polymetallic nodule samples within TOML Exploration Area 157
Table 11.4 Statistics of historical samples within the TOML Exploration Areas 158
Table 11.5 Statistics of TOML samples within the TOML Exploration Areas 158
Table 11.6 Statistics of TOML photo samples within the TOML Exploration Areas 158
Table 11.7 Variogram models 170
Table 11.8 Comparison of model areas and actual licence areas 176
Table 11.9 Mineral Resource Estimate for the TOML Exploration Area within the CCZ at a 4 kg/m2 nodule abundance cut-off 178
Table 11.10 Global mean and variance comparison (excluding NON domain, model cells weighted by volume) 184
Table 11.11 2013 Mineral Resource Estimate for the TOML Areas A to D at a 4 kg/m2 abundance cut-off 185
Table 11.12 Current (2020) Mineral Resource Estimate for the TOML Areas A-D at a 4 kg/m2 abundance cut-off 185
Table 11.13 Mean Abundance of historical and 2015 campaign nodule samples (including NON domain) 185
Table 11.14 Mean Abundance of historical and 2015 campaign nodule samples (excluding NON domain) 185
Table 11.15 Mean Ni grades of historical and 2015 campaign nodule samples (excluding NON domain). 186
Table 11.16 Mean Cu grades of historical and 2015 campaign nodule samples (excluding NON domain). 186
Table 11.17 Mean Co grades of historical and 2015 campaign nodule samples (excluding NON domain). 186
Table 11.18 Mean Mn grades of historical and 2015 campaign nodule samples (excluding NON domain). 186

 

Figures

 

Figure 1.1 Location of the Clarion Clipperton Zone ii
Figure 3.1 Location and contractors in the Clarion Clipperton Zone 4
Figure 3.2 Map of seafloor jurisdictions 6
Figure 3.3 Maritime space under the 1982 UNCLOS 7
Figure 4.1 Global cargo shipping network 9
Figure 5.1 Path of the HMS Challenger 10
Figure 5.2 Examples of the overlapping exploration areas of some of the first explorers 13
Figure 5.3 Areas researched by the Geological Survey of Japan in the 1970s 14
Figure 5.4 Kennecott priority areas of interest in the CCZ 15
Figure 5.5 Ocean Mining Associate’s Deepsea Miner II 17
Figure 5.6 Samples in the NORIA Area 18
Figure 5.7 OMI Pilot Mining System Configuration and the SEDCO 445 off Honolulu 20
Figure 5.8 INCO electro-hydraulic collector test; DOMCO hydraulic collector launch & recovery test on the RV Valdivia 20
Figure 5.9 Connection of riser to collector and in-line submersible pump 21
Figure 5.10 OMI Transport Conveyors Overflowing with Nodules 21

 

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Figure 5.11 OMCO Screw-drive collector and pilot mining vessel, the USNS Hughes Glomar Explorer 22
Figure 5.12 DOMES baseline sites in the CCZ, within the DOMES area 23
Figure 5.13 Operating Areas under the Reciprocating States Regime, circa 1993 25
Figure 5.14 Retained and returned (lighter shade) areas of the pioneer investors in the CCZ 26
Figure 5.15 1997 Japanese collector, barge and trial schematic 27
Figure 5.16 Chinese pilot scale tracked and test screw-drive subsea vehicles 28
Figure 5.17 GEMONOD crawler and hydraulic lift system 29
Figure 5.18 Preliminary metallurgical processes studied by IOM 31
Figure 5.19 DSSRS-II Benthic Disturber 32
Figure 5.20 Review of the DORD 1994 JET Benthic disturber site in 1996 using a Finder-installed Deep-sea camera 32
Figure 5.21 IOM BIE meiobethos populations for control, resedimentation and impacted area stations 33
Figure 6.1 Bathymetric map of the Clarion-Clipperton Fracture Zone 38
Figure 6.2 Formation of abyssal hills at mid-oceanic ridges 38
Figure 6.3 Semi-detailed bathymetry for the part of the TOML tenement area 39
Figure 6.4 Seamounts in TOML Area D 39
Figure 6.5 Example of “ponded” sediment drifts and corresponding low nodule abundance Area B 40
Figure 6.6 Example of sediment accumulating around seamounts 40
Figure 6.7 Types of deep-sea sedimentary processes and deposits related to bottom currents 41
Figure 6.8 Range of patterns in surficial sediment, TOML Areas D and C 42
Figure 6.9 Modelled Mn and Cu grades in nodules across the CCZ 43
Figure 6.10 Modelled Ni and Co grades in nodules across the CCZ 44
Figure 6.11 Modelled nodule abundance across the CCZ 46
Figure 6.12 Nodule densities of samples from TOML areas B-D, F, and central north Pacific 47
Figure 6.13 Nodule sample (pulp) absorption after drying to 105°C for 6 hours 48
Figure 6.14 Air drying results for a short term sample batch (L) and a long term sample batch (R) 49
Figure 6.15 Oven drying results for nodules 49
Figure 6.16 Loss on ignition (at 1,000°C) for two batches of TOML samples 50
Figure 6.17 Three stage drying curve for polymetallic nodules 51
Figure 6.18 Sections through a S-type Nodule (left) and a R-type Nodule with a S-type core (right) 53
Figure 6.19 Example nodules found in the TOML area 53
Figure 6.20 Nodule size and type within the areas sampled during TOML CCZ15 54
Figure 6.21 Nodule variance in Ni and Cu for dredge and box-core samples in the TOML Areas 55
Figure 6.22 Nodule variance in Mn and Co for dredge and box-core samples in the TOML Areas 55
Figure 6.23 Mapped areas of volcanic rocks, slopes and Nnoo sediment in part of TOML  Area B 56
Figure 6.24 Location and percentage of buried nodules found during CCZ15 57
Figure 7.1 Total Number of Samples by Pioneer Contractor. 59
Figure 7.2 Total Number of Samples by TOML tenement areas. 59

 

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Figure 7.3 Box Plots of historical sample grades within the TOML tenement areas. 61
Figure 7.4 Box Plots comparing the 6 Pioneer Investor Reserved Area Data Sets across the entire CCZ. 62
Figure 7.5 Log Probability plots comparing the 6 Pioneer Investor Data Sets. 62
Figure 7.6 Cartoon showing the recovery process of nodules using Free Fall Grab 63
Figure 7.7 Cartoon showing the recovery process of nodules using Box Corer 64
Figure 7.8 Comparison of returned abundances from BC and FFG at test stations within the KORDI exploration area 64
Figure 7.9 RV Mt Mitchell (CCZ13) and RV Yuzhmorgeologiya (CCZ15) 65
Figure 7.10 Extent of TOML exploration in the CCZ 66
Figure 7.11 MBES operations schematic 66
Figure 7.12 Box-corer Deployment Schematic 68
Figure 7.13 Details and operations with the KC box-corer 70
Figure 7.14 Details and recovery of the YMG box-corer 71
Figure 7.15 Preliminary vs. washed vs. aired box-core nodule sample weights (kg) 72
Figure 7.16 Differences in washed vs. aired box-core nodule sample weights by area 73
Figure 7.17 Details and operations regarding sample processing 74
Figure 7.18 Summary vane shear results from TOML CCZ15 study areas 75
Figure 7.19 Sample Plan – Overlying fauna and nodule 78
Figure 7.20 Sample Plan – Micro-fauna and box-core layout 78
Figure 7.21 Sample Plan – Meio-fauna 79
Figure 7.22 Sample Plan – Macro-fauna 79
Figure 7.23 Sample Plan – Sediment characterisation 80
Figure 7.24  Water Sample Collection and Water Chemistry Laboratory 81
Figure 7.25 Neptune Deployment Schematic 82
Figure 7.26 Neptune Deployment Photographs 84
Figure 7.27 MAK Deployment Schematic 85
Figure 7.28 MAK Components and Deployment 86
Figure 7.29 Epibenthic sled Deployment Schematic 87
Figure 7.30 Photos of epibenthic sled 88
Figure 7.31 Galatea Dredge Deployment Schematic 88
Figure 7.32 Operations and details of the YMG Galatea-trawl dredge 90
Figure 7.33 CCZ15 Mooring Design and deployment of Mooring S01 in Area C 91
Figure 7.34 CCZ15 CSMF Events 92
Figure 7.35 CCZ13 MBES bathymetry coverage 94
Figure 7.36 CCZ13 MBES backscatter coverage 94
Figure 7.37 Nodule Types, Area B1 95
Figure 7.38 Nodule Abundance, Area B1 95
Figure 7.39 Shear Strength Class, Area B1 96
Figure 7.40 Nodule Types, Area C1 96
Figure 7.41 Nodule Abundance Area, C1 97
Figure 7.42 Shear Strength Class, Area C1 97
Figure 7.43 Nodule Types, Area D2 98
Figure 7.44 Nodule Abundance Area, D2 98
Figure 7.45 Vane Shear Strength Class, Area D2 99
Figure 7.46 Nodule Types, Area D1 99

 

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Figure 7.47 Nodule Abundance, Area D1 100
Figure 7.48 Vane Shear Strength Class, Area D1 100
Figure 7.49 Nodule Types, Areas F and F1 101
Figure 7.50 Nodule Abundance, Areas F and F1 102
Figure 7.51 Vane Shear Strength Class, Areas F and F1 103
Figure 7.52 Neptune Photo-profile logging of % cover and outcrop types 104
Figure 7.53 Nodule sizes and types from photo-profiles and box-cores 105
Figure 7.54 Neptune Photo-profile preliminary logging summary distribution of megafauna 106
Figure 7.55 Two genus Actinia (sea anemone) in Area C1 107
Figure 7.56 Order Antipatharia (black coral) in Area B1 107
Figure 7.57 Class Holothuroidea (sea cucumber) in Area D 108
Figure 7.58 Phylum Porifera (sponge) in Area B1 108
Figure 7.59 Class Echinoidea (sea urchin) in Area D2 108
Figure 7.60 Order Decapoda (shrimp) in Area C1 109
Figure 7.61 Order Teuthida (squid) in Area B1 109
Figure 7.62 Fish in Area C 109
Figure 7.63 Phylum Arthropoda (excludes decapods) in Area D1 110
Figure 7.64 Phylum mollusca (bivalve example) in Area B1 110
Figure 7.65 Class xenophyophorida (protozoan) 110
Figure 7.66 Areas where biota was not observed 111
Figure 7.67 Dominant biota observed 112
Figure 7.68 Samples (image frames) coded by Geoform Level 3 (L) and 4 (R) 113
Figure 7.69 Samples (image frames) coded by Substrate Group 114
Figure 7.70 Dredge sample locations CCZ13 and CCZ15 115
Figure 7.71 Side scan coverage and geological interpretation of the B5338 field, Area B1 116
Figure 7.72 Abyssal hill classification from sub-bottom profiles 117
Figure 7.73 Fault bound collapse-dissolution in carbonate 118
Figure 7.74 Possible dyke swarm in western subarea D 3454 118
Figure 7.75 Possible late stage sill or peperite layer and feeders in DW0332, Area D1 119
Figure 7.76 Characterised MBES backscatter response in B5338 119
Figure 7.77 Relationships between abundance and acoustic reflection and nodule coverage 120
Figure 8.1 Ocean-0.25 Grab Sampler (Yubko, 2012) 123
Figure 8.2 Mn-nodules Inside Grab Sampler (left) and Outside Grab Sample (right) (Yubko, 2012) 124
Figure 8.3 COC sample flow (box-core samples) 127
Figure 8.4 Comparison of Nickel and Copper grades in duplicates 130
Figure 8.5 Comparison of Cobalt and Manganese grades in duplicates 131
Figure 8.6 Comparison of high grade copper duplicates 132
Figure 8.7 ALS Laboratory duplicates and non-nodule standards 133
Figure 8.8 ALS Laboratory duplicates compared to submitted portions 134
Figure 8.9 ALS performance against the CGL-131 nodule standard 135
Figure 8.10 ALS performance against the NOD-P1 standard 135
Figure 8.11 Jacobs performance against the CGL-131 and NOD-P1 standards for Cu re-analysis work 135
Figure 9.1 Comparison between TOML analyses and historical analyses 139

 

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Figure 9.2 Comparison of coefficients of variation for historical and TOML nodule samples 141
Figure 9.3 Example LAE measurement – bottom photo 142
Figure 9.4 Example LAE measurement – top shot (YMG box) and grid photo 143
Figure 9.5 Area B correlations with best fit factors (L) and Felix 1980 factors (R) 144
Figure 9.6 Comparison of physical samples and LAE in Areas B and C 145
Figure 9.7 Area C correlations with best fit factors (L) and Felix 1980 factors (R) 145
Figure 9.8 Degree of powder on visible nodules in Area D vs Area B 145
Figure 9.9 High degree of sediment “powder” and cover in Area D 146
Figure 9.10 Covered nodules B75, Area D2 146
Figure 9.11 Confirmation nodules weights Area B and histogram of nodules by long-axis length 147
Figure 9.12 Confirmation nodules weights Area C 148
Figure 9.13 Confirmation nodules weights Area F 148
Figure 10.1 Potential process flow-sheets for seafloor nodules. 1-5 studied by Haynes et al. (1985) and 6 by Wang and Li (2005) 151
Figure 11.1 TOML Exploration Area A geological domains 153
Figure 11.2 TOML Exploration Area B geological domains 154
Figure 11.3 TOML Exploration Area C geological domains 154
Figure 11.4 TOML Exploration Area D and E geological domains 155
Figure 11.5 TOML Exploration Area F geological domains 155
Figure 11.6 Location of the historical sample data provided by the ISA and IOM and the TOML data 156
Figure 11.7 Histogram and log-probability plot of Abundance for all samples within TOML Exploration Areas 158
Figure 11.8 Histogram and log-probability plot of Mn for all samples within TOML Exploration Areas 159
Figure 11.9 Histogram and log-probability plot of Ni for all samples within TOML Exploration Areas 159
Figure 11.10 Histogram and log-probability plot of Cu for all samples within TOML Exploration Areas 160
Figure 11.11 Histogram and log-probability plot of Co for all samples within TOML Exploration Areas 160
Figure 11.12 Log-probability plots for Abundance, Mn, Ni, Cu and Co by TOML Exploration Areas 161
Figure 11.13 Box-plots for Abundance, Mn, Ni, Cu and Co by TOML Exploration Areas 162
Figure 11.14 Box-plot of Mo for sample data within the TOML Exploration Areas 163
Figure 11.15 Box-plot of light rare earth elements for sample data within the TOML Exploration Areas 163
Figure 11.16 Box-plot of heavy rare earth elements for sample data within the TOML Exploration Areas 164
Figure 11.17 Photo-profile line CCZ15-F01 that crosses Area B1 Mineral Resource 165
Figure 11.18 Photo-profile line CCZ15-F02 that crosses Area B1 Mineral Resource 166
Figure 11.19 Photo-profile line CCZ15-F04 that crosses Area B1 Mineral Resource 166
Figure 11.20 Comparison of nodule percent coverage against nodule abundance 167
Figure 11.21 Comparison of nodule abundance estimated from photos against nodule abundance estimated manually using the long-axis estimation method 168
Figure 11.22 Nodule abundance photo-profile line CCZ15-F01 that crosses sub-area B1 Measured Mineral Resource 168

 

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Figure 11.23 Nodule abundance photo-profile line CCZ15-F02 that crosses sub-area B1 Measured Mineral Resource 169
Figure 11.24 Nodule abundance photo-profile line CCZ15-F04 that crosses sub-area B1 Measured Mineral Resource 169
Figure 11.25 Abundance omni-directional, 060˚ and 150˚ directional variograms 171
Figure 11.26 Mn omni-directional, 060˚ and 150˚ directional variograms 171
Figure 11.27 Ni omni-directional, 060˚ and 150˚ directional variograms 171
Figure 11.28 Cu omni-directional, 060˚ and 150˚ directional variograms 172
Figure 11.29 Co omni-directional, 060˚ and 150˚ directional variograms 172
Figure 11.30 Semi-variogram maps for Abundance, Mn, Ni, Cu and Co 173
Figure 11.31 Omni-directional and 060° directional variograms for percent nodule coverage estimated from sea floor photos 174
Figure 11.32 Omni-directional and 060° directional variograms for nodule abundance estimated using the LAE method from sea floor photos 175
Figure 11.33 Omni-directional variograms for backscatter values 176
Figure 11.34  Nodule Abundance – Tonnage Curve 178
Figure 11.35 Map showing block model and sample distribution for Abundance Mn, Ni, Cu and Co in TOML Area A 179
Figure 11.36 Map showing block model and sample distribution for Abundance Mn, Ni, Cu and Co in TOML Area B 180
Figure 11.37 Map showing block model and sample distribution for Abundance Mn, Ni, Cu and Co in TOML Area C 181
Figure 11.38 Map showing block model and sample distribution for Abundance Mn, Ni, Cu and Co in TOML Area D and Area E 182
Figure 11.39 Map showing block model and sample distribution for Abundance Mn, Ni, Cu and Co in TOML Area F 183
Figure 11.40 Comparison of nodule shapes, nodule abundance and backscatter imagery from TOML Areas (left and NORI Areas (right) 188

 

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List of Acronyms and Terms

 

AAS Atomic Absorption Spectroscopy
AP Abyssal Plain
AH Abyssal Hills
APEI Areas of Particular Environmental Interest
Abundance Abundance of polymetallic nodules expressed in kg/m2
AFERNOD Association Française pour l’Étude et la Recherche des Nodules
ALS ALS Group or ALS Laboratories
AMC AMC Consultants
AMR Arbeitsgemeinschaft Meerestechnisch Gewinnbare Rohstoffe
ANOSIM Analysis of Similarity
ASMOD Adaptive Spline Modelling of Observation Data
AUV Autonomous Underwater Vehicle
BC Box Corer
BIE Benthic Impact Experiment
BGR German Consortium
BL Bottom left
BR Bottom right
BRT Boosted Regression Trees
C Centre
CAPEX Capital Expenditure
CATAMI Collaborative & Annotation Tools for Analysis of Marine Imagery & Video
CCD Calcite Compensation Depth
CCZ Clarion Clipperton Zone
CEA Commissariat à l'Energie Atomique
CIIC Cook Islands Investment Corporation
CIM Canadian Institute of Mining, Metallurgy and Petroleum
CGL Reference material CGL131 (nodule geochemical standard)
CLB Continuous Line Bucket Group
CMECS Coastal and Marine Ecological Classification Standard
COC Chain of custody
COMRA China Ocean Mineral Resources Research and Development Association (Chinese Consortium)
COR Committee of Representatives
CSMF conservation significant marine fauna
CV Coefficient of variation
DAS Acid pressure digestion system
DEME Dredging, Environmental & Marine Engineering or DEME Group
DNA Deoxyribonucleic acid
DOMA Deep Ocean Minerals Association
DOMCO Deep Ocean Mining Co.
DOMES Deep Ocean Mining Environmental Study
DORD Deep Ocean Resources Development Company (Japanese Consortium)
DSSRS Deep Sea Sediment Re-suspension System
EC European Commission
eDNA Environmental DNA
EEZ Exclusive Economic Zone
EIS Environmental Impact Statement
EMP Environmental Management Plan
ENSO El Niño–Southern Oscillation
EPR East Pacific Rise
EUNIS European Nature Information System
FFG Free fall Grab samplers
FGDC US Federal Geographic Data Committee
FIGNR Federal Institute for Geosciences and Natural Resources (German Consortium)
FPSO Floating Production Storage and Offloading

 

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GEBCO General Bathymetric Chart of the Oceans (www.gebco.net)
GEMONOD Groupement pour la mise au point des MOyens nécéssaires à l'exploitation des NODules
GH Graben horst
GPO Government Printing Office
GSR Global Sea Mineral Resources
Gstat program for modelling geo-statistical data in one, two or three dimensions
G-TEC G-TEC Sea Mineral Resources
GU Gently undulating
HEBBLE High-Energy Benthic Boundary Layer Experiment
HPAL High temperature and high pressure sulfuric acid leach process
ICP-AES Inductively couple plasma atomic emission spectrometry
ICP-MS Inductively couple plasma mass spectrometry
ICP-OES Inductively couple plasma optical emission spectrometry
IDOE International Decade of Ocean Exploration
IDW Inverse Distance Weighting estimation method
Ifremer Institut Français de Recherché pour l’Exploitation de la Mer
IHC Royal IHC or IHC Merwede
INCO International Nickel Corporation
IOM Interoceanmetal Joint Organization (Bulgaria, Cuba, Czech Republic, Poland, Russian Federation and Slovakia Consortium)
ISA International Seabed Authority
ITLOS International Tribunal for the Law of the Sea
JAG US Navy Judge Advocates General’s Corps
JET Japan Deep Sea Impact Experiment
JORC Joint Ore Reserves Committee
JPI Oceans Joint Programming Initiative Healthy and Productive Seas and Oceans
KADOM Korean Association of Deep-Ocean Mineral Development
KCON Kennecott Consortium
KEI Kennecott Exploration Inc
KIGAM Korea Institute of Geology, Mining and Materials
KIOST Korean Institute of Ocean Science and Technology
KMPC Korea Mining Promotion Corporation
KORDI Korean Ocean Research and Development Institute (now known as KIOST; Korean Institute of Ocean Science and Technology)
KRISO Korea Research Institute of Ships & Ocean Engineering
L left
LAE Long Axis Estimation
LMS Lockheed Martin Systems
LOI Loss on ignition
LTC Legal and Technical Commission of the ISA
MAK YMG MAK-1 sidescan sonar
MAPR Miniature (mini) autonomous plume recorder
MBES MultiBeam Echo Sounding
MFES Multi-Frequency Exploration System
MIR YMG Towed sonar & photo platform
MITI Japanese Ministry of International Trade and Industry
NI 43-101 Canadian National Instrument 43-101
NIOT National Institute of Ocean Technology
NOAA National Oceanic and Atmospheric Administration
NOAA NWS US National Oceanic and Atmospheric Administration, National Weather Service
NOD-P-1 NOD-P-1 is a geochemical reference standard
NORI Nauru Ocean Resources Inc
NORIA NOdules RIches et Abondants
NORMED Chantiers du Nord et de la Méditerranée

 

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NN Nearest Neighbour estimation method
OK Ordinary Kriging estimation method
OMA Ocean Mining Associates
OMCO Ocean Minerals Co. (US Consortium)
OMI Ocean Mining Incorporated
OMS Ocean Mineral Singapore Pte Ltd
OPEX Operating Expenditure
ORP Oxygen Reduction Potential
PMA Priority mining areas
PREPCOM Preparatory Commission
PTFE polytetrafluoroethylene
QAQC Quality Assurance and Quality Control
QP Qualified Person
QQ Quantile-quantile
%RSD % relative standard deviation
R Right
R-type Rough type nodules
R-S-type Rough-smooth type nodules
REE Rare Earth Elements
ROV Remotely Operated Vehicle
ROTV Remotely Operated Towed Vehicle
RSR Reciprocating States Regime
SA-SSS Synthetic aperture side scan sonar
SIO Scripps Institution of Oceanography
SIS Sequential indicator simulation
SOEST School of Ocean and Earth Science and Technology, University of Hawaii
SOSI Sound Ocean Systems Inc
SSS Sidescan sonar
S-type Smooth type nodules
TL Top left
TM Total metals
TOML Tonga Offshore Mining Limited
TPA (tpa) Tonnes Per Annum
TR Top right
TSS Total suspended sediment
UGI YMG underwater geotechnical instrument
UH Undulating hills
UK United Kingdom
UKSR UK Seabed Resources
UN United Nations
UNCLOS United Nations Convention on the Law of the Sea 1982
UNOETO United Nations Oceans Economics and Technology Office
USBL Ultra Short BaseLine
USGS United States Geological Service
US/USA United States/United States of America
USNEL United States Naval Electronic Laboratory
USSR Union of Soviet Socialist Republics
UTM Universal Transverse Mercator Cartesian coordinate system
V/H Vertical on horizontal (vertical exaggeration in a profile or section)
WA US state of Washington
WGS World Geodetic System
WOR World Ocean Review 2010
XRF X-ray fluorescence
YMG State Enterprise Yuzhmorgeologiya (Russian Federation Consortium)

 

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Elements

 

Al Aluminium
As Arsenic
Ba Barium
Ca Calcium
Ce Cerium
Ce Cerium
Cl Chlorine
Co Cobalt
Cu Copper
Dy Dysprosium
Er Erbium
Eu Europium
F Fluorine
Fe Iron
Gd Gadolinium
Ho Holmium
La Lanthanum
La Lanthanum
Lu Lutetium
Mg Magnesium
Mn Manganese
Mo Molybdenum
Nd Niobium
Nd Neodymium
Ni Nickel
Pb Lead
PGM Platinum Group Minerals
Pm Promethium
Pr Praseodymium
Pt Platinum
REE Rare Earth Elements
S Sulphur
Sc Scandium
Si Silicon
Sm Samarium
Sr Strontium
Tb Terbium
Te Tellurium
Ti Titanium
Tm Thulium
Y Yttrium
Yb Ytterbium
Zn Zinc
Zr Zirconium

 

Direction – Azimuth Abbreviations

 

N North
E East
S South
W West
NNE North North East
NE North East
ENE East North East
ESE East South East

 

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SE South East
SSE South South East
SSW South South West
SW South West
WSW West South West
WNW West North West
NW North West
NNW North North West

 

Symbols and Units

° Degree
°C Degrees centigrade
(aq) Aqueous
µm Micrometre
cm Centimetre
g/t Grams per tonne
Gt Giga (billion) tonnes
kg Kilogram
kg/m2 Kilograms per square kilometre (abundance)
km2 Square kilometres
kn Knot
kWh/t Kilowatt hour per tonne
m Metre
M Mole
Mt Million tonnes
Mwt Million wet tonnes
m/s Metres per second
Cubic metre
mbsl Metres below sea level
mm Millimetre
Mwt Million tonnes (wet)
nm Nautical mile
ppb Parts per billion
ppm Parts per million
s Second(s) or soluble
t/m³ Tonnes per cubic metre

 

Distribution list

1 e-copy to  DeepGreen Metals Inc.

1 e-copy to AMC office

 

OFFICE USE ONLY

Version control (date and time)

25 March 2021 16:30

 

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2Introduction

 

A large deposit of polymetallic nodules is located in the Clarion Clipperton Zone (CCZ) of the northern central Pacific Ocean. Despite the nodules being located at great depths (4,000 to 6,000 m), they were explored with considerable success between the mid-1960s to the present day using a variety of increasingly sophisticated deep-sea technologies. In early 2012, Tonga Offshore Mining Limited (TOML), a 100% owned subsidiary of Nautilus Minerals Inc. acquired an Exploration Area of 74 713 km2 of the CCZ. In line with the requirements of the relevant oversight body (International Seabed Authority or ISA) TOML is sponsored by the government of the Kingdom of Tonga. The contract for exploration of polymetallic nodules was approved in July 2011, and then formalised on 11 January 2012.

 

TOML commissioned AMC Consultants Pty Ltd (AMC) to prepare a Technical Report in accordance with the Canadian National Instrument 43-101 reporting standards (NI43-101) and Form 43-101F1. The Report presented the results of exploration and related studies carried out between 2013 and 2016 and an updated Mineral Resource estimate (AMC, 2016). The Mineral Resource statement was prepared in accordance with the CIM “Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines”.

 

In 2020, DeepGreen Metals Inc (DeepGreen) acquired the polymetallic nodule exploration contract awarded by the ISA to TOML. DeepGreen commissioned AMC Consultants Pty Ltd (AMC) to recompile the NI43-101 Technical Report (AMC, 2016) as a Technical Report Summary in accordance with SEC Regulation S-K (subpart 1300).

 

2.1Purpose of the Technical Report Summary

 

AMC understands that DeepGreen may file this Technical Report Summary with Securities Exchange Commission as part of an S-4 filing to support the merger between Sustainable Opportunities Acquisition Corporation and DeepGreen Metals Inc.

 

2.2Sources of information and data

 

This Technical Report Summary was recompiled from an NI43-101 Technical Report which documented exploration and estimation of Mineral Resources in the TOML Area (AMC, 2016). No new exploration data or modifications to the Mineral Resource estimate have been presented, except that the Mineral Resource has been quoted at a cut-off of 4 kg/m2 abundance. The new cut-off is based on the estimates of costs and revenues presented in the Initial Assessment (IA) of the Mineral Resource contained in NORI Area D (AMC, 2021). The polymetallic nodule deposits in NORI Area D are similar to those in TOML Areas A through F and the QP considers that the proposed development of NORI Area D is a reasonable analogue for future development in the TOML Areas.

 

2.2.1International Seabed Authority data

 

The historical sample data used as the basis for the Mineral Resource estimate in this report was obtained by Golder Associates directly from the ISA (Golder Associates, 2013). The data was also obtained separately by TOML.

 

Under the principles of the Law of the Sea, developed nation contractors explore then relinquish or return 50% of their initial Exploration Area to the ISA. As part of this process the ISA requires each pioneer contractor to provide all sample data to a robust centrally managed database within the ISA. The ISA then analyse these data to verify that the two areas are of equal economic value. The analysis and acceptance, or otherwise, of the data by the ISA indicates a degree of verification and validation of these data.

 

The ISA also supplied TOML with other data in numerous reports (referenced accordingly in the text) and the Mining Code administered by the ISA. These reports as well as structure and authorities of the ISA are publicly available from the ISA website (http://www.isa.org.jm).

 

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The authors of this report neither supervised nor were involved with the preparation, compilation and management of data supplied by the ISA. The ISA compiled these data from multiple and independent Contractors and other sources. These data can be relied upon for the following reasons:

 

The ISA has an imperative to manage these data properly and fairly in order to maintain credibility and minimize disputes amongst its many stakeholders (the nations of the world) and to date AMC is unaware of any such disputes being raised in the context of data quality and management;

 

The ISA operates independently of any particular government or commercial stakeholder;

 

These data have been used as part of a CCZ wide study and mineral inventory estimation exercise (ISA, 2010), which involved experts not employed by the ISA, or TOML, and these data were deemed to be of suitable reliability by the ISA for this exercise.

 

2.2.2TOML exploration data

 

In addition to the above ISA data, TOML collected data including:

 

64,432 km2 of multibeam sonar bathymetry and backscatter response and interpretation thereof collected during a campaign in 2013 on the RV Mt Mitchell;

 

13 nodule bulk samples and analysis thereof collected on the above 2013 campaign;

 

113 quantitative estimates of nodule abundance from box-core sampling collected during a campaign in 2015 on the RV Yuzhmorgeologiya;

 

161 quantitative estimates of nodule abundance from 587 line km or 20,857 frames of seabed photography collected on the above 2015 campaign, as well as logging of megafauna from the photos and 192 hours of continuous video;

 

4 nodule bulk samples and analysis thereof collected on the above 2015 campaign;

 

280 line km of sidescan and sub-bottom profile sonar survey and interpretation thereof collected on the above 2015 campaign;

 

334 profiles of water chemistry and sea column characterization data and analysis thereof collected on the above 2015 campaign;

 

Biological taxonomy (in progress) of 3195 samples collected on the above 2015 campaign.

 

2.3Field involvement

 

Mr John Parianos visited the CCZ from 4 September to 7 October 2013 on board the RV Mt Mitchell and from 4 August to 10 October 2015 on board the RV Yuzhmorgeologiya. He spent a total of approximately three months within the CCZ surveying and sampling the TOML Exploration Areas.

 

2.4Personnel

 

The Sections that each of the Qualified Persons (QPs) were responsible for are summarised in Table 2.1. In addition, each of the QPs contributed to Sections 22–24, where relevant to the Sections for which they were primarily responsible.

 

AMC has relied upon information provided by the registrant in preparing its findings and conclusions regarding some aspects of modifying factors, as set out in Section 25.

 

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Table 2.1List of Qualified Persons responsible for each section

 

Qualified Person Responsible for the following report Sections:
AMC Consultants Pty Ltd Sections 1–3, 8, 9, 11.1 – 11.8, 11.9.1, 11.9.2, 11.9.3, 11.9.4, 11.9.8, 11.9.9, 12, 16–25
Canadian Engineering Associates Ltd Sections 10, 11.9.6, 14
Deep Reach Technology Inc Section 11.9.5, 11.9.7, 13, 15
John Michael Parianos, MSc (Earth Sciences), MAIG Sections 4, 5, 6, 7

 

2.5Reliance on other experts

 

The QPs have relied upon other experts for some sections in this report. These are summarised in Table 2.2.

 

Table 2.2Reliance on other experts

 

Expert Report Sections:
Picton Group Pty Ltd Section 17

 

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3Property Description and Location

 

The TOML exploration rights are located within the Clarion Clipperton Zone (CCZ) located in the Pacific Ocean Figure 3.1). The western end of the CCZ is approximately 500 km ENE of Kiribati and approximately 1,000 km south of the Hawaiian island group. The CCZ extends over 4,500 km ENE, in an approximate 750 km broad trend with the eastern limits located approximately 2,000 km west of southern Mexico.

 

Figure 3.1Location and contractors in the Clarion Clipperton Zone

 

Source: https://www.isa.org.jm/map/clarion-clipperton-fracture-zone, downloaded 18 February 2021

 

3.1Tenements and Permits

 

Tonga Offshore Mining Ltd (TOML), a 100% owned subsidiary of Nautilus Minerals Inc., was sponsored by the Government of the Kingdom of Tonga in its application for approval of a “plan of work for exploration for polymetallic nodules” by the International Seabed Authority (ISA) under the terms of the United Nations Convention on the Law of the Sea 1982 (UNCLOS) and the Mining Code of the ISA (specifically the Regulations for Prospecting and Exploration of Polymetallic Nodules).

 

The ISA approved the plan of work in July 2011 and this led to signing of a “contract for exploration for polymetallic nodules” by the ISA and TOML on 11 January 2012, that formalised an “Exploration Area” (tenement or licence; Figure 3.1, Table 3.1), a term of 15 years for the contract, and a programme of activities for the first 5-year period. The contract also formalised the rights of TOML around security of tenure leading to a “contract for exploitation”. The contract does not cover minerals other than polymetallic nodules but in this context the ISA is obligated to ensure that no other entity operates in a manner that might unreasonably interfere with TOML.

 

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TOML Mineral Resource, Clarion Clipperton Zone, Pacific Ocean
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The TOML contract area comprises six separate blocks (A through F) in the CCZ with a combined area of 74,713 km2 (Table 3.1 and Table 3.2). These areas were previously explored by Pioneer Investors.

 

Table 3.1TOML exploration area in the CCZ

 

Exploration Area Reserved Block Area
(km2)
Area A Block 2 10,281
Area B Block 15 9,966
Area C Block 16 15,763
Area D Block 20 15,881
Area E Block 21 7,002
Area F Block 25 15,820
Total 74,713

 

Table 3.2TOML area extents

 

Area Minimum Latitude
(DD)
Maximum Latitude
(DD)
Minimum Longitude
(DD)
Maximum Longitude
(DD)
Minimum
UTM X (m)
Maximum
UTM X (m)
Minimum
UTM Y (m)
Maximum
UTM Y (m)
UTM Zone
A 7.167 N 8.167 N 151.667 W 152.510 W 553972 647187 792205 902968 05N
B 13.580 N 14.667 N  132.000 W 133.200 W 694518 824685 1502009 1623605 08P
C 15.000 N 15.800 N 128.583 W 131.000 W 284947 544791 1658371 1747847 09P
D 13.125 N 14.083 N 123.583 W 125.333 W 247293 437022 1451031 1557860 10P
E 12.750 N 13.083 N  123.583 W 125.333 W 246693 436796 1409563 1447513 10P
F 9.895 N 11.083 N 117.817 W 118.917 W 289835 410804 1093917 1225828 11P

DD – Decimal degrees, UTM - Universal Transverse Mercator map projection

 

To date, no exploitation licences for extracting minerals from the seafloor within the Area have been granted.

 

3.1.1United Nations Convention on the Law of the Sea

 

The international seabed area (otherwise known as the Area) is defined as the seabed and subsoil beyond the limits of national jurisdiction (UNCLOS Article 1). Figure 3.2 shows a map of the Area (blue zone) as well as 200 nautical mile exclusive economic zones (grey zone) and extended continental shelf zones (orange zone). Figure 3.3 shows the relationships between depth, distance and jurisdiction.

 

The principal policy documents governing the Area include:

 

The United Nations Convention on the Law of the Sea, of 10 December 1982 (The Convention).

 

The 1994 Agreement relating to the Implementation of Part XI of the United Nations Convention on the Law of the Sea of 10 December 1982 (the 1994 implementation Agreement).

 

The Convention deals with, among other things, navigational rights, territorial sea limits, exclusive economic zone jurisdiction, the continental shelf, freedom of the high seas, legal status of resources on the seabed beyond the limits of national jurisdiction, passage of ships through narrow straits, conservation and management of living marine resources in the high seas, protection of the marine environment, marine scientific research, and settlement of disputes.

 

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Part XI of the Convention and the 1994 Implementation Agreement deals with mineral exploration and exploitation in the Area, providing a framework for entities to obtain legal title to areas of the seafloor from the ISA for the purpose of exploration and eventually exploitation of resources.

 

The Convention entered into force on 16 November 1994. A subsequent agreement relating to the implementation of Part XI of the Convention was adopted on 28 July 1994 and entered into force on 28 July 1996. The 1994 Implementation Agreement and Part XI of the Convention are to be interpreted and applied together as a single instrument.

 

As of 20 August 2020, the Convention had been signed by 167 States (countries) and the European Union. The United States of America is currently not a party to the Convention.

 

Figure 3.2Map of seafloor jurisdictions

 

Note: International seabed area map (blue zone) as well as 200 nautical mile exclusive economic zones (grey zone) and extended continental shelf zones (orange zone). Source: Marine Geospatial Ecology Lab, Duke University (2011).

 

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TOML Mineral Resource, Clarion Clipperton Zone, Pacific Ocean
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Figure 3.3Maritime space under the 1982 UNCLOS

 

Source: DeepGreen - adapted from UNCLOS, 1982

 

3.1.2International Seabed Authority

 

The ISA is an autonomous international organisation established under the Convention and the 1994 Implementation Agreement to organise and control activities in the Area, particularly with a view to administering and regulating the development of the resources of the Area in accordance with the legal regime established in the Convention and the 1994 Implementation Agreement.

 

All rules, regulations, and procedures issued by the ISA to regulate prospecting, exploration, and exploitation of marine minerals in the Area are issued within a general legal framework established by the Convention and the 1994 Implementation Agreement.

 

To date, the ISA has issued (https://www.isa.org.jm/mining-code/ Regulations):

 

The Regulations on Prospecting and Exploration for Polymetallic Nodules in the Area (adopted 13 July 2000; the Regulations).

 

The Regulations on Prospecting and Exploration for Polymetallic Sulphides (adopted 7 May 2010).

 

The Regulations on Prospecting and Exploration for Cobalt-Rich Ferromanganese Crusts in the Area (July 2012).

 

The ISA is currently working on the development of a legal framework to regulate the exploitation of polymetallic nodules in the international seabed area.

 

In 2014, the ISA completed a study looking at comparative extractive regulatory regimes. This was followed in March 2014 with a stakeholder survey seeking comments on what financial, environmental, and health and safety obligations should be included under the framework (ISA 2014).

 

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In March 2019, the Council of the ISA released the advance and unedited text (English only) of the Draft Regulations on Exploitation of Mineral Resources in the Area (ISBA/25/LTC/WP.1) (ISA, 2018). The revised draft incorporated the consideration of requests addressed to the Legal & Technical Commission by the Council during the first part of the 24th Session in March 2018, comments by the Commission, and also reflected the responses to the first draft from stakeholder submissions. The ISA declared a target of July 2020 to have the regulations approved, however the July session was deferred as a result of COVID-19 pandemic.

 

Pursuant to paragraph 15(a) and (b) of Section 1 of the annex to the 1994 Implementation Agreement, which relates to article 162 (2)(o)(ii) of the Convention, the ISA Council must also adopt such exploitation regulations within two years of a formal request being made by any State which intends to apply for approval of a plan of work for exploitation.

 

3.2TOML Obligations

 

The contract for exploration for polymetallic nodules contains conditions covering such areas as obligations of the sponsoring state, environmental obligations, marine scientific research, fees, and work programmes.

 

3.2.1Work Programme

 

Under ISA requirements contractors are required to submit five-year work programs. The first TOML five-year work program was completed in 2016 and reviewed and accepted by the ISA in late 2016.

 

For the second five-year period ending in 2022 TOML proposed the following program.

 

Continue environmental baseline work;

 

Complete pilot testing;

 

Complete geotechnical studies;

 

Complete feasibility studies;

 

First draft EIA/EMP;

 

Continue training.

 

TOML noted that the program was:

 

Dependent on success at each stage;

 

Subject to change based on findings at hand at any particular time; and

 

Reliant on funding which in turn is dependent to some extent on macro-economic conditions and development with regards to the Authority and its stakeholders.

 

As a result of the financial state of the company, TOML did not progress at the rate intended until TOML was purchased by DeepGreen in March 2020. TOML currently plans an aggressive program of offshore campaigns in 2021 – 2023 focussing on resource assessment and environmental base line studies with the objective of upgrading the TOML F resource area to Indicated Mineral Resource status and completing environmental baseline studies and ESIA for the TOML F resource area.

 

TOML plans to collaborate closely with NORI on offshore technology development as well as progressing in parallel proprietary nodule collection technology developed by TOML. TOML and NORI will collaborate closely on the development of nodule processing solutions.

 

3.2.2Royalties and Taxes

 

Royalties and taxes payable on any future production from the property will be finalised once the ISA has developed an ‘exploitation code’. This was formally proposed as a project by the Secretary General of the ISA and endorsed at the 17th Annual Session of the ISA. Any code will need to honour the key principles of UNCLOS.

 

TOML has agreed to pay a royalty with the Tongan government for each tonne of nodules collected from the TOML area from commercial operations in return for sponsorship.

 

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4Accessibility, Climate, Local Resources, Infrastructure and Physiography

 

4.1Accessibility and infrastructure

 

The CCZ lies between Hawaii and Mexico and is accessible by ship from various ports in the United States and South America. As the CCZ deposit does not include any habitable land and is not near coastal waters, there is no requirement to negotiate access rights from landowners for seafloor mining operations. All personnel and material will be transported to the project area by ship. The region is well located to ship nodules to the American continent or across the Pacific Ocean to Asian markets. The CCZ is generally outside major shipping lanes as indicated in Figure 4.1 which shows the global cargo shipping network, illustrating the trajectories of all cargo ships bigger than 10,000 gross tonnage during 2007.

 

Figure 4.1Global cargo shipping network

 

Note: Colour scale indicates the number of journeys along each route. Adapted from Kaluza et al. 2010.

 

4.2Climate

 

The CCZ has a tropical oceanic climate, with average temperatures of from 20 °C to 32 °C. Minimum and maximum temperatures generally occur in March and September, respectively (ISA 2001), and the average sea surface temperature is 25 °C. The CCZ is located in open ocean and is subject to tropical weather patterns.

 

Off-shore operations are planned to run throughout the year, with the exception of hurricane events, which are expected to occur once every three years for any given location. Tropical hurricanes are difficult to predict due to their erratic frequency but have high intensity over short periods and occur mostly during the period from May to October (Tilot, 2006, GSR 2018).

 

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5History

 

Manganese precipitation in the deep oceans has probably been a widespread natural process for at least the last 500 million years, which is probably when the deep-oceans first oxidized (Fike et al. 2006). The nodules currently found on the seabed within the Clarion Clipperton Zone (CCZ) are constrained by the age of the Pacific Ocean crust itself and published dating indicates that they are probably no more than several million years old (e.g., Chang et al, 2005).

 

This history of exploration of the CCZ can be considered in four periods:

 

1The discovery of the Clarion Clipperton Zone (1875-1969).

 

2The International Decade of Ocean Exploration (1970-1981).

 

3The Reciprocating States Regime and the Pioneer Investors (1982-1995).

 

4The International Seabed Authority (1996 to present day).

 

5.11875–1969: Discovery of the Clarion Clipperton Zone

 

5.1.1First Samples

 

Polymetallic nodules were first reported in the Arctic Kara Sea (Ingri, 1985) and then by the British HMS Challenger expedition, in February 1873, in the Atlantic Ocean off the Canary Islands (Murray and Renard, 1891). Fossil nodules had already been found in the Alps by C.W. von Giimbel in 1861 (Jenkyns, 1977).

 

Although the HMS Challenger was primarily sail driven, new technology in the form of a steam engine enabled her crew to winch up nodule samples at 50 of the 343 seabed sample stations surveyed by the ship. Two of these sample stations are in what was later to be called the CCZ (Murray and Renard, 1891; Figure 5.1).

 

Figure 5.1Path of the HMS Challenger

 

Location data from Natural History Museum UK, (2014)

 

The expedition resulted in numerous oceanographic discoveries including the widespread nature of nodule deposits on the deep-ocean floor. Confirmation of the extent of nodules in the Pacific was made by a contemporary of Murray and Renard, Alexander Agassiz (Mero, 1965) who made several expeditions aboard the US Fish Commission’s USS Albatross around the turn of the century, including one through the central Pacific to the Marquesas Islands. At this time nodules were only seen as items of scientific curiosity.

 

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5.1.2Commercial Recognition

 

After the Second World War a Swedish expedition reportedly recovered nodules (United Nations, 1979), and interest in exploring seabed nodules started to increase again in the 1950s (as reflected in the publication rate on the subject; Meylan et al, 1976), with people like John Mero (Mero, 1965) promoting their potential with some success. Early exploration efforts and discussion were spread around the planet but based on less than 100 samples collected from the CCZ, Mero predicted the occurrence of many millions of tons of deposits with nickel and copper concentrations each greater than 1% as well as significant manganese and cobalt (Mero 1965).

 

Two of the early explorers in the 1960s were the USSR and the US companies Kennecott Exploration Inc and Deepsea Ventures. All started exploring in areas other than the CCZ, and it was only in the late 1960s and early 1970s that it became apparent that the CCZ had the best nodule fields in the world in terms of both grade and abundance (McKelvey et al, 1979). By the late 1960s and early 1970s, these explorers had been joined by others. Their efforts are detailed in subsequent sections.

 

5.1.3USSR

 

The USSR started an integrated marine research programme in 1949, led by the USSR Academy of Sciences. Regular expeditions commenced with the RV Vitiaz and later the RV Dmitri Mendeleyev, starting with at least three campaigns to the Indian Ocean (Bezrukov and Andrushchenko, 1972; Bezrukov, 1962, 1963) then in the southwest Pacific (e.g., Skornyakova et al. 1990), including the Penrhyn Basin near the Cook Islands, and then in the central Pacific (Bezrukov, 1969). Over twenty years, some seventeen Soviet expeditions included at least some research on nodules.

 

By the late 1960s the focus of Soviet exploration shifted to the Clarion Clipperton Zone. Hundreds of samples and thousands of photos were taken along with seafloor bathymetry mapping during two campaigns. Some mineral inventory estimates were also made (Skornyakova and Andrushchenko, 1964).

 

5.1.4Kennecott

 

Source Dave Felix and John Halkyard (pers comm. 2015), unless referenced otherwise.

 

Kennecott Copper Corporation became interested in manganese nodules in part based on the publications of Dr. John Mero (e.g., Mero, 1965) and work being done at Scripps Institution of Oceanography in the 1960s. Through their subsidiary Bear Creek Mining, Kennecott’s first exploration campaign dates back as early as 1962, when 10 tons of nodules were dredged from a site west of Baja California. For the next few years, the group relied on technical associations with oceanographic research campaigns (Killing, 1983) but Kennecott followed up with two more of their own campaigns in 1967. That year, newly designed free fall grabs were used for the first time during the “Clarion” campaign, while the “Confidence” campaign investigated a portion of the CCZ with 143 sample stations, bottom photos and dredge hauls.

 

In 1969, Kennecott Exploration Inc (KEI) was formed and between 1970 and 1974 KEI conducted another seven campaigns, with progressively more detailed sampling and survey work including dredging for bulk samples (up to 197 tons of nodules and 400 cubic ft of sediment in 1972; Isaacs, 1973). In 1970, on the Crux Campaign, KEI discovered what they called the Frigate Bird deposit in the eastern CCZ (Figure 5.4).

 

Many exploration techniques and nodule deposit characterization methods were developed and used successfully, but these were never publicly released. Some of the techniques developed at this stage are still used today (e.g., large diameter box-coring and photographic analysis (Felix, 1980).

 

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5.1.5Deepsea Ventures Inc

 

Deepsea Ventures’ first campaigns were in the mid-1960s in both the Atlantic (Blake Plateau off Florida) and Pacific (ISA, 2004). They were supported by US academic efforts (e.g., Fuerstenau et al, 1973) which focussed on the geochemistry of nodules and their metallurgical processing.

 

In the summer of 1970, the company conducted successful collector and air-lift trials at a depth of 762 m on the low metal grade nodule deposits of the Blake Plateau (Kaufman and Latimer, 1971; Lecourt and Williams, 1971; Geminder and Lecourt, 1972; United Nations, 1979). Deep Sea Ventures equipped the Deep-Sea Miner, a 6,750 t freighter, with a 25 m derrick and a 6 m by 9 m central pool (the space from which the subsea devices are deployed). The nodules were raised by airlift, a system previously tested in a 250 m mine shaft (ISA, 2004). The towed collector sled was fitted with a series of tines to exclude material above a certain cut-off size and thereby reduce the chance of pipe string clogging. Material passing the first set of tines was channelled to the suction point by a second set of more closely spaced tines. The first nodules arrived aboard the mining vessel on July 30, 1970. Pumping rates between 10 and 60 tons/hour were successfully achieved during this pre-production mining trial (EC, 1997).

 

German groups also started working with Deepsea Ventures in 1970 (Backer and Fellerer, 1986) and were more formally involved when Deepsea Ventures went on to form the OMA consortium in the mid-1970s. OMA by then had changed focus to their claim area covering the higher-grade nodules in the central CCZ.

 

5.21970–1981: The International Decade of Ocean Exploration

 

As interest grew through the 1960s, more and more commercial and government funded organizations started exploring the oceans, especially within the CCZ.

 

The International Decade of Ocean Exploration (IDOE) was an international, collaborative programme to improve the use of the ocean and its resources for the benefit of mankind. It nominally spanned 1970 to 1980 (DOMES, 1981). By 1975 IDOE counted 46 nations as members, including cold world adversaries, the USA and USSR. The US participation was coordinated by their National Science Foundation. Programmes managed by IDOE were mostly scientific in nature including a large environmental research component. IDOE was charged to “Improve worldwide data exchange through modernizing and standardizing national and international marine data collection, processing, and distribution.”

 

The United Nations was keenly aware of the significance of exploiting resources under international jurisdiction and debated how this resource should be managed. On 12 December 1970, the General Assembly of the United Nations adopted 2749 (XXV) “Declaration of Principles Governing the Sea-Bed and the Ocean Floor, and the Subsoil Thereof, beyond the Limits of National Jurisdiction” (United Nations, 1970). This followed negotiations which took place in a specially established Seabed Committee. This document declares the bed and ocean floor, beyond the limits of national jurisdiction, to be the common heritage of mankind (Guntrip, 2003).

 

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The UN’s efforts eventually led to development of the Third United Nations Convention on the Law of the Sea, but with a regulatory regime not yet in place, this period of the International Decade of Ocean Exploration is characterized by totally independent and usually overlapping areas of exploration as shown in Figure 5.2.

 

Figure 5.2Examples of the overlapping exploration areas of some of the first explorers

 

Sources: ISA, (2010), Menot et al (2010), Jeong et al (1994)

 

5.2.1USSR

 

Source Andreev (pers com March 2016), unless referenced otherwise.

 

During this period Soviet studies of the ocean floor continued from their efforts in the 1960s. From 1976 the USSR Academy of Sciences was joined by State scientific-production enterprises “Sevmorgeologiya” (St.-Petersburg) and “Yuzhmorgeologiya” (Gelendzhik), subordinated to the Ministry of Geology of the USSR. Publications from this period include monographs (Bezrukov, 1976, 1979; Volkov 1979) and numerous magazine articles (e.g., Bazylevskaya, 1973, Skornyakova et al. 1981).

 

5.2.2Japan

 

Japanese companies were easily the most prolific participants in nodule exploration and development in the 1970s, usually through large consortia such as DOMA and DORD (UNOETO, 1979). Japanese government efforts started in 1974 using their newly commissioned research vessel the Hakurei-Maru which was given two main projects: “Marine geological investigations on continental shelves and shores around Japan” and “Investigations on deep-sea manganese nodule deposits” which focused mostly on the Central Pacific Basin (Figure 5.3). These efforts concluded in 1984.

 

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Figure 5.3Areas researched by the Geological Survey of Japan in the 1970s

 

Source: UNOETO, 1979

 

5.2.3Kennecott Consortium (KCON)

 

Kennecott continued their exploration in the early 1970s attracted by the large informal resource estimates for nickel and other metals. Kennecott also commissioned preliminary feasibility studies of mining by Lockheed Missiles and Space Company and Global Marine Development, Inc., starting in the late 1960s. Kennecott’s corporate processing research centre in Lexington Massachusetts was charged with developing a metallurgical process for nodules with the Kennecott Computing Center in Salt Lake City being made responsible for resource estimates.

 

As the scale of the needed investment and level of required offshore expertise became apparent, Kennecott reached out and sought partners to share the risk. The KCON consortium was formed in 1974 based on the petroleum industry model of an operator (Kennecott Copper Corp) responsible for execution of work and supporting partners. The partners were Kennecott (50%), Rio Tinto Zinc (20%), Noranda (10%), Consolidated Gold Fields (10%) and Mitsubishi (10%) (Killing, 1983). Subsequently Rio Tinto Zinc sold half their shares to BP Petroleum Development Ltd. The Consortium was led by a Committee of Representatives (COR), which approved plans and budgets, and a Technical Advisory Committee (TAC) of technical experts from each partner which helped prepare the plans and review progress. Several engineers from the partner organizations were seconded to the KCON laboratories, principally the Ocean Mining Laboratory in San Diego, California.

 

The exploration work described above ended up with two areas of interest for KCON (Figure 5.4):

 

1The Albatross area in the central part of the CCZ, which ultimately became the “USA4” license in 1984 (U.S. Department of Commerce) under the Reciprocating States Agreement (Figure 5.13).

 

2The Frigate Bird area in the eastern part of the CCZ which ultimately became the “UK” License in the early 1980s.

 

This consortium developed many of the best exploration techniques used in the CCZ including large capacity box-coring and photographic survey (Felix, 1980). Ultimately KCON reached an unpublished “inferred reserve” for parts of their concessions (David Felix pers comm. 2015). This included definition of “mineable units” on the seafloor.

 

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Once exploration was completed the consortium developed mining system designs, numerical models and tested various components of a commercial mining system (Halkyard 1980, 1982). The development work included a towed nodule pick-up system which was tested at approximately 1/5th scale (Morgan, 2011; Heine and Suh, 1978), a hydraulic and airlift system which was tested on land (Burns and Suhm, 1979; Doyle and Halkyard, 2007), and study of nodule attrition including several pump loop simulations, material handling and transportation (Halkyard, 1979).

 

Metallurgical development included pilot scale testing of the patented “Cuprion” atmospheric pressure ammoniacal leach process (Skarbo, 1975; Agarwal and Beecher, 1976; Agarwal et al, 1978). A 200-ton bulk sample of nodules collected in 1972 (Isaacs 1973) were intended for a large-scale metallurgical pilot test. These nodules were stored in Safford, Arizona, however the samples were disposed of in the 1990s.

 

Figure 5.4Kennecott priority areas of interest in the CCZ

 

Modified from Yamazaki (2008b)

 

A comprehensive cost estimate of a commercial mining venture was carried out by KCON between 1978 and 1980. The mining and processing research conducted by KCON in the 1970s was consolidated into a commercial system design and execution plan. This work was performed by Bechtel Corporation with support for the mining system provided by Global Marine Development, Inc. Two sites were selected for the land-based processing plant: Southern California near Los Angeles and the West Coast of Mexico at Lazaro Cardenas, Michoacan, Mexico. Bechtel developed preliminary Cuprion plant designs and cost estimates for both sites. Extensive investigations were conducted into permitting requirements and options for tailings disposal. Lazaro Cardenas was under development as a deepwater port and an industrial hub to support Mexico’s industrialization plans. Meetings were held at a high level with Mexican officials who were encouraging KCON to consider a development at Lazaro Cardenas.

 

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The cost estimate was based on a 3 Mtpa manganese nodule project producing about 88,000 lb per year of nickel and associated copper, cobalt and molybdenum. KCON never considered manganese a viable product. The overall conclusion of the KCON/Bechtel study was that at the time nodules could be cost competitive with new sources of nickel, but not with current sources (Dubs, 1983). Also, Kennecott and other industry representatives believed the then terms of the newly negotiated Law of the Sea Treaty would introduce unacceptable risk to the project.

 

KCON worked with government officials and other interested consortia in establishing a framework which would permit restructuring of Part XI of the Law of the Sea Treaty in a form acceptable to KCON and other active mining consortia. However, as time dragged on KCON progressively wound up their operations, stopping active exploration and closing their Ocean Mining Lab in La Jolla in 1981.

 

KCON applied for and received an exploration license for a segment of its exploration area under the US Deep Seabed Hard Minerals Resources Act in 1984 (USA-4). Although some ad hoc evaluation continued after this, in May 1993, KCON abandoned their license under the US Act. The consortium was dissolved. In June 1993, Ocean Minerals Company (OMCO) submitted to NOAA an exploration license application from the former KCON license area USA-4. OMCO also acquired the exploration data for the KCON sites.

 

5.2.4Ocean Mining Associates (OMA)

 

The OMA consortium comprised Essex Minerals Company (US), Union Seas Inc (Belgium), Sun Ocean Ventures (US), with Deepsea Ventures Inc the consortium’s service contractor (ISA, 2004).

 

In 1976, six years after the Drake Plateau trials discussed above, OMA started a programme to trial mine nodules in the CCZ. OMA equipped the Wesser Ore, a 20,000 ton iron ore carrier, with a moon pool, a derrick and revolving thrusters. The ship had the two central holds converted for equipment and the moon pool, a forward hold set aside for general use and three holds combined into two for nodule storage. The ship’s derrick was covered by a distinctive dome, whose purpose was mostly to keep proprietary technology hidden. The nodules were collected by a suction dredge towed on skis behind a rigid riser and were raised by airlift. The collector was at 1/5th scale except for the collector inlets which were at full design scale.

 

The ship renamed Deepsea Miner II (Figure 5.5), conducted its first tests in 1977 at 1,900 km southwest of San Diego, California. The tests were suspended because the electric connectors along the pipe string were not completely waterproof. Early in 1978, two further trials encountered new difficulties when the dredge floundered in bottom sediment and a cyclone struck. The latter situation was dangerous as the riser could not be retrieved in time (it took well over 6 hours to recover), so the ship had to ride out the full fury of the storm (later voyages included an emergency explosive detachment system for the riser). Finally, in October 1978, 550 tonnes of nodules were lifted in 18 hours, at a maximum capacity of 50 ton/h. The test was stopped after a blade broke in a suction pump. Ultimately the nodules recovered were taken to Belgium (home of Union Seas Inc) and used for attrition testing in a three-phase loop system (University of Virginia (2015)).

 

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Figure 5.5Ocean Mining Associate’s Deepsea Miner II

 

Source University of Virginia (2015)

 

5.2.5AFERNOD

 

Unless referenced otherwise source is Ifremer (1994) or Menot et al. (2010).

 

French interest in exploration and mining of Pacific nodules dates back to the mid-1960s but field work commenced in early 1970 when the Company "Société Le Nickel" (SLN) and the National Centre for the Exploitation of Oceans (CNEXO), which later became today’s Ifremer (Institut Français de Recherche pour l'Exploitation de la Mer), began studying the nodule deposits, focusing near the Marquesas Island Group (French Polynesia) (IFREMER, 1994, Menot et al, 2010).

 

In 1974, the Commissariat à l'Energie Atomique (CEA) and the Chantiers de France-Dunkerque, which in the meantime became Chantiers du Nord et de la Méditerranée (NORMED), formed a joint venture called Association Française d'Étude et de Recherche des Nodules Océaniques (AFERNOD). AFERNOD focused more on the CCZ.

 

In 1984 Ifremer and CEA (via their subsidiary TECHNICATOME) formed GEMONOD (which stands for Groupement pour la mise au point des MOyens nécéssaires à l'exploitation des NODules) which led the development programme of the technology of exploitation of nodules funded by the French government until 1988. Thereafter Ifremer resumed management of all aspects of the project.

 

AFERNOD used four research ships for most of their work during the 1970s, the Coriolis, the Noroit, the Suroit, and Jean Charcot. They also used one of the world’s first AUVs, the Epaulard, and the manned submersible Nautile.

 

Between August 1975 and September 1976, the French explored the entire CCZ at a wide but systematic scale with nine campaigns (called NIXO20 to 28). A wide range of technology was used in the exploration effort, but it appears that clusters of free fall grabs were typically used at each sample site.

 

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Analysis of exploration results of the area led to definition of two domains, with one having more continuous grade characteristics. For the next phase the AFERNOD selected an area with consistent grade and typically higher abundance, the 431,500 km2 “NORIA” area (NOdules RIches et Abondants). The eastern parts of this area coincide with KCON’s Albatross Area (Figure 5.6). Work at NORIA between 1976 and 1977 started with several thousand kilometres each of sonar, magnetic and seismic survey. This was followed by six campaigns of sampling and photographic survey.

 

Figure 5.6Samples in the NORIA Area

 

Source: Menot et al. (2010)

 

A “mining area” of 150,000 km2 was then selected from the NORIA area for further work starting in 1979. This worked focused on mapping the seafloor topography and nodule abundance. The latest technologies such as multibeam echo sounding (MBES) and AUV survey were brought to the problem as well as more detailed towed surveys.

 

5.2.6Ocean Mining INC. (OMI)

 

Unless referenced otherwise the following is sourced from Brockett (pers comm. 2016) or Brockett et al. (2008).

 

The International Nickel Company (INCO) first became interested in deep-ocean mining for manganese nodules back in 1958, but it was not until late in 1971 that INCO opened its Ocean Mining Development office in Bellevue, WA. During those early years, INCO contracted with outside organizations (John Mero, Dames and Moore, and Deepsea Ventures) to assist with exploration activities including several survey campaigns. INCO then explored in their own right with the MV Growler.

 

A first generation mechanised self-generating collector concept delivered by contractor Ocean Science Engineering in 1972, proved unworkable in trials in Discovery Bay, Puget Sound.

 

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INCO made the decision to develop their collector systems in-house and set about designing what became internally known as the “Electro-Hydraulic” (EH) collector that was subsequently patented in 1976. INCO constructed a version of the EH collector designed to be tested on a cable and scheduled a deep-sea collector test in the CCZ in the early 1970s. Unfortunately, the collector, its instrumentation system, and a 7600 metre electro-mechanical tow cable were lost during a shallow water test off the coast of Oahu, Hawaii. That loss triggered INCO’s decision to search for joint venture partners leading to the formation of OMI.

 

In 1975 the OMI consortium was created, led by INCO and including AMR of Germany, DOMCO of Japan and SEDCO of the USA.

 

AMR was given responsibility for the exploration programme within OMI and INCO was assigned responsibility for collector development (Brockett and Kollwentz, 1977). However, both AMR and DOMCO assisted with the design and construction of prototype test collectors. INCO excavated a land based collector test facility in Redmond, WA, and early in 1976 tested eight collectors of various designs.

 

In 1976 the OMI collector team used the RV Valdivia to conduct in-situ collector tests in the CCZ. Two collectors were chosen for a subsequent pilot mining test; the DOMCO hydraulic design and the AMR cutter blade scraper design. Two of the hydraulic collectors were constructed, one with a two metre wide active collection width and one with a three metre wide collection width.

 

The developmental mining system tested was configured around the SEDCO 445 drill ship which was a 445’ vessel (Figure 5.7). A riser pipe assembled with 9-5/8” diameter oil field casing (Figure 5.9) extended from the gimbaled rig floor on the ship to within 50 metres of the seafloor. This gimbaled rig floor was important for safe and efficient operations and allowed the casing to be safely lowered and the collector deployed without damage. The addition of motion compensation equipment completed the list of requirements for creating the stable platform to carry out successful deep mining operations. The weight of the riser pipe, pumps, instrumentation and collector assembly was over 450 metric tons.

 

During the pilot mining testing, OMI tested both a hydraulic submersible pump (Figure 5.9) and an air injection lift system to raise the nodules from the seafloor to the surface. The interface between the seafloor collector and riser pipe was a structurally strengthened flexible hose to accommodate variations in seafloor bathometry. Above the flexible section of hose a deadweight was installed to control riser pipe lift-off during towing operations. Next in line was a dump valve to prevent nodule clogging in the riser pipe during mining shutdowns. There was also a vacuum relief valve in the lower assembly to prevent collapse of the flexible hose in the event the collector became jammed with nodules.

 

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Figure 5.7OMI Pilot Mining System Configuration and the SEDCO 445 off Honolulu

 

brocket-R1-E030_modifiedbrocket-R1-E008

 

While the primary function of the collector was to gather the nodules from the seafloor, there were secondary functions; rejecting the oversized and undersized nodules, eliminating unwanted sediment, and introducing the nodules into the riser system. In addition to providing a conduit for lifting the nodules to the surface, the riser pipe was used to tow and navigate the seafloor collector through the mine site. Once on deck, an air, water and nodule separator directed the nodules to conveyors (Figure 5.10) for transporting the nodules to the ship holds and on deck storage containers. Any superfluous water and entrained sediment was returned to the ocean under supervision of NOAA environmental scientists associated with the DOMES project.

 

Three test campaigns culminated a four-year research and development programme by OMI to determine the technical feasibility and economic viability of deep-ocean mining at the time. The pilot mining test was conducted in more than 5,250 metres of water.

 

Figure 5.8INCO electro-hydraulic collector test; DOMCO hydraulic collector launch & recovery test on the RV Valdivia

 

brocket-R1-E004brocket-R1-E003

 

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Figure 5.9Connection of riser to collector and in-line submersible pump

 

brocket-R1-E010brocket-R1-E005

 

Figure 5.10OMI Transport Conveyors Overflowing with Nodules

 

brocket-R1-E022

 

The OMI team, operating aboard the SEDCO 445 drill ship successfully recovered over 800 metric tonnes of nodules during these tests during the summer of 1978. The submersible pump system recovered approximately 650 tonnes of nodules while the air lift system recovered 150 tonnes. Nodule throughput varied dramatically throughout the tests with the rate exceeding 40 tonnes per hour at times causing the material handling systems and storage containers on the mining ship to overflow with nodules (Figure 5.10).

 

Most of the 800 tonne sample was shipped to INCO’s Port Colbourne research facility for process testing and development. There it was processed into Ni-Cu-Co matte which was distributed to the consortium partners for further evaluation.

 

Kollwentz (1990) discusses the challenges faced by OMI (and thus by the other commercial consortia) both leading up to, during, and most critically after the successful pilot mining trial. Issues relating to the project specifically revolved around management and related technology development (the nodule consortia were some of the earliest large complex joint ventures; Killing, 1983).

 

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5.2.7Ocean Minerals Company (OMCO)

 

Ocean Minerals Company comprised US and Dutch interests, namely: Ocean Systems of Lockheed Missiles and Space Company Inc., Amoco Minerals Co, Billiton International Metals BV and Boskalis Westminster (UNOETO, 1979).

 

In 1978, following the end of the infamous Project Azorian (CIA, 2012), OMCO rented the Glomar Explorer from the United States Government (Spickerman, 2012) to use as the pilot mining vessel. The Glomar Explorer (Figure 5.11) had been built to raise a sunken Russian submarine but had used nodule mining as a cover story. The OMCO partners thus sought to leverage off much of the already completed engineering work.

 

OMCO conducted an extensive exploration campaign across the CCZ (Golder Associates, 2013) with a minimum of six campaigns utilising the MV Governor Ray between 1978 and 1981. Work included sampling (Spickerman, 2012), photography and video survey. Footage of some of the exploration work and subsequent pilot mining trials can be found at Periscope Film (2013).

 

The pilot mining vessel had dynamic positioning, a 33,000 ton displacement and a length of 180 m. It utilized a sophisticated system to deploy the pipe string and electric power conduits (ISA, 2004). Its large moon pool (61×22 m) facilitated the handling of a large collector and buffer. OMCO built a motorized collector outfitted with Archimedes screw-drives to crawl over soft sediment (Figure 5.11).

 

Initial experiments were at a depth of 1,800 m off California, but the first full tests were south of Hawaii at the end of 1978. These first tests were suspended because the doors of the moon pool refused to open. Finally in February 1979, the operation was carried out with more success. In addition, much data was assembled by the ship’s advanced computer system. These operations succeeded in demonstrating that OMCO’s basic approach to dredging and lifting worked (ISA, 2004).

 

Figure 5.11OMCO Screw-drive collector and pilot mining vessel, the USNS Hughes Glomar Explorer

 

 

http:||i.kinja-img.com|gawker-media|image|upload|l1k57rhm2hyyrn2ueqom.jpg

 

Sources: Spickerman (2012); Strauss (2014)

 

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5.2.8DOMES

 

In order to meet requirements of national environmental legislation, the United States in 1975 initiated a comprehensive research programme called Deep Ocean Mining Environmental Study (DOMES; Bischoff and Piper 1979; DOMES, 1981; Thiel et al, 1997). The study was described as a Draft Programmatic Environmental Impact Statement and characterised the environment in the CCZ region (which was included in a rectangular area called also the DOMES area) and the impacts of its potential mining.

 

Figure 5.12DOMES baseline sites in the CCZ, within the DOMES area

 

Modified after Piper et al. 1979 with CCZ boundaries and TOML areas.

 

Phase I of the programme, called DOMES I, was undertaken by the National Oceanic and Atmospheric Administration (NOAA) of the US Department of Commerce to provide environmental baseline information on three representative mining sites (A, B, C) in the Pacific manganese nodule province. Each covered an area of approximately 200 km by 200 km and was chosen in consultation with industry and the scientific community.

 

The programme was run by NOAA’s Pacific Marine Environmental Laboratory with significant input from academia. Twelve campaigns of NOAA's research vessel RV Oceanographer were carried out from August 1975 through November 1976, totalling approximately 240 ship days at the three sites. Scientific disciplines represented were physical oceanography (studies of solar radiation and ocean currents), biological oceanography (studies of phytoplankton and benthic fauna), chemical oceanography (studies of nutrient chemistry and suspended matter), and marine geology (studies of sediment, nodules, acoustic stratigraphy).

 

DOMES II involved monitoring of the effects of the OMI and OMA pilot trials described above (e.g., Ozturgut et al, 1981). The OMI and OMA systems required discharge of return water from the lift system, and this was monitored and characterised. Estimates of lift and collector impacts for a 5,000 dry metric tonne per day operation were also made.

 

Data review and reporting included assessment of required resources for mining and on-shore processing marketing and cost-resource-safety trade-off estimates.

 

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DOMES was designed primarily as a data gathering effort and final data reports were submitted to NOAA by early 1978. Data collected concurrently by other workers was included with the DOMES data for completeness, with a book of key findings and data published in 1979 (Bischoff and Piper 1979). The final official Draft Programmatic Environmental Impact Statement was issued in 1981 (DOMES, 1981; Ozturgut et al, 1997). The conclusions of the study at the time were that for a commercial operation most issues were likely not of serious concern, but with key focus on:

 

Surface discharge from a typical riser lift system would have no long term impact and would be very small at the scale of the CCZ. A question remained on impact of particulate matter on fish larvae.

 

Impact from a typical seabed collector would be clearly adverse to benthic organisms at the site, but that on the scale of the CCZ impact would not be significant. Recolonisation rates were unknown. High rates of biodiversity and ecosystem function were addressed but not examined in depth and the inevitability of islands of undisturbed seafloor within the mine sites was pointed out.

 

Extent and impact of sediment plumes generated at the seafloor was still largely unknown and demanding of further investigation. The benthic impact experiments discussed below were then designed to specifically address this point (Ozturgut et al, 1997).

 

5.31982–1995: The Reciprocating States Regime and the Pioneer Investors

 

By 1980, the Third United Nations Conference on the Law of the Sea had been running for eight years and a successful outcome was far from certain (Churchill and Lowe, 1988). The process was drawn out by a need for consensus in the sessions as earlier attempts to use majority votes had proven unsatisfactory.

 

In the early 1980s legislative efforts to manage deep-sea mining (and specifically development of the CCZ nodules) split with:

 

The United Nations establishing a specific Preparatory Commission (PrepCom; at the eleventh session) to look at defining principles and regulations to implement the 1982 Act and to encourage Pioneer Investors into the Area (this was often related to trying to get particular states to sign UNCLOS);

 

Establishment of the Reciprocating States Regime (RSR). This directly involved USA, Japan, France, West Germany, United Kingdom and by distant association the USSR, China, and what became the IOM consortium. The RSR was either planned as a bridging system until UNCLOS could be sorted out or was an alternative system altogether (Churchill and Lowe, 1988).

 

The UN was keen to close out UNCLOS and recognised the need to attract a group of Pioneer Investors on more attractive terms than originally envisaged (Resolution II). Many of the groups that had worked in the Area in the 1970s had the desire to register and protect past work with the hope that UNCLOS was imminent. After several initial attempts to progress discussions, the USSR and India registered first as Pioneer Investors in early 1984. With concerns about losing security of tenure, France and Japan followed suit in late 1984.

 

Issues with the applications, in part relating to overlapping areas, meant that most of these applications were resubmitted along with others in 1987 and 1988. In the meantime PrepCom worked on regulations, the RSR was progressed further, and the nations concerned discussed the issues at the UN and in other forums.

 

The RSR worked by mutual co-operation whereby each participating state:

 

Established domestic deep mining legislation of a broadly similar basis and

 

Met and agreed that mineral rights granted under their respective domestic legislation would not overlap (Figure 5.13).

 

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Figure 5.13Operating Areas under the Reciprocating States Regime, circa 1993

 

Source: NOAA (1993)

 

The RSR worked well in terms of removing the issues of the overlapping work programmes (and subsequent claims) that characterised the previous decade. By 1993 there were 18 “operating areas” recognised by the US (Figure 5.13) with all but one in the CCZ Most of these areas are now encompassed within the ISA contracts and returned areas (Figure 3.1). Today only three of these operating areas are still in force outside of UNCLOS, these being the USA-1 (two blocks) and USA-4 areas, all issued to Lockheed Martin under the US Deep Seabed Hard Minerals Act (NOAA, 2016). The deep-sea mining legislation developed by the other members of the Reciprocating States Regime is however still of value as domestic legislation is required in any event by Sponsoring States under UNCLOS.

 

Between 1989 and 1994 the commercial consortia started shutting down their nodule programmes and the UN Secretary General seriously tackled the idea of modifying Part XI (Ranganathan, 2014). In 1994, revisions to Part XI (at this stage called “The Boat Paper”) had progressed to point of widespread (if not complete) acceptance. The resulting Agreement on Implementation was included into UNCLOS and adopted as a binding international Convention.

 

Issuance of the Agreement of Implementation lead to a raft of ratifications from UNCLOS signatory states, but despite it being drafted largely in concession to the United States, the United States has not yet ratified UNCLOS, although it did provisionally sign the Agreement of Implementation. By this time the registration of the seven Pioneer Investors was complete. This included the six shown in Figure 5.14 as well as India (with a contract in the Indian Ocean). The Pioneers received special terms including application fees at cost of administration (up to USD 250,000) and the right to apply for 150,000 km2 in the first instance (returning a 150,000 km2 area of equal value at that time; Figure 5.14), reducing to their preferred 75,000 km2 over the next fifteen years.

 

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Figure 5.14Retained and returned (lighter shade) areas of the pioneer investors in the CCZ

 

Modified after ISA (2003) and Ifremer (1994)

 

5.3.1Deep Ocean Resources Development

 

DORD has its origins in DOMA (Deep Ocean Minerals Association) a consortium of some 39 different Japanese companies that was formed as a public corporation in 1974 but with oversight by the Japanese Ministry of International Trade and Industry (MITI). DORD was then established in 1982, specifically for the development of polymetallic nodules. However, since the mid-1990s, it has been involved in other deep-sea mineral resource types and hydrocarbon research (DORD, 2013). DORD is 75.83% owned by Japan Oil, Gas and Metals National Corporation with the remainder distributed amongst some 43 commercial companies (DORD, 2013).

 

DORD began manganese nodule exploration activities in 1983 and was formally accepted as a Pioneer Investor in late 1987. DORD reports through the Japanese Agency of Industrial Science and Technology to MITI. Between 1981 and 1989 it spent some JPY20 B (~USD80 M at the time; Kajitani, 1990). Much of the research and development expenditure was on a mining system concept, models and simulations and pilot development by the Technology Research Association involving:

 

Towed collector based on the OMI Asakawa design but incorporating a crusher;

 

Lift system (either pumping or airlift);

 

Flexible hose connection to collector that was key for helping managing heave and seafloor irregularities as well as landing and recovery operations; and

 

Pumps and compressors and their efficiency.

 

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In 1997, as part of the pilot programme of component testing, a trial was made using a towed collector without crushing or lifting (Figure 5.15). This was on a seamount southeast of Marcus Island (Minami-Tori-shima) at 2200 m and nodules were successfully collected (Yamazaki 2008, Yamazaki, 2011).

 

Figure 5.151997 Japanese collector, barge and trial schematic

 

Source: Yamazaki (2006)

 

In 1996, ahead of the seamount trial, DORD paused work in the CCZ, resuming only in 2008.

 

5.3.2China and COMRA

 

Formal Chinese interest in deep-sea marine science and development is believed to date back to the mid-1970s with the leadership of Deng Xiaoping (Takeda Jun’ichi, 2014; Hoagland et al, 1992).

 

The first known marine surveys took place in 1978 (RV Xiang Yang Hong 05; COMRA, 2013a), 1983 and 1985 (RV Xiang Yang Hong 16 in the central Pacific; Hoagland et al, 1992; Glasby, 1986). Between late 1986 and 1987 a campaign to the CCZ covered 48,000 km2.

 

Between 1991 and 2013, COMRA organized some 16 ocean expeditions to its area in the CCZ (COMRA, 2013b). Ultimately it delineated some 20 Gt of “mineral rich areas” (COMRA, 2013a), using in part an acoustic system called MFES (Multi-Frequency Exploration System; ISA, 2010).

 

In 2001, COMRA was involved with research institutes in pilot-miner trials in a test pool (2.8 m deep) and later in shallow water (~150 m deep; Li and Jue, 2005; COMRA 2013c). The tests included: trials of track and screw drive vehicles (Figure 5.16); determination of power requirements; ability to navigate obstacles; spud types for tracks; the ability to make turns; and the effect of sideloads. Tendency to accumulate mud is not specifically mentioned. Test work showed that the test tracked vehicle worked better than the test screw drive vehicle (Li and Jue, 2005) so a tracked vehicle was used as basis for the pilot vehicle.

 

Trials started June 2001 and in September the first successful production test were achieved with collection of 900 kilograms of synthetic nodules. At around the same time lifting tests were done using pumps and pipes in an old mine shaft (to 230 m).

 

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Figure 5.16Chinese pilot scale tracked and test screw-drive subsea vehicles

 

Source: Li and Jue (2005)

 

5.3.3GEMONOD

 

AFERNOD continued working on the CCZ project for the French government until around 1984 when they were joined by GEMONOD (Groupement pour la mise au point des MOyens nécessaires à l’exploitation des NOdules), which focused on the mining and processing sides of the project (Ifremer, 1994).

 

Work at this time included provision of samples for metallurgical test work, more detailed seabed geotechnical work and accurate characterisation of the types of seabed obstacles. The geotechnical work included using the Nautile submersible to take shear vane readings on carefully selected sites during the 1988 NIXONAUT campaign (Cochonat et al., 1992).

 

Much of the photographic and video data collected by Ifremer at this time was studied by biologists and is encapsulated in a detailed study on the megafauna (animals > 2 cm in size) of NIXO45 by Tilot (2006). This includes some of the first detailed photos of animals and landforms on the seafloor of the CCZ and a quantitative analysis of the megafauna present.

 

A 25 tonne metallurgical sample was collected from 49 dredge deployments. A trial mining site was also selected, called NIXO 45, and this area was surveyed and sampled in detail.

 

AFERNOD and then GEMONOD also considered a variety of possible mining systems during this period including one of the most exotic ever taken to testing phase. Initially in the 1970’s the continuous line bucket system was favoured (ISA, 2001b) but by the mid-late 1970s survey had discovered terrain obstacles on the ocean floor, such as blocks, steps, cliffs and potholes, convincing French engineers that a bottom collector independent of a surface vessel was needed.

 

In 1980 they worked on the concept of a free-shuttle mining system (Ifremer, 1994) consisting of a series of independent vehicles that would dive on their own to the ocean floor. Reaching the bottom, they would dump ballast to position themselves and would start to collect the nodules. After loading 250 t of nodules, they would drop additional ballast and start their ascent to the surface. It was found during the feasibility study that the system would be too expensive, because the 1,200 t weight of the shuttles far exceeded their 250 t loading capacity. Nonetheless in 1985 a prototype pilot scaled vehicle (PLA-2 6000; Préleveur Libre Autonome) was built and in late 1987 tested in the Mediterranean where it demonstrated flight, landing, seafloor movement, and return to surface (ISA, 2001b).

 

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Figure 5.17GEMONOD crawler and hydraulic lift system

 

 

Source: Herrouin 2009. (Crawler (1) hose (2) buffer (3) pumps (4) rigid pipe (5), semisubmersible platform (6))

 

By the mid-1980s GEMONOD determined that hydraulic systems seemed to have the greatest potential (Ifremer 1994; Herrouin 2009; ISA 2001b, 2004). GEMONOD’s system (Figure 5.17) consisted of: a semi-submersible surface platform; a 4,800 m rigid steel pipe string, and a flexible hose, 600 m long and with a 38 cm internal diameter, connecting the bottom of the pipe string to a dredge on the seabed. This hose would form an arc, allowing the dredge to deviate from the route followed by the surface platform so as to avoid obstacles. The self-propelled dredge would be 18 m long, 15 m wide and 5 m high, weighing 330 t for 78 t buoyancy. Crawling on the bottom, it would collect nodules and condition them for pumping through the flexible hose. Ore carriers would transport the nodules from mining ship to port, where the processing plant would be located.

 

GEMONOD also looked at mineral processing, both hydrometallurgical and pyrometallurgical options (Ifremer, 1994). This included a pilot processing plant for ammonia/acid leach circuits built in Fontenay-aux-Roses by CEA (ISA, 2001b), and smelting tests by MetalEurop.

 

5.3.4USSR and Russia

 

Studies by the USSR Academy of Sciences increased markedly in number in the 1980s. New advances were in the study of the composition and structure of nodules, as well as local factors (e.g., Kazmin, 1984; Andreev, 1994). However, the most extensive research was carried out by the Ministry of Geology (through institutes such as Yuzhmorgeologiya) of the USSR. These studies included the Indian Ocean, but focused for the most part on the CCZ, and each year between 1982 and 1987 there were four or five marine expeditions (S. Andreev pers comm. 2016). Work included development of high-quality towed sonar and photo platforms (e.g., MAK, MIR and Neptune that are still used today), as well as samplers and navigation systems.

 

During the 1980s and early 1990s the Soviet explorers examined of the order of 3 million km2 area in the CCZ, with a network of stations at an average density of ~ 50×50 km. Studies included bathymetric, gravimetric and magnetometric observations, acoustic research, as well as bottom sampling. On the sections of the CCZ regarded as promising for the future development application, the station spacing was reduced to 25×25 km, and towed sonar and video-photography was added.

 

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On May 16, 1988 the USSR formally became a Pioneer Investor through Yuzhmorgeologiya, and since then the Ministry of Geology effectively halted all nodule related work outside the CCZ. Up until 1997, YMG performed around 12,000 line km of deep-towed acoustic survey (typically side-scan and sub-bottom profiling) and 8,900 line-km of deep towed photo-television survey and collected about 1100 seafloor samples. The results of this work greatly clarified ideas about the structure of localized accumulations of the nodules.

 

In parallel with this work the Russians considerably intensified research and development into the extraction and processing of nodules. This included pilot testing of both pyrometallurgical and hydrometallurgical processing in 1989.

 

During 1988 and 1989 Yuzhmorgeologiya and Sevmorgeologiya also were closely involved in geological studies of the eastern part of the CCZ in order to prepare the applications created before the Interoceanmetal Joint Organization. This included results from some 11 research campaigns.

 

5.3.5Interoceanmetal Joint Organisation

 

Interoceanmetal Joint Organization (IOM) was formed on 27 April 1987, based on an Intergovernmental Agreement and started operations in December that year (Kotlinski et al, 2008). In early 1991 IOM registered as a Pioneer Investor with PrepCom with their Certificate of Registration issued in July 1992. Present IOM member states are: Bulgaria, Cuba, Czech Republic, Poland, Russian Federation, and Slovakia. Past members included Vietnam and East Germany.

 

After its establishment, the IOM focused on regional geological and geophysical surveys within the CCZ in 1988 and 1989. After surveying 540,000 km2 (including TOML Area E), lOM’s claim with PrepCom concerned 300,000 km2, all in the eastern part of the CCZ. Between 1987 and 2010 they were involved in some 20 research campaigns (Stoyanova, 2010).

 

In the mid to late 90s IOM started research into mining and minerals processing. Concept design of a possible mining system included computer simulations of the effects of the marine environment on the mining system, movement of the mining vessel and nodule miner and effects of the movement on the transport rise pipe length paid out, and riser pipe deformation. The simulation showed that the riser pipe shape deformation depends mainly on mining vessel movement speed and can be controlled by horizontal forces applied at low speeds.

 

Experiments were also done for nodules of different shapes and sizes for nodule and water velocity measurements at upward flow in the hydraulic laboratory at in the Department of Water Engineering and Hydrotransport of the Agricultural University of Wroclaw, Poland. The mixture phase velocity measurements were carried out with application of radioisotope-tagged natural and synthetic nodules. A volume concentration as high as 10% was used in a pipeline of 150 mm diameter, that could be considered for a trial or commercial system.

 

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Metallurgical research included desktop development of a pyro-hydrometallurgical processing circuit at the University of Chemical Technology and Metallurgy, Sofia, Bulgaria and Hutny projekt, Bratislava, Slovakia (Figure 5.18).

 

Figure 5.18Preliminary metallurgical processes studied by IOM

 

 

Pyro-hydrometallurgical (L), acid leach (C) and ammonia leach (R) processes. Source: Kotlinski et al. 2008

 

Hydrometallurgical acid leach nodule processing was also studied at CNIGRI Moscow, Russia, including benchtop test-work and hydrometallurgical acid and ammonia leach processing options at the Nickel Research Centre in Moa, Cuba. All of the process route options studied gave good metal recoveries but there were clear (unpublished) differences in terms of likely capital and operating costs.

 

5.3.6Benthic Impact Experiments

 

Benthic impact experiments were born out of US environmental studies in the 1970s, including DOMES. The first known disturber system was built in the late 1970s by Sound Ocean Systems Inc (Brockett 2016, pers comm.).

 

After several attempts by different groups to build an effective disturber and monitoring system, Sound Ocean Systems designed and built a disturber system, the second generation DSSRS-II (Figure 5.19) to lift and then suspend sediments at 5 to 10 m above the seafloor using two 7.6 hp pumps. Testing in early 1993 was followed with a cruise to the CCZ (BIE-II) with YMG, including baseline survey, recovery of the previous year’s sediment traps and a programme of 49 tows. This time the disturber worked “well” and sediment was dispersed. Key conclusions from the trial (Ozturgut et al, 1997) were positive, i.e.:

 

Sediment dispersed as a turbidity flow rather than as a low density plume - initial estimates of the far field range of dispersion may have been overestimated;

 

Burial of up to 1–2 cm thick appeared not to have the catastrophic effect that was once predicted as both meio- and macrofauna appeared to burrow or recruit to the deep-sea benthos if needed;

 

Some questions would remain until a full scale mining test is monitored.

 

The impact assessment of the site, when revisited after 9 months, indicated that, while some of the meiobenthos showed a decrease in abundance, the macrobenthos showed an increase in their numbers, probably because of increased food availability (Yamazaki, 2011). The site was then revisited again in 2000 by YMG and the key finding was that “Decreasing of macrofauna is observed on physical disturbed areas (on disturber tracks) but not on the areas of re-sedimentation” (Melnik and Lygina, 2010). Note that with a commercial mining system, that sediment from mined areas will be progressively redeposited alongside or immediately behind the collector or concentrator.

 

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Figure 5.19DSSRS-II Benthic Disturber

 

Modified from: Stoyanova (2010), Brockett (1994)

 

Subsequently the DSSRS-II “benthic disturber” was used by several other groups. One of the best reported experiments was JET (e.g. Yamazaki et al 1997; Yamazaki and Kajitani, 1999; Yamazaki, 2011). This study included baseline data collection, sediment traps, current meters etc, but the Japanese also developed a quantitative photographic analysis method to try and more intensively measure distance of sediment redeposition from the disturbance tracks (Figure 5.20).

 

Figure 5.20Review of the DORD 1994 JET Benthic disturber site in 1996 using a Finder-installed Deep-sea camera

 

Source: DORD (2010, 2014). Heavy deposition was defined as >0.26 mm (Yamazaki, 2011). NDA is no deposition.

 

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Post-experiment observations took place just after the experiment (J2 survey), about 1 year later (J3), and about 2 years later (J4), by which stage DORD’s main conclusion was that any impact had been significantly reduced. The observations centred around sediment sampling and camera surveys to determine resedimentation impact on the benthos.

 

Attempts were made to scale up the JET results to full commercial scale, but these were dependent on a number of fundamental assumptions including penetration depth (Yamazaki, 2011).

 

Radziejewska et al (2001) summarised three surveys at the IOM BIE site, namely those of 1995 (immediately pre and post disturbance), 1997 and in 2000. Research on the IOM site essentially:

 

Struggled in 1995 to find significant impact to the meiobenthic communities outside of the tracks left by the DSSRS-II;

 

Found in 1997 widespread changes (e.g., in nematode familial make-up) as a result of a phytodetritus sedimentation event (likely a natural plankton bloom event) as well as that the tracks were now substantially “levelled off”, presumably due to action of currents or bioturbation;

 

Found in 2000 that response to the phytodetritus sedimentation event was more or less reversed to the condition at the start of the trial.

 

Radziejewska et al (2001) interpreted that the implications of this are that:

 

Certain significant processes take place in the abyssal communities without human intervention;

 

This supports the notion of there being no absolute, inherent stability on the abyssal seafloor;

 

These natural processes can induce changes of greater magnitude than induced by the benthic impact experiments (and by extension potentially by commercial production)

 

That quantitative monitoring of mining impacts will be challenged by the naturally occurring variations.

 

Figure 5.21IOM BIE meiobethos populations for control, resedimentation and impacted area stations

 

 

Source: Radziejewska et al (2001) C1, C2, C3 are control stations in 1995, 1997 and 2000; R1, R2 are resedimentation stations in 1997 and 2000, Pi1, Pi2, Pi3 area impacted stations in 1995, 1997 and 2000. Nema is Phylum Nematoda (round worms), harp is Harpacticoida (copepod crustacean)

 

Kim et al, (2011) looked at sinking particle flux relationships with ENSO and found up to three-fold increase against background during a moderate La Nina event in 2007/08. Significantly with regards to the IOM experiences regarding their BIE site, the winter of 1995 was also a moderate La Nina event (1996 was neutral and 1997 a ‘super’ el Nino; NOAA NWS, 2016).

 

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5.41996 onwards: The International Seabed Authority

 

With entry into force of UNCLOS in 1994, the ISA technically came into existence. In actuality, the ISA started working as an autonomous international organisation, domiciled in Kingston Jamaica, two years later in June 1996. All signatories of UNCLOS are members of the ISA which operates as mandated by UNCLOS.

 

5.4.1Korean Research Groups

 

Korean Ocean Research and Development Institute (KORDI) was established in 1973, with a broad mandate for Korean interests in marine science and engineering.

 

Work on CCZ nodules began as early as 1983 with three campaigns to the western CCZ in what was called the KODOS Area (Korea Deep Ocean Study; Jeong et al., 1994; Jung et al., 1997). This was followed up with two in 1989/90 in collaboration with the University of Hawaii (Kang, 2008). A combination of samples, bathymetry and seismic data was collected.

 

Between 1995 and 2002, KORDI focused on exploring their contract area defining mineral inventory of some 510 Mt (Kang, 2008) and environmental baseline data collection (KIOST, 2014). Exploration, environment and mine development programmes were consolidated under one government ministry.

 

Since 2002 their focus on environmental studies has increased, including research into a Priority Mining Area and preparations for a benthic impact experiment (KIOST, 2014). This has included detailed towed sonar surveys and sampling.

 

KORDI became KIOST (Korean Institute of Ocean Science and Technology) in mid-2012 and in recent times development of their advanced mining concept has been managed by KRISO (Korea Research Institute of Ships & Ocean Engineering). The concept involves a track driver collector with colander electro-hydraulic heads feeding a sub-sea buffer with inline pumps delivering to a surface vessel. As of 2015, all of the sub-sea components had been built at a pilot scale and tested in relatively shallow waters.

 

Lab (pool) scale testing was conducted between 2002 and 2010, as well as shallow water tests in 2009 and 2010 with a first generation device (MineRo-I). Collector efficiencies as high as 95% were achieved when the collector head was manually adjusted in terms of height above the seafloor.

 

Sea trials with the second generation MineRo-II were conducted in 2012 and 2013, with shallow water tracking tests (130 m) followed by a simpler deep water test (1370 m). The shallow water test included collection and subsea crushing of seeded nodules (KIOST, 2014). Sea-trials of the buffer and lift system were completed in late 2015.

 

5.4.2The new developed nation contractors

 

In July 2006, Germany (through its geological survey Bundesanstalt für Geowissenschaften und Rohstoffe or Federal Institute for Geosciences and Natural Resources of Germany (BGR)), received an exploration contract in the CCZ. This was the first contract under UNCLOS not to have been granted to a Pioneer Investor.

 

Sponsored by Germany as a developed nation, the BGR claimed patrimonial links and supplied historical data of the OMI German license area to define approximately 150,000 km2 of seabed with half entering the ISA reserved areas and half falling under their contract.

 

Since then, the BGR has been an active explorer and developer with numerous publications, including an informal mineral resource estimate (Ruhlemann et al, 2011; Kuhn et al, 2011 and Kuhn et al, 2012). These include modern and well document reestablishment of many of the basic relationships found in the CCZ and significant contributions to current geological understanding. BGR also commissioned preliminary work on mining and processing technology. The BGR is a partner within the JPI Oceans - Ecological Aspects of Deep-Sea Mining project.

 

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In early 2013, UK Seabed Resources Ltd started an exploration contract in the eastern CCZ. The previous year they submitted an application, sponsored by the United Kingdom, based on the former KCON Frigate Bird area in Figure 5.4). The resultant UK 1 area was 58,000 km2 and the equivalent returned area was promptly acquired by partner Ocean Minerals Singapore.

 

Field work to date by UK Seabed seems to have focused on benthic biological baseline studies, specifically two campaigns in 2013 and 2015 (AB01 and AB02) that supported the Abyssline Project (http://abyssline.info/). The project is being conducted by a consortium of seven non-profit academic research institutes (University of Hawaii, USA; Hawaii Pacific University, USA; Natural History Museum, UK; Uni Research, Norway; National Oceanography Centre, UK; Senckenberg Institute, Germany; IRIS, Norway).

 

In March 2016, UK Seabed signed a second exploration contract (UK2), this time for an area in the central CCZ (based on former USA-2 area held for OMI. The retained and returned areas are each about 75,000 km2.

 

Global Sea Mineral Resources (GSR), formerly G-TEC Sea Mineral Resources, also started an exploration contract in early 2013. GSR is owned by dredging company DEME and sponsored by the Belgian government. GSR successfully claimed patrimonial links to Union Miniere, the Belgian member in the OMA consortium, and retained and returned areas are each about 75,000 km2 that correspond to the former USA-3 license area. The equivalent returned area was promptly acquired by partner Cook Island Investment Corporation.

 

Since 2013 GSR has mounted at least one campaign of their own (GSR, 2014) with box-coring and MBES. GSR may also have participated in a JPI Oceans campaign to the CCZ in 2014 (see below).

 

GSR worked on nodule mining technology with IHC Merwede forming for some time a group called OceanFlore. More recently both IHC and DEME have joined the “Blue Nodule” initiative along with a wide range of other European companies and research institutions.

 

5.4.3The new developing sponsored nation contractors

 

Nauru Ocean Resource Inc (NORI) started their exploration contract with the ISA in July 2011. The stakeholders in the company are Nauruan and domiciled in Nauru. These are the Nauru Education and Training Foundation and the Nauru Health and Environment Foundation (ISBA/17/C/9; ISA, 2011). NORI conducted a campaign to the CCZ in 2013 that included seafloor mapping and sampling.

 

Tonga Offshore Mining Limited (TOML) started its exploration contract with the ISA in January 2012. TOML is domiciled in Tonga. TOML was 100% owned by Nautilus Minerals Inc. which until 2016 had supported TOML in terms of managing two campaigns to the CCZ, environmental baseline data collection, mineral resource estimation (the main subject of this report) and mining and processing concept studies. In 2020, DeepGreen acquired TOML.

 

Marawa Research and Exploration Ltd started their exploration contract with the ISA in January 2015. Marawa's proposed scientific research and exploration programme will involve seafloor mapping, polymetallic nodule sampling as well as environmental baseline studies and environmental impact assessments in international waters (Marawa, 2012).

 

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Ocean Mineral Singapore Pte Ltd (OMS) started their exploration contract with the ISA in January 2015. OMS is a Singapore-incorporated company majority owned by Keppel Corporation, with minority shareholders being UK Seabed Resources Ltd and Singapore-based private investment company Lion City Capital Partners Pte. Ltd., (Keppel, 2015a). Keppel is, amongst other things, a shipbuilding company, and OMS is sponsored by Singapore which was classified by the UN in 2014 as a developing nation (United Nations, 2014).

 

OMS has collaborated with UK Seabed regarding the second of the Abyssline campaigns
(AB02; above).

 

In late 2013 the Cook Islands Investment Corporation (CIIC), sponsored by the Cook Islands applied for a nodule exploration contract in the reserved areas which was duly approved the following year (ISBA/20/LTC/3, ISBA/20/C/18, ISBA/20/C/29). CIIC have a formal arrangement with GSR regarding the area.

 

In late 2014 China Minmetals Corporation, sponsored by China, applied for a nodule exploration contract of about 73,000 km2 in the reserved areas. This was duly approved the following year (ISBA/21/LTC/5, ISBA/21C/L.3).

 

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6Geological Setting and Mineralisation

 

6.1Global distribution of nodules

 

Seafloor polymetallic nodules occur in all oceans, and the CCZ hosts a relatively high abundance of nodules. Other relatively dense zones are found in the Peru Basin in the southeast Pacific, the centre of the north Indian Ocean, and the Cook Islands. The CCZ also has the highest overall metal grades (Table 6.1).

 

Table 6.1Summary of Global Nodule Grades

 

Element All Pacific Ocean Pacific Ocean
outside CCZ
CCZ Atlantic Ocean Indian Ocean
Mn wt% 20.1 18.8 26.3 13.3 15.3
Fe wt% 11.4 12.8 6.6 17.0 14.2
Ni wt% 0.76 0.63 1.20 0.32 0.43
Cu wt% 0.54 0.41 0.98 0.13 0.25
Co wt% 0.27 0.29 0.20 0.27 0.21

Source: McKelvey et al., 1983.

 

Key features of the geological setting are described in this section. Further details are presented in AMC (2016).

 

6.2Tectonic setting and topographic features

 

The CCZ is defined by two major west-south-west and east-north-east trending transform fracture zones; the Clipperton Fracture Zone to the south and the Clarion Fracture Zone to the north. These fractures zones can be seen clearly on most bathymetric maps (e.g., Figure 6.1). The eastern and western limits are defined by the Mathematicians Seamounts in the east, and the Line Islands rise in the west. The CCZ seabed deepens progressively from about ~4,200 m at 115°W to ~4,800 m at 128°W, then varies between ~4,800 m and ~5,500 m until 161° W.

 

The CCZ seabed comprises “Abyssal Plains”, which are the largest physiographic province on Earth, covering some 70% of the area of ocean basins and 30% of the Earth's surface (ISA 2004). Within the abyssal plains province are sub-parallel basaltic lava ridges called abyssal hills, believed to have formed from graben-horst type faulting as a consequence of seafloor spreading. Strike of abyssal hills in the CCZ is north-north-west to south-south-east (locally ±20˚; Figure 6.3), and they typically have an amplitude of 50–300 m (maximum 1,000 m; Hoffert 2008) and a wavelength of 1 to 10 km. The abyssal hills are punctuated by typically extinct volcanic knolls and seamounts rising 50 to 4,000 m above the seafloor. Almost all of the abyssal hills, and some of the volcanic knolls are buried beneath sediment (often up to 150 m thick).

 

The surficial portion of the sediment cover has a relationship with nodule quality, and it varies regionally, i.e. from predominantly carbonate and siliceous oozes in the south-eastern extreme corner, to mixed clay-ooze in the centre, to predominantly siliceous red clay in the north.

 

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Figure 6.1Bathymetric map of the Clarion-Clipperton Fracture Zone

 

Source: ISA 2010.

 

Figure 6.2Formation of abyssal hills at mid-oceanic ridges

 

http:||cdn.phys.org|newman|gfx|news|hires|2015|5620e3446b678.jpg

 

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Figure 6.3Semi-detailed bathymetry for the part of the TOML tenement area

 

 

Also some of the areas of Yuzhmorgeologiya (Melnik and Lygina, 2010), Ifremer (Fouquet et al, 2014), IOM and BGR (Knodt, 2012), (ISA, 2010) background is a Smith & Sandwell Product (ISA, 2010). Inset of TOML Area A, with location to the west

 

6.2.1Seamounts, knolls, and other volcanic features

 

Seamounts can occur in chains (related to hotspot traces or tectonic features) or in isolation (more likely due to increased local heat flow associated with tectonic related thinning or fractures).

 

MBES mapping of TOML areas B-F confirmed that there are no chains of seamounts within the TOML tenement area, that isolated seamounts and cones are approximately 1.5% of the TOML tenement area, and that exposed basalt (typically sheet flows) makes up an additional 1.3%. While no MBES has yet been conducted in Area A, the Smith and Sandwell bathymetry indicates the likelihood only minor amounts of smaller seamounts in the area
(Figure 6.3).

 

The highest single seamount (and the only one visible in the GEBCO dataset) is the ~1,000 m seamount in TOML Area D informally named “Mt Mo” (Figure 6.4).

 

Figure 6.4Seamounts in TOML Area D

 

 

In addition to the seamounts there is evidence for other small amounts of volcanic rocks. These are typically associated with the faults amongst the abyssal hills, which likely reactivate with ongoing movement of the tectonic plate. These are typically flows in the floor of valleys or near the end of valleys.

 

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6.2.2Sediment drifts

 

Approximately 7.4 % of TOML Areas B - F are thought to be covered by large sediment drifts (coded as Nnoo below). These can be mapped from MBES, as they are normally softer and ponded in depressions (Figure 6.5). There is also evidence for significant sediment movement elsewhere around seamounts (Figure 6.6) and at the base of steeper slopes. Without detailed MBES there is no clear indication of the amount of sediment drifts in Area A, although all historical sampling returned nodules.

 

Figure 6.5Example of “ponded” sediment drifts and corresponding low nodule abundance Area B

 

Source: from TOML MBES backscatter and sample data; Diamonds are box-cores, cylinders are photo based, squares are historical samples. Abundance (coloured) in wet kg/m2; acoustic absorption (backscatter; grey scale) in dB.

 

Figure 6.6Example of sediment accumulating around seamounts

 

From MBES backscatter, TOML Area B

 

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Dynamic changes in current and temperature near the CCZ seafloor have been known since the DOMES study in the late 1970s (Hayes, 1979). This includes current changes related to: tides; likely inertial reaction (e.g., to the Coriolis force); and more significant seasonal or episodic events. The seabed is typically quiet as:

 

Seabed currents measured from moorings are typically low (~ 4 cm/s and up to ~12 cm/s); and

 

Typically there is no detectable nepheloid layer (stirred up sediment) observed during survey.

 

Eddies travelling west along the CCZ are commonly observed at the ocean surface. Inall et al. (2015) describe data from a significant eddy, associating eddy surface currents of 40 cm/s at the surface with 10 cm/s currents on the seafloor of the CCZ approximately 4,100m below.

 

A variety of seabed deposits and patterns are observed and are interpreted to be due to seabed bottom currents (Figure 6.7, Figure 6.8).

 

Figure 6.7Types of deep-sea sedimentary processes and deposits related to bottom currents

 

Sources: Rebesco et al (2014); after Stow et al. (2009)

 

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Figure 6.8Range of patterns in surficial sediment, TOML Areas D and C

 

Collected using 30 kHz side scan sonar which penetrates the sediment to some distance (cm to m) and which responds to sediment composition.

 

6.3Polymetallic mineralisation

 

6.3.1Sedimentation and nodule formation

 

Seafloor polymetallic nodules are composed of nuclei and concentric layers of iron and manganese hydroxides and formed by precipitation of metals from seawater. The metal accumulation rates are slow, and it generally takes millions of years to form a nodule (ISA 2004).

 

Nodules can be abundant in abyssal areas with oxygenated bottom waters and low sedimentation rates (less than 10 cm per thousand years). Nodules generally range from about 1 to 12 cm in their longest dimension, with the low to middle-range typically the most common (1 to 5 cm).

 

The specific conditions of the CCZ (water depth, latitude, and seafloor sediment type) are considered to be the key controls for its formation, along with the following factors:

 

Supply of metals to the growing surface of the nodule.

 

Occurrence of an oxygenated geochemically active layer at the seabed (sediment water interface).

 

Effects over time on the geochemically active layer from benthic currents.

 

Effects over time on the geochemically active layer from bioturbation.

 

The highest values of metals in nodules are thought to be best developed on the seabed in the equatorial regions. In these regions surface waters have high primary productivity. Microorganisms accumulate metals in their growth relative to seawater and on death, they sink to the seafloor (either directly or through predator wastes), dissolve, and release the metals into the pore water of seafloor sediments. Being located away from terrestrial sources of sediments means that the metals are not preferentially accumulated by clay minerals. Commonly, the upper portion of the nodules accumulate metals directly from seawater, while the lower portion of the nodules, partially buried in sediment, accumulate metals from pore-water in the host sediments.

 

Sediments from the CCZ consist mostly of clays and some siliceous biological remains (e.g. frustules). Sands and larger sediments are not generally found so far from land, and any carbonate biological remains (e.g. skeletons) dissolve on the seabed in these deep-water regions faster than they accumulate. Some siliceous biological remains also dissolve at the seabed.

 

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6.3.2Nodule grades

 

Grade variation through the CCZ is well summarised by ISA (2010) and Morgan (2009) who combined datasets provided by several of the ISA contractors. Within the CCZ nodule field, nodule chemistry varies only slightly compared to the differences in mean nodule grades from other basins elsewhere in the world. The strongest trend is observed for Mn and Cu, which both increase towards the southeast (Kazmin in ISA, 2003; ISA, 2010; Morgan, 2009; see Figure 6.9). This may relate to proximity to metal sources from the East Pacific Rise or the American continents.

 

Figure 6.9Modelled Mn and Cu grades in nodules across the CCZ

 

Source: Morgan (2009), point data attributed to OMI

 

In contrast, Ni and Co partly correlate along the central axis of the CCZ (Figure 6.10), with the Co appearing to be offset to the north from the Ni. The reason for the distribution of these metals is unknown but may relate to a lack of competition for the metals in the sediments, which have both lower chlorite and lower smectite in this region (Futterer, 2006).

 

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Figure 6.10Modelled Ni and Co grades in nodules across the CCZ

 

Source: Morgan (2009), point data attributed to OMI.

 

6.3.3Grades of other metals

 

Grades for elements other than Mn, Ni, Cu and Co are not reported in the mineral resource for the TOML tenement area. Boxcores from CCZ15 campaign where analysed for a range of metals and these broadly agree with grades for a wider range of metals reported on Pacific nodules by McKelvey et al (1983), except for Rare Earth Element (REE) which are lower in the TOML dataset (see below). McKelvey et al (1983) do not separate out the grades of nodules from the CCZ but document average grades for nodules with Ni+Cu >1.8%, the bulk of which come from the CCZ. These are summarised below per the classification of McKelvey et al (1983) with their average grade followed by the average grade determined by TOML:

 

Other base or alloy metals such as Zn (0.14%; 0.147%), Mo (0.039%; 0.064%), Ti (0.58%; 0.301%) and Pb (0.071%; 0.019%)

 

Rare earth elements and other transition metals such as Sr (0.077%;0.057%), Y (0.012%; 0.009%), Zr (0.027%), Te (0.021%), La (0.019%; 0.012%), Ce (0.066%; 0.029%) and Nd (0.023%; 0.013%)

 

Possible deleterious elements or reagent consumers and enhancers such as F (3%), Mg (1.57%; 1.94%), Al (2.96%; 2.47%), Si (8.26%;6.82%), S (0.319%; 0.13%), Cl (0.860%), Ca (1.73%; 1.76%), As (0.012%; <0.005% in some analysed dredge samples), and Ba (0.224%; 0.284%)

 

These levels of metals are supported in some cases (Zn, Mo) by data presented by Haynes et al. (1985), who also reported very limited data on Au and platinum group metals (all at the ppb level except Pt which averaged 0.1 ppm from 5 samples).

 

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The REE values in the TOML tenement areas more closely agree with those published from the historical Lockheed Martin Exploration Area by Spickermann, (2012). This area is adjacent to TOML Exploration Areas B, D, and E. Total REE reported by Spickermann is about 0.08% (0.079% from TOML Areas A, C, B, D and F) with a median of 617 (619, TOML) ppm light REE (La-Eu) and 171 (180, TOML) ppm heavy REE (Gd-Y).

 

Also of interest is a clear trend of increasing Ba and S from TOML Area A, B and C to D and then to F. This trend suggests increased barite (BaSO4) whose presence in turn is thought to represent increased primary productivity (or rather activity) within the diagenetic environment (Ba preferentially captures S released from decaying organic material in the sediment below the calcite compensation depth (e.g., Schulz and Zabel, 2006). This trend corresponds well with modern sea surface primary productivity.

 

6.3.4Nodule abundance and estimation of tonnages

 

6.3.5Nodule abundance

 

Polymetallic nodules lie on the seafloor sediment, often partly buried. Some nodules are completely buried, although the frequencies of such subsurface occurrences are very poorly defined. Kotlinski and Stoyanova (2006) document up to five discrete layers of buried nodules, although all were within 45 cm of the surface despite using sediment cores of 250 to 380 cm depth (i.e., all of these nodules are near surface). Other images of box corers also suggest that all or most of the nodules are at the surface. Consequently, drilling is not required for definition of the Mineral Resources.

 

The nodules vary in abundance, in some cases touching one another and covering more than 70% of the seafloor. They can occur at any depth, but the highest concentrations have been found on abyssal plains between 4,000 and 6,000 mbsl.

 

Nodule abundance is estimated either by:

 

Taking a sample from the seafloor and dividing the weight of nodules by the area of the primary sampler;

 

Using a photograph of nodules on the seabed to estimate their individual weight (e.g., as used by Kennecott; Felix 1980) which has been used with considerable success in some areas by TOML and dividing the weight of nodules by the area of the image.

 

Nodule abundance is typically reported in wet kg/m2:

 

Wet weights are the most relevant in any collecting and transport operation;

 

Often the nodule samples have multiple uses once collected at sea, some are for assay, others for environmental or metallurgical test work and some for reference (retaining the sample to dry and then weigh is less convenient);

 

With complexity related to drying conditions and determining wet/dry density, weighing of the samples at surface is the simplest and most effective way to measure and compare nodule abundances between different campaigns and between the different contractors.

 

Sample aliquots were dried, crushed and pulverised before assaying. Using dry weight percent assays on wet weight mineral resource and inventory is a commonly accepted practice for similar bulk commodities that can contain significant amounts of free water (e.g., iron ore or Ni-Co laterite).

 

Nodule abundance variability is significantly higher than metal grades in most areas, suggesting that abundance estimation will be the key variable of uncertainty in mineral resource estimation. Figure 6.11 shows evidence of this compared to Figure 6.9 and Figure 6.10.

 

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Figure 6.11Modelled nodule abundance across the CCZ

 

a_abundance.png

Source: Morgan (2009), point data attributed to OMI.

 

6.4Nodule Density and Moisture Content

 

6.4.1Nodule density

 

Polymetallic nodules have an average wet density of about 2 t/m3 (Table 6.2; Figure 6.12). TOML confirmed historical results from the north Pacific (Hessler and Jumars, 1974) through ~60 water displacement density measurements. The density measurements were done for both single nodules and for nodules in bulk, including fragments and sand resulting from attrition during transport and handing.

 

The results are similar except that the mean of the single nodules is ~2.8% lower than that of the bulk measurements. This might be due to air or water filled expansion cracks in the single nodules (that were collected ~7 months before the density measurements were made) the bulk nodule samples contained many more fragments that presumably relate to fractures along these cracks. The bulk nodule measurements are preferred over the single nodule measurements as they are likely more accurate due to larger sample size. The bulk nodule measurements also have a lower standard deviation.

 

Also noted is that Area F nodules might be slightly less dense than the other TOML tenement areas (Table 6.2; Figure 6.12). By averages this is of the order of 2–4%, being slightly more pronounced in the single nodule estimates. Nodule densities have not yet been measured for Area A.

 

Table 6.2Nodule Density measurements TOML Area B, C, D and F

 

  Count g/cm3 Standard deviation
Min Median Mean Max Range
Single nodules 34 1.78 1.95 1.95 2.38 0.60 0.11
Bulk nodules 27 1.94 2.01 2.01 2.07 0.13 0.03
Single nodules area F 9 1.83 1.91 1.90 1.99 0.16 0.06
Bulk nodules area F 6 1.94 1.97 1.97 2.01 0.07 0.02

 

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Figure 6.12Nodule densities of samples from TOML areas B-D, F, and central north Pacific

 

Single and bulk measurements from nodules collected during the CCZ15 campaign; historical values from Hessler and Jumars (1974)

 

6.4.2Nodule water content

 

Exploitation of polymetallic nodules is likely to be done on a wet tonnage basis in that nodules will be transported, stored and sold without oven drying. In exploration, the abundance of nodules collected by free fall grabs or box-corers is also typically measured on the exploration vessel immediately after collection before the sample has time to air dry. Reporting a polymetallic nodule mineral resource on a wet basis is thus simpler and more appropriate than reporting on a dry basis, as is done for grade.

 

Total water content in wet nodules is estimated at 44% (Table 6.3), but the situation is further complicated as two main types of water are present:

 

Water of crystallization included within manganese and iron oxide minerals. This was determined in TOML test work to consistently be about 16% by wet weight (including other likely trace levels of other volatiles). A very small amount of water of crystallization likely starts being removed at temperatures as low as 50–70 °C through a transformation of the manganese mineral buserite into birnessite, but most is stable until much higher temperatures (115 °C and greater; Novikov and Bogdanova (2007)).

 

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Free water included within pores and other cavities within the nodules including water adsorbed onto minerals – this is estimated to be around 28% by wet weight depending on the micro and macro void space in the nodules. Air-drying may remove approximately 16% (absolute) of this, with the rest by oven drying (up to 105 °C).

 

Estimating the water content is then complicated further again due to two properties specific to the nodules:

 

The nodules have very high porosity (~50%; Ifremer, 2010) and are hygroscopic (Figure 6.13). Within a day of drying to 105°C pulped nodules will absorb at least 7% of moisture by mass if exposed to ambient air.

 

Depressurization of the nodules after collection leads to mineral transformation (e.g., breakdown of feroxyhyte) and micro-fractures and fractures. Free water might be added into the cracks and micro-cracks. TOML tests suggest that four months after collection about 3% free water on a wet basis can be added into samples that are soaked in water (this 3% is not included in the totals indicated above).

 

Published moisture values from the very comprehensive metallurgical reports by Haynes et al. (1985) and Fuerstenau et al. (1973) are summarised below along with TOML results.

 

Table 6.3Comparison with published moisture contents

 

Source Total Moisture Free Moisture Water of Crystallisation
Mero (1965) p233 30-36*
Fuerstenau et al. (1973)** >22.66% 13.1% >8.74%
Haynes et al. (1985) 45-50% 35–45% with about half able to be dried in air 5-10%
Wiedicke-Hombach et al (2012) 44% Not specified Not specified
TOML measurements 44% 28% with about 60% of this able to be dried in air 16%***

* drying temp not specified may include some water of crystallization; **used in the 2012 Nautilus CCZ NI43-101 report (Golder, 2013) to characterise moisture; *** includes ±2% water of crystallisation lost up to 105°C

 

Figure 6.13Nodule sample (pulp) absorption after drying to 105°C for 6 hours

 

 

Test work done by TOML on select nodules involved three stages of drying. Stage one was air drying at up to 260 hours at ambient temperatures of 22 °C to 25 °C and humidity of 50% to 60% (Figure 6.14). Moisture content lost by the time of stabilisation (around 200 hours at these ambient temperature and humidity) varied between 13% and 19%.

 

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Figure 6.14Air drying results for a short term sample batch (L) and a long term sample batch (R)

 

 

Stage two was oven drying at up to 978 hours in seven temperature steps. From Figure 6.15 the moisture content lost was a very consistent 15% to 16.5% at 105°C and 18% to 19.5% at 160 °C.

 

Figure 6.15Oven drying results for nodules

 

 

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Between each oven drying temperature the samples were left exposed to ambient air for one hour to measure hydroscopic weight increase. Whole nodules absorbed water more slowly than pulverised nodules (e.g., Figure 6.13).

 

Stage three was loss on ignition (LOI) where samples were pulverised and effectively sintered at 1,000°C, driving off all moisture that might include other types of "combined water" (hydrates and labile hydroxy-compounds) and carbon dioxide although the latter is thought to be minimal in nodules.

 

From Figure 6.16 the LOI from 160°C was remarkably constant for the test samples between 14% and 15.2% which equates to:

 

10.6% to 11.8% from 160 °C on a starting wet basis.

 

16.8% to 18% from 105 °C. The results are comparable with other TOML analyses and figures from some sources:

 

Mero (1965) reports LOI (1100°C) of 15% to 39% averaging 25.8% but from nodules at an “air dried” level.

 

Reference material CGL131 (a nodule standard from the eastern German area in the CCZ) averaged an LOI of 16.98% from 16 laboratories, although the figure is not certified.

 

Other workers report higher LOIs (20% to 25%) but do not specify the drying method in enough detail for valid comparison. The chance of hygroscopic absorption of moisture cannot be discounted.

 

Figure 6.16Loss on ignition (at 1,000°C) for two batches of TOML samples

 

 

A combined drying curve is summarised in Figure 6.17. Average total moisture content is 47% with most of the variance in total moisture apparent from the earliest stages of air-drying (48 hours at ambient temperature). With consideration of ~3% storage water absorbed into post sampling expansion cracks (see above) a standard total moisture content of 44% is derived.

 

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Figure 6.17Three stage drying curve for polymetallic nodules

 

Average total moisture content is 47% with most of the variance in total moisture apparent from the earliest stages of air-drying (48 hours at ambient temperature). After adjustment for absorbed water (determined in a separate test involving samples sealed from collection and sampled soaked before drying) an effective moisture content of 44% is arrived at.

 

In the estimation of moisture content (or other component) wet basis is taken before any air drying or soaking, dry basis is taken at 105 °C and a volatile free basis is taken after LOI at 1,000 °C with all volatiles removed. Other bases are mentioned in the text with the temperature specified.

 

6.5Diagenetic Crusts

 

The minor amounts of ferro-manganese crust found in the CCZ are not the same as hydrogenetic cobalt-rich crusts typically found on the top of seamounts e.g., in the Pacific Prime Zone in the north-west Pacific Ocean (e.g., Hein and Koschinsky, 2013).Two types have been logged, both by TOML and other workers (e.g., Ifremer; Menot et al., 2010):

 

Massive crust is five to ten centimetres thick and is typically found in blocks several decimetres a side but occasionally as pavement; and

 

Crustal-nodules are small to medium sized (<20 cm) discrete fragments of ferro-manganese that can grade into nodules.

 

In total, crusts were logged in ~0.6% of the photo-profiles, with crustal nodules more common (~0.5%) and massive crusts being present only ~0.1% of the time. Neither type was collected in box-cores during the TOML CCZ15 campaign, and their extent is deemed insignificant in terms of the mineral resource estimation in Section 11.

 

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6.6Deposit Types

 

Surface and near surface polymetallic seafloor nodules are the only mineralisation type classed as a deposit in this report.

 

6.7TOML Nodule Types

 

TOML’s classification system was developed near the end of the CCZ15 campaign, once a wide range of characteristic nodules had been studied (Table 6.4). The classification aims to be simple and modular with two required codes (size then type, as per the ISA system) and three optional suffix codes (aspect of the nodules form, degree of fragmentation typically seen, and degree of development of botryoidal texture); as summarised in Table 6.4. Examples of type are also shown in Figure 6.18 and Figure 6.19.

 

Table 6.4TOML CCZ15 Nodule classification and proportions seen in logging during CCZ15

 

  1:size Long Axis
=<2 cm   2-5 cm   >5 cm  
s sm m ml l mx (mixed)
(small)   (medium)   (large) 18%
8% 11% 20% 24% 18%  
2: type S s-S 1% sm-S 2% m-S 1% ml-S 1% l-S 0% mx-1%
(smooth)
10%
RS s-SR 7% sm-SR 8% m-SR 13% ml-SR 22% l-SR 18% mx-SR 17%
(rough-smooth)
84%
R s-R 1% sm-R 2% m-R 2% ml-R 1% l-R 0% mx-R 1%
(rough)
6%
3: aspect/oblate
high regular low irregular prolate
-hi -rg -lw -ir -pr
4: fragmentation
rare mod common
-ra -md -cm
5: botryoidal
well dev. poorly dev absent
-bo -po -no

From Table 6.4 it is apparent that in the TOML area at least, rough-smooth nodules are the most common, especially in the medium to large size range.

 

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Figure 6.18Sections through a S-type Nodule (left) and a R-type Nodule with a S-type core (right)

 

Source: von Stackelberg and Beiersdorf, (1991).

 

Figure 6.19Example nodules found in the TOML area

 

Smooth (top left), rough-smooth (top right), rough (bottom left) and overturned rough-smooth (bottom right) types

 

Between TOML tenement areas B - F there are notable differences in the sizes and types of nodules present (Figure 6.20). Area F is distinctive for having generally more medium S type nodules than the other areas (although it also contains large SR type nodules of generally high aspect). Area C1 has very few truly large nodules with medium to large SRs dominating. Areas B1, and D1-D2 have a wider range of sizes again mostly (70–90%) of SR type although B1 has some discrete areas of smaller nodules. Two dredge samples from Area A contained mostly small smooth nodules, and as mentioned below one of these looks to be mostly of hydrogenetic character.

 

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Figure 6.20Nodule size and type within the areas sampled during TOML CCZ15

 

Codes are per Table 6.4

 

6.8Variation in TOML Nodule Grades

 

Grade variation in CCZ nodules is remarkably low. Basic statistics pertaining to grade are included with the Mineral Resource data review in Section 11.

 

During the CCZ13 and CCZ15 TOML campaigns, dredge samples were taken for metallurgical test work and the opportunity was taken to analyse numerous (~30 per dredge) sub-samples of nodules to better establish grade variation within a small area.

 

These dredge sub-sample results are compared below with box-core and historical results for Ni, Cu, Co and Mn (Figure 6.21 and Figure 6.22). Bear in mind that the three datasets all cover different areas with:

 

historical samples covering all of TOML A-E;

 

TOML box-cores (BC) all of selected sub-areas in Areas B, C, D and F; and

 

dredge samples in select locations.

 

Key conclusions from this comparison are that:

 

There is generally good to excellent agreement between dredge samples and the more widely sampled but internally consolidated samples from box-cores;

 

There is generally excellent agreement between the historical data (section 9.1) and the TOML dredge and box-core samples with the exception of Mn (higher in the TOML samples from some areas as discussed in Section 11);

 

Some of the regional grade trends are seen between the TOML Areas (e.g., Area B has generally higher Ni and lower Cu than Area C, while Area F has distinctly lower Co);

 

The lower grade nodules from box-cores from Area B1 seen in Figure 6.21 and Figure 6.22) tend to be found in a single area in the central-eastern part of the area (B3645 and surrounds), that is characterised by typically R-type nodules and frequently low to very low abundances;

 

Area A and B nodules have a greater range in grade consistent with more variable ratios of diagenetic to hydrogenetic formation (higher Co and Fe).

 

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Figure 6.21Nodule variance in Ni and Cu for dredge and box-core samples in the TOML Areas

 

 

Figure 6.22Nodule variance in Mn and Co for dredge and box-core samples in the TOML Areas

 

 

6.9Nodule Distribution

 

The distribution of nodules though the CCZ is not constant, and likewise their abundance varies within the TOML contract areas. Areas with few or no nodules that can be discriminated in mapping are:

 

Volcanic areas (seamounts and more recent flows)

 

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Slopes or escarpments (from ongoing normal faulting and both of basement basalt and overlying sediment)

 

Areas of “no nodules on ooze” (Nnoo) that are thought to be areas of drifting sediments that preclude nodule formation.

 

As noted in Table 6.5, only the volcanic areas and Nnoo sediment drifts were domained separate to the sediment bearing nodules in the mineral resource estimate.

 

Table 6.5MBES mapped seabed classification and proportions

 

Area Volcanic exposure Nnoo sediment Slopes Nodule bearing
B 5.9 6.0 3.9 84.2
C 1.8 5.6 3.2 89.4
D + E 3.0 12.9 4.2 79.9
F 1.5 2.1 4.9 91.6

Note that without MBES survey, it is not possible to estimate the proportions of the above mapped units in Area A.

 

Strictly speaking, most of the above discriminated areas still contain some nodules. Small nodules are found on seamounts and in amongst the escarpments. Sediment drifts also usually contain the occasional nodule as seen in seafloor photos. There may also be nodules buried near the edge of sediment drifts.

 

Dealing with these areas in the mineral resource estimate is described in Section 11. Mapping based on MBES (e.g., Figure 6.23) estimates the area with no or insignificant nodules to comprises 10 to 20% of the total area (Table 6.5).

 

Figure 6.23Mapped areas of volcanic rocks, slopes and Nnoo sediment in part of TOML Area B

 

 

Note that over-estimation of area of slopes is likely due to smoothing from the relatively coarse (60–120 m) resolution of the shipborne 12 kHz MBES and the nature of interpretation. Slopes were not significant enough to be domained out in the mineral resource estimate. There is also the possibility that many of the mapped volcanics of lower relief are partly covered with sediment and nodules. Box-core sampling of Nnoo type areas was done if that unit was covered by the planned sample grid in the CCZ15 campaign. Direct correlation of nodule abundance with MBES backscatter was relatively poor.

 

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6.9.1Importance of buried nodules

 

Sediment is thought to cover even surficially located nodules from time to time, due to ongoing sedimentation and the effect of seafloor currents. In many cases, grazing holothurians clear any accumulated sediment off the nodules.

 

In logging during TOML’s CCZ15 campaign, a clear distinction was made between:

 

1.Powder a thin coating of sediment, usually so little (~ 5 mm) that the outline of the nodule can be seen in a photograph;

 

2.Cover is up to several centimetres of sediment, obscuring the nodule completely from vision, maintaining the nodule within the geochemically active layer and with the amount of cover irrelevant to sampling and collecting methods;

 

3.Buried was defined as when there is greater than 10 cm of sediment on the nodule. Buried nodules often are below the geochemically active layer. As they are likely located too deep for a nodule collector, they were collected from the box-cores in CCZ15 purely for reference purposes and their weights and chemical analyses were not included in the dataset supporting the mineral resource statement.

 

Buried nodules often have a very soft brown powdery surface, which is thought to reflect surface ‘corrosion’ due to reduction and breakdown of the nodule. However, this was always seen on the surface of nodules and no extensively degraded remnants were seen. Many buried nodules have the size and textures of large to medium SR type (see TOML classification in Table 6.4 above) indicating that they were at the surface for a long period of time before burial. When present in the box-cores, the buried nodules were often found in groups at the same depth, and it is suspected that they became buried by falling into burrows due to undermining. Buried nodules tend to be larger than the average nodules found at the surface.

 

Buried nodules are uncommon. A total of 16 out of the 113 box cores taken during CCZ15 had buried nodules and all of these were located in Area D and F (Figure 6.24). If just Areas D and F are considered, then buried nodules were found in about 23.8% of samples which is a similar ratio to that described by Kotlinski and Stoyanova (2006) who found 22.6% within the part of the IOM contract area (59 of 261 sample sites).

 

Figure 6.24Location and percentage of buried nodules found during CCZ15

 

 

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7Exploration

 

Exploration in the TOML tenement area comprises two main phases:

 

Historical work and data collected by the pioneer contractors who returned Reserved Areas to the ISA. This work underpins much of the inferred mineral resource estimated in Section 11 and reported previously (Golder Associates, 2013).

 

TOML work and data acquired by TOML during two exploration campaigns in 2013 and 2015 (called CCZ13 and CCZ15 respectively in this report). This work underpins part of the inferred mineral resource estimate as well as all of the indicated and measured mineral resource estimates.

 

7.1Historical Data

 

Six exploration groups are known to have surveyed areas within the TOML tenement area and collected samples of polymetallic nodules. Much of this work overlapped as it predated the signing of the Law of the Sea. These include the Japanese group (DORD), the South Korean group (KORDI), the Russian Federation group (Yuzhmorgeologiya), the French group (Ifremer), the German group (FIGNR or BGR), and the consortium, Ocean Minerals Company (OMCO). The timing and location (ISA, 2003) of the OMCO sampling is known but the results are not available outside of ISA published contour maps.

 

Virtually all the samples in the TOML tenement area were obtained by free fall grab (FFG) samplers, although a few results from box corers (BC) were also included. As detailed in section 7.5.6, nodule abundance (wet kg/m2) is derived by dividing the weight of recovered nodules by the surface area covered by the open jaws of the sampler or corer (typically 0.25 to 0.5 m2 but in some cases as much as 1 m2). Assays were done on dried sample splits by commonly used spectrometric methods (AAS and XRF).

 

7.1.1Nodule Sample Data Supplied to TOML

 

The TOML tenement area was a Reserved Area and as such was sampled by Pioneer Investor or developed nation sponsored contractors. These samples provided the basis of a database held and maintained by the ISA. These data were used initially to define the areas of the TOML application, and subsequently to estimate an inferred mineral resource for the part of the TOML tenement area they covered (Golder Associates, 2013).

 

Bar plots showing the total number of samples within the TOML tenement area collected by each Pioneer Investor or developed nation contractor are presented in Figure 7.1 and Figure 7.2. The statistics for the samples that contain both abundance and grade data inside the TOML tenement area are tabulated in Table 7.1 to Table 7.6. Samples in the CCZ but outside the TOML tenement area are presented in Table 7.6.

 

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Figure 7.1Total Number of Samples by Pioneer Contractor.

 

Pioneer Contractors are sometimes referred to as Pioneer Investors

 

Figure 7.2Total Number of Samples by TOML tenement areas.

 

Note that 8 additional samples were received for Area E from IOM (see Table 7.5).

 

Table 7.1Summary of Historical Grab Samples Area A

 

(ex-DORD) Mn (%) Co (%) Ni (%) Cu (%) Abundance (wet kg/m2)
Count 18 18 18 18 18
Minimum 21.46 0.15 0.71 0.46 2.68
Maximum 30.05 0.30 1.47 1.51 17.93
Mean 25.40 0.22 1.14 1.00 10.12
Median 25.50 0.21 1.15 1.02 9.19
Standard Deviation 2.44 0.04 0.24 0.35 5.08
Coefficient of Variation 0.10 0.18 0.21 0.35 0.50

 

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Table 7.2Summary of Historical Grab Samples Area B

 

(ex-Yuzhmorgeologiya) Mn (%) Co (%) Ni (%) Cu (%) Abundance (wet kg/m2)
Count 88 88 88 88 88
Minimum 10.30 0.02 0.53 0.40 0.03
Maximum 31.20 0.35 1.51 1.40 26.00
Mean 25.40 0.25 1.16 0.94 8.82
Median 26.55 0.25 1.23 1.02 8.09
Standard Deviation 4.19 0.06 0.23 0.26 5.87
Coefficient of Variation 0.16 0.22 0.20 0.27 0.67

Excludes samples that had no nodules.

 

Table 7.3Summary of Historical Grab Samples Area C

 

(ex- Ifremer) Mn (%) Co (%) Ni (%) Cu (%) Abundance (wet kg/m2)
Count 78 78 78 78 78
Minimum 22.01 0.14 0.93 0.71 1.35
Maximum 30.90 0.32 1.42 1.44 21.25
Mean 27.91 0.25 1.27 1.15 9.98
Median 28.55 0.25 1.29 1.19 9.17
Standard Deviation 2.13 0.03 0.10 0.15 4.20
Coefficient of Variation 0.08 0.13 0.08 0.13 0.42

Excludes samples that had no nodules.

 

Table 7.4Summary of Historical Grab Samples Area D

 

(ex-DORD) Mn (%) Co (%) Ni (%) Cu (%) Abundance (wet kg/m2)
Count 36 36 36 36 36
Minimum 22.79 0.19 1.09 0.79 0.12
Maximum 30.45 0.30 1.44 1.36 16.37
Mean 28.52 0.22 1.31 1.16 7.68
Median 28.76 0.22 1.32 1.17 7.78
Standard Deviation 1.47 0.02 0.08 0.10 4.09
Coefficient of Variation 0.05 0.10 0.06 0.08 0.53

 

Table 7.5Summary Historical Grab Samples Area E

 

(ex-KORDI, IOM) Mn (%) Co (%) Ni (%) Cu (%) Abundance (wet kg/m2)
Count 10 10 10 10 10
Minimum 24.04 0.16 0.96 0.69 1.48
Maximum 31.34 0.27 1.43 1.27 22.90
Mean 27.54 0.21 1.21 1.07 11.34
Median 27.17 0.22 1.21 1.11 9.22
Standard Deviation 2.58 0.04 0.18 0.17 6.82
Coefficient of Variation 0.09 0.18 0.15 0.16 0.60

 

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Table 7.6Summary of Historical Samples from the Reserved Areas outside the TOML tenement area

 

  Mn (%) Co (%) Ni (%) Cu (%) Abundance (wet kg/m2)
Count 2188 2188 2188 2188 2188
Minimum 4.14 0.05 0.15 0.12 0.01
Maximum 35.62 3.23 1.75 1.62 52.20
Mean 27.47 0.21 1.25 1.04 8.21
Median 28.47 0.21 1.30 1.09 7.10
Standard Deviation 4.06 0.08 0.20 0.24 6.06
Coefficient of Variation 0.15 0.40 0.16 0.24 0.74

 

The above tables and Figure 7.3 indicate that all of the TOML tenement areas have similar ranges of grade and abundance to the rest of the CCZ deposit. The coefficients of variation of grades are low compared to most terrestrial mineral resources. Abundance values vary more widely, making abundance estimates the key variable of uncertainty in mineral resource estimation. For the historical data, sample spacing is predominantly wide (10 km to 30 km). However, there are a number of closely spaced samples (500 m to <10 km) but these are insufficient to constrain the short range controls on grade and abundance within the TOML tenement areas. TOML’s own sampling (see below) serves to constrain the short range.

 

Figure 7.3Box Plots of historical sample grades within the TOML tenement areas.

 

Box size represents 1st and 3rd quartiles centred on the median and box width reflects number of samples

 

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Figure 7.4Box Plots comparing the 6 Pioneer Investor Reserved Area Data Sets across the entire CCZ.

 

 

Figure 7.5Log Probability plots comparing the 6 Pioneer Investor Data Sets.

 

 

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7.1.2Historical Sampling Method

 

Virtually all the historical samples used in the TOML Mineral Resource estimates were obtained by FFG samplers plus a few by BC samplers. Research has shown that free fall grab samplers consistently underestimate the actual abundance (Hennigar, Dick and Foell, 1986), but even today they are the most productive tool available for the assessment of nodule abundance. This is because a number of them can be deployed at any one time from the survey vessel allowing an order of magnitude increase in collection efficiency, i.e., approximately 10 to 20 samples per day for a FFG, versus about three samples per day for a BC that is winched to and from the seafloor.

 

Lee et al. (2008) compared FFG and BC data in some detail. They found a wide range but consistent differences with FFG under-reporting compared to BC (Figure 7.8). They also illustrate why BC results should be much more accurate than FFG results based on mechanical effectiveness (Figure 7.6, Figure 7.7). They then recommend an overall correction factor of 1.4 to convert a FFG abundance to a BC abundance. However, they acknowledge that any simple factor lacks precision. One key issue is the size of the FFG or BC (area covered) versus the nodule diameter. Free fall grab samplers have been demonstrated to underestimate the actual abundance as smaller nodules may escape some grabs during ascent and larger nodules around the edge of the sampler may be knocked out or fall out during the sampling process.

 

No conversion has been applied to the TOML nodule abundance because:

 

Sample collection type is not specified in the historical data (i.e. proportion and identity of BC versus FFG samples is unknown (although most are likely to be FFG).

 

The size of collector and nodule sizes is not specified in the historical data.

 

Therefore estimates of nodule abundance based on historical samples are likely to be conservative.

 

Figure 7.6Cartoon showing the recovery process of nodules using Free Fall Grab

 

Source: Lee et al., (2008).

 

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Figure 7.7Cartoon showing the recovery process of nodules using Box Corer

 

Modified after: Lee et al., (2008).

 

Figure 7.8Comparison of returned abundances from BC and FFG at test stations within the KORDI exploration area

 

Source: Lee et al., (2008).

 

Metal content in the historical samples was determined by a variety of standard analytical methods, including atomic absorption and X-ray fluorescence. Limited information is available on historical sample preparation and analytical methods. The various groups reportedly used polymetallic nodule Certified Reference Materials (e.g., NOD-P-1; Flanagan and Gottfried, 1980) for QAQC, however details of the Certified Reference Materials and analytical results were not included in the dataset supplied by the ISA to TOML and Golder.

 

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7.2TOML Work Programmes

 

In 2012, TOML realised the need for two campaigns to effectively define a mineral resource of sufficient confidence and size to likely support the building, commissioning and payback of a mining operation.

 

The first campaign in 2013 utilised the MBES system of the chartered RV Mt Mitchell (Figure 7.9) to map the seafloor in Areas B through F, as well as to test equipment and collect sufficient sample to confirm grades and support metallurgical test work.

 

The second campaign in 2015 used the experienced team and equipment spread on the RV Yuzhmorgeologiya (Figure 7.9) to sample and image mapped priority areas so that a higher confidence and expanded mineral resource could be estimated, and to collect environmental baseline and geotechnical data.

 

Figure 7.9RV Mt Mitchell (CCZ13) and RV Yuzhmorgeologiya (CCZ15)

 

 

Table 7.7 and Figure 7.10 summarise collected data from each TOML area and sub-area. MBES (12 kHz MBES echosounding) includes bathymetric and backscatter products and geological geomorphological interpretation. Photo-profile includes still and video products and logging. Dredge sample data includes grade characterisation and some size distribution data. Water column includes temperature, pressure, turbidity and in some cases physical samples and current. Box-core data includes nodule grade and abundance; fauna, and in some cases vane shear and/or sediment characterisation. Deep-tow sonar includes sidescan sonar, sub-bottom profiler and micro survey and altimetry.

 

Table 7.7TOML datasets by area and by campaign

 

 

MBES

km2

Photo-profile

line km

Dredge

#

Water column

#

Box-core

#

Deep Tow Sonar

line km

Area A

2

CCZ15

Area B

9,966

CCZ13

Sub-area B1 Included in B

178

CCZ15

1

CCZ13

14

CCZ15

30

CCZ15

88

CCZ15

Area C

15,763

CCZ13

Sub-area C1 Included in C

231

CCZ15

1

CCZ15

14

CCZ15

16

CCZ15

32

CCZ15

Area D

15,881

CCZ13

92

CCZ15

6

CCZ13

Sub-area D2 Included in D

47

CCZ15

2

CCZ13

26

CCZ15

26

CCZ15

120

CCZ15

 

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Figure 7.10Extent of TOML exploration in the CCZ

 

 

7.3TOML Sampling Methods

 

Details of key resource data collection processes and methods are presented here.

 

7.3.1Multibeam Bathymetry

 

MBES is used to determine the depth of water (bathymetry) and the acoustic reflectance (backscatter) of the seabed. It operates by transmitting a focused acoustic pulse (Figure 7.11) from a specially designed transducer across a swath across the vessel track. These pulses return as a set of receive beams that are weaker and narrower and whose arrive time varies depending on speed and distance. Thus position and depth can be measured and seafloor hardness can be qualitatively assessed.

 

Figure 7.11MBES operations schematic

 

 

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During the CCZ13 campaign the RV Mt Mitchell operated a hull mounted Kongsberg EM120 MBES over areas B through F. This equipment operates at 12 kHz and is capable of operation up to 11,000 m water depth. It has better than 5 m vertical resolution and ~60 m horizontal resolution for bathymetry and ~30 m for backscatter at water depths between 4,500–6,000 m. It has a maximum swath width of 6 times the water depth but the effective swath width varies from 2 to 6 times the water depth depending on the depth, sea state and heading.

 

The only pre-existing bathymetric data over the TOML tenement areas (excluding occasional widely spaced transit lines collected by research vessels) was the Sandwell and Smith based, satellite bathymetry (BODC, 2014). This bathymetry is calculated using mean sea levels to estimate depth to seafloor and is good for a resolution of 30 arc seconds (within the TOML areas this roughly equates to 900 m). In a general sense, this data is usually accurate to within a hundred metres vertically, but it lacks the definition necessary to define the smaller seamounts, ridges and smaller bathymetric features. No publicly available backscatter or seafloor reflectance data exists for these survey areas. As a result, conducting these MBES surveys provides TOML with a significant improvement in the vertical and horizontal resolution of the bathymetry, and with unprecedented intensity definition of the backscatter, resulting in visibly crisper, and much more interpretable imagery.

 

CTD (conductivity-temperature-depth) soundings were performed at each of the survey areas in 2013. The primary reason for this is that the MBES system requires an accurate full water column sound velocity profile with which to perform real time beam steering and location calculations.

 

7.3.2Box-coring

 

Box-coring was undertaken in 2015 to collect samples for mineral resource estimation, to collect biological samples for environmental base-line measurement and to collect geotechnical data. Box-core operations adhered to the following:

 

Deployment and recovery off the stern of the vessel using three strand wire and the vessel’s starboard hydrographic sample winch (Figure 7.12)

 

The vessel maintained minimum forward speed, typically 0.3 to 0.7 knots into result (combination of surface wind and waves)

 

The box-core’s progress and status (fired or not) was tracked using a signal from a 12 kHz pinger

 

Landing points were within 500 m of the planned grid co-ordinates (as per Dive Plans) with the following pre-conditions:

 

Landing points avoid steeper areas (>10° slope) based on pre-existing multi-beam bathymetry

 

The hydrographic surveyors guiding the landing never sight the backscatter product of the existing multi-beam coverage (to eliminate chance of sighting bias)

 

USBL navigation provides location to within ±15 m.

 

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Figure 7.12Box-corer Deployment Schematic

 

 

7.3.3Box-coring Overview

 

Box-corers have been used in the CCZ since the 1970s. As they collect a seabed sample effectively intact (Figure 7.7), they are seen by most workers as the best possible sampling device to estimate the nodule abundance in any given area. As such, the box-core samples were the most important contributor to the CCZ15 campaign results and by extension, to an independently validated, mineral resource estimate.

 

Box-corers come in different sizes: typically 0.1 m2 or 0.25 m2 (plan area of sample box or tube), but box-corers of 0.75 m2 and 1 m2 have also been used.

 

Smaller box-corers are good for micro-biological sampling of the epibenthic zone and are adequate for the estimation of abundant nodule resources, especially those involving smaller nodules. For accurate estimation of the abundance of larger nodules, especially in lower quantities, larger box-corers are more accurate.

 

The largest box-corers used in the CCZ were 1 m2 (Afernod’s Sympas system and one built by the OMCO consortium), but by all accounts, these were very large and difficult to handle. Kennecott built a 0.75 m2 corer and used it extensively, deeming it to be an effective compromise (Felix, 1980).

 

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7.3.4Box-corer Equipment

 

Two types of box-corers were used during the TOML CCZ15 campaign:

 

0.75 m2 box-corer manufactured by KC Denmark (80.740 code) and supplied by Nautilus Minerals (Figure 7.14). For part of the campaign, the KC box-corer included a carrousel of 12 small volume (300 ml) Niskin bottles for water sampling. Each side of the box has an internal width of just below 87 cm (there are minor variances of 1–2 mm with the corner welds), so the true area of 7569 cm2 is used for the abundance estimation.

 

0.25 m2 box-corer manufactured by YMG (Figure 7.15) based on a USNEL/Scripps design from the 1970s.

 

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Figure 7.13Details and operations with the KC box-corer

 

KC BC_mosaic.jpg

 

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Figure 7.14Details and recovery of the YMG box-corer

 

YMG BC_mosaic.jpg

 

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7.3.5Nodule sampling

 

Logging was completed manually by the Lead Scientist on shift. The manual logs were scanned and then transposed into MS Excel.

 

All weights were taken using a Wedderburn Marine motion compensated scale (WM42; Serial number #3380724) that was checked and calibrated in Brisbane, Australia, before shipping to the vessel. The scale has a 40 cm x 40 cm plate with vessel motion recorded and corrected electronically. Scales are claimed to be accurate to 60 kg ± 50 g, which was as observed during the campaign. The scales were checked using 12×1.5 litre or 12×2 litre water bottles and recorded weights were consistent with the mass of water plus packaging.

 

Upon arrival on deck, the nodules were photographed in situ, removed from the box and weighed three times:

 

1st time with mud still attached (preliminary weight) to enable biological analysis

 

2nd time after washing in filtered salt water (washed weight)

 

3rd time several days later and after exposure to 30–90 minutes in air conditioning and removal of ponded or sweated free water (aired weight).

 

Note that at each stage of handling, despite due care, some attrition of the nodules occurred with loss of a small (generally <1%) of fine material (dust to sand sized). The bulk of this loss occurred at the washing stage, but it was noticeable at the aired stage as well. The rate of attrition varied by nodule type (rough nodules broke up more) and by area (the rough and smooth rough nodules in the southern part of Area F were especially soft).

 

The difference between the washed and other weights is illustrated below in Figure 7.16. There is almost no difference between the washed and aired weights (average for all samples over 1 kg is –0.87%; in Area F it is –1.86%), with the cause of the minor differences debatable (moisture or attrition).

 

Figure 7.15Preliminary vs. washed vs. aired box-core nodule sample weights (kg)

 

 

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Figure 7.16Differences in washed vs. aired box-core nodule sample weights by area

 

 

Handling of nodules was at all times supervised by the Chief or Lead Scientists, who were also the only people permitted to weigh the nodules, record the weights and seal bags and pails for transport. Nodule sampling was managed as follows (refer Figure 7.17, Plates 1 to 24):

 

From the box, nodules were removed to the weighing station (in the geology laboratory or adjacent to the box-core landing spot on the back deck; (Plates 8 &13)

 

Here, preliminary weight was taken and recorded, the nodules were washed, firstly the selection with observed fauna, then the rest of the nodules.

 

Then the washed weight was taken and recorded (Plate 14).

 

Then the nodules were carried to the geology laboratory where they were arranged and photographed by a designated scientist before temporary storage in sealed plastic bags in a designated area.

 

Then at the conclusion of sampling of an area (1-7 days after collection), the samples were laid out about 6-20 at a time for airing (Plates 21 & 22).

 

After 30 to 90 minutes of airing, reference and duplicate samples were selected, re-packed weighed again, sealed in plastic bags security tagged with tamper-proof tags or tape and then photographed (Plates 19 & 20).

 

Then the nodules were packed into specially marked paint pails with tamper-proof tape (Plate 23).

 

Duplicates were collected from roughly one in ten samples. Subsamples were taken using cone and quartering.

 

Pails were then transported (escorted by Chief or Lead Scientist) to a refrigerated container (reefer) on deck for transport to Brisbane, Australia, where the main assay laboratory is located (Plate 24).

 

Reference samples were placed in specially marked and labelled pails for airfreight to Brisbane, Australia (in case of loss of the reefer in transit). These samples are for general reference purposes, but also serve as backup for chemical analysis. These samples were not sealed with security tags or tamper-proof tape.

 

Duplicate samples were placed in specially marked containers and labelled for air-freight to Jacobs University, Bremen, Germany, where the check laboratory is located. These samples and all container pails were sealed with tamper-proof tape.

 

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Figure 7.17Details and operations regarding sample processing

 

Mosaic_Samples Processing.jpg

  

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7.3.6Buried Nodules

 

In most samples, there were no buried (i.e. >10cm) nodules although some were occasionally entrained by the sides of the box or the shovel. If present, buried nodules were separated at the point of collection from the box and were washed, weighed, and packed separately. Entrained nodules were sampled for reference purposes only and were not weighed.

 

7.3.7Vane Shear Readings

 

Vane shear was measured in all box-cores that returned with undisturbed sediment. A 33 mm vane on a calibrated hand held shear vane device was used. Measurement location and readings were recorded on the Box-core Sample Log Sheet then transferred to a spreadsheet.

 

Vane shear was classified into one of four classes:

 

W is mostly weak from top to base

 

A is all stiff from top to base

 

G is soft at the top with gradual stiffening with depth

 

S is soft at the top with more sudden stiffening with depth.

 

Data were also reviewed by box and the most coherent reading selected. Averaging of readings was not undertaken as some measurements were taken in disturbed sediment, especially near the base. The most coherent readings were generally taken in the centre of the box.

 

Summary results are included in the maps further below, but the classes vary by area as shown in Figure 7.18.

 

Figure 7.18Summary vane shear results from TOML CCZ15 study areas

 

 

 

These data shows clear differences in the uppermost part of the sediment between areas, with:

 

Area C1 showing consistently suddenly stiffening ground conditions (mostly class S);

 

Area D1 showing a slightly wider range to C1 including some more rapidly stiffening situations (mostly class S);

 

Areas B1 and D2 have a wider range of conditions and both areas have occurrences of sediment drift (Nnoo);

 

Area F (and F1) has a universally weak upper layer then generally and gradually stiffens (mostly class G).

 

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7.3.8Biological-Sediment sampling

 

Biological-sediment base-line samples were collected from the majority of box-core samples. These samples were collected in accordance with ISA Technical Study: No.10 “Environmental Management Needs for Exploration and Exploitation of Deep Sea Minerals”. If TOML is to proceed to trial mining/full scale mining, these samples will play a key role in the environmental impact assessment of the proposed mine site(s).

 

Samples were collected to obtain an understanding of the in-fauna and epi-benthic community composition and sediment characterisation within the TOML tenement areas. A variety of sample types were collected from each box-core, which were fixed and preserved separately for morphological and molecular taxonomy.

 

Sample types collected and planned analysis:

 

Overlying water fauna

 

Megafauna (animals greater than 2 cm)

 

Nodule fauna

 

Micro-fauna (animals smaller than 32 µm)

 

Meio-fauna (animals greater than 32 µm and less than 250 µm)

 

Macro-fauna (animals greater than 250 µm and less than 2 cm)

 

Sediment chemistry

 

Particle size distribution

 

Special core samples. Sample type collected occasionally to capture unusual sediment characteristics of interest in their original sediment layers.

 

Collection method, fixing and preservation are illustrated in Figure 7.19 to Figure 7.23. Biological-sediment samples were only collected if the box-core sample was in relatively good condition. If the box-core sample was damaged during collection, or recovery resulting in the mixing of sediment layers, most sample types were not collected. Biological-sediment samples were collected in conjunction with nodule samples. However, care was taken to minimise the mixing of sediment layers during the extraction of nodules.

 

Between sampling events, all sampling equipment was washed thoroughly using 25 µm filtered seawater to prevent contamination of samples. Sterilised Nalgene sample containers and Whirl-Pak sample bags were used to collect samples. During the collection of sediment chemistry samples, no equipment containing metal was used in order to prevent cross-contamination due abrasion and to trace level analyses.

 

The following are the essential operations undertaken to collect all samples types listed above. Figure 7.17 displays the order of sample collection and processing:

 

Upon retrieval of the box-core to deck and delivery of the box-core samples to science team, overlying water was siphoned off into clean pails using plastic tubing and large pipettes. The water was then poured through a 32 µm sieve and the contents collected and fixed/preserved in 99% ethanol. (Figure 7.17 – Plates 5 & 6)

 

Visible mega-fauna were collected from the surface of the sample using forceps, placed in a sample container and preserved. After preliminary weighing of the nodules, selected nodules were washed over a sieve (32 µm) and the contents of the sieve collected and fixed/preserved in 6% formalin or 99% ethanol. Large mega-fauna attached to the nodules were photographed before being removed from the nodule

 

The required amount of 5 cm and 10 cm PVC cores were pushed into a box-core sample to a depth of over 20 cm. Rubber bungs were then inserted into the cores (Figure 7.17 – Plates 10 & 11)

 

Residue samples were collected using heavy-duty geological sample bags (Figure 7.17, Plate 12),

 

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PVC cores were extracted from the box-core and placed upright in pails to prevent mixing of layers. Cores were washed to prevent contamination during processing

 

PVC cores were analysed either for fauna type or for sediment characterisation, using horizon measurers and core cutter (Figure 7.17 – Plates 15, 16, 17 & 18):

 

Micro-fauna (2 x 5 cm diameter cores) ― 0–2 cm, 2-5 cm and 5-10 cm horizons were extracted, placed in the appropriate Nalgene sample container and fixed/preserved in 99% ethanol

 

Meio-fauna (4 x 10 cm diameter cores) – 0-2 cm, 2-5 cm and 5-10 cm horizons were extracted, placed in the appropriate Nalgene sample container and fixed/preserved in 4% formalin or 99% ethanol

 

Macro-fauna (4 x 10 cm diameter cores) – 0-2 cm, 2–5 cm, 5–10 cm and 10–20 cm horizons were extracted and sieved (250 µm). The contents of the sieve placed in the appropriate Nalgene sample container and fixed/preserved in 6% formalin or 99% ethanol

 

Sediment chemistry – 0-2 cm, 2–5 cm, 5–10 cm and 10–20 cm horizons were extracted and placed in sterilised Whirl-Pak sample bags

 

Particle size distribution 0-2 cm, 2–5 cm, 5–10 cm and 10–20 horizons were extracted and placed in sterilised Whirl-Pak sample bags

 

Duplicate samples – were collected

 

All samples collected were labelled using the q-Core database, following a pre-determined sample numbering system

 

After fixing/preservation, all samples were packed into pails and stored in a refrigerated container kept at 2–4 °C (Figure 7.17– Plate 24)

 

Samples fixed in 4% and 6% formalin were transferred to buffered 99% ethanol after approximately two weeks for long-term storage and preservation.

 

The bulk of the samples collected were shipped to Nautilus Minerals in Brisbane, Australia. A selection of overlying fauna, nodule fauna, meio-fauna, macro-fauna and mega-fauna have been shipped to YMG, Gelendzhik, Russia for expert morphological taxonomic identification. Sediment chemistry and particle size distribution samples were sent to SGS, Cairns for analysis. The bulk of the fauna samples will be stored until they can be analysed in accordance with a yet to be scoped environmental impact statement project.

 

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Figure 7.19Sample Plan – Overlying fauna and nodule

 

 

Figure 7.20Sample Plan – Micro-fauna and box-core layout

 

 

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Figure 7.21Sample Plan – Meio-fauna

 

 

Figure 7.22Sample Plan – Macro-fauna

 

 

 

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Figure 7.23Sample Plan – Sediment characterisation

 

 

7.3.9Sediment residue sampling

 

Most box-cores with good returned sediment had three samples taken after all other sampling was complete:

 

Top sample was typically 0–5 cm and comprised any remaining semi-liquid layer and geochemically active layer. Typically very soft and selected by this characteristic.
Second sample was of more solid sediment typically taken at 5–20 cm.
Third sample was remaining to base of box, usually a further 10–20 cm down, depending on depth of penetration.
Each sample weighed between 5 kg and 25 kg and in total about 330 samples were taken, making this the highest volume-weight sample collected and shipped.
The sediment was taken for use in future geotechnical/engineering studies
(e.g., reconstruction for traction and nodule collection bench top trials) and for reference.

 

7.3.10Water sampling

 

Water column samples were collected during CCZ15 as part of the environmental base-line characterisation of the TOML tenement areas in order to meet the recommendations per the ISA document; Environmental Management Needs for Exploration and Exploitation of Deep Sea Minerals. Samples were collected via the Niskin bottle rosette attached to the box-corer (Figure 7.13, Figure 7.24). The Niskin bottle rosette contained 12×300 ml Niskin bottles, which were triggered using a pressure sensor. Samples were collected for both infield and on-shore laboratory analysis.

 

Water sample types collected were:

 

Total Metals (TM) - 125 ml sterilised Nalgene container – 1 ml of nitric acid added for preservation (on-shore analysis);
Total Suspended Solids (TSS) - 1 L sterilised container (on-shore analysis);
pH and Oxidation-Reduction Potential (ORP) - In-field measurements – approximately 150 ml required to obtain measurements.

 

The water sampler (Niskin rosette) was programmed with the selected depth strata for full water sampling programme conducted in Area C, D and F and the Niskin bottles set to the open position, each time before deploying the box-core. The water-sampling programme was designed to collect samples from varying depth strata across all areas where box coring was conducted.

 

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Depth strata sampled for the majority of samples collected were:

 

50 m
200 m
500 m
1,000 m
1,500 m
500 m from the seafloor
100 m from the seafloor
50 m from the seafloor

 

Upon recovery of box-core and Niskin rosette to deck, the Niskin bottles were processed depending on the sample type being collected. TM and TSS were collected using the appropriate sterilised sample containers and refrigerated at 4°C The pH and ORP samples were collected and taken to the water chemistry laboratory for analysis. Samples were analysed using YSI Pro10 handheld multi-probe with pH and ORP sensors. A three-point calibration was conducted on the pH sensor prior to every sampling event.

 

Niskin bottles were fired during the decent due to the limitations of the device, as there was no way of programming the device to delay firing at the set depth strata on ascent. To minimise the risk of contamination from residue left from previous sample, the box-core was washed out between deployments. Due to commissioning issues the water sampler was not operational until Area C. Therefore, water samples were only collected in Area C, D and F.

 

All water samples collected for laboratory analysis were priority hand-carried back to Brisbane and shipped to SGS Cairns for analysis.

 

Figure 7.24Water Sample Collection and Water Chemistry Laboratory

 

 

7.3.11Water column profiling

 

During CCZ15, water column profiles were collected as part of the environmental base-line characterisation of the TOML Areas in order to meet the recommendations per the ISA document: Environmental Management Needs for Exploration and Exploitation of Deep Sea Minerals. The majority of water column data were collected via a Mini Autonomous Plume Recorder (MAPR) with the following sensors:

 

Temperature (°C);
Turbidity (NTU);
Depth (m).

 

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The MAPR was deployed during most operations by attaching it to either the box-core cable (50 m above the box-corer) or the umbilical of the MAK (side-scan) or Neptune (photo-profiler) at 50 m above either instrument, see Figure 7.13-Plates 7 & 9. Upon recovery of the MAPR to deck, these data were downloaded and processed and Excel template.

 

Along with the MAPR, an Aanderaa Seaguard single-point current sensor was deployed on a select number of box-core deployments in Area F.

 

7.3.12Photo-Profiling Programme

 

Photo-profiling was undertaken to provide data on short range continuity of nodules and visual based estimates of nodule abundance for mineral resource estimation. It also provided a census of mega-fauna and macro-fauna for environmental base line measurement and habitat mapping. Finally, it helped calibrate MBES and deep towed sonar results in terms of understanding seafloor rugosity.

 

Deployment and recovery of the camera was off the stern of the vessel using an umbilical and the vessels aft tow winch (Figure 7.25). The system was deployed just above the seafloor with the winch operator taking line in and line out to compensate partially for vessel heave. Video was streamed constantly to the vessel where it was logged by TOML team into the Nautilus Minerals’ proprietary Nautical logging system.

 

Figure 7.25Neptune Deployment Schematic

 

 

Photographs were taken automatically at a prescribed altitude of 3.5 m above the seafloor, a minimum.

 

30 seconds apart and continually uploaded to the vessel where scientists collected them from the central server and logged them for geology and biology. These were also subsequently logged by the TOML biologist in more detail.

 

Neptune lines were pre-planned to place the vessel into “prevailing result” where it maintained a forward speed of about 1.2 knots. As the line got longer, more line tended to be fed out and vessel speed tended to increase. Average velocities also tended to increase as the campaign progressed and the team optimised survey settings.

 

The system’s position was monitored using a 12 kHz USBL beacon except on line CCZ15-F08, where an estimate of position had to be made from line out and vessel position.

 

Hydrographic surveyor and bridge shared the same navigation display and the vessel was steered so that the profiles never moved more than 1 km off line and typically was well within 500 m of the planned line.

 

Survey data from the vessel, USBL location of the camera and attitude sensor was collected and subjected to preliminary analysis to learn more about towing dynamics.

 

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Figure 7.26Neptune Deployment Photographs

 

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7.3.13Deep Towed Sonar Programme

 

YMG’s MAK-1M deep towed system was brought on the CCZ15 campaign primarily to map and characterise the seafloor bathymetry in detail via its 30 kHz side scan system. The system also provided useful data on seafloor composition from its 5 kHz sub-bottom profiler and on seafloor surface survey from its altimeter-USBL survey data.

 

Essential operation was as follows:

 

Deployment and recovery of the sled and depressor was off the stern of the vessel (Figure 7.27, Figure 7.28).
MAK lines were pre-planned to place the vessel into prevailing result where it maintained a forward speed of about 1.5 knots.
The system’s position was monitored using an integrated 12 kHz USBL beacon and altimeter.
The system was towed behind a depressor weight about 100 m above the seafloor with slight elevation changes to follow the seabed. Speed of towing was limited by ping rate and data quality.
Hydrographic surveyor and bridge shared the same navigation display and the vessel was steered so that the sled never moved more than several hundred metres off line.
All processing through to delivered products was done on-board by the YMG MAK team.

 

As with the Neptune photo-profile systems, analysis of the sled versus ship position as well as some attitude/MAPR sensor data provided information on deep tow dynamics that might be of help in the design of future towed systems (e.g., for the Nautilus mining concept).

 

Figure 7.27MAK Deployment Schematic

 

 

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Figure 7.28MAK Components and Deployment

 

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7.3.14Dredging Programmes

 

Dredging was carried out during both the CCZ13 and CCZ15 campaigns, albeit with different methodologies. The intent was to collect sample for metallurgical test work, including chemical whole rock analysis.

 

7.3.14.1CCZ13 Epibenthic sled

 

An epibenthic sled was designed and built for the CCZ13 dredging (Figure 7.29, Figure 7.30). An epibenthic collector was chosen so as to:

 

Be able to be set up to skim the seafloor collecting epibenthic and inbenthic located nodules with minimum mud;
Be more able to clean itself of mud;
Consequently, impact the environment less.

 

Figure 7.29Epibenthic sled Deployment Schematic

 

 

Sample handling procedures essentially comprised weighing on recovery, followed by screening (±and 3/8” or approximately 6 cm) and photography of all, or if an excess of material for the photo sheet, a typical sub-sample. Many of the nodules were broken from their time in the dredge.

 

After some trial and error, the approach generally taken to dredge was:

 

About 1.5 km before the edge of the target zone, steam into the wind at 1.5–2.5 knots paying out line to 6–7 km.
On reaching the bottom or the target line out slow to slowest effective forward speed (i.e., having available steerage). this was typically 0.3–0.8 kt speed over ground.
Use line out to regulate load as transmitted to the load cell.
Run the load between minimum (line slack) and maximum loads (lift off), decreasing the range around what was judged to be the effective towing load (this was typically a range of only about 40–80 kg).

 

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Once or twice during the deployment (later increased to 3–4 times) lift and lower the sled using the vessel speed to wash out excess mud that might be filling the sled (termed a “tea-bag” manoeuvre). Minimise use of the winch to avoid tipping the nose of the sled and losing sample.
End the dredge by starting line in and speed up the boat to 2 knots.

 

Figure 7.30Photos of epibenthic sled

 

 

 

7.3.14.2CCZ15 Galatea dredge

 

The dredging approach was changed in CCZ15 for reasons of practicality.

 

Figure 7.31Galatea Dredge Deployment Schematic

 

 

The sample locations were picked to ensure that between the sampling of this campaign and the CCZ13 campaign, at least one dredge sample was taken in each contract area. Dredges were also the quickest and most effective way to sample Area A, albeit in a non-quantitative manner.

 

The process of dredging involved:

 

Dredge lowered at 0.5 m/s for first 200 m then 1 m/s to the bottom, then slowed to 0.5 m/s till touching the seabed.
Recovery to surface all the way at 1 m/s (full speed).
The vessel maintained forward speed into the weather at all times (~0.8–1.3 knot SOG was OK no change in speed needed).
Winch speed slowed but not stopped and the pinger trace height (~10 m) used to estimate when the dredge touches.
“Teabag” manoeuvres used to clean the dredge between landings (each landing is about 1 minute and after lifting at about 0.7 m/s to 100 m the cleaning takes about 2–3 minutes before return to the seafloor at 0.5 m/s).
3–7 “teabags” were carried out depending on weight of sample required.

 

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Figure 7.32Operations and details of the YMG Galatea-trawl dredge

 

Dredge_mosaic.jpg

 

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7.3.15Marine Survey

 

During CCZ13 a TOML contract surveyor operated Caris HIPS (Hydrographic Data Processing System) software through the MBES system’s dual head GPS array and maintained a digital survey log. Deployments and co-ordinates were written into a logbook. Communications were verbally to the bridge on the same level and via handheld radio to the back deck.

 

During CCZ15 RV Yuzhmorgeologiya’s survey department coordinated operations and logged events (TOML personnel also kept a logbook). Various sensors (e.g., GPS, weather station, USBL) all fed to a central computer with most data read into Hydropro software. The main navigation screen from Hydropro was replicated on the bridge so that the officers there received real-time updates on current and planned movements. Communication between Hydrographer, Bridge, Pinger Operator, Winch Operator and Back Deck Supervisor was via a dedicated open intercom system. A USBL antenna was deployed through a small opening in the base of the ship and an IXSEA Posidonia 6000 gen1 system used this and an umbilical to transmit to the MAK deep tow system, and to communicate with a variety of 12 KHz beacons.

 

7.3.16Other Programmes

 

7.3.16.1Long Term Moorings

 

During and shortly after CCZ15, two moorings were deployed, one in Area C (S01) and one in Area B (S03).

 

The moorings were designed to be simple and inexpensive and to have a minimum two-year life (Figure 7.33). Engineering was by Sound Ocean Systems Inc based on environmental parameters provided by the Nautilus environmental team and an Erias Group (Melbourne, Australia) consultant.

 

Figure 7.33CCZ15 Mooring Design and deployment of Mooring S01 in Area C

 

 

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7.3.16.2Other Environmental Data

 

A complete summary of environmental data collected during the CCZ15 campaign is presented in Table 7.8 below. Other specific data collected was:

 

CSMF, or marine mammal observations, were recorded on a log by the bridge. During CCZ13 marine mammals were only seen outside the CCZ and during CCZ15 two mammal sightings were made with a solitary dolphin to the east of Area A and two whales (likely Sperm Whales) within Area D. Birds were seen on both campaigns but were only logged during CCZ15 (Figure 7.34)
Weather Information, including logs, weather reports as well as interpretation of these data.

 

Figure 7.34CCZ15 CSMF Events

 

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Table 7.8CCZ15 Environmental Data Matrix

 

 

7.4TOML Exploration Results

 

The exploration results discussed here include all data relevant to the mineral resource estimate. Much of the supporting data collected during the TOML CCZ13 and CCZ15 campaigns is still being processed. This includes much of the environmental and geotechnical data collected, but also includes mineralogy from samples and detailed geological interpretation from acoustic survey. This information will be reported, as relevant, at a later time.

 

7.4.1TOML MBES results

 

The MBES results are shown at a small scale in Figure 7.35 and Figure 7.36. The bathymetry shows that almost the entire area is composed abyssal hills and the bathymetry and backscatter together show that most of the area is covered by nodule bearing sediment.

 

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Figure 7.35CCZ13 MBES bathymetry coverage

 

 

Relief range blue to yellow is about 400 m scaled by each area. Background is the GEBCO bathymetric product (BODC, 2014)

 

Figure 7.36CCZ13 MBES backscatter coverage

 

 

Background is the GEBCO bathymetric product (BODC, 2014)

 

The MBES bathymetry is used repeatedly in the following figures as the backdrop to the box-core results.

 

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7.4.2TOML Box-core results

 

Figure 7.37 to Figure 7.51 summarises nodule and sediment characteristics of the box-core sites. Note that data exists at many of the same sites for water column characteristics and chemistry and fauna numbers and taxonomy data.

 

Figure 7.37Nodule Types, Area B1

 

 

Nodule abundances are reported in wet kg/m2, estimated using the process and principles discussed in section 7.5.6.

 

Figure 7.38Nodule Abundance, Area B1

 

 

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Shear strength is classified per the process and classification detailed in Section 9.3.7.

 

Figure 7.39Shear Strength Class, Area B1

 

 

Figure 7.40Nodule Types, Area C1

 

 

 

 

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Figure 7.41Nodule Abundance Area, C1

 

 

Figure 7.42Shear Strength Class, Area C1

 

 

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Figure 7.43Nodule Types, Area D2

 

 

Figure 7.44Nodule Abundance Area, D2

 

 

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Figure 7.45Vane Shear Strength Class, Area D2

 

 

Figure 7.46Nodule Types, Area D1

 

 

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Figure 7.47Nodule Abundance, Area D1

 

 

Figure 7.48Vane Shear Strength Class, Area D1

 

 

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Figure 7.49Nodule Types, Areas F and F1

 

 

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Figure 7.50Nodule Abundance, Areas F and F1

 

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Figure 7.51Vane Shear Strength Class, Areas F and F1

 

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7.4.3TOML Photo-profile results

 

Photo-profiling provided key data on nodule type and abundance as well as for baseline logging of mega-fauna. Ten lines were completed, with one in two parts after equipment repair (Figure 7.52).

 

Use of photographs in nodule abundance estimations is not new and is discussed by Felix (1980) and by UNOETO (1979). These results are included with the box-core based abundance data used for mineral resource estimation.

 

An estimation of nodule cover (% visible cover by nodules on the seafloor) was also possible. This is much simpler to measure than nodule long axis as it is a simple colour contrast. Percentage cover does relate to abundance, but the relationship is much weaker than nodule long axis, so nodule cover was not used in the mineral resource estimate except to support interpreted and measured continuity.

 

When combined with observations of outcrop, the nodule coverage plots in Figure 7.52 give a good indication of the high levels of continuity for the nodules amongst the fault bounded abyssal hills. The process clearly does not work in Area D where sediment cover is high.

 

Figure 7.52Neptune Photo-profile logging of % cover and outcrop types

 

 

Insets only shown for Area B (L) and C (R)

 

Nodule size analysis (combined with box core observations) is shown in Figure 7.53. An understanding of nodule sizes and other characteristics such as rugosity and strength will be useful in designing the mining system. Considerable information was collected in respect of long axis measurements taken from photo-profile images (roughly every 100th image for abundance estimation purposes).

 

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Figure 7.53Nodule sizes and types from photo-profiles and box-cores

 

LAEpies.png

 

Top: B1, Middle-left: C1, Bottom-left: D1-D2, Bottom right: F and F1

 

All the surveyed areas host nodules of different sizes but Area B has mixed sized nodules and includes many of the smaller nodules. In Area C, nodule size increases to an average of small to medium and they are well distributed throughout. Within Area D, there is a mixture of sizes with some very large nodules found in the box-core samples. Bigger nodules were recovered from the box-corer than measured on the photo-profiling lines due to a frequent underestimation related to the sediment cover in this area. Area F has typically medium sized nodules but very large size nodules are seen in places.

 

Photos were also logged as they were collected for visible megafauna with preliminary logging results in Figure 7.54.

 

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Figure 7.54Neptune Photo-profile preliminary logging summary distribution of megafauna

 

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