Fortuna Silver Mines Inc., Schedule 13G

¹ This calculation is based on 125,268,751 common shares, without par value, of Fortuna Silver Mines Inc. (the “Issuer”) outstanding as of November 7, 2012 as reported in the Issuer’s Condensed Interim Consolidated Financial Statements for the period ended September 30, 2012, which was filed as Exhibit 99.1 to the Issuer’s Report of Foreign Private Issuer on Form 6-K, which was filed with the Securities and Exchange Commission on December 3, 2012.

¹ See Footnote 1.

CUSIP No. 349915108

SCHEDULE 13G

Page 9 of 15

Item 1.

(a) Name of Issuer

The issuer is Fortuna Silver Mines Inc., a company incorporated in British Columbia (the “Issuer”).

(b) Address of Issuer’s Principal Executive Offices:

355 Burrard Street, Suite 840, Vancouver, British Columbia, Canada V6C 2G8.

Item 2.

(a) Name of Persons Filing

The persons filing this Amendment No. 1 to Statement on Schedule 13G are Mason Hill Advisors LLC, a Delaware limited liability company (“Mason Hill”), Equinox Asset Management LLC, a Delaware limited liability company (“EAM”), Equinox Partners, L.P., a Delaware limited partnership (“Equinox Partners”), Mason Hill Partners, LP, a Delaware Limited Partnership (“Mason Hill Partners”), Equinox Illiquid General Partner, LP, a Delaware limited partnership (“Illiquid GP”), Equinox Illiquid Fund, LP, a Delaware limited partnership (“Illiquid”), and Sean M. Fieler (together with Mason Hill, EAM, Equinox Partners, Mason Hill Partners and Illiquid GP, the “Reporting Persons”).

Mason Hill’s principal business is serving as an investment adviser to certain affiliated funds, including Equinox Partners, Mason Hill Partners and Illiquid.

EAM’s principal business is serving as the sole general partner of each of Equinox Partners and Mason Hill Partners.

Illiquid GP’s principal business is serving as the sole general partner of Illiquid.

Each of Equinox Partners, Mason Hill Partners and Illiquid is a private investment fund.

Mr. Fieler owns a controlling interest in Mason Hill and is the managing member of each of Mason Hill and EAM.

The Reporting Persons have entered into a Joint Filing Agreement, a copy of which was attached as Exhibit 99.1 to the Schedule 13G filed by the Reporting Persons on April 3, 2012, pursuant to which the Reporting Persons have agreed to file the statement and any amendments thereto jointly in accordance with the provisions of Rule 13d-1(k)(1) promulgated under the Securities Exchange Act of 1934, as amended.

(b) Address of Principal Business Office or, if none, Residence

The address of the principal business office of each of the Reporting Persons is 623 Fifth Avenue, 27th Floor, New York, New York 10022.

(c) Citizenship

CUSIP No. 349915108

SCHEDULE 13G

Page 10 of 15

Mr. Fieler is a United States citizen. Each of the other Reporting Persons is organized under the laws of the State of Delaware.

(d) Title of Class of Securities

Common shares, without par value (“Common Shares”).

(e) CUSIP Number

349915108

Item 3.

If this Statement is Filed Pursuant to Rule 13d-1(b), or 13d-2(b) or (c), Check Whether the Person Filing is a:

(a)

Broker or dealer registered under Section 15 of the Exchange Act;

(b)

Bank as defined in Section 3(a)(6) of the Exchange Act;

(c)

Insurance company as defined in Section 3(a)(19) of the Exchange Act;

(d)

Investment company registered under Section 8 of the Investment Company Act;

(e)

An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);

(f)

An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F);

(g)

A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G);

(h)

A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act;

(i)

A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act;

(j)

Group, in accordance with Rule 13d-1(b)(1)(ii)(J).

Item 4.

Ownership.

Each of Mr. Fieler, Mason Hill and EAM may be deemed to beneficially own (as that term is defined in Rule 13d-3 under the Act) the Common Shares which each of Equinox Partners and Mason Hill Partners directly beneficially owns. Each of Mr. Fieler, Mason Hill and EAM disclaims beneficial ownership of such Common Shares for all other purposes. Each of Mr. Fieler, Mason Hill and Illiquid GP may be deemed to beneficially own (as that term is defined in Rule 13d-3 under the Act) the Common Shares which Illiquid directly beneficially owns. Each of Mr. Fieler, Mason Hill and Illiquid GP disclaims beneficial ownership of such Common Shares for all other purposes.

A. Mason Hill Advisors LLC

(a) Amount beneficially owned

As of December 31, 2012, Mason Hill may be deemed to beneficially own 7,932,400 Common Shares.

(b) Percent of class

The number of Common Shares that Mason Hill may be deemed to beneficially own is 6.3% of the Common Stock outstanding.

CUSIP No. 349915108

SCHEDULE 13G

Page 11 of 15

(c) Number of shares as to which the person has

(i) Sole power to vote or to direct the vote: 0

(ii) Shared power to vote or to direct the vote: 7,932,400

(iii) Sole power to dispose or to direct the disposition of: 0

(iv) Shared power to dispose or to direct the disposition of: 7,932,400

B. Equinox Asset Management LLC

(a) Amount beneficially owned

As of December 31, 2012, EAM may be deemed to beneficially own 7,890,400 Common Shares.

(b) Percent of class

The number of Common Shares that EAM may be deemed to beneficially own is 6.3% of the Common Stock outstanding.

(c) Number of shares as to which the person has

(i) Sole power to vote or to direct the vote: 0

(ii) Shared power to vote or to direct the vote: 7,890,400

(iii) Sole power to dispose or to direct the disposition of: 0

(iv) Shared power to dispose or to direct the disposition of: 7,890,400

C. Equinox Partners, L.P.

(a) Amount beneficially owned

As of December 31, 2012, Equinox Partners may be deemed to beneficially own 7,042,994 Common Shares.

(b) Percent of class

The number of Common Shares that Equinox Partners may be deemed to beneficially own is 5.6% of the Common Stock outstanding.

(c) Number of shares as to which the person has

(i) Sole power to vote or to direct the vote: 0

(ii) Shared power to vote or to direct the vote: 7,042,994

(iii) Sole power to dispose or to direct the disposition of: 0

CUSIP No. 349915108

SCHEDULE 13G

Page 12 of 15

(iv) Shared power to dispose or to direct the disposition of: 7,042,994

D. Mason Hill Partners, LP

(a) Amount beneficially owned

As of December 31, 2012, Mason Hill Partners may be deemed to beneficially own 847,406 Common Shares.

(b) Percent of class

The number of Common Shares that Mason Hill Partners may be deemed to beneficially own is 0.7% of the Common Stock outstanding.

(c) Number of shares as to which the person has

(i) Sole power to vote or to direct the vote: 0

(ii) Shared power to vote or to direct the vote: 847,406

(iii) Sole power to dispose or to direct the disposition of: 0

(iv) Shared power to dispose or to direct the disposition of: 847,406

E. Equinox Illiquid General Partner, LP

(a) Amount beneficially owned

As of December 31, 2012, Illiquid GP may be deemed to beneficially own 42,000 Common Shares.

(b) Percent of class

The number of Common Shares that Illiquid GP may be deemed to beneficially own is 0.0% of the Common Stock outstanding.

(c) Number of shares as to which the person has

(i) Sole power to vote or to direct the vote: 0

(ii) Shared power to vote or to direct the vote: 42,000

(iii) Sole power to dispose or to direct the disposition of: 0

(iv) Shared power to dispose or to direct the disposition of: 42,000

F. Equinox Illiquid Fund, LP

(a) Amount beneficially owned

As of December 31, 2012, Illiquid may be deemed to beneficially own 42,000 Common Shares.

CUSIP No. 349915108

SCHEDULE 13G

Page 13 of 15

(b) Percent of class

The number of Common Shares that Illiquid may be deemed to beneficially own is 0.0% of the Common Stock outstanding.

(c) Number of shares as to which the person has

(i) Sole power to vote or to direct the vote: 0

(ii) Shared power to vote or to direct the vote: 42,000

(iii) Sole power to dispose or to direct the disposition of: 0

(iv) Shared power to dispose or to direct the disposition of: 42,000

G. Sean M. Fieler

(a) Amount beneficially owned

As of December 31, 2012, Mr. Fieler may be deemed to beneficially own 7,932,400 Common Shares.

(b) Percent of class

The number of Common Shares that Mr. Fieler may be deemed to beneficially own is 6.3% of the Common Stock outstanding.

(c) Number of shares as to which the person has

(i) Sole power to vote or to direct the vote: 0

(ii) Shared power to vote or to direct the vote: 7,932,400

(iii) Sole power to dispose or to direct the disposition of: 0

(iv) Shared power to dispose or to direct the disposition of: 7,932,400

Item 5.

Ownership of Five Percent or Less of a Class.

If this statement is being filed to report the fact that as of the date hereof, the Reporting Persons have ceased to be the beneficial owner of more than five percent of the class of securities, check the following ¨.

Item 6.

Ownership of More than Five Percent on Behalf of Another Person.

Not applicable.

Item 7.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person

CUSIP No. 349915108

SCHEDULE 13G

Page 14 of 15

See information in Item 2 above.

Item 8.

Identification and Classification of Members of the Group.

Not applicable.

Item 9.

Notice of Dissolution of Group.

Not applicable.

Item 10.

Certification.

Each of the Reporting Persons hereby makes the following certification:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

CUSIP No. 349915108

SCHEDULE 13G

Page 15 of 15

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: February 21, 2013


1.	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Mason Hill Advisors LLC
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) ¨ (b) ¨
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 7,932,400
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER 7,932,400
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 7,932,400
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) ¨
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 6.3%¹
12.	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) IA


1.	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Equinox Asset Management LLC
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) ¨ (b) ¨
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 7,890,400
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER 7,890,400
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 7,890,400
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) ¨
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 6.3%¹
12.	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) HC, OO


1.	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Equinox Partners, L.P.
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) ¨ (b) ¨
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 7,042,994
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER 7,042,994
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 7,042,994
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) ¨
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 5.6%¹
12.	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) PN


1.	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Mason Hill Partners, LP
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) ¨ (b) ¨
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 847,406
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER 847,406
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 847,406
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) ¨
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 0.7%¹
12.	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) PN


1.	NAME OF REPORTING PERSONS I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) Equinox Illiquid General Partner, LP
2.	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS) (a) ¨ (b) ¨
3.	SEC USE ONLY
4.	CITIZENSHIP OR PLACE OF ORGANIZATION Delaware
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH		5.	SOLE VOTING POWER 0
		6.	SHARED VOTING POWER 42,000
		7.	SOLE DISPOSITIVE POWER 0
		8.	SHARED DISPOSITIVE POWER 42,000
9.	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 42,000
10.	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES (SEE INSTRUCTIONS) ¨
11.	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 0.0%¹
12.	TYPE OF REPORTING PERSON (SEE INSTRUCTIONS) PN