Exhibit 99.1

Report of Independent Auditors

To the Board of Directors of Minera Santa Cruz S.A.:

We have audited the accompanying financial statements of Minera Santa Cruz S.A. which comprise the balance sheet as of December 31, 2012, and the related statements of income, changes in stockholders’ equity and cash flows for the year then ended, and the related notes to the financial statements, which, as described in Note 2 to the financial statements, have been prepared on the basis of accounting principles generally accepted in Argentina.

Management’s Responsibility for the Financial Statements

Management is responsible for the preparation and fair presentation of these financial statements in conformity with generally accepted accounting principles in Argentina; this includes the design, implementation, and maintenance of internal control relevant to the preparation and fair presentation of financial statements that are free of material misstatement, whether due to fraud or error.

Auditor’s Responsibility

Our responsibility is to express an opinion on these financial statements based on our audits. We conducted our audits in accordance with auditing standards generally accepted in the United States of America. Those standards require that we plan and perform the audit to obtain reasonable assurance about whether the financial statements are free of material misstatement.

An audit involves performing procedures to obtain audit evidence about the amounts and disclosures in the financial statements. The procedures selected depend on the auditor’s judgment, including the assessment of the risks of material misstatement of the financial statements, whether due to fraud or error. In making those risk assessments, the auditor considers internal control relevant to the entity’s preparation and fair presentation of the financial statements in order to design audit procedures that are appropriate in the circumstances, but not for the purpose of expressing an opinion on the effectiveness of the entity’s internal control. Accordingly, we express no such opinion. An audit also includes evaluating the appropriateness of accounting policies used and the reasonableness of significant accounting estimates made by management, as well as evaluating the overall presentation of the financial statements.

We believe that the audit evidence we have obtained is sufficient and appropriate to provide a basis for our audit opinion.

Opinion

In our opinion, the financial statements referred to above present fairly, in all material respects, the financial position of Minera Santa Cruz S.A. as of December 31, 2012, and the results of its operations and its cash flows for the year then ended, in accordance with accounting principles generally accepted in Argentina.

Emphasis of Matter

As discussed in Note 2 to the financial statements, the Company prepares its financial statements in accordance with accounting principles generally accepted in Argentina, which differ from accounting principles generally accepted in the United States of America (see note 9 to the financial statements). Our opinion is not modified with respect to this matter.

City of Buenos Aires, Argentina

April 25, 2014

1

MINERA SANTA CRUZ SA

BALANCE SHEETS

AT DECEMBER 31, 2012 AND 2011

(Stated in Argentine pesos — see Note 2.II)

The accompanying Notes 1 to 10 and Exhibits I to VII are an integral part of these financial statements.

2

MINERA SANTA CRUZ SA

STATEMENTS OF INCOME

FOR THE YEARS ENDED DECEMBER 31, 2012, 2011 AND 2010

(Stated in Argentine pesos — see Note 2.II)

The accompanying Notes 1 to 10 and Exhibits I to VII are an integral part of these financial statements.

3

MINERA SANTA CRUZ SA

STATEMENTS OF CHANGES IN SHAREHOLDERS’ EQUITY

FOR THE YEARS ENDED DECEMBER 31, 2012 AND 2011

(Stated in Argentine pesos — see Note 2 II)

The accompanying Notes 1 to 10 and Exhibits I to VII are an integral part of these financial statements.

4

MINERA SANTA CRUZ SA

STATEMENTS OF CASH FLOWS (1)

FOR THE YEARS ENDED DECEMBER 31, 2012, 2011 AND 2010

(Stated in Argentine pesos — see Note 2 II)

(1) Cash and Cash Equivalents includes cash in bank and investments with original maturities of less than three months

The accompanying Notes 1 to 10 and Exhibits I to VII are an integral part of these financial statements.

5

MINERA SANTA CRUZ S.A.

NOTES TO THE FINANCIAL STATEMENTS

FOR THE YEARS ENDED DECEMBER 31, 2012, 2011 AND 2010

(Amounts stated in Argentine pesos - except where expressly indicated)

1.                   PURPOSE AND BUSINESS OF THE COMPANY

Minera Santa Cruz S.A. (the “Company”) was incorporated in 2001 in order to, on its own, by means of third parties or in association with third parties, engage in the exploration, mining, extraction and processing of minerals and the marketing of the derived products and byproducts.

The Company owns 18 Minas (approved mining claims) and 32 Manifestaciones de Descubrimiento (claims that are in the application process for mining claim status), all of which are located in the Province of Santa Cruz. There are several mineralized structures on these properties, identified through geophysical surveys and diamond drilling.

In order to maintain its current right to mining concessions, the Company is required to pay a semi-annual mining royalty to the Province of Santa Cruz.

The Company’s activities are focused on the exploration and exploitation of the “San José” project.The commissioning of the processing plant took place in September 2007.

Until October 2008, the processing plant had a production capacity of 750 tonnes per day. Subsequent to this, the production capacity was increased to 1,500 tonnes per day.

Moreover, the feasibility study was presented in November 2005 at the Ministry of Mining. Additionally, the environmental impact study submitted to the Provincial Mining of Santa Cruz in November 2005, was approved in March 2006 by the authorities. Its biannual update was submitted, the first one in 2008, the second one, in 2010 and the third one in 2012.

The project has shown sufficient potential to continue operation in the areas of interest with a remaining mine life of approximately 12 years. According to the studies performed, the operation is economically viable and the carrying value of the Company’s assets does not exceed their recoverable value.

2.                   SIGNIFICANT ACCOUNTING POLICIES

I.               Generally accepted accounting principles

The financial statements of the Company have been prepared in accordance with generally accepted accounting principles in effect in Argentina (“Argentine GAAP”).

I.a)     Judgments, estimates and significant accounting assumptions

The preparation of financial statements in accordance with Argentine GAAP requires the development and consideration by management of judgments, estimates and significant accounting assumptions that affect the reported balances of assets and liabilities, income and expenses, as well as the determination and disclosure of contingent assets and liabilities at the date of such statements. In this sense, the uncertainty associated with the estimates and

6

MINERA SANTA CRUZ S.A.

NOTES TO THE FINANCIAL STATEMENTS

FOR THE YEARS ENDED DECEMBER 31, 2012, 2011 AND 2010

(Amounts stated in Argentine pesos - except where expressly indicated)

assumptions used could result in future final results which could differ from those estimates and require significant adjustments to the reported balances of assets and liabilities affected.

I.b)     Measurement issues not covered by Argentine GAAP: Application of supplementary regulatory sources

Measurement issues not covered by Argentine GAAP can be resolved by (i) the use of specific accounting standards dealing with similar and related issues (unless such standard prohibits its application in the particular case being considered, or it has been indicated that the accounting treatment it establishes should not be applied by analogy to other cases), (ii) the application of accounting measurement standards in general, and (iii) the application of concepts included in the Conceptual Framework of Argentine GAAP, in the order of priority as indicated above.

When the resolution of the issue is not evident based on the above-mentioned sources, the following may be considered, in descending order of priority, on a supplementary basis for the management to make a judgment and develop appropriate accounting policies: (i) International Financial Reporting Standards (IFRS) and interpretations that have been approved and issued by the International Accounting Standards Board (IASB); and (ii) in no particular order, the most recent pronouncements of other issuers that use a similar conceptual framework to issue accounting standards, accepted industry practices and accounting doctrine, provided that the extra sources used do not conflict with the regulatory sources listed in the previous paragraph, and until the Argentine Federation of Professional Councils in Economic Sciences (“FACPCE”) issues a standard covering the measurement issue in question.

II.          Restatement in constant currency

The Company’s financial statements recognize the variations in the currency purchasing power until February 28, 2003, having discontinued the incorporation of adjustments to reflect such variations as of that date, in accordance with the provisions set forth in Argentine GAAP and as required by Presidential Decree No. 664/2003.

However, as observed in recent years, there continues to exist significant fluctuations in the price of the relevant economic variables affecting the Company’s business, such as wage costs, prices of key raw materials and foreign exchange rates, even though such fluctuations have not reached levels leading professional and regulatory bodies to reinstate an obligation to apply the adjustments mentioned above. However, these fluctuations still affect the financial position and results of the Company and, therefore, the information provided in these financial statements. As such, these fluctuations should be taken into account in the interpretation of the financial position and results of operations presented by the Company in these financial statements.

7

MINERA SANTA CRUZ S.A.

NOTES TO THE FINANCIAL STATEMENTS

FOR THE YEARS ENDED DECEMBER 31, 2012, 2011 AND 2010

(Amounts stated in Argentine pesos - except where expressly indicated)

III.     Valuation Criteria

The main valuation criteria used by the Company are as follows:

a)             Cash and cash equivalents, and balances with companies in accordance with Article 33, Law No. 19,550 and related parties.

·                  In local currency: at nominal value.

·                  In foreign currency: at nominal value, converted at the prevailing exchange rates using the year-end date as settlement date.

Receivables from and payables to Companies in accordance with Article 33 of Law 19,550 and related parties have been valued in accordance with conditions agreed upon for each transaction and include, if applicable, the accrued amount up to the end of each financial year presented in these financial statements.

b)             Investments

·                  In local currency: corresponds to government securities valued at market value less estimated selling costs.

·                  In foreign currency: corresponds to deposits valued at nominal value plus financial income accrued at the end of each year, converted at the prevailing exchange rate using the year-end date as settlement date.

c)              Receivables from customers and other receivables, trade payables, payroll and social security taxes payable, loans, taxes payables and other liabilities.

·                  In local currency: valued, as appropriate, at their cash value or based on discounted cash flows, in accordance with the guidelines set forth in applicable Argentine GAAP accounting standards.

·                  In foreign currency: valued as mentioned above, converted at the prevailing exchange rates using the year-end date as settlement date.

·                  They include, if applicable, accrued financial income at the end of each year.

d)             Inventories: they include, as appropriate, stockpiles, concentrates and doré, which are valued at production costs by applying absorption costing, which is the best estimate of their reproduction value at the end of each year.

e)              Materials: includes materials, parts and supplies, which are valued at their replacement costs at end of each year.

8

MINERA SANTA CRUZ S.A.

NOTES TO THE FINANCIAL STATEMENTS

FOR THE YEARS ENDED DECEMBER 31, 2012, 2011 AND 2010

(Amounts stated in Argentine pesos - except where expressly indicated)

f)               Property, plant and equipment: valued at cost of acquisition or construction as restated in accordance with Note 2.II above, less related accumulated depreciation at the end of each year.

The Company capitalizes estimated discounted future mine abandonment and closure costs. These assets are included in property, plant and equipment. Additionally, a liability for these costs is recognized as a counterpart to these assets.

Property, plant and equipment are presented net of impairments.

The value of property, plant and equipment, net of impairments referred to in the preceding paragraph, does not exceed their recoverable value at the end of each financial year.

g)              Intangible assets

Intangible assets primarily include rights for the use of electrical transmission lines, in addition to capitalized pre-operating and exploration costs incurred by the Company. These are valued at original cost less accumulated amortization at the end of each year.

Intangible assets do not exceed their recoverable value at the end of each year.

h)             Provisions

·                  For lawsuits, claims and contingencies: provisions for lawsuits, claims and contingencies are constituted to cover contingencies in which there is a high likelihood that the Company will have to use economic resources to settle a present obligation arising in past events and whose existence depends on one or more future events that may occur or fail to occur. The evaluation and estimate of the amounts for contingent liabilities is made by the Company’s management based on available evidence and considering the opinion of its legal counsel, if applicable. In the opinion of Company’s management, the provision made at the end of each year is sufficient to meet the situations to which the Company is exposed. When the probability that a loss will materialize is not high, but is not remote either, or if the probability is high but the amount of the loss cannot be reasonably estimated, a liability is not recorded. In these cases, Argentine GAAP are followed in order to define the measurement requirements and, in the opinion of the Company, the Company’s position should prevail against such contingencies. The contingencies assessed as remote are not accounted for or disclosed in the notes to the financial statements.

·                  For impairments of construction-in-progress assets: provisions for impairments of construction-in-progress assets are established when their carrying value exceeds their recoverable value.

·                  For doubtful tax credits: provisions for tax credits are established when their carrying value exceeds their recoverable value.

·                  For obsolescence of materials: provisions for obsolescence of materials are established when their carrying value exceeds their recoverable value.

9

MINERA SANTA CRUZ S.A.

NOTES TO THE FINANCIAL STATEMENTS

FOR THE YEARS ENDED DECEMBER 31, 2012, 2011 AND 2010

(Amounts stated in Argentine pesos - except where expressly indicated)

i)                 Income tax and minimum presumed income tax

Law No. 25,063, published in the Official Gazette on December 30, 1998, establishes amongst other things, the tax on minimum presumed income, expressly excludes from its scope companies included in the provisions of Law No. 24,196, known as the Investment Regime for Mining Activity. As the Company was incorporated in accordance with this regime, as described in Note 7, it is therefore not within the scope of this tax.

Argentine GAAP require the recognition of income taxes under the deferred tax method, which establishes the determination of deferred income assets or liabilities based on temporary differences between the accounting measurement of assets and liabilities and their respective tax values. Temporary differences result in deferred tax assets or liabilities when future reversals decrease or increase income taxes, respectively. Also, a deferred tax asset is recognized when there are unused tax losses which may be offset against future taxable income, but only to the extent that the future use of those losses is probable.

A breakdown of the net deferred tax liability as at December 31, 2012, 2011 and 2010 is as follows:

At December 31, 2012 and 2011, the reconciliation between the income tax expense charged to the statement of income, and the result of applying the rate of 35% set by tax regulations to accounting profits before income tax of each exercise is as follows:

10

MINERA SANTA CRUZ S.A.

NOTES TO THE FINANCIAL STATEMENTS

FOR THE YEARS ENDED DECEMBER 31, 2012, 2011 AND 2010

(Amounts stated in Argentine pesos - except where expressly indicated)

Income tax expense is composed of the following:

j)                Shareholders’ equity

Restated, as described in Section II of this note, except the “Capital Stock” account, which is stated at nominal value. The adjustment resulting from the restatement in constant currency is included in the “Adjustment to capital stock” account.

k)             Statement of income accounts

·                  Accounts which relate to monetary transactions are valued at their nominal value.

·                  Expenses relating to the consumption of non-monetary assets were valued at their restated cost, in accordance with the provisions described in Note 2.II.

·                  Financial income (expense) and holding gains (losses), net, include accrued interest and foreign exchange differences generated by assets and liabilities, among other items.

3.                   COMPOSITION OF MAIN ACCOUNTS

11

MINERA SANTA CRUZ S.A.

NOTES TO THE FINANCIAL STATEMENTS

FOR THE YEARS ENDED DECEMBER 31, 2012, 2011 AND 2010

(Amounts stated in Argentine pesos - except where expressly indicated)

12

MINERA SANTA CRUZ S.A.

NOTES TO THE FINANCIAL STATEMENTS

FOR THE YEARS ENDED DECEMBER 31, 2012, 2011 AND 2010

(Amounts stated in Argentine pesos - except where expressly indicated)

13

MINERA SANTA CRUZ S.A.

NOTES TO THE FINANCIAL STATEMENTS

FOR THE YEARS ENDED DECEMBER 31, 2012, 2011 AND 2010

(Amounts stated in Argentine pesos - except where expressly indicated)

4.                   BALANCES AND OPERATIONS WITH COMPANIES ART. 33 LAW No. 19,550 AND RELATED PARTIES