Sample Preparation and Analysis .1 Legacy Programs

Sample preparation and analysis during the legacy programs comprised:

• BHC (1980): AMEC has no documented references for sample preparation;

• SCMG (1987–1990): AMEC has no documented references for sample preparation. It is not known what analytical technique was used by Cesmec for Au, but it is assumed that it is the same as that used by the mine laboratory. This technique was conventional fire assay (FA) and gravimetric finish on a 60 g aliquot;

• Amax (1991–1997): The entire drill core split was crushed to -10 mesh in roller mills. The -10 mesh material was passed through a Jones splitter and 1 kg was then reduced to -40 mesh in a disc pulverizer. After homogenization, the -40 mesh material was then riffle split into two equal portions. One half was put into storage for possible later metallic sieve testing for coarse gold. The other half was dried in an oven and pulverized to -150 mesh using a ring-and-puck mill. The product was rolled, quartered, and split into two 250 g portions. One was stored on site and the other was shipped for analysis. Sample preparation for RC samples comprised crushing to minus 2.0 mm (10 mesh) in roller mills, splitting to obtain a 1,000 g sub-sample using a Jones splitter, pulverizing to minus 0.422 mm (40 mesh) using disc pulverizer, splitting to obtain a 500 g sub-sample using a

riffle splitter, pulverizing to minus 0.104 mm (150 mesh Tyler) using a ring-and-puck mill and finally homogenization and splitting to obtain two 250 g portions for storing and analysis. SGS assayed for Au using FA and atomic absorption spectroscopy (AAS) finish on a 50 g sample. Prior to determination the FA bead was dissolved with aqua regia. For samples with Au grades greater than 1 g/t Au, a gravimetric finish was used instead. Silver was determined by AAS on a 5 g aliquot digested by hydrofluoric acid and aqua regia. Copper analyses were assayed by atomic absorption on a 1 g sample digested in a mixture of hydrofluoric acid and aqua regia. Bonder Clegg assayed for Au using FA and AAS finish on a 30 g sample digested in aqua regia. Silver was assayed using AA on a 1 g sample digested in aqua regia. Copper was determined by AA on samples digested in a mixture of hydrofluoric acid and aqua regia. Samples with Cu grades greater than 10% were analyzed by a potentiometer titration method.

The Minera Guanaco mine laboratory typically used fire assay and gravimetric methods on a 60 g aliquot to determine gold and silver. The method used for assaying for copper is not known;

• Kinam (1999–2000): The on-site preparation procedure included drying at 100° to 105°C, crushing, 80% below 10 mesh, with a Rhino jaw crusher, and splitting with a Jones splitter in order to obtain a 1,000 g sample. The rejected material was kept in the original sample bag. A Bondar Clegg supervisor was present on a permanent basis at the sample preparation facility. Once the samples arrived at the laboratory in la Serena, they were dried and ground to 95% under 150 mesh.

Two bags were then prepared: 250 g for analysis and 750 g for back up. Gold was assayed by FA and AA finish on 30 g aliquots with a lower detection limit of 5 ppb Au. Silver, copper, lead, and arsenic were assayed by AA after digestion of a 0.5 g sample with HNO3–HCl digestion and HCl re-dissolution. The detection limits were 0.1 ppm for Ag, 1 ppm for Cu, 2 ppm for Pb, and 5 ppm for As.

13.2.2 Minera Guanaco Programs

During the Minera Guanaco 2004 drill programs, sample preparation at ALS Chemex was as follows:

• Weighing;

• Drying at 60ºC on stainless steel trays;

• Crushing to 70% minus 1.68 mm (10 mesh Tyler) with a Rhino jaw crusher;

• Homogenization and splitting to obtain about 500 g sub-sample;

• Pulverizing the collected sub-sample to 85% minus 0.074 mm (200 mesh Tyler) in

Gold was assayed by FA and AAS finish. Samples with Au grades greater than 10 g/t were finished by gravimetry. The lower detection limit for gold was 0.005 g/t. Copper and silver were assayed by total digestion and AA finish.

In 2006–2007, sample preparation at Geoanalítica was as follows:

• Weighing;

• Drying at 105ºC on stainless steel trays;

• Crushing to 85% minus 2 mm with a jaw crusher with a 10 mesh vibrating screen;

• Homogenization and splitting to obtain about a 1,000 g sub-sample;

• Pulverizing of the collected sub-sample to 95% minus 0.105 mm in an LM-2 pulverizer.

Gold was assayed by FA and AA finish in 50 g aliquots. The lower detection limit was 0.01 g/t. For Au grades greater than 3 g/t the assays were finished by gravimetric method.

Samples were also assayed at Geoanalítica in 2006–2007 for total copper (CuT) and Ag by AAS in approximately 1.0 g aliquots digested with aqua regia and acid dilution (HCl). For Ag grades greater than 50 ppm the assays were finished by gravimetry.

The lower detection limits were 0.001% Cu and 1 g/t Ag.

Leach pad sonic drill samples were prepared by Geoanalítica as follows:

• Drying

• Splitting by rotary divider. One half for normal assays and the other half for metallurgical testwork to be done at a later stage.

• The half sample for assaying could follow one of two different procedures:

- Normal assay:

ƒ Crushing to minus 10 mesh.

ƒ Approximately 1.0 kg sample split by rotary divider for pulverizing.

Reject sent to Minera Guanaco.

ƒ Pulverizing to minus 150 mesh.

ƒ Envelope containing 250 g for Au, Ag, and Cu assays, rest for Minera Guanaco.

- Screening and Assaying:

ƒ Samples were screened into five fractions: +¾”, - ¾” + ⅜”, -⅜” + ¼”, - ¼”

+ 10#, and –10#.

ƒ Each fraction was prepared and assayed as described above.

ƒ Fraction weighted averages were calculated for each sample.

A total of 334 and 660 samples were obtained from Phase I and II heaps respectively.

Of these, 67 and 132 samples were split into size fractions, prepared and assayed.

The rest were submitted for normal sample preparation and assaying as per the core and RC sampling described above for Geoanalítica.

There is no information on the 2008 sample preparation methodology. It is likely that Vigalab and Geoanalítica used the same standard procedures for Au by FA with AA finish or gravimetry finish and others metals such as Cu and Ag by acid digestion and AA were applied.

No information was available to AMEC for the sample preparation and analytical methods employed for the 2009 and 2010 drill programs.

13.3 Quality Assurance and Quality Control

During the campaigns, the operator companies applied different programs quality assurance and quality control (QA/QC programs).

Little to no documentation from drilling campaigns prior to 2000 is available. There is no information for the BHC and SCMG programs. Amax implemented a QA/QC protocol which included the insertion of 10 to 15% of field duplicates from RC samples and some check samples. The field duplicate consisted of approximately a quarter of the original sample (5 kg sample); however, no details and results are available. No details of certified reference materials (CRMs) and blank samples are documented for the Amax drilling campaigns.

During the drilling program in 2000, Kinam implemented QA/QC protocols consisting of the insertion of field duplicates, pulp duplicates, coarse blanks, and CRMs.

Austral’s QA/QC program comprised insertion of field duplicates, check samples, coarse blanks, and CRMs. The control samples for the 2004 drill program were inserted in the submission batches on site prior to submission to ALS Chemex. Minera Guanaco also submitted check samples (pulverised samples) to Actlabs at La Serena, (2.8% of the routine samples). Minera Guanaco personnel inserted the control samples (field duplicates and coarse blanks) in the submission batches on site for the 2006–2007 drill programs, prior to submission to Geoanalítica. Minera Guanaco also submitted check samples (pulverised samples) to Actlabs in La Serena during 2006 (at a rate of about 6.77% of the routine samples). The 2007 check samples (pulverised samples) were submitted to Actlabs in La Serena, in a proportion of about 2.1% of the

routine samples. A similar procedure was followed for the 2008 drill program that was submitted to Vigalab.

No information was available to AMEC for the QA/QC procedures employed for, and results of the 2009 and 2010 drill programs.

13.4 Databases

The Project data are stored in a Vulcan software database.

The database was first compiled from various Excel, MineSight and Gems files into a single Vulcan database in 2006. While performing this first compilation, Minera Guanaco compared the electronic entries with the original certificates, when available.

Such certifications only became fully available from 2006 onwards.

All geological and geotechnical data collected during the Minera Guanaco drill programs were entered electronically directly into the system. Assays were received electronically from the laboratories and imported directly into the database. Drill hole collar and down hole survey data were manually entered into the database.

Data are verified on entry to the database by means of in-built program triggers within the mining estimation software. Checks are performed on surveys, collar co-ordinates, lithology data, and assay data.

Paper records were kept for all assay and QA/QC data, geological logging and bulk density information, downhole, and collar coordinate surveys from the Minera Guanaco drill programs. For data acquired prior to 2006, some paper records were missing.

Overall, approximately 50% of the data within the mineralized grade-shell have an original paper assay certificate, and approximately 43% have a paper copy of the assay certificate. Only approximately 7% of the data within the grade-shell have no paper support.