Exploration Properties
Exploration Properties :: San Anton
 
Processing RC Drill Samples, Cerro del Gallo

CERRO DEL GALLO MINERAL RESOURCES


On June 17 2008, San Anton Resource Corporation announced an updated mineral resource estimate, including a significant increase in tonnes and contained metal for the Cerro del Gallo copper-gold-silver deposit at San Antón, Guanajuato State, central Mexico. The updated mineral resource estimate now contains 1.4 billion pounds of copper, 4.5 million ounces of gold, and 202 million ounces of silver. Measured and Indicated (M&I) categories account for 81% of total contained metal.

The updated mineral resource estimate is based on 350 drill holes for a total of 94,403 metres completed since December 2004. This new data represents a significant increase in information since the last mineral resource estimate announced on 13 March 2007, which was based on a total of 57,592 metres and 232 holes. New information acquired during the last 18 months has assisted in improving the geological interpretation of the deposit which in turn has lead to a refinement of the 3-D model for mineral resource estimation. 

Geological Modelling

The Cerro del Gallo deposit was modelled as three broader geological domains based on the primary rock types and alteration, which was further sub-divided based on the predominant metal occurrence. The domains were defined from the drilling and surface mapping as shown in Figure 1. The central intrusive domain is based on surface mapping and drill hole logging. The gold domain is a gold-rich zone based on gold grades greater than a nominal 0.2 g/tAu that predominantly occurs within the hydrothermally altered ash-flow tuff sequence peripheral to the major intrusives, but also in part transects the major intrusives. The copper domain forms an outer copper-silver-rich zone also within the altered ash-flow tuff sequence and was based on gold equivalent grades nominally greater than 0.3 g/tAuEq. The mineralization appears to be constrained within the altered tuff sequence, with some apparent structural controls on the limits of the alteration. All major constraining faults were modelled to the north, south and west of the deposit, and a constraining shale contact along the eastern side of the deposit. The outer limit of the alteration domain appears to have been defined by these major constraining faults and or drilling, except in the south-eastern and north-western areas.

Mineral Resource Estimate

The significant amount of new drilling from both infill and step-out drill holes has allowed for the significant increase in the size and confidence of the mineral resource with an increase in the higher confidence Measured and Indicated Mineral Resources of 43% in tonnes and 28% in contained metal to now contain 1,087 Mlbs Cu, 3.9 Moz Au, and 163 Moz Ag. The Inferred Mineral Resources have increased by 48% in tonnes and 14% in contained metal to now contain 356 Mlbs Cu, 0.6 Moz Au, and 39 Moz Ag.

The majority of the Inferred Mineral Resources occur in the outer copper domain, and remain open to the north-west, south-east, and at depth. The mineral resource has only been reported for material above the 1,800 mRL, which is considered to be the maximum depth with reasonable prospects of eventual economic extraction with the prevailing metal prices.

The classification of the mineral resource estimate, reported with a 0.2g/t Au cut-off grade in the gold domain and 0.07% Cu cut-off grade in the copper and intrusive domains, is shown in the table below. The classification of the mineral resource by geological domain is shown in the second table below.

 

Cerro del Gallo Mineral Resource

(0.2g/t Au cut-off grade in the gold domain and 0.07% Cu cut-off grade in the copper and intrusive domains)


Category     Tonnes (M)    Au g/t    Ag g/t    Cu%    Au Moz    Ag Moz    Cu Mlbs

Measured           225             0.35         13         0.11        2.5           91           541
Indicated           236             0.19         10         0.11        1.4           72           546
   M&I                461             0.27         11         0.11        3.9          163         1,087

 Inferred            166             0.11         7          0.10        0.6            39           356

                           1.4 Billion lbs copper, 4.5Moz gold and 202 Moz silver

 

Cerro del Gallo Mineral Resource Geological Domains


Category     Tonnes (M)    Au g/t    Ag g/t    Cu%    Au Moz    Ag Moz    Cu Mlbs
Intrusive Domain
Measured            25              0.14         12         0.10        0.1           9            53
Indicated            23              0.14         12         0.09        0.1           9            45
   M&I                48              0.14         12         0.08        0.2          18            97
 Inferred             3              0.15         10          0.08        0.0           1             6 
Gold Domain
Measured           129             0.54         12         0.09        2.2          50           250
Indicated            80              0.38          8         0.08        1.0           21           140
   M&I               209             0.48         11         0.08        3.2           71           391 
 Inferred            20              0.30         7          0.09        0.2            4            37
Copper Domain
Measured            71             0.08         14         0.15        0.2           32          237
Indicated           133             0.08         10         0.12        0.3           43          361
   M&I               205             0.08         11         0.13        0.5           74          599 
 Inferred           144             0.08         7           0.10        0.4           34          313