The Petlacala property is located in southern Mexico, in the central part of the State of Guerrero, Municipality of San Miguel Totolapan, approximately 55 km south of the city of Arcelia, and 4 km west of the village of Petlacala. The Petlacala property covers 3,182 ha and consists of a block of four contiguous exploration concessions located just west of the village of Petlacala
Petlacala is located in the Au-Ag belt of the Sierra Madre known for hosting deposits such as El Oro, Tayoltita, Guadalupe and Clavo and is underlain by a metamorphic Jurassic basement rock consisting of flysch type meta-sandstones and -mudstones overlain by the Triassic andesite and rhyolite volcanic sequences of Sierra Madre del Sur. These rocks were intruded by granodiorites and felsic dikes of late Tertiary age.
Mineralization is structurally controlled and hosted by andesitic and rhyolitic volcanic rocks. The majority of structures on the Petlacala property have a NW-SE trend and dip steeply to the SW.
The Petlacala veins are classified as a low sulphidation epithermal, quartz-adularia-sericite type and consist fundamentally of sugary quartz and minor chalcedony. High-level textures were observed including; comb, colloform, crustiform, cockade, and replacement textures of bladed quartz after calcite.
Since 1996, Minera Petlacala S.A. de C.V., Luismin, and Peñoles have explored the property and collected over 600 rock samples from the Petlacala veins.
Eight distinct exploration targets, Astro, Karla Guadalupe, Madre, Armazon, Elena, California, Filo Gallegos and El Tigre have been identified. Assay results obtained from the Petlacala veins by Minera Petlacala, Luismin, and Peñoles indicate the presence of Au-Ag mineralization.
The Petlacala veins have never been drill tested.
Albinson (1997) classified the mineralized structures of the Petlacala property as deep boiling veins. In his report he suggested that the economic potential of the Petlacala veins could be expected to be between 50 to 250 meter depth below the surface exposure of the veins, and the mineralized structures presently exposed on the surface were formed at a depth of 60 to 220 meter in relation to paleosurface and probably correspond to the upper part of a low sulphidation epithermal system.
The Astro vein can be traced for over 200 meter with the potential to extend to 900 meter and an average width of 1.5 meter. It is associated with quartz-chalcedony and a strong presence of iron oxides. Locally, the vein can be up to 10 meter wide, a strike of 124 degrees and a dip of 85-degree to the NW.
The Karla vein can be traced intermittently for over 600 meter. The vein and silicified wall rock can reach up to 15 meter in width with a strike of 145 degrees and a dip of approximately 60 degrees to the SW.
The Guadalupe vein is sub-parallel to the Karla vein and these two veins may merge further to the SE to form the Madre vein. The Guadalupe vein can be traced for at least 300 meter and is hosted in rhyolite tuff. The Guadalupe vein extends further to the SE probably forming the Ninfas vein.
The Madre vein is likely located at the southeastern extension of the Karla vein. The Madre structure probably consists of two veins hosted in rhyolite welded tuffs. It can be traced for approximately 700 to 1,000 meter and has an attitude of 130/60 to 83SW. In some parts of the Madre vein, the silicified zones can reach up to 30 meter in width (Peñoles, 2009).
The Armazon vein target can be followed along its trace for approximately 300 meter and maybe a southeastern extension of the Madre vein. There are no known workings along this vein.
The Elena vein target can be traced for over 700 meter with a NW-SE strike and southwest dip. Two shafts, one 5 meter and another over 15 meter deep (with some horizontal workings) were identified along the trace of the vein.
The California vein can be traced for 450 to 600 meter. The average width of the vein has been estimated at 1 meter. Mineralization along this vein is probably associated with a fault breccia with discontinued quartz stockwork, lenses, and veins. Abundant manganese oxide stain is present in the mine and on the surface it appears to be associated with the California structure.
Recommendations
A two phase exploration program is recommended to evaluate the property.
The Phase 1 drill program should focus on testing the vertical zonation within the low sulphidation epithermal vein system of the Petlacala veins. A detailed multi-element geochemistry should assist in understanding zonation and distribution of Au-Ag mineralization within the veins. This phase of work is estimated to cost approximately US$ 643,200.
Contingent on the success of Phase I, a Phase II exploration program is recommended including 2,000 meter of diamond drilling. Some of the drill targets tested in Phase II would have been developed in Phase I. The total cost of phase II is estimated at US$ 868,800. The total cost estimate for the two phases of exploration is estimated at US$1.5 million.
*Excerpt from Piotr Lutynski, 'Petlacala 43-101', June 15, 2010, www.sedar.com
