THE PLAY – EXPLORATION THEORY
The Milena property is an exploration and development opportunity that covers a partially exposed porphyry system that shows fragments of “ore shell” material in drill holes and which shows untested surficial exposures of a chalcanthite bearing pyrite-rich breccia pipes in road cuts.
The exposed felsic Au-Mo bearing dikes and gold mineralization tested indicate the system has experience significant magmatic differentiation. The abundance of hematite boulders and strong reddish coloration of outcrop are suggestive of an alkali-alteration type porphyry system. It is consistent with air-mag surveys and showing destruction magnetite adjacent to a large bimodal Miocene dome and staining of wallrock feldspars to form a hematitic lithocap. The high sulfidation system “covellite after pyrite” is interpreted as the roots of lithocap mineralization and the discovery of dike pebbles of chalcopyrite/covellite and sulfide vein filling material in the one hole examined by Milena suggests hydrothermal activity continues at depth.
Teck’s last round of drilling shows ore-grade mineralization at 175 m on a long steep slope suggesting exploration under the magmatic dome will be fruitful. The geomorphology of the exposure is consistent with relatively new El-Indio geomorphological geological models incorporating groundwater, geomorphology and depth of erosion (see: http://www.sgp.org.pe/wp-content/uploads/Conf-18.02.16_Thomas-Bissig-expo.pdf). Siliceous reefs found on outcrop are the remains of where lithocap is deeply dissected on the steep face of Desfiladero.