Del Carmen Geology
The Del Carmen property contains two large hydrothermal alteration systems that are visible as colour anomalies on satellite imagery: Del Carmen Norte and Del Carmen Sur (see Del Carmen Overview map). Pre-Malbex exploration of the Del Carmen Norte alteration system included 48 reverse circulation (RC) drill holes (10,172 m) while Del Carmen Sur had only five RC holes (1,003 m). Being more advanced, Del Carmen Norte has been the focus of our recent exploration.
We have identified numerous targets within the 9 km2 Del Carmen Norte alteration system, based on mapping, surface sampling and geophysical surveying completed over the past two field seasons (see Alteration and gold values map).While our understanding of the system continues to evolve, there appears to be a correlation between late-stage dacite bodies within the predominantly andesite volcanic rocks, and the localization of favourable alteration and gold-silver mineralization. In general, the style of hydrothermal alteration grades outwards from barren quartz-kaolinite in the massive core of the dacite porphyry intrusions, to mineralized quartz-alunite and silicification at the dacite margins. Gold-silver mineralization is typically best developed in silicification but also occurs locally in quartz-alunite alteration. The mineralization and favourable styles of alteration are most strongly developed in the brecciated margins of the dacite porphyry suggesting the possible localization of fluid flow at the dome margin (see Rojo Grande section).However, favourable alteration and gold-silver mineralization also occur in the andesite wall rocks without apparent dacite.
This pattern of alteration zonation (quartz-kaolinite to quartz-alunite to silicification) and concentration of mineralization in silicification and to lesser degrees in quartz-alunite alteration is typical of many high-sulphidation epithermal gold-silver systems including the Veladero and Pascua-Lama deposits. The silicification associated with gold-silver mineralization often appears as a strong resistivity anomaly on controlled source audio-magneto-telluric (CSAMT) or Induced Polarization surveys, as demonstrated by the results of our 2009/2010 CSAMT survey over Rojo Grande. Read more about our geophysics results.
Malbex began exploration at Del Carmen Sur in December 2009. Mapping and sampling of the slightly smaller (5 km2) high sulphidation epithermal system some 5 km to the south of Del Carmen Norte have returned encouraging results, including rock chip samples with up to 4.2 g/t gold, 43.5 g/t silver and 4.6% Cu. Del Carmen Sur was not explored during the 2010/2011 field season and no exploration is planned for the 2011/2012 season due to our focus on Del Carmen Norte.
