Garwin - 21-Nov-201818 Nov 2018 10:14
https://www.aig.org.au/events/megwa-november-2018-2/
The discovery and geology of the world-class Alpala porphyry copper-gold deposit in northern Ecuador
Date - Wednesday, 21/11/2018 (5:30 pm - 8:00 pm) - Irish Club of WA - Subiaco
The recently discovered Eocene Alpala porphyry copper-gold deposit is located in the under-explored northern section of the Andean Copper Belt. The maiden mineral resource estimate (SolGold, 3rd January 2018) includes 1.08 billion tonnes at 0.68% Cu equivalent, using a cut-off of 0.3% Cu equivalent, for 5.2 million tonnes of copper (11.4 billion pounds Cu) and 12.3 million ounces of gold. This resource includes a high-grade core that contains > 120 million tonnes at 1.82% Cu equivalent (1.2 Mt Cu and 4.7 Moz Au; cut-off of 1.1% Cu equivalent). The deposit remains open and continues to grow with drilling.
The recognition of geochemical zoning has assisted in drill-targeting within the deposit and tenement-wide exploration. This zoning is characterized by central Cu-Au; proximal Mo; proximal to distal Bi, Se and Te; and distal As, Mn and Zn. Within the Alpala deposit, variations of Au/Cu in drill-hole assist in the delineation of different intrusion stages.
The applications of the Anaconda method to geological mapping and drill-core logging have facilitated the identification of more than six major intrusion stages and a vein paragenesis that allows for the prediction of copper-gold grades in the Alpala deposit. The most important indicators of high-grade include the presence of the early-stage causal intrusion(s), elevated porphyry-style vein abundance and an increased ratio of chalcopyrite to pyrite.
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