The discovery and geology of the world-class Alpala porphyry copper-gold deposit in northern EcuadorPosted on November 21, 2018 | Updated on October 25, 2018 10:11
Date(s) - Wednesday, 21/11/2018
5:30 pm - 8:00 pm
Irish Club of WA - Subiaco
MEGWA November 2018
The discovery and geology of the world-class Alpala porphyry copper-gold deposit in northern Ecuador
Wednesday 21 November 2018
5.30pm Drinks, 6.00pm Presentation
Irish Club, 21 Townshend Rd, 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.
About the presenter
Dr Garwin has 30 years of experience as an exploration geologist and is one of the leading authorities on porphyry, epithermal and Carlin?style mineralization in the circum?Pacific region. He previously worked with Newmont Mining for ten years, including two years as Chief Geologist in Nevada, USA. He has been involved with several exploration and mining projects including the Batu Hijau copper-gold porphyry deposit in Indonesia and mines of the Carlin Trend and Battle Mountain district in Nevada. Steve has been instrumental in the discovery of copper-gold mineralisation at Alpala.
AIG WA branch thanks our MEGWA sponsor