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Talk titleIngredients for high-grade IOCG mineralisation – towards a consistent model of ore formationTalk duration: 55 min-1h + 2 h core viewing The talk will focus on the similarities and differences of 3 major IOCG deposits, namely Starra, Ernest Henry and Prominent Hill. Systematically collected mineralogy combined with petrophysical and structural datasets from the Starra and Ernest Henry deposits enable a consistent model for IOCG deposit formation in which hydrolytic alteration plays an essential role in high-grade Cu-Au mineralisation. The deposit-scale distribution of key mineral assemblages indicate that hydrothermal alteration produced a mappable zonation within and around the ore bodies. Although the mineral zonings around the two deposits differ in size and style, they resulted from a sequence of iron oxide-alkali-calcic alteration, shearing, brecciation, and previously unrecognized hydrolytic alteration, which was coincident with the location of high-grade Cu-Au mineralization. The outcomes from Starra and Ernest Henry will be compared with data from Prominent Hill and some aspects can be directly tested on drill core from the Gawler IOCG province laid-out in the core yard. The workshop will also offer the possibility to discuss gaps in the understanding of IOCG ore formation in the Gawler, and how one may close these to increase discovery. Core on display at the Tonsley Core Library will include: Olympic Dam: RU39-5293 (0-120, and 180-220m) topic: allows discussion on iron oxide- and hematite-qtz alteration (see attached and below). Carapateena discovery hole CAR002 from top of unconformity – topic: deomonstrating aluminosilicate leaching Prominent Hill discovery hole DHHURAN1 – topic: different host rocks to Olympic Dam and Carrapateena but same alteration anda development of zonation. Catering: There will be no catering at the Core Library. Drinks and food can be purchased at the Café in the Tonsley hub. Geological Data: All holes on display have geochemical assays and hylogger available that can be downloaded from SARIG. SpeakersDr Tobias Schlegel, CSIRO Minerals CostFree to everyone, but registration of your details is essential. Register with Eventbrite here https://www.eventbrite.com.au/e/iocg-workshop-tickets-657368034487?aff=oddtdtcreator Other informationFor geologists, geophysicists and students. Everyone is welcome. This is an AIG event and comes under the AIG Code of Ethics. Respect is a key principle of this code. The Core Library is managed by the Department for Energy and Mining. Attendees must wear closed toes shoes to view the core. |
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