T290 Integrated Approaches to Deciphering Major Crustal Boundaries in Polyphase Orogenic Settings (Posters)

Tuesday, 24 October 2017
9:00 AM - 6:30 PM
Halls 4EF

LINKING DEEP CRUSTAL ARCHITECTURE TO MINERAL SYSTEMS

Paper number: T290-1
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

Abstract

The mineral systems concept describes how an ore deposit is the expression of a number of processes that operate at a range of spatial and temporal scales. The recognition that mantle-penetrating crustal-scale faults are critical for ore formation has changed the way both industry and government assess the prospectivity of terrains at the regional scale. Linking geographically widespread, deep-penetrating geophysical datasets to a well-defined tectonothermal and mineralizing history is critical for mapping and understanding the key fluid/metal source zones, migration paths and energy sources at a regional scale. However, collecting and integrating such regional-scale data sets is typically beyond the capability of a single organization. In Australia, long-term cooperation between the Geological Survey of Western Australia, AuScope, Geoscience Australia, ANSIR, and CSIRO, as well as universities including The University of Western Australia, Curtin University, the Australian National University, Macquarie University and the University of Adelaide has led to a deeper understanding of the regional-scale mineral system processes operating in the Capricorn Orogen of Western Australia.

The Capricorn Orogen is a ~1000 km long, 500 km wide region of variably deformed Neoarchean to Proterozoic rocks between the Archean Pilbara and Yilgarn Cratons. The orogen records a long and complex tectonic history involving the punctuated Paleoproterozoic assembly of these two cratons as well as over one billion years of subsequent intracratonic reworking. Despite a lack of Tier 1 mineral deposits, the orogen is well mineralized and hosts a wide variety of deposits including gold, base metals, and rare earth elements. Geophysical imaging, including active and passive seismic and magnetotelluric techniques, has defined the deep-crustal architecture, identifying the main crustal-scale faults that appear to host most of the major mineral deposits. Precise dating of key gold and base metal deposits demonstrates that (re)activation of these key structures during episodes of regional-scale orogenesis was the principle driver for hydrothermal fluid flow. Multi-disciplinary, multi-organizational cooperative research has proven critical to understanding mineral systems and reducing the financial risk to explorers.

Geological Society of America Abstracts with Programs. Vol. 49, No. 6

doi: 10.1130/abs/2017AM-304800

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