Case, George, Blenkinsop, Thomas, Chang, Zhaoshan, Huizenga, Jan Marten, Lilly, Richard, and McLellan, John (2017) Delineating the structural controls on the genesis of iron oxide–Cu–Au deposits through implicit modelling: a case study from the E1 Group, Cloncurry District, Australia. Geological Society, London, Special Publication, 453.

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Abstract

Iron oxide–Cu–Au (IOCG) deposits encompass a range of ore body shapes, including strata-bound replacement ores and hydrothermal breccias. We use the implicit method to make a detailed three-dimensional geological model of a strata-bound IOCG in the Cloncurry District, the E1 Group, to elucidate structural controls on mineralization. This model is compared with the nearby, world-class, Ernest Henry breccia-hosted IOCG deposit. Cu–Au mineralization in the E1 Group occurs as structurally controlled, mainly strata-bound, replacement bodies hosted in metasedimentary and metavolcaniclastic rocks intercalated with barren meta-andesite. Replacement bodies in the E1 Group conform to a series of NNW-plunging folds formed in regional D2 during peak metamorphism. Folding was followed by local D3/regional D4 shortening, which formed a dextral, transpressional Riedel brittle to ductile system along the regional Cloncurry Fault Zone. Modelling suggests that much of the Cu–Au mineralization is controlled by synthetic R structures associated with this Riedel system. The deformation sequence at Ernest Henry is comparable, but differences in host rock rheology, permeability and fluid pressure may explain the variation in ore body types and total Cu–Au resource between the two deposits. The results carry implications for other districts containing these styles of IOCG mineralization.

Item ID:	49999
Item Type:	Article (Research - C1)
ISSN:	2041-4927
Related URLs:	https://researchonline.jcu.edu.au/49998/
Additional Information:	A version of this publication was included as Chapter 3 of the following PhD thesis: Case, George N.D. (2016) Genesis of the E1 group of iron oxide-copper-gold deposits, Cloncurry district, North West Queensland. PhD thesis, James Cook University, which is available Open Access in ResearchOnline@JCU. Please see the Related URLs for access.
Funders:	James Cook University (JCU), Mt Isa Mines (MIM), Ernest Henry Mining (EHM), Society of Economic Geologists Foundation (SEGF), Economic Geology Research Centre (EGRC), Dr Schurmann Foundation (DSF)
Projects and Grants:	SEGF GSF 13-31, SEGF SRG 14-93, DSF Grant 98-2014
Date Deposited:	31 Aug 2017 03:43
FoR Codes:	37 EARTH SCIENCES > 3705 Geology > 370508 Resource geoscience @ 50% 37 EARTH SCIENCES > 3703 Geochemistry > 370399 Geochemistry not elsewhere classified @ 50%
SEO Codes:	84 MINERAL RESOURCES (excl. Energy Resources) > 8401 Mineral Exploration > 840199 Mineral Exploration not elsewhere classified @ 100%
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