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Geochronological and geochemical evidence for two ore-forming events in the Northparkes district NSW
conference contribution
posted on 2023-05-24, 17:00 authored by Wells, TJ, David CookeDavid Cooke, Michael BakerMichael Baker, Lejun ZhangLejun Zhang, Hoye, JThe Northparkes district hosts economic Cu-Au mineralisation associated with discrete pencil porphyry systems emplaced in the Late Ordovician (∼439 Ma; Lickfold et al., 2003, 2007, Crawford, 2007a). Geochemical and geochronological data from the recently discovered Two-Thirty Prospect ~25 km northwest of Parkes, NSW indicates that two ore-forming events occurred within the Northparkes district. The Two-Thirty Prospect is hosted by the moderately east dipping Goonumbla Volcanic Complex on the western-limb of the Milpose syncline (Fig. 1). Mineralisation at the Two-Thirty Cu-Mo-(Au) prospect is hosted by a magmatic-hydrothermal breccia related to the 448±4.4 Ma intrusion of the Two-Thirty porphyry, one of five dated porphyry intrusions that make up the Two-Thirty intrusive complex.
Whole-rock geochemical data indicate that the Two-Thirty porphyry is calc-alkaline, distinguishing it from the alkalic porphyry deposits typical of the Northparkes district. Both Ce4+/Ce3+ and Eu/Eu* ratios from whole rock and zircon trace element analysis indicate that the Two-Thirty porphyry has a geochemical signature consistent with signatures for fertile, oxidised, medium tonnage, calc-alkaline porphyires from Northern Chile and the Central Asian Orogenic Belt (Ballard, 2002, Loucks, 2014; Shen et al., 2015).
The discovery of the Two-Thirty prospect has implications for the exploration in the Northparkes district and Macquarie Arc. It is the only significant occurrence of magmatic–hydrothermal breccia-hosted mineralisation discovered within the Macquarie Arc to date, and is older than mineralised porphyry deposits at Northparkes and Cadia, and younger than the deposits at Cowal, Copper Hill, Marsden and Ridgeway.
Funding
Australian Research Council
Alkane Exploration NL
AngloGold Ashanti Australia Limited
CMOC Mining Services Pty Ltd T/A Northparkes Mines
Department of Economic Development, Jobs, Transport and Resources
Department of State Growth (Tas)
Emmerson Resources Limited
Evolution Mining
Geological Survey of New South Wales - Department of Industry
Geoscience Australia
Heron Resources Limited
New South Resources Limited
Rio Tinto Limited
Sandfire Resoures NL
History
Publication title
Abstracts from the FUTORES II Conference - Future Understanding of Tectonics, Ores, Resources, Environment and SustainabilityVolume
EGRU Contribution 69Editors
JM Huizenga, C Chang, C Spandler, K Camuti, M Corkeron, E Roberts, A Ford, C Placek, A ParkerPagination
127Department/School
School of Natural SciencesEvent title
FUTORES II Conference - Future Understanding of Tectonics, Ores, Resources, Environment and SustainabilityEvent Venue
James Cook University, Townsville, QLDDate of Event (Start Date)
2017-06-04Date of Event (End Date)
2017-06-07Repository Status
- Restricted