Constraints on the structural setting, relative timing, and geochemistry of the Fimiston, Hidden Secret, and Oroya gold-telluride lode types, Kalgoorlie gold camp, Western Australia

2021 ◽  
Author(s):  
Jordan A. McDivitt ◽  
Steffen G. Hagemann ◽  
Nicolas Thébaud ◽  
Laure A. J. Martin ◽  
Kai Rankenburg
Keyword(s):  
Western Australia ◽  
Relative Timing ◽  
Gold Telluride ◽  
Structural Setting

U-Pb and Sm-Nd Evidence for Episodic Orogenic Gold Mineralization in the Kalgoorlie Gold Camp, Yilgarn Craton, Western Australia

2021 ◽  
Author(s):  
Jordan A. McDivitt ◽  
Steffen G. Hagemann ◽  
Anthony I.S. Kemp ◽  
Nicolas Thébaud ◽  
Christopher M. Fisher ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Western Australia ◽  
Late Stage ◽  
Gold Mineralization ◽  
Hydrothermal Systems ◽  
Orogenic Gold ◽  
Yilgarn Craton ◽  
Gold Telluride ◽  
Icp Ms ◽  
Metamorphic Fluids

Abstract Different genetic and timing models for gold mineralization in the Kalgoorlie gold camp (Yilgarn craton, Western Australia) suggest either broadly synchronous, late-stage mineralization related to metamorphic fluids at ca. 2640 Ma or a punctuated mineralization history from ca. 2675 to 2640 Ma with the involvement of early magmatic-hydrothermal systems (represented by the Fimiston, Hidden Secret, and Oroya gold-telluride lodes) and late metamorphic fluids (represented by the Mt. Charlotte gold stockwork veins). The results of U-Pb and Sm-Nd geochronological studies of zircon, apatite, and titanite from pre-ore dikes and syn-ore dikes constrain the absolute timing of mineralization and provide new evidence to this timing controversy. Emplacement ages constrained by U-Pb sensitive high-resolution ion microprobe (SHRIMP) zircon data are interpreted to be similar for both the pre-ore dikes (n = 10) and syn-ore dikes (n = 7) at ca. 2675 Ma. An inferred emplacement age of ca. 2675 Ma for the syn-ore dikes is supported by a Sm-Nd isochron age from apatite (laser ablation-inductively coupled plasma-mass spectrometry; LA-ICP-MS) of 2678 ± 15 Ma and by a U-Pb titanite age (LA-ICP-MS) of 2679 ± 6 Ma. The results of chemical abrasion-isotope dilution-thermal ionization mass spectrometry U-Pb zircon analysis from the pre- and syn-ore dikes are complicated by multistage Pb loss, reverse discordance, and potential inheritance. However, the data are compatible with the emplacement of Fimiston/Hidden Secret gold mineralization at ca. 2675 Ma and suggest a younger age for Oroya mineralization at ca. 2665 Ma. These results contrast with models for orogenic gold deposits that invoke broadly synchronous, late-stage mineralization related to metamorphic fluids at ca. 2640 Ma. The bulk of the Kalgoorlie gold camp’s estimated 2,300 t Au endowment was emplaced at ca. 2675 Ma as Fimiston/Hidden Secret Au mineralization. This early Au mineralization was deformed and overprinted twice by subordinate Au mineralization at ca. 2665 (Oroya mineralization) and ca. 2640 Ma (Mt. Charlotte mineralization). Gold mineralization in the Kalgoorlie gold camp was protracted in nature from ca. 2675 to 2640 Ma and reflects the interplay of early magmatic (Fimiston, Hidden Secret, Oroya) and late metamorphic (Mt. Charlotte) hydrothermal fluid systems in the formation of hybrid intrusion-related and metamorphic orebodies.

Metamorphic and structural setting of Archaean amphibolitehosted gold deposits near Southern Cross, Southern Cross province, Yilgarn Block, Western Australia

1994 ◽  
Vol 9 (3) ◽  
pp. 183-208 ◽  
Author(s):  
Erik J.M. Bloem ◽  
Hilko J. Dalstra ◽  
David I. Groves ◽  
John R. Ridley
Keyword(s):  
Western Australia ◽  
Gold Deposits ◽  
Structural Setting
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