Dating fluid flow and Mississippi Valley type base-metal mineralization in the Paleoproterozoic Earaheedy Basin, Western Australia
Access Status
Authors
Date
2012Type
Metadata
Show full item recordCitation
Source Title
ISSN
Collection
Abstract
The ages of deposition and metamorphism of low-grade Precambrian metasedimentary sequences canbe difficult to define in the absence of interlayered volcanogenic rocks. Monazite and xenotime can growat temperatures below 400 ?C and can give vital evidence for the timing of diagenesis, hydrothermalfluid flow, and low-grade deformation and metamorphism in Precambrian basins. The histories of sedimentary basins in the eastern Capricorn Orogen of the West Australian Craton are generally poorlyconstrained. However, sandstones and siltstones of the basal Yelma Formation in the Earaheedy Basincontain authigenic monazite and xenotime associated with sulphide minerals related to Mississippi Valley Type base-metal mineralization hosted within carbonate of the overlying Sweetwaters Well Member. In the Teague area, within the Earaheedy Basin, siliciclastic rocks overlying granites of the Yilgarn Craton contain authigenic monazite that gives an in situ SHRIMP 207Pb/206Pb age of 1811 ± 13 Ma. Monazite in weathered sandstones and siltstones of the Cano secondary Pb deposit on Magellan Hill, overlying the Yerrida Basin, gives an indistinguishable age of 1815 ± 13 Ma. The Cano monazite is interpreted to have been intergrown with primary sulphide minerals and therefore to record the age of mineralization.Xenotime outgrowths on detrital zircons from Cano have high common Pb but define an isochron with an age of 1832 ± 36 Ma. The isochron is co-linear with Pb isotope ratios from Pb ore at Magellan, suggesting that xenotime growth is also related to mineralization. The timing of fluid flow is synchronous with the 1820–1770 Ma Capricorn Orogeny, and is the first evidence for activity of this age in the eastern part of the Capricorn Orogen. The age of mineralization provides a firm minimum age for the Yelma Formation, and constrains its deposition to between ~2.0 Ga, the youngest age of detrital zircons, and the mineralization age.
Related items
Showing items related by title, author, creator and subject.
-
Tessalina, Svetlana; Sergeev, N.; Burlow, R. (2017)The Paroo Station Mine lead project is situated near Wiluna in the central part of Western Australia. It is located in an outlier of the Paleoproterozoic Earaheedy Group overlying the southeast Yerrida Basin. The total ...
-
Zi, Jianwei; Rasmussen, Birger; Muhling, J.; Fletcher, Ian; Thorne, A.; Johnson, S.; Cutten, H.; Dunkley, Daniel; Korhonen, Fawna (2015)The Proterozoic Capricorn Orogen is a major tectonic zone that records the assembly and subsequent reworking of the West Australian Craton. Recent seismic transects across the orogen have identified major crustal structures, ...
-
Fielding, I.; Johnson, S.; Zi, J.; Rasmussen, Birger; Muhling, J.; Dunkley, D.; Sheppard, S.; Wingate, M.; Rogers, J. (2017)Paulsens is a mesothermal orogenic gold deposit located in the Wyloo Inlier on the southern margin of the Pilbara craton of Western Australia. Gold occurs in quartz-sulfide veins hosted within a folded and faulted gabbro ...