scholarly journals The Aries Diamondiferous Kimberlte Pipe, Central Kimberley Block, Western Australia: Mineralogy, Petrology and Geochemistry of the Pipe Rock and Indicator Minerals

2019 ◽  
Keyword(s):  
Western Australia ◽  
Petrology And Geochemistry ◽  
Indicator Minerals

scholarly journals Interface Sampling and Indicator Minerals for Detecting the Footprint of the Lancefield North Gold Deposit under the Permian Glacial Cover in Western Australia

Minerals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1131
Author(s):  
Walid Salama ◽  
Michael Verrall ◽  
Kirsty Culver ◽  
Ravi Anand
Keyword(s):  
Water Table ◽  
Western Australia ◽  
Gold Mineralization ◽  
Mineral Exploration ◽  
Drill Hole ◽  
Dispersal Distance ◽  
Coarse Grained ◽  
Reducing Conditions ◽  
Glacial Cover ◽  
Indicator Minerals

Areas under a thick Permian glacial cover in Western Australia formed as glaciers gouged fresh bedrock and deposited diamictites in disconnected valleys and basins. These areas now present the greatest challenge for mineral exploration in the northeast Yilgarn Craton. At the Lancefield North gold prospect, in the southern part of the Duketon Greenstone Belt, Permian diamictites on average 40 m thick cover unweathered basalt hosting gold mineralization. The basal Permian diamictites consist of fresh, very poorly sorted, angular to rounded, pebble- to boulder-sized, polymictic clasts supported by a matrix of coarse-grained sand and mud. The framework and matrix are cemented by calcite, dolomite, chlorite, and pyrite. These diamictites are stable under alkaline and reducing conditions below the water table. Detrital; fresh sulfides; gold; and opaque oxides, such as pyrite, pyrrhotite, chalcopyrite, sphalerite, arsenopyrite, gersdorffite, cobaltite, pentlandite, scheelite and galena, chromite, ilmenite, and magnetite, are identified in the framework and matrix of the fresh diamictites, and these are identical to those in the primary gold mineralization. Weathering of diamictites and oxidation of detrital and diagenetic sulfides above the water table produced several Fe- and Mn-rich redox fronts and secondary chalcocite and bornite. Interface sampling across the Archean–Permian unconformity shows Au, As, Zn, Ni, Co, and Cd anomalism over the mineralization compared to the background. However, these elements are low in concentration in the redox fronts, where Fe is correlated with As, Cu, Mo, and Sb and Mn is correlated with Co, Ni, and Ba. Gold shows elevated levels in the fresh basal diamictites and decreases in the weathered diamictites over the mineralization. A sampling at or near the Archean–Permian unconformity (interface sampling) only delineates gold mineralization, with no hydromorphic dispersion halo beyond the peripheries. At the Lancefield North prospect, the detrital indicator sulfides are mechanically dispersed up to 500 m to the east of the mineralization in the direction of ice flow. This dispersal distance is controlled by the rough topography of the Archean–Permian unconformity, and it may be greater, but the estimation of the actual distance of transport is limited by the distribution of drill hole locations.

Petrology and geochemistry of the Boolgeeda Iron Formation, Hamersley Basin, Western Australia

2018 ◽  
Vol 316 ◽  
pp. 155-173 ◽  
Author(s):  
Tyler Warchola ◽  
Stefan V. Lalonde ◽  
Ernesto Pecoits ◽  
Konstantin von Gunten ◽  
Leslie J. Robbins ◽  
...  
Keyword(s):  
Western Australia ◽  
Iron Formation ◽  
Petrology And Geochemistry
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