Legacy product - no abstract available

Legacy product - no abstract available

This report describes the results of a microexamination of four rock samples from the Kimberley area.

This report describes the results of a microexamination of rock samples collected from Dampier Downs, Mt. Clarkson, and Mt. Anderson.

Paragenesis of Fimiston Style lodes at the Golden Mile, Kalgoorlie, Western Australia (Gauthier et al)

The late Mesozoic Marum and Papuan ophiolites of Papua New Guinea dip from the continental margin towards accreted Paleogene island-arcs and appear to represent frontal-arc basement emplaced as a result of a mid-Tertiary continent/arc collision.

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In the recent past, geologists have been inclined to confine their study to the structural traps and openings which localize individual ore shoots and have tended to neglect most other features, including considerations of ore genesis. L.C. Graton has recently remarked that "the out-standing unfilled need lying ahead is the discovery of new mineralized districts". In this connection he speaks of "the all-important standpoint of genetic understanding". As a contribution towards filling this need, the following points, relating to mineralization in the Cobar-Nymagee province, are here presented for consideration.

Proterozoic Granites in Australia crop out over at least 145 000 km2 (Table 1). To assess their metallogenic potential a systematic study was undertaken of all granites as well as the composition of rocks within five kilometres of the granite boundaries (Budd et al., 2001). For the granites, data on the field characteristics (presence of alteration, miarolitic cavities, presence or absence of pegmatites etc) as well as the mineralogical, major and trace element compositions of the granites were compiled. Individual granite plutons were then aggregated into suites and Supersuites on a province basis. Data were also assembled on the mineralogical composition of the host rocks, specifically the presence of reactive minerals such as carbonate, carbon, feldspar, magnetite and hematite. A GIS was constructed of all data, and simply proximity analysis was used to intersect the granite plutons as well as 5 km buffers around each pluton with known mineral deposits and occurrences. The commodities and ore deposit types were recorded around each pluton. Each occurrence was checked to ensure its age was ? the age of the related intrusion. On the basis of similarities between Suites/Supersuites of different provinces nine granite associations were identified based on their chemical characteristics, pressure/temperature conditions in their source region and their associated metallogeny. Due to insufficient data, 8.3% of exposed Australian Proterozoic granites could not be classified (Table 1). The differences between each Association and its metallogeny is believed to be controlled by first order differences in temperature and pressure conditions in their source regions. Second order changes that also influenced metallogeny, are imposed by interaction with their host rocks.

Legacy product - no abstract available