Authors / CoAuthors
Champion, D.C.
Abstract
A significant proportion of the mineral endowment of eastern Australia is related to Phanerozoic granites and comagmatic volcanic rocks. Accordingly, considerable scientific research and data gathering has been focussed on these magmatic systems within eastern Australia, over the last 15 years. A major outcome has been the recognition that the nature and style of this mineralisation (porphyry Cu-Au, porphyry Cu-Mo, vein-style W, Mo, Sn, Au) clearly varies with both the mineralogy and chemistry of the related magmatism (e.g., Blevin & Chappell, 1992). Further research is increasingly recognising that the development of mineralisation, is controlled by many factors other than just the chemistry and intensive parameters intrinsic to the magmatic systems. Wall rock controls, such as oxidation state, chemical reactivity, competency, porosity and structural preparation, are now considered critical as to whether mineralisation will form. The mineralogical composition of the host rocks also appears important; certainly playing an important role in metal precipitation, e.g., many deposits are hosted by rocks rich in reductants such as magnetite, graphite and/or sulphide. Interestingly, empirical data also indicate that deposit types may be host rock specific, e.g., Haynes (2003) suggests Fe-oxide Cu-Au and porphyry Cu deposits are found in settings where host rocks contain little or no reduced carbon minerals (e.g., graphite); conversely, Wyborn (2003) suggests Au-only deposits occur where host rocks are carbonaceous. The potential for host rocks to play a significant role in the mineralising environment is clear, even more so when it is considered that mineralisation may occur up to 2-3 km from the granite body (ref). Unfortunately, previous studies of magmatism and related metallogenesis in eastern Australia have largely ignored country rocks and their role, beyond simple criteria such as level of emplacement and level of exhumation.
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nonGeographicDataset
eCat Id
60866
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Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
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Keywords
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- GA PublicationAUSGeo News Article
- ( Theme )
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- metallogenesis
- ( Theme )
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- mineral exploration
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- economic geology
- ( Theme )
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- mineral deposits
- ( Theme )
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- geoscience
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- AU-QLD
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_Internal
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2002-01-01T00:00:00
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geoscientificInformation
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[-21.0, -10.0, 142.0, 147.5]
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