Authors / CoAuthors
Hoatson, D.M. | Stewart, A.J.
Abstract
Field investigations by AGSO-Geoscience Australia in late 2000, as part of a National Geoscience Agreement with the Northern Territory Geological Survey (NTGS), evaluated the geological setting of Proterozoic mafic-ultramafic intrusions in the Arunta Province of central Australia. The major aims of this regional study were to constrain the various mafic-ultramafic magmatic systems within the event chronology of the Arunta Province, and to provide a geoscientific framework for assessing the prospectivity and resource potential of the intrusions. This report summarises the field relationships and mineralisation features of the major mafic-ultramafic intrusions in the Arunta Province. They form large homogeneous gabbroic bodies, folded high-level mafic sills, steeply dipping amphibolite sheets and relatively undeformed ultramafic plugs with alkaline and tholeiitic affinities. Metamorphic grades range from granulite to sub-amphibolite facies. Chilled and contaminated margins and net-vein complexes resulting from the commingling of mafic and felsic magmas indicate that most intrusions crystallised in situ and were not tectonically emplaced. The intrusions were subdivided into western, central and eastern groups on the basis of lithology, metamorphic-structural history, degree of fractionation and limited geochronology. The field investigations described here and preliminary geochemical data (see Hoatson 2001) indicate that the western and central intrusions have some potential for Ni-Cu-Co sulphide deposits, whereas the eastern intrusions appear to be more prospective for platinum-group element (PGE) mineralisation. The recent emerging evidence that the eastern Arunta is prospective for PGE mineralisation is supported by exploration companies defining anomalous PGE-Cu-Au concentrations in hydrothermal veins hosted by the Riddock Amphibolite and in magnetite layers of the Attutra Metagabbro. These results, for the first time, highlight geographical differences in the mineral prospectivity of mafic-ultramafic rocks in the Arunta Province.
Product Type
document
eCat Id
38048
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Keywords
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- GA PublicationRecord
- ( Theme )
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- economic geology
- ( Theme )
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- stratigraphy
- ( Theme )
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- geology
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- AU-NT
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_External
Publication Date
2001-01-01T00:00:00
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geoscientificInformation
Series Information
Record 2001/039
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Unknown
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[-23.45, -22.0, 130.42, 136.25]
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