Authors / CoAuthors
Champion, D.C.
Abstract
As recognised by the Academy of Science's UNCOVER group in their `Searching the Deep Earth' document, a goal for geoscientific advancement in Australia is a `holistic understanding of our continent so that we might better predict the location of large-scale mineral systems. This view included the investigation of Australia's lithospheric architecture to establish a whole-of-lithosphere architectural framework as a priority. An important component of the Earth's lithosphere is the crust, most of which is clearly inaccessible. Just as the study of basaltic rocks has provided insight into the earth's mantle, granites provide a (not always wholly transparent) window into the middle and lower continental crust. Studies of these rocks are enhanced by isotopic tracers, such as Samarium-Neodymium, which can affectively `see through' the granite to provide constraints on crustal formation, and enable us to map the Australian crust. This approach and the application of Samarium-Neodymium isotope data were used by Geoscience Australia for the Archean Yilgarn Craton of Western Australia. Studies in that region showed that regional scale Samarium-Neodymium signatures in felsic igneous rocks (tonalite to granite and volcanic equivalents) were not only able to map crustal architecture but that this architecture had unexpected correlations with mineralisation. The successful results in the Yilgarn Craton, coupled with the UNCOVER focus, warranted that this approach be extended to the whole of the continent to test its general applicability for crustal mapping and predicting mineralisation. A database of Sm-Nd isotopic data, and associated metadata, for >2650 samples of Australian rocks was compiled from published and unpublished sources. This included location, unit, geochronology and bibliographic data and metadata for all data points; this dataset is available for download at www.ga.gov.au. Data were compiled for a range of lithologies, including felsic and mafic igneous rocks, sedimentary rocks, as well as some mineral data. Just over 1630 of these data points were from felsic igneous rocks which had reliable locational details and a reasonable estimated or known magmatic age. A comparison of the magmatic ages from these samples with compilations of Australian igneous rock ages showed a generally good agreement confirming the representative nature of the compiled Nd data set.
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document
eCat Id
77772
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Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
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2601
Australia
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- GA PublicationRecord
- ( Theme )
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- isotopes
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_External
Publication Date
2013-01-01T00:00:00
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geoscientificInformation
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Record 2013/044
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The Sm-Nd dataset has been compiled from unpublished Geoscience Australia isotopic data, unpublished Northern Territory Geological Survey isotopic data, as well as published isotopic data. All data sources are fully attributed. The structure of the dataset has been developed to be compatible with the GeoSciML data standard, published by the IUGS Commission for Geoscience Information.
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Extents
[-50.0, -10.0, 110.0, 155.0]
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