Authors / CoAuthors
Roach, I.C.
Abstract
The Frome airborne electromagnetic (AEM) survey (Figure 1) is the largest of three regional AEM surveys flown under the 5-year Onshore Energy Security Program (OESP) by Geoscience Australia, and the largest survey by area ever flown in Australia. The aim of the survey is to reduce risk and stimulate exploration investment for uranium by providing reliable pre-competitive data. The Frome AEM survey was released with two different Geoscience Australia layered earth inversions (GA-LEI): a sample-by-sample inversion (SBS GA-LEI) to enhance vertical features; and, a line-by-line inversion (LBL GA-LEI) to enhance horizontal features (see Hutchinson et al. 2010). A separate depth of investigation was calculated for each inversion using a method modified after Christiansen and Auken (2010) for the SBS inversion and Oldenburg and Li (1999) for the LBL inversion. A range of data products were produced including point-located ASCII data, georeferenced conductivity sections and grids, PDF multiplots, GOCAD surfaces and ancillary data. A range of under-cover features are mapped in the conductance image (Figure 1), including (but not limited to): extensions to known palaeovalley networks in the Frome Embayment; the under-cover extent of the Benagerie Ridge; regional faults in the Frome Embayment and Murray Basin; folded and faulted Neoproterozoic rocks in the Adelaide Fold Belt; Cenozoic - Mesozoic stratigraphy in the Frome Embayment; neotectonic offsets in the Lake Eyre Basin; conductive Neoproterozoic rocks associated with copper-gold mineralisation; and, coal-bearing structures in the Leigh Creek area, as well as groundwater features. A depth of investigation (DOI - depth of reliable signal penetration) of up to 400 m is calculated in areas of thin cover and resistive basement, e.g., Adelaidean rocks in the Olary Ranges (Figure 2). In Cenozoic - Mesozoic sediments in the Frome Embayment and the Murray Basin the DOI is about 100-150 m, decreasing to less than 50 m under the salt lakes. The Frome AEM data set is available for free download from Geoscience Australia: http://www.ga.gov.au/minerals/projects/current-projects/airborne-electromagnetics.html For more information contact: Dr Ian Roach Continental Geophysics, Geoscience Australia Ian.Roach@ga.gov.au
Product Type
nonGeographicDataset
eCat Id
73358
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Custodian
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Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
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- GA PublicationPoster/Image
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_Internal
Publication Date
2012-01-01T00:00:00
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geoscientificInformation
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[-34.0, -29.0, 138.0, 141.0]
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