Authors / CoAuthors
Johnston, S. | Hackney, R. | Nicholson, C.
Abstract
Seismic reflection and gravity potential field data acquired during the Geoscience Australia SW Margins Survey 2008-09 was used to investigate the distribution of volcanic facies and large-scale structural architecture of the Mentelle Basin, located on the southwestern margin of Australia. Based on structural differences the basin is subdivided into the Western (WMB) and Eastern (EMB) Mentelle Basins. Isopach and seismic facies maps were used to identify the thickness and distribution of volcanic facies. These maps show that volcanism is generally confined to the Western Mentelle Basin, with two distinct areas of thick volcanic deposits occurring in the central and northern portion. Two and three dimensional gravity forward models were used to investigate the structural architecture of the Mentelle Basin. Two dimensional gravity modelling shows that the crust is extremely thin in the WMB (c.10km), associated with two mantle highs. The crust thickens from the EMB (>20km) towards mainland Australia. The two modelled mantle highs coincide with the two seismically defined areas of thick volcanic deposits. Analogue models indicate that rift related volcanism is generally confined to the locus of extension where crustal thinning and strain are greatest. Thus results of gravity modelling and seismic interpretation have been interpreted to indicate that Jurassic - Cretaceous extension was focussed in the WMB. This thinning of the crust and presence of mantle highs suggests that the WMB is a failed rift formed during the initial breakup between Australia and Greater India and abandoned at the onset of spreading in the Perth Basin.
Product Type
nonGeographicDataset
eCat Id
70304
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Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
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Keywords
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- External PublicationAbstract
- ( Theme )
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- seismic sections
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- gravity
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- sedimentary basins
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- model
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- petroleum exploration
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_Internal
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2010-01-01T00:00:00
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