Authors / CoAuthors
Johnston, S. | Hackney, R. | Nicholson, C.
Abstract
Recently acquired seismic reflection and gravity potential field data 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. Isochron 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 to the centre and north of the area. Two and three dimensional gravity forward models were created in IGMAS+. Two dimensional gravity modelling shows that the crust is extremely thin in the Western Mentelle (c.10km), associated with two mantle highs observed to the north and centre of the Western Mentelle. The crust thickens from the Eastern Mentelle (>20km) towards mainland Australia and the Naturaliste Plateau. 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 the pressure is lowest. Thus results of gravity modelling and seismic interpretation in this study indicate that Jurassic - Cretaceous extension was focussed in the Western Mentelle. This conclusion conforms to models of rift related basin formation, where the flanks of the basin are uplifted; an angular unconformity in the Eastern Mentelle may support the occurrence of rift-flank uplift in this area as a result of asthenospheric rise and rifting while the deposition of volcanic material was focussed in the Western Mentelle.
Product Type
nonGeographicDataset
eCat Id
69851
Contact for the resource
Custodian
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Custodian
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
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- External PublicationAbstract
- ( Theme )
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- volcanology
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- AU-WA
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_External
Publication Date
2010-01-01T00:00:00
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unknown
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geoscientificInformation
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Unknown
Parent Information
Extents
[-35.0, -33.0, 112.0, 114.5]
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