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Recherche Sub-basin

Entity ID: 27360 Compiled by: Bradshaw, B.E. Year: 2003 Status: Defined

Last Revised: 2013

Rank: subprovince Type: sedimentary Subtype: polyhistory Location: SA, WA Off-shore

Synonyms: NA Symbol: NA

Minimum age: Late Cretaceous Age method: inferred, seismic interpretation

Maximum age: Middle Jurassic Age method: inferred, seismic interpretation

Summary: The Middle Jurassic to Late Cretaceous Recherche sub-basin is a major offshore rift basin on the southern Australian margin that contains up to 8000 m of siliciclastic marine and non-marine sedimentary rocks.

Attributes:
Area (square kilometres): 377000
State: SA
State: WA
Minimum present water depth (m): 500
Maximum present water depth (m): 5500
Main rock types: siliciclastic sediments and sedimentary rocks
Main depositional environment: marine and non-marine
Maximum sediment thickness (m): 8000
approximate; based on seismic interpretation
Present crustal setting: oceanic
Present crustal setting: continental
Present crustal setting: transitional
Country: AUS

Parent: Bight Basin

Child Provinces: No data

Relationships:
Adjoins - Bremer Sub-basin, Ceduna Sub-basin, Denmark Sub-basin, Madura Shelf, Otway Basin, Yallingup Shelf
Underlies - Eucla Basin

Constituent units: Hammerhead Supersequence, Tiger Supersequence, White Pointer Supersequence, Blue Whale Supersequence, Bronze Whaler Supersequence, Southern Right Supersequence, Minke Supersequence, Sea Lion Supersequence

Events: Australia-Antarctica break-up, Eyre extension, Ceduna extension, Southern Margin Late Cretaceous and Cenozoic magmatism

Mineral Deposits: No data

Key Reference: Bradshaw, B.E., Rollet, N., Totterdell, J.M., Borissova, I. 2003, A revised structural framework for frontier basins on the southern and southwestern Australian continental margin., Geoscience Australia. Record, 2003/03, 44 (Refid:13490)

Comments: No data

Overview: The Recherche Sub-basin is a major offshore rift basin on the southern Australian margin that extends over an area of 377 000 sq. km from the western to eastern limits of the Bight Basin (~2100 km along-strike). The Recherche Sub-basin forms a depocentre for approximately 8000 m of Mesozoic strata in water depths of 3000 to more than 5500 m. The only well drilled in the Recherche Sub-basin is a shallow stratigraphic well (ODP 1128). Consequently, little is known about its stratigraphy. However, it is interpreted to consist of a Middle Jurassic to Lower Cretaceous syn-rift section of fluvial and lacustrine deposits, overlain by a relatively unstructured Lower to Upper Cretaceous post-rift section of non-marine, to marine and deltaic deposits. Middle Jurassic to Lower Cretaceous syn-rift strata extend about 60 km basinward of the main northern rift border fault system, the Wallaroo Fault System, and infill a series of half graben. These syn-rift deposits are overlain by up to 6000 m of post-rift Cretaceous strata, and 500 m of deep water Cainozoic deposits. Post-rift strata continue basinward of the last seismic evidence for older syn-rift deposits as a relatively unstructured sag-fill, until they become extensively faulted and intruded over a 15 to 120 km wide continent-ocean transition zone. The southern boundary of the Recherche Sub-basin is defined as the maximum extent of the Upper Cretaceous Hammerhead supersequence, which actually extends over oceanic crust where it infills a series of small half graben that probably formed during the early phase of seafloor spreading. Mesozoic deposits from the Recherche Sub-basin may include organic-rich non-marine facies in Middle Jurassic to Lower Cretaceous strata, and organic-rich marine shales in Lower to Upper Cretaceous strata, which are overlain by sufficient overburden to generate hydrocarbons. The Recherche Sub-basin therefore has the potential to contain hydrocarbon accumulations.

Images: Eastern Bight Basin structural elements and cross-section location map (82 KB), Western Bight Basin structural elements and cross-section location map (67 KB), Eastern Bight Basin regional cross-section Profile 1 (59 KB), Eastern Bight Basin regional cross-section Profile 3 (80 KB), Eastern Bight Basin regional cross-section Profile 5 (50 KB), Western Bight Basin regional cross-section Profile 8 (35 KB)

Other media: No data

Source Information:

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This report was generated on Monday, April 21, 2014 5:20:54 AM EST.