Geoscience Australia - Product Database



Capricorn Basin

Entity ID: 21093 Compiled by: Taubert, S. Year: 2002 Status: Defined

Last Revised: 2013

Rank: province Type: sedimentary Subtype: rift Location: QLD Off-shore

Synonyms: NA Symbol: NA

Minimum age: Recent Age method: inferred, biostratigraphic correlation

Maximum age: Early Cretaceous Age method: inferred, isotopic correlation

Summary: The Cretaceous to Cainozoic age Capricorn Basin is an offshore frontier petroleum basin located off southeast Queensland containing 4 km of volcanics, continental siliciclastics and coals, and marine siliciclastics and carbonates.

Area (square kilometres): 24400
State: QLD
Small portion of basin also in CSIT
Minimum present water depth (m): 100
Maximum present water depth (m): 3500
Main rock types: carbonate sediments and sedimentary rocks
Main rock types: siliciclastic sediments and sedimentary rocks
Early Cretaceous volcanics may also be present.
Main depositional environment: marine and non-marine
Maximum sediment thickness (m): 4000
Present crustal setting: continental
Country: AUS

Parent: No data

Child Provinces: No data

Adjoins - Marion Plateau

Constituent units:

Events: No data

Mineral Deposits: No data

Key Reference: Hill, P.J. 1994, Geology and geophysics of the offshore Maryborough, Capricorn and northern Tasman Basins: results of AGSO Survey 91, Canberra, Australian Geological Survey Organisation Record 1994/1, 1994/1, (Refid:12543)

Comments: No data

Overview: The Cretaceous to Cainozoic age Capricorn Basin is a northwest to southeast elongate basin located off the southeast coast of Queensland. Water depths range from 3500 m in the southeast where sediments are up to 4000 m thick, to 100 m at the northern basin margin. There has been only limited exploration in the Capricorn Basin, with three dry wells drilled (Sep 2003) and no significant exploration activity since 1968. There are two possible models for the tectonic evolution of the Capricorn Basin. One model is that the Capricorn Basin formed during the Late Jurassic to Early Cretaceous from the same extensional event that formed the Townsville and Queensland basins farther north. An alternative model is that the Capricorn Basin formed in the Late Cretaceous as a failed rift arm at the northern end of the Tasman rift system. This second model divides the basin fill into five basin phases: Late Cretaceous to Early Paleocene rift phase; Late Paleocene to Early Eocene late rift phase; Early to Middle Eocene early thermal sag phase; Middle to Late Eocene post-tectonic structural reactivation phase; and a Late Oligocene to Recent late sag/rapid regional subsidence phase. The stratigraphy of the Capricorn Basin consists of continental rift-phase conglomerates and red beds of Late Cretaceous to Early Paleocene age. These are overlain by Eocene age mixed marine and continental quartzose sandstones and lignites, in turn overlain by a thick marine sequence of Late Oligocene to Recent age limestone and marl. Although potential reservoirs and traps appear to be present, the petroleum prospectivity is considered low due to a lack of evidence for burial and thermal maturity of potential source rock intervals. Petroleum prospectivity is also downgraded by the absence of a proven regional seal and the Capricorn Basin's location beneath the Great Barrier Reef Marine Park in which petroleum exploration is prohibited.

Images: No data

Other media: No data

Source Information:

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This report was generated on Monday, June 25, 2018 12:28:55 PM EST.