Roebuck Basin

Location Map

Map showing the location of Roebuck Baisn in relation to Australia
© Geoscience Australia

Basin Details and Geological Overview

Previously known as part of the Offshore Canning Basin (prior to 1994), the Roebuck Basin is located on the central North West Shelf between the Northern Carnarvon and Browse Basins and outboard of the Offshore portion of the predominantly Palaeozoic Canning Basin. The Roebuck Basin consists of the Bedout and Rowley Sub-basins.

The Roebuck Basin is one of the least explored offshore basins of the Westralian Super-basin, containing Permian to Cretaceous siliciclastic sediments and Tertiary carbonates.

The Roebuck Basin developed on the North West Shelf as a result of multi-phase rifting on the western flank of the Palaeozoic Canning Basin. The Mesozoic geology of the Roebuck Basin is similar to that of the adjoining Northern Carnarvon and Browse basins, yet the Roebuck Basin is one of the least explored regions of the North West Shelf.

The Roebuck Basin was initiated by northwest-southeast extension in the Late Carboniferous to Early Permian as part of the Westralian Superbasin. Regional uplift and faulting in the latest Permian was associated with volcanism. Thermal sag in the Triassic led to the deposition of a thick sequence of transgressive marine claystone and deltaic deposits. This was followed by a series of transpressional events in the Late Triassic/earliest Jurassic. Early Jurassic extension ultimately led to Callovian breakup in the adjacent Argo Abyssal Plain. Lower and Middle Jurassic sediments represent fluvial and deltaic environments. Callovian break-up resulted in a phase of regional uplift and erosion. Upper Jurassic to Cretaceous sediments grade into a thick section of prograding Cainozoic carbonates.

The Roebuck Basin lacks the thick marine Upper Jurassic source rocks that are found in the inner parts of the Northern Carnarvon Basin to the southwest and adequate source rocks represent a major risk in the basin. However, potential Triassic source rocks have been intersected in wells drilled in the Bedout Sub-basin and on the Bedout High. An additional risk is that the major, trap-forming structural events preceded the main phase of hydrocarbon generation and migration. The primary exploration targets in the basin are Lower to Middle Jurassic deltaic-fluvial sandstones. As yet, no oil or gas discoveries have been made in the Roebuck Basin.

Stratigraphy

Chrono-stratigraphic chart
(key wells) for the Roebuck
Basin
© Geoscience Australia

Regional Cross-sections

Roebuck Basin Regional Structural Elements Map

Roebuck Basin Regional Structural
Elements Map
© Geoscience Australia

The location of the seismic cross-section is shown on the Regional structural elements map.

The Rowley Sub-basin, situated on the outer continental margin, comprises a seaward-thickening wedge of Triassic to Recent sediments that are terminated at the continental-oceanic crust boundary by massive down-to-the-northwest faults. The thickest section in the sub-basin comprises six kilometres (4 seconds TWT) of Mesozoic to Recent sediments underlain by nine kilometres (5 seconds TWT) of Palaeozoic sediments.

Roebuck Basin Cross-section
© Geoscience Australia

Key references

Author(s) Year Title
Colwell, J.B. and Stagg, H.M.J. 1994 Structure of the offshore Canning Basin: first impressions from a new regional deep-seismic data set. In: Purcell, P.G. & Purcell, R.R. (editors), The Sedimentary Basins of Western Australia: Proceedings of Petroleum Exploration Society of Australia Symposium, Perth 1994, 757-768.
JNOC (Japan National Oil Corporation) 1988 Geological and geophysical study of the offshore Canning Basin on the Northwest Shelf of Australia. (Open-file report available for inspection at the WA Geological Survey, Perth and Geoscience Australia, Canberra).
JNOC (Japan National Oil Corporation) 1989 Geological and geophysical study of the northeastern part of the offshore Canning Basin on the Northwest Shelf of Australia. (Open-file report available for inspection at the WA Geological Survey, Perth and Geoscience Australia, Canberra).
Lipski, P. 1994 Structural framework and depositional history of the Bedout and Rowley Sub-basins. In: Purcell, P.G. & Purcell, R.R. (editors), The Sedimentary Basins of Western Australia: Proceedings of Petroleum Exploration Society of Australia Symposium, Perth 1994, 769-777.
Smith, S.A., Tingate, P.R., Griffths, C.M. and Jull, J.N.F. 1999 The structural development and petroleum potential of the Roebuck Basin. The Australian Petroleum Production & Exploration Association (APPEA) Journal, 39 (1), 364-385.
Stagg, H.M.J. and Exon, N.F. 1981 Geology of the Scott Plateau and Rowley Terrace off northwestern Australia. Bureau of Mineral Resources Australia Bulletin, 213

Topic contact: petroleum@ga.gov.au Last updated: May 31, 2012