Amadeus Basin

Last updated:7 June 2023

Basin Details and Geological Overview

The intracratonic Neoproterozoic to Early Carboniferous Amadeus Basin occupies much of the southern quarter of the Northern Territory and extends about 150km into Western Australia, covering about 170 000km2 in total. It has a maximum sediment thickness of 14 000m with several major depocentres including the Idirriki, Carmichael and Ooraminna Sub-basins and Missionary Plain Trough along the northern margin and the Mount Currie and Seymour Sub-basins in the south. Early Neoproterozoic volcanics and fluvial siliciclastics in the west form a rift sequence associated with an extensional event caused by the breakup of the Rodinia Supercontinent.

Subsequent thermal relaxation and subsidence initiated widespread marine siliciclastic and carbonate sedimentation associated with extensive evaporites. This marine succession is terminated by an erosional surface which is overlain by fluvial and glacigene sediments associated with the Sturtian and Marinoan glaciations. Subsequent marine siliciclastic and carbonate sedimentation extended into the latest Proterozoic.

Depositional patterns were changed abruptly by the Petermann Ranges Orogeny with extensive uplift along the southwest margin of the basin feeding deposition of widespread fluvial and marine siliciclastics during the latest Proterozoic-Early Cambrian. This was followed by deposition of a succession of marine siliciclastics and carbonates with minor evaporites for most of the remainder of the Cambrian. In the latest Cambrian, the Delamerian Orogeny caused a change to predominantly marine siliciclastic deposition. This continued until the Middle Ordovician when evaporites again appeared.

The final phase of deposition in the basin comprised shallow marine, fluvial and aeolian siliciclastics, which are capped by synorogenic (Alice Springs Orogeny), molasse-type, coarse siliciclastics extending into the Early Carboniferous. Hydrocarbons are currently produced from an Early Ordovician source at Mereenie Oilfield and Palm Valley Gasfield. The Neoproterozoic sourced Dingo Gasfield is currently underdeveloped. Most anticlinal closures in the basin have been tested, but other possible plays such as fault controlled structures and stratigraphic traps have not been drilled.

Key References

Author(s) Year Title
Wells, A.T., Forman, D.J., Ranford, L.C. and Cook, P.J. 1970 Geology of the Amadeus Basin, Central Australia. Bureau of Mineral Resources, Australia, Bulletin 100
Jackson, K.S., McKirdy, D.M. and Deckelman, J.A. 1984 Hydrocarbon generation in the Amadeus Basin. The APEA Journal, 24(1), 42.65.
Lindsay, J.F. and Korsch, R.J. 1991 The evolution of the Amadeus Basin, central Australia. In Korsch, R.J., & Kennard, J.M. (Editors). Geological and geophysical studies in the Amadeus Basin, central Australia. Bureau of Mineral Resources, Australia, Bulletin 236, 7-32.
Ozimic,S., Passmore, V.L., Pain, L. and Lavering, I.H. 1986 Amadeus Basin, central Australia. Bureau of Mineral Resources, Australia, Australian Petroleum Accumulations Report 1.
Shaw, R.D. 1991 The tectonic development of the Amadeus Basin, central Australia. In Korsch, R.J., & Kennard, J.M. (Editors). Geological and geophysical studies in the Amadeus Basin, central Australia. Bureau of Mineral Resources, Australia, Bulletin 236, 429-461.
Shaw, R.D, Korsh, R.J., Wright, G. and Goleby, B.R., 1991 Seismic interpretation and thrust tectonics of the Amadeus Basin, central Australia, along the BMR regional seismic line. Bureau of Mineral Resources, Australia, Bulletin 236.
Burgess, J.M., Johnstone, A.L., Schaefer, B.F., Brescianini, R.F. and Tingate, P.R. 2002 New perspectives of the Amadeus Basin, Northern Territory. PESA Journal, 29, 14-23.