Geology & Resources
South Australia's geology covers every geological period in Earth's history. Depositional, igneous, orogenic and alteration events ranging in age from 2.7 billion years ago to the present day, covering every geological period, are represented in South Australia's rock record.
South Australia's central position within the Australian continent gives the state the advantage of hosting rocks with a wide range of ages and lithologies which are all potential (and proven) targets for mineral exploration.
Geological Timescale
The Geological Timescale from the start of the Archaean (3.8 billion years ago) is available in a selection of viewable and downloadable timescales.
A Brief Geological History of South Australia
In the Australian context, South Australia's geological evolution until the early Mesozoic (~550 Ma) displays an overall eastward-younging trend where rocks in the western part of the State are much older than those in the east. This is due to the successive sedimentary basins and orogenic (mountain) belts that were added to the west and centre areas of what is now the present-day continent.
Within South Australia, an Archaean (~2700 Ma) core sits in the centre of the state and is bounded on the west, north and east by orogenic belts. These orogenic belts are related to the collision and assembly of crustal fragments at intervals during the Proterozoic.
By the start of the Neoproterozoic (~1000 Ma), Australia is thought to have occupied a central position within the supercontinent Rodinia, being surrounded by parts of the present Antarctica, India, Siberia, China and North America.
The early Neoproterozoic (1000–750 Ma) was a period of relative crustal stability, dominated by intracratonic sedimentation over much of the Australian continent, but active rifting commenced in eastern South Australia.
Break-up of Rodinia followed during the late Neoproterozoic (750–540 Ma), with sedimentation on a passive continental margin bordering the proto-Pacific Ocean terminated by Cambro-Ordovician orogeny.
To the east of South Australia from the middle Palaeozoic until the early Mesozoic, a series of rifted basins developed on thinned continental and some oceanic crust and evolved through basin closure and accretionary orogenesis into an eastward-younging series of fold belts comprising the majority of the Tasman Fold Belt System; this was a component of the assembly of the supercontinent Gondwana.
In contrast, South Australia's geological history during this period, and continuing until the present, is dominated in the interior by stacked intracratonic sedimentary basins, while Mesozoic to Cainozoic sedimentary basins along the southern continental margin resulted from the rifting and separation of Antarctica from Australia during the break-up of Gondwana.
Geological Provinces and Basins
South Australia is comprised of distinct geological provinces coupled with a number of sedimentary basins.
Geological Provinces
The main geological Provinces are:
- Curnamona Province
- Gawler Craton
- Musgrave Province
- Adelaide Fold Belt and Stuart Shelf
(including the Kanmantoo Trough)
More information on the Geological Provinces of South Australia.
Sedimentary Basins
Some of the more well-known basins of South Australia include:
- Officer Basin
- Murray Basin
- Gambier Basin
- Eucla Basin
More information on South Australian Basins.
- Page URL: http://outernode.pir.sa.gov.au/minerals/geology
- Page Last Modified: June 10, 2008