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Late Palaeozoic Basins

Late Carboniferous to Permian sedimentation is preserved mainly in six intracratonic basins — Arckaringa, Pedirka, Cooper, Denman, Troubridge and Nadda Basins.

 

Age

Late Carboniferous to Permian.

 

Sediments are largely of continental origin but begin with a characteristic shallow-marine to fluvial glaciogenic unit at the base. Sedimentation rarely exceeds 1000m in total thickness yet extends more or less continuously over very large areas within the basins. Each of the principal Permo-Carboniferous basins contains fault-bounded troughs in which sedimentary units thicken locally. There are also a number of small subsidiary late Palaeozoic basins that are similarly narrow and fault-bounded (Mulgathing Trough, Polda Basin).

 

In addition, Permian sediments occur in two small intramontane basins in the Flinders Ranges — near Blinman and in the Springfield Basin. Age determination and differentiation of Late Palaeozoic sediments from younger terrestrial sediments requires application of palynology in many instances.

 

 

Prospective Commodities

Coal, placer diamonds. silca sand, dimension stone.

Large coal deposits occur in the Arckaringa, Pedirka and Cooper Basins, and are source rocks for hydrocarbons in the Cooper Basin with the Arckaringa Coalfield comprising of the Wintinna, Westfield, East Wintinna and Murloocoppie coal deposits.

 

The Late Palaeozoic overall is also likely to be a secondary source of Diamonds with Permian conglomerates of the Springfield Basin yielding diamonds and diamond fragments.

Sand, which is partly sourced from the Troubridge Basin near Mount Compass, is mined for silica and a dimension stone, the Finniss River Sandstone, has also been quarried from Troubridge Basin sediments.

 

Arckaringa Basin

 

The Arckaringa Basin covers an area of 80 000 km2 and is mostly restricted to the subsurface with the outcropping Officer Basin, Gawler Craton and Stuart Shelf rocks mark approximately its western, southern and southeastern limits.

 

Drillhole samples indicate that scattered subcrops of late Palaeozoic sediment extend well beyond the western margin of the basin. The eastern margin is formed in part by the Peake and Denison Inliers, whereas the northern and northeastern margins are not readily defined due to lack of outcrop and subsurface data.