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Cambrian Basins

Cambrian-aged basins in South Australia are characterised by the Arrowie Basin and the Stansbury Basin. 

Age

Early to Middle Cambrian

 

Prospective Commodities

Zn–Pb–Cu, dolomite, limestone, petroleum, phosphate, dimension stone.

 

Early Cambrian carbonates such as the Wilkawillina Limestone and equivalents in the Flinders Ranges are important for mineral prospects and host several Zn–Pb deposits. Archaeocyath-bearing limestone at Beltana hosts ~1 million tonnes of ore while the Arcoona deposit, hosted by the Woodendinna Dolomite and adjacent to the Arcoona Fault, contains ~150 000 tonnes of ore. Zinc as willemite has also been found at Puttapa.

 

The Arrowie Basin contains potential petroleum resources with a major tectonic uplifting and thermal event during the Early Permian potentially maturing Cambrian rocks for petroleum generation.

 

Arrowie Basin

The Arrowie Basin is well exposed in the Flinders Ranges containing thick carbonates and siliciclastics with sequences up to 4200m in its northern depositional centres.

 

The basin is divided into four depositional regimes:

  • The western carbonate platform on the Stuart Shelf
  • Central ramp to trough deposits in the Flinders Ranges
  • The eastern Moorowie and Yalkalpo Synclines, which are separated by the Benagerie Ridge.

 

To the south, the basin is considered to have been interconnected to the Stansbury Basin during the Early Cambrian even though the two basins are now ~150km apart.

 

Stansbury Basin

The Stansbury Basin extends from Yorke Peninsula to eastern Fleurieu Peninsula and southern Kangaroo Island, where it has a faulted contact with thick, metamorphosed siliciclastic sediments of the Kanmantoo Trough.

 

The sediments, up to 4000m thick in the depocentres, are divided into three megasequences on Yorke Peninsula and under St Vincent Gulf, ranging in age from the from the Tommotian to Amgaian.

 

The Cambrian carbonates on Yorke Peninsula have attracted the attention of base metal exploration for many years, and its mineralisation is commonly related to hydrothermal events of the Delamerian Orogeny.