RB 79/00024 Adelaidean sedimentation. The Adelaide Geosyncline and Stuart Shelf.
Published: 01 Jan 1979 Created: 06 Nov 2024 Revised: 06 Nov 2024

In southern South Australia, the meridional Torrens Hinge Zone, at approximately longitude 138º, separates the cratonic Stuart Shelf with its undeformed, relatively thin sedimentary cover in the west, from the folded Adelaide Geosyncline to the...

In southern South Australia, the meridional Torrens Hinge Zone, at approximately longitude 138º, separates the cratonic Stuart Shelf with its undeformed, relatively thin sedimentary cover in the west, from the folded Adelaide Geosyncline to the east. The thick late Proterozoic and Cambrian sequences of the Adelaide Geosyncline are preserved in a complex, sinuous and branching system of fold belts, imposed during the Cambro-Ordovician Delamerian Orogeny (Thomson, 1969), and outcropping as the present Flinders and Mount Lofty Ranges. It is the stratotype for the Adelaidean period (late Proterozoic), and probably contains the thickest and most complete record of Adelaidean sedimentation in Australia. At their northern extension, the Torrens Hinge Zone and adjacent fold belt curve to the north-west, and the Adelaidean sediments emplaced here were formerly probably partly continuous with those of the Officer and Amadeus Basins of central Australia. Between the central Flinders Ranges and the Muloorina Ridge of interpreted shallow basement (Thomson, 1970), a fold belt extends from the Mount Painter basement inlier in the east through the north Flinders Ranges to the Peake and Denison Ranges in the north-west. In the south, the fold belt swings westerly through Kangaroo Island, to the west of which it is truncated by the present continental margin. The Adelaide Geosyncline was compared by Sprigg (1949, 1952) with typical miogeosynclines developed on continental shelves, but Scheibner (1973) identified it as an aulacogen. However, the Adelaide Geosyncline actually embraces a number of contrasting tectonic environments: of these, the gently folded central Flinders Ranges zone is essentially symmetrical and intracratonic between the Stuart Shelf to the west and the Curnamona Cratonic Nucleus (Thomson and others 1976) to the east. It thus resembles aulacogens, although it does not die out within the craton as do type examples of aulacogens. In contrast, the sigmoidal Kangaroo Island - Mt Lofty - Olary arc displays a polarity of sedimentary facies, tectonic structures and metamorphism, from a craton with marginal sediments in the north-west to a mobile belt with basinal sediments to the south-east; as such, it could represent an ancient continental shelf.

More +

About this record

Record No rb7900024
Topic Geoscientific Information
Type of Resource Document
Category Type
Document Type Departmental Publication - Geological Survey Geoscience Publication
Contributor
Sponsor
Tenement
Tenement Holder
Operator
Geological Province
Mine Name
Stratigraphy
Commodity
    Notes
    Doc No: RB 79/00024

    Doc No: RB 79/00024

    Language English
    Metadata Standard ISO 19115-3

    Citations

    Use constraints License
    License Creative Commons Attribution 4.0
    Persistent identifier https://pid.sarig.sa.gov.au/document/rb7900024
    Citation Preiss, W.V. 1979. RB 79/00024 Adelaidean sedimentation. The Adelaide Geosyncline and Stuart Shelf. Departmental Publication - Geological Survey Geoscience Publication. Government of South Australia.
    https://pid.sarig.sa.gov.au/document/rb7900024

    Technical information

    Status
    Maintenance and Update Frequency
    Geographic Reference GDA2020 (EPSG:7844)
    Geo bounding box {"type":"Polygon","coordinates":[[[129,-39],[141,-39],[141,-26],[129,-26],[129,-39]]]}
    Purpose
    
                        
                        
    
                        
                      
    Lineage