A Review of Allochthonous Salt Tectonics in the Flinders and Willouran Ranges, South Australia
Author ORCID Identifier
Mark Fischer:https://orcid.org/0000-0003-1186-8844
Publication Title
Australian Journal of Earth Sciences
ISSN
08120099
E-ISSN
43506
Document Type
Article
Abstract
The Flinders and Willouran ranges of South Australia contain over 20 examples of exposed allochthonous salt sheets and canopies comprising the Callanna Group megabreccias. The identification of a given diapir or portion of a diapir as allochthonous is well documented in some cases but more speculative in others. Here we summarise most of the examples, citing the evidence and arguments supporting allochthonous origins and discussing relevant geometries and aspects of salt–sediment interaction. The allochthonous bodies are distributed over a large area, from the eastern Willouran Ranges to the Northern and Central Flinders Ranges, with fewer occurrences in the Southern Flinders Ranges. However, apparent base-salt flats are largely confined to four specific stratigraphic intervals that are in places linked by base-salt ramps. These levels are the Skillogalee Dolomite (Burra Group), the Tapley Hill Formation (Umberatana Group), and the Brachina and Bunyeroo formations (Wilpena Group), with ramps and minor flats continuing up through the Pound Subgroup and into Cambrian strata. At least three of the units with flats represent times of slow deposition, which favours lateral salt emplacement. Those in the Wilpena Group may also have been facilitated by minor contractional squeezing of feeder diapirs during early stages of the Delamerian Orogeny. The Flinders and Willouran ranges provide an exceptional natural laboratory for studies of outcropping structures analogous to those found in the subsurface of other salt basins such as the Gulf of Mexico and Atlantic margins. The diapirs and allochthonous salt sheets of the Flinders Ranges were also a key component of the basin framework in which strata containing Ediacaran fauna were deposited.
First Page
787
Last Page
813
Publication Date
8-17-2020
DOI
10.1080/08120099.2018.1553063
Keywords
allochthonous salt, Flinders Ranges, salt canopies, salt diapirs, salt sheets, salt tectonics, South Australia, Willouran Ranges
Recommended Citation
Rowan, Mark G.; Hearon IV, T. E.; Kernen, Rachelle A.; Giles, K. A.; Gannaway-Dalton, C. E.; Williams, N. J.; Fiduk, J. C.; Lawton, T. F.; Hannah, P. T.; and Fischer, Mark P., "A Review of Allochthonous Salt Tectonics in the Flinders and Willouran Ranges, South Australia" (2020). NIU Bibliography. 370.
https://huskiecommons.lib.niu.edu/niubib/370
Department
Department of Geographic and Atmospheric Sciences
