Mount Desire Dyke
Mount Desire Dyke is designated place of geological significance. It is located 16 km (9.9 mi) north-east of Hawker in South Australia, on the edge of the Flinders Ranges. The dyke (or dike) is a rock structure where mobile material, being a breccia of rock salt and rubble (as in 'salt diapirs') has intruded into cracks in folded Adelaidean sediments in the geological past (PhD thesis of Trev J Mount, 1975, on "Diapirs and diapirism in the Adelaide Geosyncline" (Flinders Ranges) now is published online (free download) by the Department of Energy & Mining (Geological Survey of South Australia) as Report Book 2021/00006.
On the State Heritage Register the site is described as significant because "This site contains a number of features of considerable importance to research and debate concerning the nature and origin of the Mt Desire Dyke and other diapirs of the Flinders Ranges, including: typical dolomitic-vanished evaporite breccia and dolostone/metasediment xenoclasts (to km in size) of probable Willouran origin; sharp irregular and distinctive contacts with early Cambrian units such as the Mernmerna Formation, Oraparinna Shale, and Wilkawillina Limestones, including a particularly important apophysis interpreted as an intrusive re-entrant; and significant brecciation in, and metamorphic incongruence between, the material of the dyke and the adjacent Cambrian limestones."(Mount,1975).|url=http://maps.sa.gov.au/heritagesearch/HeritageItem.aspx?p_heritageno=16363 |title=Mount Desire Dyke (designated place of geological significance) |author= |date=30 March 1998 |website=SA Heritage Places Database Search |publisher=Government of South Australia |access-date=24 January 2020 |quote=}}</ref>
References[]
- Geology of South Australia
- Australian geology stubs