Mount Desire Dyke


Mount Desire Dyke is designated place of geological significance. It is located north-east of Hawker in South Australia, on the edge of the Flinders Ranges. The dyke is a rock structure where heat-softened igneous rock has intruded into cracks in folded Adelaidean sediments in the geological past.
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 breccia and a large limestone xenoclast of probable Willouran origin; sharp irregular and distinctive contacts with early Cambrian Parara 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."