DIAPIRISM IN THE ADELAIDE GEOSYNCLINE

Abstract

Approximately 20,000 feet of the Willouran Callanna Beds were deposited under shallow-water conditions in the western zone of the Adelaide Geosyncline. Diapirs were produced by the lower Callanna sequences. The initiation of diapiric growth is considered to be structural, but isostasy is thought to have played a subsequent role in the rise and emplacement of diapirs. Evidence for positive movements of diapir domes during deposition of Adelaide System and Lower Cambrian sediments is presented. The influence of diapiric emplacement on tectonics and sedimentation is described.