In the North Flinders Basin, which is the northern portion of the Adelaide “geosyncline,” late Proterozoic (Sturtian), glacigenic deposits lie unconformably on older Proterozoic sedimentary rocks of the Adelaidean succession or on crystalline basement. The glacigenic succession is highly variable in thickness and includes sections as much as 6,000 m thick. A four-fold regional stratigraphic subdivision (Units 1–4) contains two diamictite-laminated mudstone cycles. In the more distal, northern part of the basin, Unit 1 is mainly stratified diamictite, possibly formed by rain-out from floating ice while submarined) glacial erosion was taking place in more proximal settings. As the ice receded,...