WOOLNOUGH HILLS AND MADLEY DIAPIRIC STRUCTURES, GIBSON DESERT W.A.

Abstract

A diapiric origin is indicated for several domal structures with arcuately linear trends, in the western Gibson Desert, Western Australia. The most prominent of these trends is approximately latitudinal, although a minor trend north of Woodnough Hills, is north to northeasterly.

Foundered blocks of Upper Proterozoic, Permian and possibly Jurassic sediments occur within the gypsum-cores of several of the diapirs. The sharp angular unconformities between Upper Proterozoic and Permian and Permian and Jurassic sediments respectively, suggests that diapiric uplift and piercement has continued, at least intermittently, for extensive periods of geologic time. Gentle doming of the late-Tertiary laterite surface evidences the continuation of diapiric uplift into post-Tertiary times.