Structural fabric and tectonics associated with the Polda Lineament, South Australia ? a geophysical and morphotectonic assessment

Abstract

A knowledge of the structural and tectonic processes which have controlled the evolution of the Archaean/Proterozoic Gawler Craton in South Australia is crucial to an understanding of the geology of the southern central Australian continent. A particular feature transecting the southern portion of the Craton is the Polda Lineament, which extends east-west for possibly up to 1600 kilometres. Both vertical and lateral movements have been prevalent within this zone of crustal yielding from ?Lower Proterozoic to Cenozoic times. The most obvious indication of the lineament is the Polda Trough, an area of deep sedimentary section. However, extensions to the lineament are now recognised eastwards across lead-zinc mineral fields in the eastern Gawler Craton, and, albeit less prominently, cutting the ?Adelaidean to ?Cambrian basement of the Murray Basin. The Polda Lineament is now seen as a major zone of crustal yielding, with important connotations for mineral and petroleum exploration.