Fluvial response to tectonic activity in an intra-continental dryland setting: The Neales River, Lake Eyre, Central Australia

Abstract

Geomorphological studies in the centre of the Australian continent have emphasised the antiquity of the Australian landscape typically considered tectonically stable. Evidence from the Neales River on the western shore of Lake Eyre indicates that mild epeirogenic forces have deformed sediments of Miocene age. Deformed bedding planes, small-scale folds and fracture systems reflect consistent Miocene and younger tectonic activity in central and southern Australia. This compression was mild, resulting in broad, gently plunging folds. These folds are evident in the Miocene strata but not in the overlying Quaternary strata. Elsewhere in the study area the landscape has been rearranged to preserve features in the geomorphic record that indicate a second phase of tectonic activity in the early to mid-Pleistocene. These include stream diversions preserved on alluvial fans and floodplains formed downstream of faults.