Aspects of landscape evolution in the Lapstone Monocline area, New South Wales

Abstract

The concept that the Lapstone Monocline and associated faults are old structures which have dominated landform development in the lower Blue Mountains of New South Wales by exhumation of structural ridges of resistant Hawkesbury Sandstone is examined. It is suggested that the Lapstone Monocline is of pre‐Jurassic age and that landforms developed initially on a land surface of more uniform lithology, some features of which are now incised into the topographically higher levels of the Hawkesbury Sandstone. The Rickabys Creek Gravel, the age of which is critical in determining the timing of events and the testing of this theory, has defied all attempts to obtain internal evidence of age.