Lithology and the evolution of bedrock rivers in post-orogenic settings: Constraints from the high elevation passive continental margin of SE Australia

Bishop, P. and Goldrick, G. (2010) Lithology and the evolution of bedrock rivers in post-orogenic settings: Constraints from the high elevation passive continental margin of SE Australia. Geological Society, London, Special Publications, 346, pp. 267-287. (doi: 10.1144/SP346.14)

Abstract

Understanding the role of lithological variation in the evolution of topography remains a fundamental issue, especially in the neglected post-orogenic terrains. Such settings represent the major part of the Earth's surface and recent modelling suggests that a range of interactions can account for the presence of residual topography for hundreds of millions of years, thereby explaining the great antiquity of landscapes in such settings. Field data from the inland flank of the SE Australian high-elevation continental margin suggest that resistant lithologies act to retard or even preclude the headward transmission of base-level fall driven by the isostatic response to regional denudation. Rejuvenation, be it episodic or continuous, is ‘caught up’ on these resistant lithologies, meaning in effect that the bedrock channels and hillslopes upstream of these ‘stalled’ knickpoints have become detached from the base-level changes downstream of the knickpoints. Until these knickpoints are breached, therefore, catchment relief must increase over time, a landscape evolution scenario that has been most notably suggested by Crickmay and Twidale. The role of resistant lithologies indicates that detachment-limited conditions are a key to the longevity of some post-orogenic landscapes, whereas the general importance of transport-limited conditions in the evolution of post-orogenic landscapes remains to be evaluated in field settings. Non-steady-state landscapes may lie at the heart of widespread, slowly evolving post-orogenic settings, such as high-elevation passive continental margins, meaning that non-steady-state landscapes, with increasing relief through time, are the ‘rule’ rather than the exception.

• Item Type: Articles
• Additional Information: Geological Society, London, Special Publications, 2010, http://dx.doi.org/10.1144/SP346.14 © Geological Society of London 2010
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Bishop, Professor Paul
• Authors: Bishop, P., and Goldrick, G.
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences > Geography
• Journal Name: Geological Society, London, Special Publications
• ISSN: 0305-8719
• Copyright Holders: Copyright © 2010 Geological Society of London
• First Published: First published in Geological Society, London, Special Publications 346:267-287
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher