Modern Anastomosing-Fluvial Deposits in Arid Central Australia, and a Carboniferous Analogue in New Brunswick, Canada
- J. D. Collinson and
- J. Lewin
Published Online: 29 APR 2009
Copyright © 1983 The International Association of Sedimentologists
Modern and Ancient Fluvial Systems
How to Cite
Rust, B. R. and Legun, A. S. (2009) Modern Anastomosing-Fluvial Deposits in Arid Central Australia, and a Carboniferous Analogue in New Brunswick, Canada, in Modern and Ancient Fluvial Systems (eds J. D. Collinson and J. Lewin), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303773.ch31
- Published Online: 29 APR 2009
- Published Print: 7 FEB 1983
Print ISBN: 9780632009978
Online ISBN: 9781444303773
- modern anastomosing-fluvial deposits – arid Central Australia, and carboniferous analogue – New Brunswick, Canada;
- Cooper's Creek;
- nodular calcrete;
- braided sheet sandstones;
- tectonic rejuvenation
Cooper's Creek is an extensive, mud-dominated fluvial system in arid Central Australia, which overlies a relict braided sand sheet. The active channels have a low-density anastomosing pattern, covering up to 3% of the system and accumulating medium sand in alternating side bars. Overbank sedimentation from the anastomosing channels deposits sandy mud, commonly without primary structure due to desiccation cracking and bioturbation. Compared with anastomosing-fluvial deposits of temperate climates, Cooper's Creek sediments have a higher ratio of floodplain mud to channel sand, lower carbonaceous content, and contain deep desiccation cracks, evaporites and duricrusts.
Member B of the Carboniferous Clifton Formation on the northern New Brunswick coast resembles Cooper's Creek sediments in many respects. The lower part of the succession is predominantly red mudstone, with carbonaceous layers, stratiform calcrete and calcreted vertical sheets interpreted as deep desiccation cracks. Isolated channel sandstones and associated levee, crevasse-splay or mouth-bar deposits are restricted in vertical and lateral extent. This suggests limited lateral and vertical accretion interrupted by avulsion, an interpretation similar to that deduced for the modern anastomosing channels of Cooper's Creek.
The upper part of the Clifton B succession is an extensive sheet sandstone with stacked channel units, dominated by trough cross-strata. It is attributed to braided-fluvial deposition, and is regarded as analogous to the relict braided sand sheet a few metres beneath the active alluvial plain of Cooper's Creek.