Fielding, C.R.1, J.D. Trueman2, J. Alexander3
(1) University of Nebraska-Lincoln, Lincoln, NE
(2) University of Queensland, Brisbane, Australia
(3) University of East Anglia, Norwich, United Kingdom
ABSTRACT: Holocene Depositional History of the Burdekin River Delta of Northeastern Australia: a Model for a Low-Accommodation, Highstand Delta
The Burdekin River Delta of northeastern Australia has previously been used as a type example of a wave-tide-interactive or mixed-influence delta. Recent work by us, however, has shown that the Holocene delta platform has been constructed principally by accumulation of distributary channel and mouth bar sand bodies, and is better described as a flood-dominated delta. The Holocene succession, typically 10-20 m thick, has accumulated through the repeated switching of distributary channel and associated mouth bar systems over the past 8000 years. At least eleven such systems are recognised, based on surface and subsurface investigations, including a large suite of radiocarbon ages. The Holocene succession comprises a basal mud unit formed during the post-glacial transgression, overlain by a sand-dominated interval formed by channel and mouth bar progradation. The limited sediment supply and efficient longshore drift system have combined to restrict deltaic progradation to shallow water depths (<20 m), such that the thin, complex Holocene succession of the delta can be viewed as the product of a low-accommodation setting, formed almost entirely during the present sea-level highstand.
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.