Publication Name: Central Australian Basins Symposium IV
Authors: Daniela Garrad
Publication Volume: 2
Date Published: August 2024
Number of Pages: 12
https://doi.org/10.36404/VXDS4113
Abstract:
The Beetaloo Sub-basin is a major Proterozoic depocentre in the central region of the informally named greater McArthur Basin in the Northern Territory, Australia. Paleoproterozoic Glyde package sediments of the greater McArthur Basin are present to the west and east of the Beetaloo Sub-basin, but there is considerable uncertainty as to their subsurface extent. Previous studies have inferred the package to be present at depth within the sub-basin despite a lack of drill intersections. This inference was mainly based on seismic interpretations that have relied on regional geological knowledge to identify seismic reflectors. A high amplitude reflector package (HARP), interpreted as a bedded carbonate sequence, has previously been used to identify the Glyde package. In this paper, surface geology and magnetic images are used to calibrate seismic reflectors on the eastern margin of the Beetaloo Sub-basin. The HARP is shown to correlate to igneous intrusions of the Derim Derim Dolerite, not to bedded carbonate rocks, and the base of the Mesoproterozoic Wilton package is correlated with an angular unconformity previously interpreted as the base of the underlying Glyde package. This indicates that the Glyde package is missing throughout the eastern Beetaloo Sub-basin, probably as a result of erosion.