Publication Name: The Canning Basin, W.A.
Authors: D.H. Tucker, M. Bacchin and R. Almond
Date Published: December 1984
Number of Pages: 31
Reference Type: Book Section
Abstract:
The BMR 1980 regional airborne survey used 1500m line spacing and 150m continuous ground clearance andprovides new detail of both short and long wavelength magnetic anomalies, not evident in earlier wide line spacing constant altitude surveys over the Canning Basin.
Long wavelength magnetic anomalies indicate sources at depths of lOkm or more beneath Proterozoic rocks.Some of these anomalies trend subparallel to the northwest-southeast axis of the basin, possibly indicating a deep crustal control on all basins in the area. Crosscutting breaks in the short wavelength magnetic
pattern trend 45 to 55 degrees. They extend basinwards from the Proterozoic rocks across the Phanerozoic cover, indicating basement controlled fractures with a long history of movement.
Short wavelength magnetic anomalies (15-20km) may indicate intrasedimentary magnetic horizons in the Permian sediments near Carnegie Bluff. Surface sporadic anomalies were detected in at least three areas and are probably caused by surface maghemite. There is the possibility that some of the anomalies may be of interest as petroleum related magnetite or igneous intrusion related features.
The gamma spectrometric pattern shows the most prominent high count rates over the general area of Permian
outcrop in Lucas and Stansmore. This is attributed to elevated Thalium 208 (Thorium) and less Bismuth 214 (Uranium) concentrations in laterite capping. Trends of various zones of highs approximately 5-10km across appear to trace closures around various structures. Good examples occur near Point Moody No.1. Such features are likely to be caused by the combined effects of structure and laterite exposure.
Surveys flown over the rest of the Canning Basin with parameters similar to those of the BMR survey are likely
to reveal significant new information to aid exploration. The information would relate not only to basin
framework, geological mapping and structure, but may also may include identification of intrasedimentary
magnetic beds and igneous intrusions, and possible detection of indicators of radioactive minerals, fluid migration paths, and subsurface hydrocarbons.