The Tectonic Framework Of The Murteree Ridge, Warburton Basin: Structural Implications For The Cooper And Eromanga Basins.
Boucher, Rodney Kenneth
Honours Degree, 1991
University of South Australia
The Murteree Ridge in northeast South Australia is a structural high of Warburton Basin sediments and volcanics; against which Cooper Basin sediments pinch out. It is entirely buried beneath the Eromanga Basin.
The principle data for the study are from volcanic geochemistry and the soon-to-be-published isopach and depth structure maps for the Strzelecki 1:250,000 map sheet. Aeromagnetics, gravity, seismic and magnetic susceptibility data are also incorporated in the study.
The volcanics of the Murteree Ridge are alkaline, within-plate basalts developed during Early Cambrian, but possibly Late Proterozoic, east-west rifting. This ridge is reactivated during the development of the Cooper and Eromanga Basins and evident as influencing depositional patterns. Immobile elements of the Murteree Ridge basalts correlate well with the Mt Wright Volcanics in western New South Wales and with Suite 1 volcanics beneath the Murray Basin, both of Early Cambrian age. This is suggestive of a similar tectonic framework with the basalts of the Murteree Ridge.
NE & NW structural trends, possibly inherited from the Mootwingee Movements of the Delamerian Orogeny, are similarly expressed throughout the Cooper and Eromanga Basins and outline very important hydrocarbon trapping structures. The Murteree Ridge itself is formed from NNW thrust faulting initiated during the Alice Springs Orogeny.
Magnetic susceptibility measurements on cores and cuttings has been a useful lithology discriminator and continuing work of this nature will determine its value as a logging tool. Better gravity aeromagnetic surveys will help future Warburton Basin studies when combined with well control of pre-Permian formations. A better understanding of the Warburton Basin will provide a clearer insight into the development of the Cooper and Eromanga Basins.