ABSTRACT
The recent review of the Lopingian (upper Permian) stratigraphic framework of the Galilee Basin, prompted a reconsideration of the paleo-environments of deposition. This study interpreted the distribution of sedimentary facies from geophysical logs across the basin complemented by detailed logging from four key wells (GSQ Tambo 1-1A, OEC Glue Pot Creek 1, CRD Montani 1 and GSQ Muttaburra 1). Seven facies associations were identified: terrestrial fluvial, floodplain, lacustrine and mire; and paralic to marine estuarine shoreline, delta and restricted marine. Coal measures (mire facies) are best developed in the northeastern margin of the basin, whereas the southern Springsure Shelf was dominated by marine conditions throughout the Lopingian, only developing terrestrial facies towards the very uppermost Lopingian. The ‘Colinlea Sandstone equivalent’ was deposited in a fluvial system, with tidal influence exhibited in the southern part of the basin, which decreases further north as lacustrine environments become common. The regional transgression represented by the Black Alley Shale can be mapped into the central part of the basin, but based on new exploration data its northern extent is more limited than previously thought. The ‘Burngrove Formation equivalent’ and Bandanna Formation represent a southerly prograding fluvial-deltaic system during the regional regression in the upper part of the Lopingian.
Acknowledgements
The authors of this paper would like to thank the Australian Coal Association Research Program, grant number C22028, for funding, and the Vale-UQ Coal Geosciences Program. The Geological Survey of Queensland's Exploration Data Centre in Zillmere, Brisbane, is thanked for use of their facilities and assistance while viewing drill core. Dr Renate Sliwa is thanked for her helpful review of an early draft of the manuscript. Dr Mike Martin and an anonymous reviewer greatly helped to improve the quality of this manuscript.
Disclosure statement
No potential conflict of interest was reported by the authors.