The development and distribution of sedimentary rocks in the Rangal Coal Measures, South Blackwater, Central Queensland

Abstract

An investigation of the elastic interseam sedimentary rocks has elucidated the depositional and contemporaneous tectonic history of the Upper Permian Rangal Coal Measures at the C.S.R. South Blackwater Mine, Central Queensland, The studied section is stratigraphically bound by the Orion and Aries coal seams. The approximately 84 square km study area is located on the eastern flank of the Comet Ridge, within the Bowen Basin. The geological data used in this study consists of Qorehole information, approximately derived 2800 from bores, a geological and detailed database, containing examination of representative core material. The interseam sedimentary rocks indicate that deposition occurred within an upper mixed-load channels, delta plain environment, incorporating lacustrine (interchannel/interdistributary lakes), fluvio-lacustrine (crevasse splay/minor suspended-load channels. deltas), and Normal faults occurred contemporaneously with the accumulation of the Castor Seam. These faults displaced the sequence underlying the Castor Seam and modified subsequent deposition. The faults also show brittle deformation due to post-lithification tectonism. Split and/or absent coal in the Castor Seam displays a close association with faults, which disrupt the Pollux Seam. Such locations can be used as primary drilling targets during the delineation of faults and the definition of fault-free mining blocks