ABSTRACT: Regional structural evolution of the northern Bowen Basin: Application to coal mining
Pryer, Lynn1 and Frans Bos2
(1) SRK Consulting, Deakin West, Australia
(2) Shell Coal Pty Ltd, Brisbane, Australia
Aeromagnetic, radiometric and DEM data from a single airborne survey was obtained at 400 m line spacing over the regional area and 80 m line spacing over the Shell Coal deposits in the Northern Bowen Basin. Calibrated integration with seismic profiles, gravity measurements, borehole information and mapping in underground and open cut mines produced a structural/tectonic model of the evolution of the basin. This model explains the geological evolution on a regional scale which can be applied at underground mine scale to explain differences in the distribution of mine structures and predict where structural complexity is most likely to occur. The model provides ages, orientations and styles to different sets of structures that may be encountered in the mine and delineates deep structures at the highest risk of younger reactivation and delineates zones with a high risk of faulting that could effect mining conditions. The main points of the model at both the regional and mine scale are 1) the basement structures control location and nature of younger faults, 2) the vergence of Permian faults can control the style of Triassic faults, and 3) the highest density of faults occurs over the shallowest basement. A further important benefit of the aeromagnetic survey is that the position of the basalt flows filling the palaeo drainage channels can be accurately defined. As these channels often contain large quantities of ground water, the knowledge of their position assists in the design of ground water controls required for the mining operations.
AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia