Quantitative geophysical log analysis in coal measure sequences

Abstract

Geophysical logging is routinely undertaken as part of coal mine exploration programs. With minimal analysis, coal seam depth can be determined and estimates made of coal quality, lithology and rock strength. Quantitative log interpretation will add to this information. We discuss log responses in terms of the mineralogy of the clastic sedimentary rocks frequently found in the black coal mining areas of the Sydney and Bowen Basins. We find that the log responses can be tied to the mineralogy with reasonable confidence. If a full suite of logs is run, ambiguities in the interpretation may be resolved. A key driver in this work is geotechnical characterisation. With this additional geophysical input, it should be possible to develop improved rock mass classification schemes.