Coal

Geophysics for Coal

Stephen Mudge has been applying a variety of geophysical techniques to coal exploration and production in Australia since the late 1970s. One of the common uses of geophysics is detecting and mapping the occurrence of igneous rocks; such as dolerite and basalt dykes, sills and flows; to assist with exploration, to help optimize the location of seismic surveys, and to assist with mine planning. In addition, a range of data-processing techniques have been developed and tested to detect the geophysical responses characteristic of igneous dykes, sills and flows, and to map structures in magnetic basement rocks.

The fastest and most cost-effective geophysical method for broad- area mapping of magnetic dolerite and basalt in coal seams, and to map the magnetic basement rocks, is surveying with low-level, high- resolution aeromagnetics. Specialised data processing techniques are applied to the aeromagnetic data using TargetMap^TM in order to resolve the magnetic responses of dolerite and basalt, and structures in the basement rocks. Details of TargetMap^TM can be found elsewhere on this web site.

A number of aeromagnetic surveys from several eastern Australian coal basins have been processed with TargetMap^TM to detect and map magnetic igneous rocks in the basins and to map the structure of the hard-rock basement. Details of TargetMap^TM can be found elsewhere on this web site, including an example of reprocessed total magnetic intensity data from the Clermont coal field in the Bowen Basin, Queensland, Australia.

References

Here is a reference to a very good paper describing the application of TargetMap^TM (previously known as the Overburden Filter^TM) to aeromagnetic data from the Blair Athol coal field in the Bowen Basin, Queensland, Australia.

Searle, D., 2005. New Overburden Filter technology sees through basalt in Blair Athol area - unlocking the secrets of the Bowen Basin from the air. In Carloss, B. (Ed.), Queensland Government Mining Journal, Department of Natural Resources and Mines, Queensland Government, Australia, Vol. 103, (1218), March 2005, p 82 - 83.