Geophysical examination of coal deposits
Abstract
Geophysical techniques for the solution of mining problems and as an aid to mine planning are reviewed. Techniques of geophysical borehole logging are discussed. The responses of the coal seams to logging tools are easily recognized on the logging records. Cores for laboratory analysis are cut from selected sections of the borehole. In addition, information about the density and chemical composition of the coal may be obtained. Surface seismic reflection surveys using two dimensional arrays of seismic sources and detectors detect faults with throws as small as 3 m depths of 800 m. In geologically disturbed areas, good results have been obtained from three dimensional surveys. Smaller faults as far as 500 m in advance of the working face may be detected using in seam seismic surveying conducted from a roadway or working face. Small disturbances are detected by pulse radar and continuous wave electromagnetic methods either from within boreholes or from underground. Other geophysical techniques which explicit the electrical, magnetic, gravitational, and geothermal properties of rocks are described.
- Publication:
-
Unknown
- Pub Date:
- April 1981
- Bibcode:
- 1981gecd.rept.....J
- Keywords:
-
- Chemical Composition;
- Coal;
- Electromagnetic Measurement;
- Geophysics;
- Mineral Exploration;
- Mines;
- Mining;
- Pulse Radar;
- Seismographs;
- Boreholes;
- Continuous Radiation;
- Density (Mass/Volume);
- Geological Faults;
- Geological Surveys;
- Seismic Waves;
- Geophysics