Localization of tectonic faults below Quaternary deposits using geophysical methods

Tectonic faults in coal-bearing rock formations are one of the most common geological factors that hamper the mining process. One of the most promising methods to localize tectonic faults below the Quaternary deposits is a complex that comprises geophysical methods (electrical tomography and seismic surveys using the correlation refraction method), geomorphological features of the terrain, and the hypsometry of the coal seams. The research was carried out at the Verkhne-Taluminskoye deposit in the South Yakutsk Basin. The principles of localizing tectonic faults in complex geological and geophysical interpretation included identification of significant anomalies by comparing geoelectric and velocity sections within a single profile and detection of the anomalous points; comparison of geophysical sections made using selected methods between the profiles (two different types of comparison based on the number of geophysical methods), correlation of the anomalous points' position on the geophysical sections. The main factors in identifying anomalous points included low values of elastic wave propagation, low values of specific electrical resistivity, and morphological similarity of anomalies on geophysical sections. These points were plotted on a topographic map of the investigated area and used for further interpretation. The next stage was interpretation of several adjacent profiles. These were used to correlate anomalies associated with the predicted tectonic faults. Correlation of anomalies between the profiles was made based on the similarity of the following parameters: the intensity of anomalies, the morphology of anomalous manifestations according to the methods, and the mutual arrangement of anomalies. The correlation was corrected on a topographic map with account of the geomorphological features. A tectonic diagram with lines of the predicted tectonic structures for mine takes of the Verkhne-Taluminskoye deposit was built based on the results of geological and geophysical interpretation of the profile groups, morphostructural features of the deposit terrain, and hypsometry of the coal seams.