Degree of Faulting of Hard Coal Deposits of Upper Silesian Coal Basin

The paper presents the results of research on the degree of faulting of deposits/mining areas of the Upper Silesian Coal Basin having been carried out since the 1970s. The results of these works are comprised of an analysis of the density of faults and an of the faulting index for 26 deposits/mining areas in the borders of the USCB. The statistical presentation of the problem includes three main parameters that characterize the tectonic complication of hard coal deposits in the borders of mining areas: lineal density GUL, surface density GUP and synthetic faulting index WU. The comparison of values of these parameters for particular deposits/mining areas was used for drawing up maps of their changes, whereas the results of the obtained view of variability have been interpolated and extrapolated to the borders of the entire basin. The results of the research showed that the values of GUL vary between 0.2 and 9.4 of faults/ m·10-3 and for all four analyzed directions: W-E, N-W, NW-SE i NE-SW, indicate a significant growing tendency in the following directions: N and NW and in SW. According to an analysis of GUP, it was stated that the largest part of the study area is occupied by the area in which there are no faults and the percentage of surface with GUP > 300 m/m2·10-4 is insignificant and does not have an essential influence on the rate and value of the faulting index. WU varies between 1.4 and 131.4 m/m2·10-4 (average for USCB: WU = 52.1 m/m2·10-4) and indicates a significant increasing tendency in the directions: N and NW as well as in the direction of SW. This determines the occurrence of USCB deposits of extreme different grade of tectonic complication in the borders: from not complicated (I grade) to very strongly complicated (VI grade).