Fault Dimensions and Displacements in Mining Area: Northern Part of the Upper Silesian Coal Basin

Abstract

Fault network of northern part of the Upper Silesian Coal Basin (the USCB) was mapped with regards to structures having more than 1 m of vertical throw that were surveyed in mine driving roadways and worked panels of coal. The map was digitized on SUN workstation using ZYCOR software. Parameters of size and geometry catalogued while digitizing for each item considered were, as follows: 1) local Cartesian coordinates of the fault terminations (Sucha Góra grid), 2) attachment to a proper azimuthal set defined by vectorial analysis, 3) order (rank) of the structure interpreted by means of structural analysis, 4) maximum throw, 5) angle of dip of the fault surface. Original programs were created for data selection. They enabled sampling populations with optionally established limits of separate fault features listed above. One can figure out and depict on graphs relationships between the parameters employing programs made for analysis of these particular data sets. Relationship between width of a fault and its maximum throw is ruled by power function with exponent between 1.5 and 2.0. The result is nearest to those presented in the last papers by the team of the Fault Analysis Group from the University of Liverpool (Gillespie et al., 1992). Distribution of dimension in the fault population is illustrated on log-log graphs by curve which may be estimated by a straight line whose slope is equal -2.3 roughly. Obtained results are comparable with those concerning another regions and/or groups of faults from variety of geological environments provided by other scientists. Their position in combined dataset is useful for adjusting existing models and interpretations, especially they help with stating more precisely formulae that express scaling laws governing the relationships studied. The displacement/dimension relationship determined precisely implies more accurate description of fault growth over geological time. Furthermore, this relationship gives a possibility to calculate total brittle strain for this deformed rock-complex. Therefore the study on faults displacement and dimension, as well as essential follow-ups are of such importance for the USCB area.