O przydatności schematu wydzieleń litologicznych stosowanego w kopalniach węgla kamiennego dla celów sedymentologicznych

Abstract

APPLICABILITY OF COAL MINING SCHEME OF LITHOLOGICAL DIFFERENTIATION FOR SEDIMENTOLOGICAL PURPOSES Summary The paper presents a method of use of lithological columns of mining works from the Wałbrzych Basin in sedimentological studies. Because of practica1 reasons, the scheme of lithological differentiations used in the mines is based on basic rock properties only and, therefore, fairly simple. That is why it is advantageous for comparing geology of individual mining works. However, the mining data appear too schematic to be widely used in more detailed, geological studies, e.g. sedimentological ones. In order to use archival mining records it appears necessary to adjust lithological classification applied in field works in such a way to make it comparable with the mining one (see 19). This leads to decrease in accuracy but, at the same time, makes possible marked increase in space which may be covered by the studies. The two classifications should be adjusted in such way that, if possible, only a single mining unit will correspond to that differentiated in field studies and the number of equivalents of a given mining unit in the latter scheme should be limited as much as possible. In order to test usability of the above mentioned method a lithological sequence has been first described according to the principles of mining classification and, subsequently, with the use of the field work criteria modified according to the above mentioned requirements. The two descriptions were subsequently analysed by the embedded Markov chain method. Figure 1 shows results of matrices of probability of transitions and differences of probability. Interpretations of modal transitions appear highly similar for both types of descriptions. This is well shown by schemes of a sedimentary cycle with grains fining upwards, obtained with the use of both methods (Fig. 2). The use of a modified scheme of the author's classification to supplement columns of mining works may be useful in interpretations based on the mining classification.