Charakter i geneza dyslokacji świętokrzyskiej

Abstract

ON THE NATURE AND ORIGIN OF THE ŚWIĘTOKRZYSKA DISLOCATION Summary The Świętokrzyskie Dislocation divides the Holy Cross Mts into southern - Kielce, and northern - Łysogóry regions (Fig. 1). The nature of that dislocation, the greatest in this _area, was interpreted in various ways by individual authors (5, 6, 15, 21, 22, 25) (Fig. 2). The interpretations hitherto presented are revised here with reference to the results of new mapping and tectonic studies (8, 9, l O, 15, 23). The dislocation passes south of the Łysogóry and Jeleniów ranges and separates outcrops of Middle Cambrian shales and Upper Paleozoic strata of the Kielce-Łagów Synclinorium (Fig. 3). Taking into account results of an analysis of tectonic structures from opposite sides of the dislocation and the course of the dislocation in area between the Sufraganiec and Lubrzanka valleys (Fig. 4), it is concluded that Cambrian rocks of the Łysogóry unit are thrusted over folded ones of the Kielce region under a low angle. The Łysogóry unit is a nappe with thrust plane passing within plastic Middle Cambrian shales. Comparisons showed similarities of its structure and that of nappes of the Flysch Carpathians (1, 13). The analysis of shows of igneous and hydrothermal activity in northern part of the Holy Cross Mts (see 6, 19, 20, 24) made it possible to state that they were related to a major WNW-ESE oriented dislocation, passing north of the Łysogóry and Jeleniów ranges and obscured by overthrusted Paleozoic rocks of the Łysogóry unit. Taking into account the nature of igneous processes active in proximity of that dislocation it may be inferred that the dislocation represents a trace of Variscan subduction zone in the Holy Cross Mts. The magnitude of overthrust of the Łysogóry unit on the Kielce-Łagów Synclinorium is estimated at least at 11 km.