Blizny tensyjne w dolomicie płytowym południowo- zachodniej części wysadu solnego Kłodawy - implikacje kinematyczne

Abstract

TENSION GASHES IN THE PIATY DOLORNITE (ZECHSTEIN) OFTHE SW PART OF THE KŁODAWA DIAPIR (CENTRAL POLAND) - KINEMATIC IMPLICATIONS Summary The paper presents kinematic implications resulting from mesostructures observed within a synclinal structure in the SW part of the Kłodawa salt mine at the level 600 (Fig. 1). The syncline has subhorizontal axis, subvertical axial plane and is defined by clays, dolomite, anhydrites and salts of the Zechstein Z3 (Fig. 3). The competence contrasts between the rocks involved enabled the development of different structures, of which tension gashes and boudines are the most important for the kinematic interpretation. There are three sets of tension gashes, labelled A, B, C. A and B form en-echelon arrays. On the basis of their orientation relative to the bedding-parallel boundaries of the brittle shear zones two phases of the development of the syncline were recognized: 1 - phase of dominant buckling and flexure-slip folding, followed by 2 - phase of dominant shear folding. Subvertical tension gashes C are indicative of a period of subvertical shortening. The latter might result from temporary impedements of the upward motion of the salt masses, due to different mechanical properties of the rocks pierced through.