Tektoniczne uwarunkowania lokalizacji i genezy złóż siarki w Czarkowach i Posądzy (zapadlisko przedkarpackie)

Abstract

TECTONIC CONDITIONS FOR LOCATION AND FORMATION OF SULPHUR DEPOSITS AT CZARKOWY AND POSĄDZA (CARPATHIAN FOREDEEP) Summary Sulphur deposits at Czarkowy and Posądza are located at two opposite ends of the Działoszyce Depression, at eastern side of Nida Horst (Czarkowy deposit) and Słomniki Horst (Posądza deposit). Reasons for such location of deposits come from the asymetrie structure of the horsts. Faults that limit them indicate greater throw on their western sides and therefore, chemical deposits occur at larger depths to the west of the horst structures. Due to that, a penetration of surface waters with dissolved oxygen (needed in metasomatosis for oxidation of sulphuretted hydrogen into sulphur) was here difficult. Besides, antithetic rotations of beds that result in a formation of tectonic traps, firstly for hydrocarbons and finally for sulphur deposits, are noted only at eastern side of horsts whereas a lack of rotation of beds or their homothetic type occurs in the west. A tectonic spatial model of deposit location depends on a dislocation pattern, composed of two fault assemblages: dip-slip ones of northwest-southeast azimuth and strike-slip as well as oblique slip ones of northeast-southwest and east-northeast- west-southwest azimuths. A tectonic evolution that enabled a formation of deposits, ran in three phases: 1. Upper Badenian one when throws of northwest - southeast faults enabled a development of deposit traps, 2. post-Lower Sarmatian one when shifts of northeast-southwest and east-northeast -west-southwest faults enabled a movement of hydrocarbons from bedrock reservoirs and their "pumping" into the Miocene complex, resulting in a reduction of gypsum into sulphuretted hydrogen, 3. Quaternary one that lasted until recent times, when a whole dislocation system got rejuvenated, inflow of surface waters and oxidation of sulphuretted hydrogen caused a development of native sulphur.