Facje i paleogeografia cechsztynu zachodniego części syneklizy perybałtyckiej

Abstract

FACIES AND PALEOGEOGRAPHY OF THE ZECHSTEIN OF WESTERN PART OF THE PERI - BALTIC SYNECLISE (NORTH POLAND) Summary The boundaries of paleogeographical zones during deposition of Zechstein deposits in the western part of the Peri - Baltic Syneclise are distinctively linear what suggests their tectonic predestination. In the Puck Bay region which is especially well studied, NW - SE and NE – SW directions predominate; they are reflected in the distribution of facies and thickness of the Lower Werra Anhydrite (Fig. 4), Oldest Halite (Figs 5 and 6), Upper Werra Anhydrite (39, Fig. 1; 42, Fig. 1, 13), Main Dolomite (Fig. 9), Basal Anhydrite (Fig. 9), Platy Dolomite (Fig. 10) and Main Anhydrite (Fig. 10). In the Zechstein Limestone, a general NW - SE direction is also visible in the Puck Bay region (Fig. 1). West of the Puck Bay region, the main direction influencing the patterns of facies and thickness is close to meridional except of the northern part of the studied area where it changes to NNW - SSE. The change of NNW - SSE direction to NE - SW direction (i.e., one of dominant directions in the Puck Bay region) takes place south of Kopalino and is particularly well expressed during the deposition of Lower Werra Anhydrite (Fig. 4), Oldest Halite (Figs 5 and 6) and Main Dolomite (Fig. 9). The persistence of the directions influencing the pattern of facies and thickness distribution as well as the changes of intensity of dominant directions in time seem to be related to subtle changes of subsidence of particular blocks in the Zechstein basement. The influence of such movements for the patterns of facies and thickness of Zechstein evaporates was earlier suggested in other parts of the Zechstein basin. The study defined zones of possible occurrence of potassium - magnesium chlorides in the western part of the Peri - Baltic Syneclise.