Stratygrafia i historia sedymentacji cechsztynu niecki północnosudeckiej

Abstract

STRATIGRAPHY AND SEDIMENTARY HISTORY OF THE ZECHSTEIN (UPPER PERMIAN) OF THE N ORTH SUDETIC TROUGH (SW POLAND) Summary The subdivision of the Zechstein deposits in the northern part of the North-Sudetic Trough (NST) and the southern part of the Żary Pericline does not present difficulties in contrast to the central and southern parts of the NST In Kościelna Wieś IG 1 borehole located in the central part of the NST (Fig. 2), except of the Zechstein Limestone and Platy Dolomite carbonate complexes that were recorded by M. Podemski (32), also the middle carbonate complex developed in carbonate-sulfate sabkha facies was recently found. This proves that in the borehole and its neighbourhood the PZ2 deposits occur and that Main Dolomite limit should be moved significantly towards the south. The sabkha complex in the Kościelna Wieś IG 1 borehole comprises subaerial facies of the supratidal flats as well as the intermittently subaqueous environments. Towards the south, the carbonate- sulfate sabkha of the PZ2 cycle passes into sulfate-siliciclastic complex that was recorded in the Czerwona Woda IG 1 borehole (Fig. 4, 6). The Zechstein deposition in the NST and the Żary Pericline was controlled by the Szprotawa Elevation that existed in the northern part of the Fore-Sudetic Block (Figs 7 -9). Frequent falls of sealevel led to subaerial exposures of major parts of the area. Consequently, the application of the cyclothem subdivision of the Zechstein which is of great use in more central parts of the Zechstein Basin, is of limited importance here what is reflected in the fundamental differences of the Zechstein subdivision in the NST It seems that the sequence stratigraphy concept should be used instead of the classical cyclothem subdivision.