Porównanie wybranych sekwencji osadów jeziornych czerwonego spągowca z basenów śródsudeckiego, północnosudeckiego i boskowickiego
Abstract
Comparison of Rotliegende lacustrine depositional sequences from the Intrasudetic, North-Sudetic and Boskovice basins, (Central Europe)
Abstract
Depositional sequences which originated in deep lakes with stratified water column are particularly thick and contain diversified lithofacies and biofacies, as compared with the other lacustrine deposits of the Rotliegende of the Central Europe. Such sequences include several facies assemblages which have been connected with the following subenvironments: 1) coastal mudflat, 2) sabkha/playa, 3) delta plain, 4) nearshore, 5) subaqueous delta slope, 6) subaqueous fan and 7) open lake. Rotliegende lacustrine depositional sequences from the Intrasudetic, North-Sudetic and Boskowice basins reveal a number of features in common. Symmetric vertical organization of these sequences, which resulted from the transgressive-regressive cycle of the lake development is one of the most striking common features. Depositional sequences of the lakes under description exhibit evidence of frequent lake level fluctuations, subaerial exposition and contain small-scale shallowing-up motifs. Regressive segments of these sequences consist of progradational deltaic deposits. The general similarities resulted from similar evolution of the lakes within individual basins. Thus, it is suggested that the general characteristics and tectonic regime of the host sedimentary basins were similar, assuming uniform palaeoclimatic conditions for the area of Central Europe. Details of the facies composition and vertical organization, which vary within individual sequences resulted, in turn, from the conditions specific of individual basins, and they depended on exceptional events and on the location of the studied sections within the basins.