Autor: Tadeusz Peryt

The Upper Permian Zechstein basin of Central and North-Western Europe became a model of chemical precipitation of evaporites several decades ago and as such is a classical one in the literature. Due to the initial success of the chemical approach to the evaporites, sedimentary aspects were but rarely discussed, similarly as in other ancient carbonate/evaporite basins. The studies in the last decade revealed the value of looking at evaporites as sediments rather than as chemical precipitates, and this approach resulted in a rapid increase of sedimentological observations and papers. Two basins attracted special attention: the Miocene basin of the Mediterranean and the Upper Silurian basin of Michigan. This volume presents papers on the third ancient carbonate/evaporite basin which was often referred to in the works on the two men- tioned basins. The thick cyclical Zechstein evaporite series (up to 1500 m and more) lies between thick red clastic deposits of mainly desert origin of the Upper Rotliegendes (Lower Permian) at the bottom and the similar series of the Buntsandstein (Lower Triassic) deposits at the top. Due to the cyclicity, the characteristical Zechstein members are easily correlated over the basin and furthermore, one may expect that the conclusions reached from the sedimentological study of particular sites within the Zechstein basin have general implications. Apart from the limited well-exposed outcrops representing mainly the primary near-shore zone with classical buildups in England and Thuringia, the majority of information derives from the sub-surface. As the three-dimensional characteristics are well defined, such situation favours the sedimentary modelling. Therefore, when this book was at an initial stage of its editing, we planned to complete it with a summary, being a synthesis of developments in the Zechstein sedimentology, and presenting the general sedimentological model of carbonate/evaporite basin development. But although our knowledge of the sedimentary evolution, of particular parts of the Zechstein basin, of the diagenesis in evaporitic sequences, of the depositional environment as well as of some general points has been considerably increased, many important problems remained and new arose.