Abstract

The European Zechstein is a Late Permian group of formations that consists of shale, limestone and dolomite, anhydrite, rock salt, and potash salts in cyclic alternation over 1,000 m thick. Some of the anhydrite formations contain (a) beds with a distinct fining-upward texture, sharp bases and gradational tops, here interpreted as turbidites; (b) other beds with tightly packed clasts of anhydrite up to one meter in size, here interpreted as mass-flow breccias, and (c) bedded anhydrite with folds and concave sliding planes which may represent slumps. The thickness variation of the sulphate body along with the facies pattern in the overlying and underlying carbonates suggests that the sulphates were piled up in a platform similar to a shallow-water carbonate platform along the basin margin. The sediments described in this paper were all found along the steep basinward slope of this platform. Depositional structures similar to those in the Zechstein have been described in the Messinian gypsum formation (Miocene, Italy) Here the evaporites were deposited on pre-existing topography and did not create the relief by their own accumulation as in the Zechstein. Both the Zechstein and the Messinian sulphate bodies, however, were shaped by a similar interplay of localized precipitation in shallow water (or adjacent sabkhas), reworking and downslope transport as clastic material, and not by in situ precipitation alone. During the evaporite stages sulphates accumulated in all parts of the basin from the marginal tidal flats to the basin interior.

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