TY - JOUR
T1 - Initiation and growth of gypsum piercement structures in the Zechstein Basin
AU - Williams-Stroud, Sherilyn C.
AU - Paul, Josef
N1 - Funding Information:
AcknowledgemenrsThe authors would like to thank Walter Dean of the U.S. Geological Survey for inviting us to participate in the USGS Polish Initiative Project, which gave the first author the opportunity to visit the Zechstein localities described in this paper, and resulted in the introduction of the two authors, making this collaboration possible. S.C.W.-S. would also like to thank two USGS reviewers, Linda Gunderson and Haydee Salmun, whose comments and suggestions greatly improved the original manuscript, and a very thoughtful review by Daniel Schultz-Ela that significantly corrected our view on how diapirs initiate. This work was funded by the Marie Sklodowski Curie Fund and the USGS Evolution of Sedimentary Basins Project.
PY - 1997/7
Y1 - 1997/7
N2 - The importance of tectonic processes in initiating halite diapirs has become much better understood in recent years. Less well understood is the development of diapiric structures involving rocks composed predominantly of gypsum. Below about 1000 m, gypsum dehydrates to anhydrite, which often obscures primary sedimentary textures. If the strain associated with diapiric rise in the rock induces the transition to anhydrite, obliteration of primary features in the gypsum can be expected. In our study, we infer that the diapiric movement in the Werra Anhydrite member of cycle 1 of the Zechstein Formation of Europe occurred before the initial transition of gypsum to anhydrite based on the presence of pseudomorphs of bedded primary gypsum crystals, the overburden lithologies and depositional environment, and the mechanical properties of gypsum, anhydrite and carbonate rocks. Faulting and differential loading of a shallow overburden were the key components in initiating the gypsum diapirism. The transition to anhydrite occurred after burial and after cessation of diapirism. In comparison, the diapirism of calcium sulfate of the Leine Anhydrite into the Leine Halite members of cycle 3 of the Zechstein Formation probably occurred much later after burial and appears to have been triggered by halite diapirism, which in turn triggered the dehydration reaction, causing the calcium sulfate to become the incompetent phase relative to the halite. Published by Elsevier Science Ltd.
AB - The importance of tectonic processes in initiating halite diapirs has become much better understood in recent years. Less well understood is the development of diapiric structures involving rocks composed predominantly of gypsum. Below about 1000 m, gypsum dehydrates to anhydrite, which often obscures primary sedimentary textures. If the strain associated with diapiric rise in the rock induces the transition to anhydrite, obliteration of primary features in the gypsum can be expected. In our study, we infer that the diapiric movement in the Werra Anhydrite member of cycle 1 of the Zechstein Formation of Europe occurred before the initial transition of gypsum to anhydrite based on the presence of pseudomorphs of bedded primary gypsum crystals, the overburden lithologies and depositional environment, and the mechanical properties of gypsum, anhydrite and carbonate rocks. Faulting and differential loading of a shallow overburden were the key components in initiating the gypsum diapirism. The transition to anhydrite occurred after burial and after cessation of diapirism. In comparison, the diapirism of calcium sulfate of the Leine Anhydrite into the Leine Halite members of cycle 3 of the Zechstein Formation probably occurred much later after burial and appears to have been triggered by halite diapirism, which in turn triggered the dehydration reaction, causing the calcium sulfate to become the incompetent phase relative to the halite. Published by Elsevier Science Ltd.
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U2 - 10.1016/S0191-8141(97)00017-5
DO - 10.1016/S0191-8141(97)00017-5
M3 - Article
AN - SCOPUS:0031190845
SN - 0191-8141
VL - 19
SP - 897
EP - 907
JO - Journal of Structural Geology
JF - Journal of Structural Geology
IS - 7
ER -