The Badenian evaporite basin of the northern Carpathian Foredeep as a model of a meromictic selenite basin
M. Bąbel, A. Bogucki, 2007. "The Badenian evaporite basin of the northern Carpathian Foredeep as a model of a meromictic selenite basin", Evaporites Through Space and Time, B. C. Schreiber, S. Lugli, M. Bąbel
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The hydrography and brine flow patterns in the Middle Miocene (Badenian) evaporite basin of the northern Carpathian Foredeep (in Ukraine, Poland and the Czech Republic) are reconstructed based on studies of the peculiar, conformably oriented, bottom-grown gypsum crystals present in the selenite deposits along the basin margin. The crystal apices are turned in a similar horizontal direction that is interpreted as the product of consistent flow of the bottom brines during crystal formation. Similarly the regular millimetre-scale growth zoning in these crystals presumably reflects the annual stratification-mixing pattern in the brine column typical of monomictic basins. In the central, deeper parts of the basin deposition was dominated by Na-chloride, and the selenitic facies are lacking. These central areas are interpreted as being meromictic during the oriented selenite deposition. The permanent pycnocline separated a mixolimnion, at the surface, from an anoxic (euxinic) monimolimnion, at the bottom, where direct evaporative crystallization of gypsum was not possible. The mixolimnion, which extended far onto the shallow margin of the basin, showed only a seasonal (annual) pycnocline and monomictic hydrography. Oriented selenites grew just in this mixolimnetic marginal zone, under predominantly counterclockwise (cyclonic) flow.
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Evaporites Through Space and Time
This book is an exploration of varying approaches to the study of the deposition, diagenesis and stratigraphy of evaporites. The volume includes papers from chemical modellers, who work on the basis of geochemical representations of the formative water bodies, and from basin-wide depositional-stratigraphical modellers, who propose depositional scenarios that are fitted to individual basinal pictures.
Until now there have been only a few studies of evaporite formation that explain the characteristic features we observe in the real rock record. This volume is a collection of relevant papers in which these features are integrated in a realistic manner, based on our new understanding of saline water bodies, to the diverse tectonic, chemical and depositional constraints of their individual basins. In additional there are several review articles that offer oversight and extensive referencing of basins worthy of further study.
This book is a valuable resource for sedimentologists and stratigraphers looking for an up-to-date reference on evaporite deposits.