The Badenian evaporite basin of the northern Carpathian Foredeep as a model of a meromictic selenite basin

Abstract

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.

The Middle Miocene of the Fore-Carpathian Basin (Poland, Ukraine and Moldova)

“…This idea was also accepted by Połtowicz (1993), Bukowski (2011), and Głuszyński and Aleksandrowski (2016). Similarly Bąbel and Bogucki (2007), who applied limnological terminology to the evaporite basin, suggested a meromictic lake model for the basin, in which halite deposition was restricted to the deepest monimolimnion zone. It was assumed that the selenite deposits were formed only in the well oxygenated and Ca-sulphate saturated mixolimnion zone, on the marginal platform or shelf only.…”

“…5E). These studies revealed the counter clockwise pattern of brine flow in the basin, interpreted as cyclonic circulation typical of the closed and semiclosed basins of the northern hemisphere (Bąbel 1996(Bąbel , 2002bBąbel et al 1999Bąbel et al , 2011Bąbel et al , 2015Bąbel and Becker 2006;Bąbel and Bogucki 2007). The Badenian basin is possibly the only ancient example where the cyclonic basinal water flow pattern has been detected.…”

“…It was assumed that the selenite deposits were formed only in the well oxygenated and Ca-sulphate saturated mixolimnion zone, on the marginal platform or shelf only. In both models the halite deposition in relatively deep subbasins could be connected with the shallowing and emersion of the surrounding shelves (Bąbel and Bogucki 2007;cf. Bukowski 2011).…”

“…5B, C; Bąbel 1987Bąbel , 1999aPeryt 1996), never recorded outside of the Badenian basins and widespread microbialite and stromatolite facies (Text- fig. 5D, Kwiatkowski 1970Kwiatkowski , 1972Kasprzyk 1993c;Peryt 1996;Bąbel 2005bBąbel , 2007bBąbel et al ANNA WYSOCKA ET AL. 360 .…”

“…1. A -Sketch map of the Mediterranean Tethys and Paratethys bioprovinces in Europe (after Rögl and Steininger 1983); B -the present-day extent of the Middle Miocene deposits of the Fore-Carpathian Basin in Poland and western Ukraine (foredeep depozone -deep yellow, back-bulge depozone -light yellow); C -the present-day distribution of the Badenian evaporites, without carbonate facies (after Khrushchov and Petrichenko 1979, and other sources) with the location of the exposures described in the text (Poland: B -Bęczyn (=Benczyn), Bh -Bochnia, Gl -Gliwice, Gr -Grobie, HL -Huta Lubycka, HR -Huta Różaniecka, J+P -Józefów and Pardysówka, K -Korytnica, N -Niskowa, NA -Nida area, N+R -Nawodzice and Rybnica, O+A+W -Oświęcim, Andrychów, Wadowice, PPińczów, Sm -Smerdyna, Sw -Świniary, W -Wieliczka, Z -Zgłobice; Ukraine: Br -Bridok, G+R -Glebiviti and Romaniv, Kh+H -Khorosno and Hlukhivets, L -Lozova, M -Mohyla, M+N -Maksymivka and Halushyntsi, O -Ohryzkovtsi, Pi -Pisky, Pr -Peremyshlany, S -Skoviatyn, Sh -Sykhiv, St+P -Stratyn and Pukiv, S+N+H -Sakhkamin, Nihyn, Humentsi, U -Ustechko, Za -Zakupne, Zh -Zhalybory; Moldova: Balatina) Górka et al 2006Górka et al , 2012Radwański et al , 2011Radwański et al , 2012Radwański et al , 2014Wysocka et al 2006Wysocka et al , 2011Wysocka et al , 2012Bąbel and Bogucki 2007;Ceranka 2007a,b;Czarniecka 2011) and inside the Carpathians (Bałuk 1966(Bałuk , 1970Łoziński et al 2015. The staff of the Faculty were joined in their researches by their associates, students, friends, and a number of colleagues from the Polish Geological Institute, Polish Academy of Sciences, Jagiellonian University and University of Science and Technology (e.g., Musiał, 1977, 1979a,b;Studencki 1979Studencki , 1988aStudencka 1986Studencka , 1987Studencka , 1994Studencka , 1999Studencka , 2015Studencka and Studencki 1988;Peryt 1994, 2015;Peryt et al 1995Peryt et al , 2012…”