Malacofauna of Holocene freshwater calcareous deposits of Lithuania

Abstract

. Vilnius. 2010. Vol. 52. No. 1–4(69–72). P. 16–24. ISSN 1392-110XTh e malacofauna of freshwater calcareous deposits of Lithuania was studied. Sections of the Mūsos Tyrelis and Pabaliai peatbogs near the town of Siauliai, as well as Dubiciai section (three sites) in SE Lithuania and Dūkstos in Central Lithuania were investigated. Freshwater calcareous deposits are attributed to three groups of facies – lacustrine, valley-hollow-peatbog and terres-trial. Each group of facies consists of sub-facies (freshwater lime, “gazha” (limno-calcite), peat-tufa, calcareous tufa, “mada”) varying the formation conditions, composition and other charac-teristics. Th e mollusc fauna in the lacustrine facies group (Mūsos Tyrelis and Pabaliai sections) is represented by lacustrine species containing euryecological freshwater molluscs. Terrestrial and rheophilous species are rare or absent in the lacustrine group. Deposits of valley-hollow-peatbog facies contain shells of euryecological freshwater and lacustrine molluscs together with rheophyl shells, sometimes with abundant terrestrial shells, as was observed in the Dubiciai-4 section. A characteristic feature of the terrestrial facies group deposits is the occurrence of solely terrestrial mollusc shells (Dūkstos section).Key words: malacofauna, freshwater calcareous deposits, Holocene, LithuaniaReceived 23 October 2010, accepted 08 November 2010Aleksander Sanko. Belarusian State Pedagogical University, Sovetskaya St. 18, 220030 Minsk, Be-larus. E-mail: sankoaf@tut.by. Julius Vainorius . Nature Research Center Institute of Geology andGeography, T. Sevcenkos 13, LT-03223 Vilnius, Lithuania. E-mail: juliusvainorius@yahoo.com.Monika Melesytė. Department of Geology and Mineralogy, Vilnius University, M. K. Ciur-lionio 21/27, LT-03101 Vilnius, Lithuania. E-mail: monika.melesyte@gf.vu.lt