Folia Historico-Naturalia Musei Matraensis - A Mátra Múzeum Természetrajzi Közleményei 17. (1992)
Füköh, L.: Malacostratigraphical Investigation of the Late Quaternary Subsided Zones of Hungary
Fol. Hist.-nat. Mus. Matr., 17: 97-106, 1992 Malacostratigraphical Investigation of the Late Quaternary Subsided Zones of Hungary FŰKÖH Levente ABSTRACT: The author briefly performs the ecelogical, biostratigraphical and malakostratigraphical elaboration of the Mollusc faunae of the most complete sequences and with the knowledge of the results gives the general concludes. During the investigation of the Hungarian Holocene Mollusc-fauna more and more and Important flat-land fauna became known, beside the faunae of the medium high mountain-ranges. The increase of these data enabled to attempt with full knowledge of the facts until now - giving outline history of the succession of the juvenile subsided zones with the help of malacostratigraphy . Because the ecological conditions of the species of our fresh-water fauna is less explored than the ecological conditions of the terrestrial ones,so such detailed analysis cannot be expected than have been made from the medium high mountain territories (FUKÜH, L. 1987). The faunal evolution of these territories (Fig. 1.) is approximately the same, it is why we made attempt to publish the fundamental Informations about courses of development and stratigraphical examinations. In the next part of this paper I Introduce to biostratigraphical-malacostratigraphical elaboration of the most complete sequences and with the knowledge of the results I give the general concludes. MALACOSTRATIGRAPHICAL INVESTIGATION OF THE TRANSDANUBIA 5árrét, Fejér county The finding place can be found at the Transdanubian part of Hungary at the so celled Mezőföld (Ä0ÄM, L. - MAROSI, S. - SZILÄRD, J. 1955). The first collection, with the consideration of stratigraphical data was done by E. KROLOPP in 1964, during the geological mapping of this territory (RÖNAI, A. SZENTES, F. 1972). The examinations suited to the fine-stratigraphical malacostratigraphical requirements were begun in 1972 (FÖKÖH, L. - SZABÓ, I. 1975, FÖKÖH, L. 1976). Meanwhile the peat and bog-lime production accomplished here made possible the soil research investigation of the utillzable deposits (DÖMSÖ0I, J. 1977). The results of the investigations, done until now is contained by great number of papers. The most significants were written by FŰKÖH, L. and KROLOPP, E. in 1986 and by FÜKÖH, L. in 1988. According these works are determinable the next about this subsided zone and its fauna: The territory of the Sárrét (Fejér county) was sunk during the Upper Pleistocene and was filled up with fluvial deposits. It is shown by the series of sediments consisting of strongly abraded, well-classified grevels, covered by fine-grained sand locally. It is explored at several point of the basin. These sediments occur in different depths. Its supposable reason is a significant settlement on the Pleistocene - Holocene boundary (ÄDÄM, L. MAROSI, S. - SZILÄRD, J. 1955). The samples contain good deal of Litoghlyphus natlcoldes which, according to our ecological knowledge prefers fresh-water envlroment primarily. As a result of a new subsidence the basin were filled with fluvial deposits, becamlng without an outlet during the Holocene. The subsidence might dissect this former homogenous basin into small ones (FÖKÜH, L. 1988). After it we can point out three periods of the lake's slow siltatlon (fig. 2). the dominant species of the first period is the Velvets plscinalis. The characteristic gastropod species of the second period are the Gyarulus albus and the Bithynla tentaculata. This is the main period of the lime mud formation. 97
