Folia Historico-Naturalia Musei Matraensis - A Mátra Múzeum Természetrajzi Közleményei 17. (1992)
Füköh, L.: Malacostratigraphical Investigation of the Late Quaternary Subsided Zones of Hungary
Among the lakes of the Kiskunság National Park we have some informations from the fossil fauna of the Háromszéki-tó. SZABÖ, S. (1990) remarks in his paper, in the course of representation of the recent fauna of the lake, that he had collected Lithogliphus naticoides, Valvata piscinalis, Bithynia tentaculata, from the deposits of the outcrop which is situated at the SE part of the lake. These species are not living here, nowdays. South - east Hungary (Békés county) The till now published south-east Hungarian data are reviewed reffering to literary details. Detailed analysis is given by Tamás Domokos (19B4) about the Holocene Mollusc-fauna of Fehér-tó (Kardoski'it) . According the author the deposits are Holocene resedimented, marsh-loesses in one of the remained branches of the Anclent-Maros river. Because of the unified sediment biostratigraphical evaluation were not performed, only the ecological analyses of the malacological material were completed. The chronological ranking of the fauna was accomplished on the basis of the results of parallel examinations (malacological, archeological , vertebrate paleontological) . According the author the fauna lived in the period following the Atlanticum, in the Late Holocene. The other exposed Holocene sediments of this teritory is the profile of the Körösladány Brickworks (KR0L0PP, E. - SZÓN0KY, M. 1982). The profile represents the sequence of the Ancient-KörÖs river. The type of the sediment mainly clay end silt. Because of the rapid sedimentation unambiguous stratification was failed to reveal. So the Mollusc-fauna were published jointly by the authors. It is why malacostratigraphical evaluation couldn't be done. But here we have to stress the presence of Gyraulus riparius, which can be found in three sampling horizons. And we have to mention about the presence of Lithoglyphus naticoides and about the frequency of Bithynia leachi in contradiction to Bithynia tentaculata. The Jászság (Northern border of the Great Plain) The third examined teritory of the Great Plain is the Jászság. Fine-stratigraphical collections were performed between Jászberény and Jásztelek in the fossil meanders of the Ancient-Zagyva river, in connection with archeological examinations. Detailed analysis is not performed yet. This is the first publication of the preliminary examination of the fauna. The sediments exposed by boring can be taken to two parts. The upper is highly humlc loam with fluvial sand separated by clay deposits under it. Its fauna bears marks of fluvial mixed character, but in spite of this, its elements can be separeted well from each other. The borings were deepened in the fossil river-bed and on the margin of the river-bed. The number of the mollusc species in the loam is very little. With the exception of one or two terrestrial species (Pupilla muscorum, Vallonia pulchella) these are palaudal species. The most frequent are: Anisus splrorbis, Planorbis plenorbis, Bithynia tentaculata operculum and Pisidium species. The problem of turning up the species and the operculum was mentioned by KR0L0PP (KR0L0PP, E. - SZÓN0KY, M. 1982). In the lower, sandy sediments appears the Lithoglyphus naticoides, the Valvata piscinalis and the Valvata pulchella . The value of the fauna is the occurrence of the Gyraulus riparius. The dissimilar character of the sediments and their fauna points to the fact that the sediments deposited by the Ancient-Zagyva formed rapidly in consequence of the repeated channel-changing of the river. This may be the cause of the poor fauna, and even we can suppose that the river gave place to a shallow, in a phase dry marsh territory. This is the cause, that those terrestrial species are absent characterise, like in case of Fert6-tó, the intermittent humid, intermittent arid territories. The above mentioned faunae, by all means do not contain the all exposed in the foregoing Holocene fluvial sediments. Beside the territories examined by me, I was anxious to introduce those which are the most significant in the view of the examination of the Hungarian subsided zones. 103
