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Preliminary Malacological Investigations on East Croatian Loess Profiles

Quaternary sediments are prevalent in Eastern Croatia and include predominantly alluvial, marshy, lucustrine sed ments that are partly covered with aeolian material. At least six paleolsol, ranging in age from the Middle to Upper Pleistocene, are intercalated in the loess sections in Eastern Croatia. Geochemical, sedimentological and geochronological analyses of these paleosols have been used to reconstruct the environmental and climatic changes that occurred in Eastern Croatia during the Middle to Late Pleistocene. With a few expectations, results of malacological investigations of loess profiles in Eastern Croatia were published mostly in Croatian language so far. In 2008, conjunction with Croatian-Hungarian bilateral project, two of these loess profiles were investigated at Zmajevac and Šarengrad villages, in Eastern Croatia. Both profiles are situated in the vicinity of the Danube. Samples were taken at every 25 cm of the profiles, and the main goal of the investigation was to study the Quaternary malacofauna. The examined profiles yielded nearly 9, 000 specimens of 55 mollusc species. The abundance and dominance values of taxonomically identified specimens were noted for each profile. In addition, charts were prepared depicting the specimen and percentage distribution of individual species with depth. The main characteristics of the Zmajevac profile are the appearance of chronospecies (Ena montana, Mastus bielzi, Cochlodina laminata, Macrogastra ventricosa, Clausilia pumila, Trichia unidentata, Trichia edentula), the presence of Pseudofusulus varians which taxa is a curio in the Carpathian Basin ; and a probable change in temperature demand of Vallonia tenuilabris in the lower parts of the profile. Based on composition of the mollusc fauna and the age data, the lower part of the profile is deposited during the Middle Pleistocene. The duality of Šarengrad profile can be revealed in the composition of the mollusc fauna. The lower part of the profile has fluvial origin (sandy silts with infusion loess layers on the top) and on the upper part aeolian loess layers deposited. Secondly, this profile – compared with the other nearby profiles – provides one of the most diverse collections of mollusc species in the lower Danube area. It yielded 51 different mollusc species, 34 terrestrial and 17 freshwater taxa.

Quaternary malacology; Loess profile; Šarengrad; Zmajevac; Croatia

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