Geomorphology, palaeogeography and geoheritage in Semeliškės area

Valentinas Baltrūnas, Bronislavas Karmaza

The investigations performed and the present study are aimed at generalising all available data on geology and geomorphology of the Semeliškės area and presenting it as chart schemes (maps) as well as discussing the palaeogeographical evolution of the area in Post Glacial time. Now, at least five typical micro-regions are distinguished with only the margins of some of which entering the area of former rural district Semeliškės. Going from north to south, the following micro-regions are to be mentioned: Juodeliai–Laičiai, Semeliškės–Dainiai, Aukštadvaris–Beižioniai, Trakai–Bagdanoniai and Vilkokšnis–Tolkiškės. The latter two ones appear in the defined area only by their eastern and northern margins. The micro-regions marked differ in geological setup, hydrogeological, hydrological and geomorphological features as well as landscape. All this was caused by a retreat of the melting ice margin of the Last (Nemunas) Glaciation, its tongue-like configuration, local meltwater streams, giant ice lobes buried under the deposits, the Strėva ice-marginal valley being formed, as well as age and duration of all these phenomena. There are no state protected nature heritage objects yet. However, some of them can be included into such a list; first of all, these are Strėva and Nečiūnai pits of karst origin, also the Rudauka Spring at Semeliškės, quite a few interesting and valuable boulders witnessing the glacier routes as well as a landscape preserve at the upper reaches of Strėva and the northern margin of Spindžius landscape preserve.