A geological setup of the Aukštadvaris area
Aleksandras Šliaupa, Valentinas Baltrūnas, Bronislavas Karmaza
The geological mapping of the Aukštadvaris area had been performed for several times, therefore now there are favourable conditions to generalise all the collected geological information and, for the first time, to present a detailed description of the geological setup of the former rural area called valsčius. The surface geology and structure maps, geological profiles and other schemes featuring the peculiarities in the subsurface setup have been made. The knowledge on the Aukštadvaris area setup has been refreshed by adding data from the latest literary sources. The data from drillings as well as gravimetric and magnitometric surveys have shown that the crystalline basement in the area studied consists mainly of metamorphic rocks (primary sedimentary and volcanic) rocks and is laid over by a 650750 m thick sedimentary cover. The latter is found to consist of Vendian, Cambrian, Ordovician, Silurian, Permian, Triassic, Jurassic, Cretaceous, Neogene and Quaternary beds. The formation of sedimentary cover had been caused y the evolution of large Earth crust strictures, i.e. Baltic Syneclise and Masurian-Belarusian Anteclise. The beds of Quaternary and Cretaceous systems are best investigated in the area of Aukštadvaris. According to the base of the Cretacoeus beds, small deformations have been revealed, which are formed due to differentiated small movements of the Earth crust blocks during the Palaeogene, Neogene and Quaternary periods. These small movements affected the formation of buried and recent valleys as well as glacier retreat that mainly caused the peculiarities of land surface in the area of Aukštadvaris. The Quaternary intertill beds of sand, cobble and gravel are rich in water and promising for extraction of groundwater of high quality.