Baltic Artesian Basin

one of the largest artesian basins in Europe. The basin is located in the northwestern part of the East European platform (in the Estonian, Latvian, and Lithuanian SSR’s), the northwestern part of the Byelorussian SSR, and Kaliningrad and Pskov oblasts of the RSFSR. The southwestern part of the basin is in Poland. In the USSR the basin covers an area of roughly 214,000 sq km. The typical relief consists of an alternation of hills and outwash and glacial-lake plains. The basin’s large platform structures includes the southern slope of the Baltic shield, the Baltic syneclise, and the Byelorussian anteclise. The region is composed of a complex of metamorphic and igneous Archean and Proterozoic rocks and strata of terrigenous and carbonate rocks from the Cambrian to the Anthropogenic. There are two layers of subterranean water. The lower layer includes the Cambrian-Wendian aquiferous horizon, and the upper layer encompasses the Cambrian-Ordovi-cian and overlying aquiferous horizons. The two layers are separated from each other by a thick and persistent bed of Cambrian clays.

The fresh waters of the upper layer are in a zone of intensive water exchange caused by river drainage. Waters from Silurian, Devonian, Upper Cretaceous, and Anthropogenic beds are used extensively for water supply. Natural resources of fresh subterranean waters in the Baltic artesian basin total 16.8 cu km/yr. The greatest modulus of average long-term subsurface flow (1.5-1.7 l/sec per sq km) is characteristic of the strongly fissured and karstic limestones of the Silurian and Ordovician, while the smallest modulus (about 0.5 1/sec per sq km) is characteristic of Paleogenic and Cambrian-Ordovician aquiferous complexes, which are marked by weak water conductivity and unfavorable conditions for infiltration supply. An average of between 5 and 30 percent of atmospheric precipitation supplies fresh subterranean waters. From 15 to 60 percent of river flow goes to form subterranean water flow. This ranges to as much as 70 percent on the Silurian and Ordovician plateaus and in the Merkys River basin.

Sulfate-fluoride and calcium-sodium mineral waters contained in submerged parts of the Cretaceous, Devonian, and Cambrian-Ordovician beds are used at the Druskininkai, Birštonas, and Baldone resorts. Hydrogen sulfide solutions from the basin are used at the Kemeri resort.