Anomalies in the composition of Baikal pore waters

Anomalies in pore water composition have been found in the 100 m long core BDP-93 that was drilled in southern Lake Baikal, in four piston cores (1 to 8 m in length) taken from the same region, and in recent sediments from Fr olikha Bay, a hydrothermal vent site in northern Lake Baikal. Pore water an omalies are manifested as significant increases in concentration of sulfate s, bicarbonates, chlorides, and the ions of alkali and alkali-earth metals. Anomalies were found at different depths below the sediment-water interfac e (from centimeters to tens of meters), and the level of pore water enrichm ent in these components varies from station to station. Anomalies have specific features in each of the Lake Baikal basins. It is s hown that there is a genetic relationship between subaquatic and terrestria l centers of thermal-water discharge in northern Lake Baikal. These anomalo us pore-water concentrations are presumably due to the leaching of ambient sediments. In southern Lake Baikal, in the Selenga river delta, ground waters of speci fic composition that are relies of ancient salt lakes could serve as a sour ce of anomalous concentrations in pore-water components. Their influence ma y be realized through the extensive zones of increased permeability.