Zmiany składu fizyko-chemicznego wód z utworów oligoceńskich w rejonie Warszawy

Abstract

CHANGES IN PHYSICO-CHEMICAL COMPOSITION OF WATERS FROM OLIGOCENE HORIZON IN THE WARSAW REGION Summary The waters originating from Oligocene strata of the Warsaw area have very high utilization value. Their physico-chemical composition is not uniform throughout their occurrence area. To the west from the Vistula river the highest minerallization occurs; to the east the minerallization rapidly decreases. Long-term water consumption caused a dynamic development of the regional depression. Theoretically, a decrease in the water pressure may bring about qualitative changes of the physico-chemical composition, as suggested by the previous authors (J. Samsonowicz, W. Olendski), i.e.: (1) influx of salty waters from the underlying Cretaceous strata; (2) gradual freshening of waters in result of increasing inflow of waters characterized by lower salinity; (3) the effect of Miocene coloured waters, in the case of too high mutual pressure difference. A comparison of the results of physico-chemical analyses made at various times showed the present aerial stability in waters composition; the observed fluctuations in quantities of various components did not display any tendencies towards their decrease or increase. It does not mean, however, that further exploitation will not effect radical quantitative changes in macrocomponents of Oligocene waters along with the development of regional depression.