Charakter wód mineralnych w przystropowej strefie ich występowania na obszarze Polski północno -wschodniej

Abstract

W artykule omawia się przestrzenną zmienność głębokości do wód mineralnych na obszarze NE Polski oraz skład chemiczny tych wód w przystropowej strefie ich występowania. Głębokość do strefy wód mineralnych zmienia się w bardzo dużych granicach, bo od powierzchni terenu do ponad 1200 m. Określono przeciętny skład chemiczny wód mineralnych w strefie przystropowej (CI-Na) oraz odchylenia od tego składu.CHARACTER OF MINERAL WATERS AT THEM SURFACE IN THE NORTH-EASTERN PART OF POLANDSummaryThe north-eastern part of Poland belongs to different structural elements. The most evident ones are: elevated part of Precambrian platform (Fig. 1, I), the Kujavian-Pomeranian swell (II) and a depression dividing these elevated structures with the Peri-Baltic syneclise. The surface separating mineral and fresh waters is found at the depths ranging from 0 m in SW to more than 1200 m in SE part of this area (Fig. 1). This surface continues in different stratigraphic units: Quaternary, Tertiary, Cretaceous, Jurassic and even Cambrian formations on the south-east (Fig. 1). The mineralization of water grows below the separating surface rather quickly, in shallow position of mineral waters as well as in the deep one (Fig. 2 - diagrams I-XI). The shallowest occurrence of mineral waters is connected with tectonically disturbed salt deposits. Their deepest position is met on limited spaces, also within the basin structures.On the basis of the frequency of certain chemical features of the mineral . waters at their surface the typical content is determined, the deviation from it for the particular ions being marked on the map (Fig. 2). The Mg content did not reveal noticeable deviations. Taking into consideration low water mineralization, typical values were chosen at large intervals, and so: CI- 50-90. SO24 below 20, HC03- 10-50, Na+ above 75, Ca2+ and Mg2+ below 2% mvals.At a general predominance of CI-Na waters, local considerable deviations are noted, which can be connected with gypsum- and sulphid deposits, or with the differentiation in the intensity of water circulation. Some anomalies be treated as the reflexions of tectonic processes operating at present or in the past.