Warunki hydrogeologiczne Pojezierza Myśliborskiego i obszarów sąsiednich w granicach jednolitej części wód podziemnych nr 23

The area of the GWB (groundwater body) No. 23 is a part of West Pomeranian and Lubusz Voivodeships and the water region of the Lower Odra and Przymorze Zachodnie. It includes districts: gryfiński, myśliborski, pyrzycki and gorzowski. The geological conditions of the study area are visibly corresponding to the deep tectonic structures of Szczecin basin and Gorzów block. Fresh groundwater is occurring here in porous sediments of the Quaternary, Neogene and Paleogene and fissured-porous rocks of the Upper Cretaceous. In the area of Szczecin basin, structures of Cretaceous aquifers are associated with Mesozoic secondary anticlines. In the Odra valley the aquifers are constituted from shallow laying Quaternary sediments (depth: 10 to 50 m). Thickness of Upper Cretaceous marbles leading fresh water does not exceed 30 m. The primal structures of the youngest sediments of Neogene- Miocene (-50 to -80 m above sea level) were disrupted during the earlier glaciations. During this geological period many of the geomorphological forms - egzaration depressions and glacitectonic extrusions formed from the Paleogene and Neogene sediments, and also elevations built from xenoliths coming from deeper rock bed, were formed by the complex of different geomorphological processes. The sediments of Neogene-Miocene have variable thickness, from a few meters within the deep erosion structures, up to 200 m within the Tertiary elevations. The Quaternary aquifers occur in multilayer system of groundwater layers constituted by fluvioglacial and fluvial sedimentation (sand and gravel) during successive glaciations and interglacials. Aquifers are often divided in multiple different layers, isolated by low-permeable layers of clays or glacial silts and proglacial clays. There are selected few regional aquifers: four Quaternary aquifers - first unconfined; upper, interior and lower intertill aquifers; two Miocene - upper and lower aquifers and one Cretaceous aquifer. The thickness of individual aquifer is variable; it's locally up to 50 m. The GWB No. 23 aquifers were aggregated to 3 levels (hydrogeological zones) belonging to different systems of groundwater flow: I level - first unconfined and upper intertill aquifer (locally Cretaceous aquifer); II level - interior intertill aquifer; III - lower intertill aquifer and upper Miocene aquifer. Because of the multilayer character, the GWB No. 23 groundwater system is very rich in water.