Deposits in carbonated waters from selected springs of the Polish Carpathians LUCYNA RAJCHEL, JACEK RAJCHEL, TADEUSZ RATAJCZAK, GRZEGORZ RZEPA Faculty of Geology, Geophysics and Environment Protection, AGH  University of Science & Technology, Mickiewicza St. 30, 30-059 Kraków, Poland; rajchel@geolog.geol.agh.edu.pl Abstract: Deposits associated with the outlets of carbonated waters in the Magura Unit of the Polish Carpathians occur within spring niches and along headwater outflows. Min- eralogical investigations of these deposits have identified a rusty-coloured, abundant precipitate of goethite and ferrihydrite, accompanied by calcite, dolomite, siderite and native sulphur. Key words: the Carpathians, carbonated water, goethite, ferrihydrite INTRODUCTION The authors studied deposits formed at the outlets of carbonated waters, i.e. waters that contain in 1 dm 3 more than 1 g of free CO 2 . The springs dealt with are situated in the Magura Unit in the Polish part of the Outer Flysch Carpathians. Mineralization (TDS content) of their waters is up to 8 g/dm 3 and the content of free CO 2 up to 3 g/dm 3 . An- ions are represented by HCO 3 - and insignifi- cant amounts of Cl - , while cations by main Ca ++ and Mg ++ and lesser Na + . These waters belong to the hydrogeological outer- Carpathian region DII (PACZYÑSKI ET AL., 1996) and their occurrences is limited to the Magura Unit. The sediments of this Unit rep- resent a profile from the Middle Jurassic to Lower Oligocene and are developed as flysch, sandstone-shale complexes with in- tercalations of conglomerates and marls, de- formed during Upper Cretaceous-Middle Eocene times. The carbonated waters of the Polish Carpathians are associated with zones of tectonic deformation, mainly with discon- tinuous dislocations. The deposits studied occur within spring niches and along headwater outflows, cover- ing their bottoms and walls either as thin coats, a foaming gel or a jelly-like suspen- sion (RAJCHEL ET AL., 1999, WIDZIÑSKI, 1972). The thickness of these deposits varies from several millimetres to fifteen or so centi- metres. The deposits resemble ochre and have colours grading from yellow to red, but most often they are rust coloured. Dry deposits are brownish-yellow and are earthy, brittle and knotty. Their presence in fields mark the ex- istence of former springs that have disap- peared due to a change in hydrogeological conditions. Such deposits were described in the area of the Carpathians in the 16 th century (ZEUSCHNER, 1836). In recent times they were Short scientific paper RMZ - Materials and Geoenvironment, Vol. 52, No. 1, 107-110, 2005 107