Minerały w utworach triasu syneklizy perybałtyckiej

Abstract

 W utworach triasu rejonu Krynicy Morskiej stwierdzono rentgenograficznie minerały uranu: coffinit i nasturan. Są to najbardziej rozpowszechnione minerały w złożach „piaskowcowych” uranu w USA, w stanach Colorado i Wyoming. URANIUM MINERALS IN TRIASSIC ROCKS IN THE PERI-BALTIC SYNECLISE The paper presents results of studies on uranium minerals in Buntsandstein and Middle Triassic rocks from the vicinities of Krynica Morska, the Peri-Baltic Syneclise (Fig. 1). The hitherto obtained data made it possible to find three uranium-bearing horizons in that area.The lower uranium-bearing horizon (III) is situated in the section of Lidzbark Formation (Middle Buntsandstein), being related to gray and green claystones. Content of uranium in these claystones is low and this horizon was not covered by the studies on uranium minerals.The middle uranium-bearing horizon (II) is situated at the base of Elbląg Formation (Upper Buntsandstein). The horizon, characterized by the richest uranium mineralization, is related to fine and coarse-grained sediments, gray and gray-green in colour. The studies involving microscopic analyses in transmittent and reflected light, microradiographic analyses (Tables 1–2) and X-ray-structural ones on the separated below 0.06 mm fraction of sandstones, made it possible to identify uranium minerals: coffinite and nasturan.The same minerals as above have been also identified in samples of gray fine-grained sandstones of the upper uranium-bearing horizon (I). That horizon is stratigraphically related to Upper Buntsandstein or Middle Triassic rocks.Final part of the paper presents an attempt to characterize geochemical associations and mineral parageneses of the studied strata.