Perspektywy odkrycia złóż uranu na obszarze północno-zachodnich Sudetów

Abstract

PERSPECTIVES OF DISCOVERING URANIUM DEPOSITS WITHIN THE NORTH-WESTERN SUDETES Summary In the present paper the author stresses that almost throughout the whole Palaeozoic and Mesozoic the North-Western Sudetes (Fig. l) constituted a labile geosynclinal zone filled up, during the Permian and Triassic and Upper Cretaceous, with the terrigenous material coming from the then elevated Kaczawa Caledonids, Izerskie Mts and Karkonosze Mts. It is known that in these areas are found fairly rich uranium concentrations of hydrothermal origin. The facts mentioned above allow to draw conclusions that, together with terrigenous material also uranium was brought to the sedimentary basin. Under favourable physical and chemical conditions it might have concentrated in the secondary deposit on a larger scale. On the basis of lithological features of deposits we may believe that great chances exist of discovering 4 uranium-bearing horizons, at least, in the series mentioned above. The first horizon connected with the so-called combustible shales has been recognized by means of anomalies ascertained during surface emanation survey. The two other horizons have been graphically presented on Fig. 2. According to the author's opinion they are most promising in search for uranium deposits. Chances are particularly great as to the area stretching along the southern margin of the North-Sudetic synclinorium. The lower horizon of the Zechstein bas so far been traced in many localities at mine workings of the active copper mines. However, the upper horizon bas not been studied, as yet. A fact that some deposits characterized by changing facies and rich in plant detritus are found in the Upper Cretaceous of the synclinorium, allows the author to stress a necessity of searching for uranium deposits also in these series, as well. In his considerations, the author takes into account also the uranium contents observed at the Cretaceous outcrops in the vicinities of Lwówek. To substantiate his conclusions, the author takes also into consideration a regional and lithological resemblance, known from persona! observations and from literature (7), to the analogous formations containing rich uranium deposits, such as those occurring in Thuringia, Saxony and Lusatia.