Profil geochemiczny uranu, selenu i renu W cechsztynie niecki leszczyńskiej

Abstract

GEOCBEMICAL PROFILE OF·URANIUM, SELENIUM AND RHENIUM IN THE ZECHSTEIN OF THE LESZCZYNA TROUGHThe Zechstein deposits occurring in the Leszczyna trough have been examined as to their uranium, selenium and rhenium contents. It has also been ascertained that the highest concentrations of these elements occur in the Lower Zechistein beds, where their mean contents are as follows: uranium - 1,3 1 ppm; selenium - 2.31 ppm; and rhenium - 1,06 ppm. The results of the examinations are presented on Fig. 1.In the underlying, post-eruptive series of the Rotliegendes the uranium content does not exceed 1,5 ppm. In the limestones of Middle Zechstein age the mean uranium contents amount to 2,2 ppm. In these beds selenium and rhenium are found in small quantities, beneath the sensitivity of the analytical methods applied during the study.No interrelations have been ascertained between the elements examined. It was stated that neritic facies, connected with not too deep marine basin with oscillating bottom, rich in clayey and organic material, was the most favourable geochemical environment for concentration of the elements considered.