Organic substance as a collector of recoil atoms Th-234( U-234) in black shales

The content and isotopic composition of uranium extracted under various lea ching and extraction conditions from the dyctionemic shale from Estonian de posits are determined by alpha-spectrometry. The interaction of uranium wit h organic matter (OM) was confirmed by a correlation between the specific r adioactivity of uranium and contents of OM in the fractions obtained by ele ctrostatic separation of the ground shale powder. Correlation between the r esults of two different analytical schemes is shown. The thickness of urani um phase layer deposited on organic matter in two parts of the seam is comp ared.