USE OF ELEMENT-MINERAL CORRELATIONS TO INVESTIGATE FRACTIONATION OF RARE-EARTH ELEMENTS IN FINE-GRAINED SEDIMENTS

Relative concentrations of elements in the minerals of fine-grained se diments can be inferred from element-mineral correlation coefficients. The technique is applied to the distribution of REE in Middle Ordovic ian shales from South Wales analysed by ICPAES, Leco C/S125 and XRD. P hosphate and chlorite show mid-REE enrichment; muscovite+biotite shows mid-REE depletion. The complementarity of the chlorite and muscovitebiotite patterns may be due to fractionation during diagenetic recryst allisation. Partial correlation analysis is used to infer the presence of zircon.