Trace Metal Contents of Iron Sulfide Minerals From the Tertiary Carbonaceous Clays of Kerala

The Tertiary carbonaceous clay deposits of Kerala abound in iron sulfide minerals such as pyrite and marcasite. Pyrite is confined mainly to the Quilon beds and marcasite to the Warkalli beds. Manganese, Zn, Pb, Ni, Co, Cd and Cu are substantially high in marcasite than in pyrite. Trace metals (except Zn) are markedly high in the carbonaceous clays of the Warkalli section than in those of the Pozhikkara section. The observed variation in the trace metal contents of sulfide minerals as well as carbonaceous clays of the two sections might have resulted from differences in depositional environments.