Atypical ferromanganese micronodules from middle fan-valley system, Bay of Bengal

Abstract

Ferromanganese micronodules having botryoidal and spheroidal morphogroups have been observed over a 0.22 million km@u2@@ area from the middle fan region of the Bay of Bengal. The bulk micronodules have 26.26% Mn, 1.02% Fe, 1.82% Ca, 0.12% Ni, 0.14% Zn and 0.08% Cu. Their Mn/Fe ration (25.74) is much higher than the world average. Based on the results of the present study, we suggest that early diagenesis may be the contributory process for their formation