OCCURRENCE OF FE, MN-RICH LAYER IN THE DISTAL BENGAL FAN

Dark tan-coloured Fe, Mn-rich stiff layer was observed at 45-50 cm and 40-42 cm levels in the Sagar Kanya 72/1 and 100/6 sediment cores resp ectively, which were collected from distal Bengal fan under BOBCRUST p rogramme. SK 72/1 and SK 100/6 cores were analysed for Fe, Mn, Ni, Co, Cr, CaCO3 and organic carbon (OC) contents. A remarkable increase in Fe, Mn and drastic decrease in CaCO3, OC, compared to overlying and un derlying sediment layers was observed at this stiff layer. Change of t hese elements concentration correlates with the change of fauna from t he cold assemblage to warm assemblage. Increase of Fe, Mn, Ni, Co and decrease of Cr, CaCO3, OC indicate that this layer is formed due to po st-depositional migration of these elements during the Pleistocene/Hol ocene transitional period, because of emasculated influence of terrest rial input into these sites.