Metal accumulation rates in sediments and ferromanganese oxide crusts from the Romanche Fracture Zone (RFZ), equatorial atlantic

Abstract

A suite of sediments and FeMn oxide crusts from the Romanche Fracture Zone (RFZ) in the equatorial Atlantic has been investigated by radiochemical techniques to determine the rates of metal accumulation in the deposits. This approach was used to assess any possible hydrothermal inputs to the deposits.

The metal accumulation rate data for the sediments indicate that there is no significant hydrothermal influence in the deposits. The concentration of metals can be accounted for largely in terms of normal oceanic sedimentation processes. This was confirmed by metal accumulation rate data of the crusts that represent hydro-genetic deposit formed by slow accumulation of trace-enriched oxides directly from the water column.