Potential diagenetic and detrital sources for calcareous sediments from the Carlsberg Ridge, Indian Ocean

摘要

Six sediment cores from the Carlsberg Ridge (CR) were studied for elemental concentration, magnetic susceptibility (chi), grain size and clay mineral distribution, and sedimentation rate to decipher possible detrital and diagenetic contributions. The sediments were characterized by very low chi, moderate total organic carbon, high CaCO3 content and high accumulation rate (3 cm/ kyr). Clay mineralogical and geochemical data suggest major continental source from the Arabian Sea, and very low Mn distribution, absence of tephra and characteristic magnetic signatures rule out volcanic or hydrothermal input. Consistent peaks around 10, 25, 45, 60 and 80 cm depth and high uranium are due to sedimentary diagenesis.