Climatic impact on Al, K, Sc and Ti in marine sediments: Evidence from ODP site 1144, South China Sea

Abstract

Al, K, Sc and Ti concentrations of the terrestrial material-dominant sediments from ODP site 1144 were reported. Comparison between the bulk and the acid-leached sediments indicates that about 20∼30% of the Al, K and Sc in the bulk sediments are not hosted in terrestrial detritus, rather they are of authigenic origin. However, authigenic Ti is negligible. The results indicate that Ti rather than Al is the best proxy for terrestrial materials. Significant climate controls are displayed in the Al/Ti, K/Ti and Sc/Ti variation patterns both for the bulk and the acid leached sediments. Such variation patterns can be mainly accounted for in terms of climate change in their provenance areas in South China. Elevated Al/Ti, K/Ti and Sc/Ti ratios during interglacial periods indicate that chemical weathering then was stronger than during glacial periods, which might be related to a more humid climate in interglacial periods.