Geochemical implications for changing dust supply by the Indian Monsoon system to the Arabian Sea during the last glacial cycle
- 67 Downloads
Element concentrations of 43 elements as well as inorganic and organic carbon content of sediment core 70KL from the western Arabian Sea were measured with high (1 cm) sample resolution. Principal components of the sediment’s chemical composition were determined with the help of statistical principle component analysis. These components are representing the major environmental factors at the site. The most important processes controlling the observed variations are the changing lithogenic influx derived from the major wind systems of the region (i.e., the Arabian northwesterly winds, the northeast winter monsoon and the southwest summer monsoon), summer monsoon associated upwelling and biogenic productivity as well as the redox conditions at the sediment-water interface.
The variations of these components show quasiperiodic oscillations in the Dansgaard/Oeschger band (1000-3000 ka) with a significant presence during the entire last glacial. The dominating periods are near 2000 and 1200 years for the variations in the summer monsoon activity, 950 year variations in the winter monsoon and near 1450 and 1050 year oscillations in the dust content transported by the Arabian northwesterly winds.
KeywordsSummer Monsoon Indian Monsoon Rare Earth Element Northwesterly Wind Oxygen Isotope Record
Unable to display preview. Download preview PDF.