Isotopic evidences of past upwelling intensity in the Arabian Sea

Oxygen and carbon isotopic analyses have been performed on the tests of Globigerina bulloides, Globigerinoides sacculifer, Neogloboquadrina dutertrei and Pulleniatina obliquiloculata to study the Δδ18O and Δδ13C of shallow and deeper depth living planktic foraminifera species. High and low Δδ18Oobl-bul and Δδ13Csac-dut coincides respectively with the low and high flux of G. bulloides (established monsoon upwelling index). The tangible relationships between the flux of G. bulloides and oxygen and carbon isotope differences between the shallow and deeper depth habitat planktic foraminiferal species appear to suggest that Δδ18O and Δδ13C of surface and subsurface living foraminifera can be used as isotope indices of upwelling in the Arabian Sea.