Isotopic evidences of past upwelling intensity in the Arabian Sea

Abstract

Oxygen and carbon isotopic analyses have been performed on the tests of Globigerina bulloides, Globigerinoides sacculifer, Neogloboquadrina dutertrei and Pulleniatina obliquiloculata to study the delta super(18)O and delta super(13)C of shallow and deeper depth living planktic foraminifera species. High and low delta super(18)O sub(obl-bul) and super super(13)C sub(sac-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 delta super(18)O and delta super(13)C of surface and subsurface living foraminifera can be used as isotope indices of upwelling in the Arabian Sea.