Stable oxygen isotope records of different benthic foraminiferal species of core GeoB3004-1 from the western Arabian Sea

The d18O records reveal species-specific metabolic effects, susceptibility to changes in carbonate ion concentration, and supralysoclinal calcite dissolution.

The foraminiferal d13C records reveal changes in the stable carbon isotope gradients of pore water dissolved inorganic carbon (d13CDIC) and in the microhabitat depth of infaunal species. Maximum d13CDIC offsets between bottom and pore waters ranged between mean values of 0.8 and 1.2% corresponding to estimates of deepwater oxygen concentration between approximately 1 and 2.7 ml/l. Intervals of improved deepwater oxygenation coincided with high benthic foraminiferal diversity and indicate the admixture of well-oxygenated deepwater masses during interglacials.