Pleistocene paleoclimatic zonation in northern Indian ocean as revealed from <i>Globorotalia menardii</i> abundance

Abstract

The fluctuations in frequency of occurrence of Globorotalia menardii a commonly occurring planktonic foraminifera at DSDP Sites 219, 220 and 241 have been correlated with the Pleistocene paleoclimatic (Ericson) zonation. Abundance of Gr. menardii has been found to be high to moderate during R, T, V, X and Z (all interglacial, interstadial and post-glacial) zones while it was remarkably low during S, U, W and Y (all glacial) stages. Varying thicknesses of the above paleoclimatic zones at these three sites are due to differences in sediment accumulation rates. A comparison of Gr, menardii and total planktonic foraminiferal abundance at these sites show very good correspondence, the correlation coefficients of which are highly significant, indicating Ericson paleoclimatic zones can be precisely delineated with the help of total planktonic foraminifera also in tropical region.