Shifts in North Atlantic surface water regimes during the last interglacial-glacial cycle (late Quaternary) investigated by coccolithophore-based ecological and chemical proxies

Abstract

Coccolith-based palaeoenvironmental proxies were tested and applied for the reconstruction of environmental conditions and likely influences in the North Atlantic during the last c. 150 000 years (MIS 6-1), combining palaeoenvironmental tools such as coccolith assemblages, coccoliths carbonate contribution, fine fraction (<20 Ã µm) oxygen isotopes and morphometric analyses on Emiliania huxleyi on the sediment material of two sediment cores (ODP Site 980 and GeoB 11035-1). Coccolith assemblage studies and morphometric variations were successfully used to reconstruct climatic changes in the marine environment, especially glacial-interglacial and short-term stadial-interstadial variations. Though, partly uncertain results appeared in the application of the geochemical signal of the calcareous coccolith plates for palaeoenvironmental reconstructions, which are due to vital effects, polyspecific samples and the influence of non-coccolith carbonate.