Atmosphere-ocean linkages in the Eastern Equatorial Pacific over the early Pleistocene

Sediment composition from Ocean Drilling Program Sites 1240 and 1238 is used to reconstruct past changes in the atmosphere-ocean system. Particularly remarkable is the presence of laminated diatom oozes (LDOs) during glacial periods between 1.85 and 2.25 Ma coinciding with high fluxes of opal and total organic carbon.

Relatively low lithic particles (coarse and poorly sorted) and iron fluxes during these glacial periods indicate that the increased diatom productivity did not result from dust-stimulated fertilization events. We argue that glacial fertilization occurred through the advection of nutrient-rich waters from the Southern Ocean. In contrast, glacial periods after 1.85 Ma are characterized by enhanced dust transport of finer lithic particles acting as a new source of nutrients in the EEP.