Biotic and geochemical evidence for a global latitudinal shift in ocean biogeochemistry and export productivity during the late Pliocene

摘要: During the late Pliocene (~ 3 to 2.5 Ma), oceanic records of opal and C37 alkenone accumulation from around world show a secular shift towards lower values in high latitudes higher low mid latitudes. These shifts are broadly coincident with intensification northern hemisphere glaciation suggestive changes export productivity, potential implications for atmospheric carbon dioxide concentrations. The interpretation global latitudinal however, requires testing because uncertainties associated site comparisons that can be influenced by highly nonlinear processes production, export, preservation. Here, we assess inferred productivity presenting new Ocean Drilling Program (ODP) Site 982 North Atlantic biotic assemblages (calcareous nannoplankton) this ODP 846 eastern tropical Pacific. Our results corroborate as proxy gross at these sites, indicating large-scale decreases increases sites recorded robustly. We conclude during was profound reorganisation ocean biogeochemistry.