Insight into the latest Messinian (5.7-5.2 Ma) palaeoclimatic events from two deep-sea Atlantic Ocean ODP sites

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doi: 10.1016/j.palaeo.2014.03.039
Author(s): Vautravers, Maryline J.
Author Affiliation(s): Primary:
British Antarctic Survey, Cambridge, United Kingdom
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, Vol.407, p.14-24. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 87 refs.; illus., incl. charts, sketch map
Summary: The results of a multi-proxy study, including quantitative planktonic foraminifera faunal analysis, geochemistry of foraminifera tests, and lithogenic counts (IRD) are presented for two open marine sites. The sites are located in the eastern South Atlantic (ODP Leg 177 Site 1088) and the western tropical North Atlantic (ODP Leg 154 Site 925). Both sedimentary records span the interval 5.7-5.2 Ma (i.e. late Miocene to early Pliocene), which encompasses the time of deposition of the upper evaporites (UE) in the Mediterranean basin. The observations confirm a major oceanographic and climatologic event which occurred during the Messinian at the transition between the glacial TG12 and the prominent TG11 warm interglacial at 5.5 Ma. However, some oceanographic changes also occurred at the Miocene-Pliocene (M-P) transition in the northern tropical Atlantic and in the Southern Ocean with the first input of IRD at ODP Site 1088. In contrast to the termination across the lower evaporites (LE) at 5.5 Ma, the M-P transition may not have involved a large change in ice volume. The potential causes behind the data across the major climatic transient are examined in the light of published information, including evidence from polar areas with focus on the climatic impact of fluctuating meridional oceanic circulation (MOC). A thermal seesaw mechanism in pre-Quaternary times is hypothesised as part of the large late Messinian deglaciation across the TG12-TG11 transition. An implication of the major Southern Atlantic warming before 5.5 Ma is that an abrupt event freshening the surface of the North Atlantic might be present in the sub-polar Northern Hemisphere, but this has yet to be verified. This deglaciation may have been reinforced by a freshening of the North Atlantic as a result of discontinuous connection of the Mediterranean Sea. Abstract Copyright (2014) Elsevier, B.V.
Year of Publication: 2014
Research Program: ODP Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Alkaline earth metals; Ancient ice ages; Asterigerinoidea; Atlantic Ocean; Benthic taxa; C-13/C-12; Calcium; Carbon; Ceara Rise; Cenozoic; Climate change; Controls; Deep-sea environment; Deglaciation; Empstomariidae; Equatorial Atlantic; Foraminifera; Glacial geology; Globigerinacea; Globigerinidae; Globigerinoides; Globigerinoides trilobus; Invertebrata; Isotope ratios; Isotopes; Leg 154; Leg 177; Lower Pliocene; Magnesium; Marine environment; Messinian; Metals; Mg/Ca; Microfossils; Miocene; Neogene; North Atlantic; Northwest Atlantic; Nutallides; Nutallides umbonatus; Nuttallidinae; O-18/O-16; ODP Site 1088; ODP Site 925; Ocean Drilling Program; Oxygen; Paleo-oceanography; Paleoclimatology; Planktonic taxa; Pliocene; Protista; Rotaliida; Rotaliina; Sea-surface temperature; South Atlantic; Southeast Atlantic; Stable isotopes; Tertiary; Tropical environment; Upper Messinian; Upper Miocene
Coordinates: S410810 S410810 E0133346 E0133346
N041215 N041216 W0432920 W0432922
Record ID: 2014064509
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands