Evolution of the zonal gradients across the Equatorial Pacific during the Miocene-Pleistocene

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doi: 10.2110/jsr.2019.15
Author(s): Beltran, Catherine; Rousselle, Gabrielle; de Rafélis, Marc; Sicre, Marie-Alexandrine; Labourdette, Nathalie; Schouten, Stefan
Author Affiliation(s): Primary:
Pierre and Marie Curie University, Paris, France
Université Paul Sabatier, France
Nederlands Instituut voor Zeeonderzoek, Netherlands
Volume Title: Journal of Sedimentary Research
Source: Journal of Sedimentary Research, 89(3), p.242-252. Publisher: Society for Sedimentary Geology, Tulsa, OK, United States. ISSN: 1527-1404
Note: In English. 117 refs.; illus.
Summary: Combining - and TEX86-derived temperatures and oxygen isotopic values of mixed-layer and thermocline species from the IODP site U1338 (East Equatorial Pacific) and ODP Site 806 (West Equatorial Pacific) we assess the evolution of the zonal sea-surface temperature gradients and thermocline depth across the equatorial Pacific from the late Miocene through the Pleistocene. Data suggest a long-term shoaling of the thermocline along the equator throughout the Miocene-Pliocene that accelerated around 5.3 Ma. We identify a critical transition at about 3.8 Ma from a El-Nino-like-dominated mean state during the late Miocene and early Pliocene to a La-Nina-like-dominated state during the late Pliocene-Pleistocene. This transition coincides with the restriction of the Indonesian seaway and the onset of ice growth in the northern hemisphere and in Antarctica that led to the long-term strengthening of the Walker circulation and affected low-latitude zonal gradient.
Year of Publication: 2019
Research Program: IODP Integrated Ocean Drilling Program
ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Algae; Cenozoic; Diatoms; East Pacific; Equatorial Pacific; Expedition 321; Expeditions 320/321; Foraminifera; Geochemical indicators; Geochemistry; IODP Site U1338; Integrated Ocean Drilling Program; Isotope ratios; Isotopes; Leg 130; Microfossils; Miocene; Neogene; North Pacific; Northeast Pacific; Northwest Pacific; O-18/O-16; ODP Site 806; Ocean Drilling Program; Ontong Java Plateau; Oxygen; Pacific Equatorial Age Transect; Pacific Ocean; Paleo-oceanography; Paleoclimatology; Paleoecology; Paleoenvironment; Pleistocene; Quaternary; Sediments; Stable isotopes; Tertiary; West Pacific
Coordinates: N001906 N001907 E1592142 E1592140
N023028 N023028 W1175811 W1175811
Record ID: 2019032114
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States, Reference includes data supplied by SEPM (Society for Sedimentary Geology)