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Faunal re-evaluation of mid-Pliocene conditions in the western Equatorial Pacific

Harry Dowsett
Faunal re-evaluation of mid-Pliocene conditions in the western Equatorial Pacific
Micropaleontology (2007) 53 (6): 447-456


Mid-Pliocene low-latitude Pacific faunal (planktic foraminifer) sea surface temperature (SST) estimates are normally based upon the Modern Analog Technique (MAT). In the Eastern equatorial Pacific (EEP), where upwelling of cool water predominates, MAT can be used to discern both cooling and warming in Neogene records. SST today is approximately 30 degrees C in the western equatorial Pacific (WEP) warm pool the upper limit of the modern calibration data, and past warming above that level is difficult to assess using faunal methods. Mid-Pliocene fossil samples from the WEP have been analyzed using several variations of MAT with different outcomes and associated levels of confidence. While SST above approximately 30 degrees C in the WEP during the mid-Pliocene cannot be ruled out due to the limitations of the method, temperatures this warm seem unlikely. In addition to the mid-Pliocene, planktic foraminifer assemblages from the coretop, last glacial maximum, last interglacial and the penultimate glacial (Marine Isotope Stage 6) show striking similarity to each other which suggests little to no change in the region between times of global climate extremes. There is generally good agreement between the Mg/Ca paleothermometer and MAT derived faunal SST estimates. Both suggest stability of the WEP warm pool.

ISSN: 0026-2803
Serial Title: Micropaleontology
Serial Volume: 53
Serial Issue: 6
Title: Faunal re-evaluation of mid-Pliocene conditions in the western Equatorial Pacific
Author(s): Dowsett, Harry
Affiliation: U. S. Geological Survey, Reston, VA, United States
Pages: 447-456
Published: 2007
Text Language: English
Publisher: American Museum of Natural History, New York, NY, United States
References: 42
Accession Number: 2008-109952
Categories: Stratigraphy
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. 1 table, sketch maps
N25°31'21" - N25°31'22", E133°12'29" - E133°12'30"
N00°19'06" - N00°19'07", E159°21'40" - E159°21'42"
N03°36'22" - N03°36'26", E156°37'28" - E156°37'30"
N08°47'06" - N08°47'09", E121°13'09" - E121°17'42"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2018, American Geosciences Institute.
Update Code: 200840
Program Name: USGSOPNon-USGS publications with USGS authors
Program Name: ODPOcean Drilling Program
Program Name: DSDPDeep Sea Drilling Project
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