Late Miocene development of the western Pacific warm pool; planktonic foraminifer and oxygen isotopic evidence

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doi: 10.1016/j.palaeo.2005.12.019
Author(s): Li Qianyu; Li Baohua; Zhong Guangfa; McGowran, Brian; Zhou Zuyi; Wang Jilang; Wang Pinxian
Author Affiliation(s): Primary:
Tongji University, Sate Key Laboratory of Marine Geology, Shanghai, China
University of Adelaide, Australia
Chinese Academy of Sciences, China
Volume Title: Palaeogeography, Palaeoclimatology, Palaeoecology
Source: Palaeogeography, Palaeoclimatology, Palaeoecology, 237(2-4), p.465-482. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0031-0182 CODEN: PPPYAB
Note: In English. 76 refs.; illus., incl. 2 tables, sketch map
Summary: The disappearance at ∼10 Ma of the deep dwelling planktonic foraminifer Globoquadrina dehiscens from the western Pacific including the South China Sea was about 3 Myr earlier than its final extinction elsewhere. Accompanying this event at ∼10 Ma was a series of faunal turnover characterized by increase in mixed layer, warm-water species and decrease to a minimum in deepwater species. Paleobiological and isotopic evidence indicates sea surface warming and a deepened local thermocline that we interpret as related to the development of an early western Pacific warm pool. The stepwise decline of G. dehiscens and other deep dwelling species from the NW and SW Pacific suggests more intensive warm water pileup than equatorial localities where surface bypass flow through the narrowing Indonesia seaway appears to remain efficient during the late Miocene. Planktonic δ18O values from the South China Sea consistently lighter than the tropical western Pacific during the Miocene also suggest, similar to today, more variable hydrologic conditions along the periphery than in the core of the warm pool. Stronger hydrologic variability affected mainly by monsoons and increased thermal gradient along the western margin of the late Miocene warm pool may have contributed to the decline of deep dwelling planktonic species including the early extinction of G. dehiscens from the South China Sea region. The late Miocene warm pool became influential and paleobiologically detectable from ∼10 Ma, but the modern warm pool did not appear until about 4 Ma, in the middle Pliocene.
Year of Publication: 2006
Research Program: DSDP Deep Sea Drilling Project
ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 12 Stratigraphy, Historical Geology and Paleoecology; Biostratigraphy; Calcium carbonate; Carbonate sediments; Catapsydracidae; Cenozoic; Chemostratigraphy; Cores; DSDP Site 289; DSDP Site 77; Deep Sea Drilling Project; East Pacific; Equatorial Pacific; Extinction; Foraminifera; Globigerinacea; Globigerinidae; Globigerinoides; Globoquadrina dehiscens; Invertebrata; Isotope ratios; Isotopes; Leg 184; Leg 30; Leg 9; Marine sediments; Microfossils; Miocene; Neogene; North Pacific; Northwest Pacific; O-18/O-16; ODP Site 1143; ODP Site 1146; ODP Site 1148; Ocean Drilling Program; Ocean circulation; Oxygen; Pacific Ocean; Paleo-oceanography; Paleoclimatology; Planktonic taxa; Protista; Rotaliina; Sediments; South China Sea; Spatial variations; Stable isotopes; Tertiary; Upper Miocene; West Pacific
Coordinates: N092143 N092143 E1131707 E1131707
N192724 N192724 E1161622 E1161622
N185010 N185010 E1163356 E1163356
S002956 S002955 E1583042 E1583041
Record ID: 2006069612
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands