Quaternary palaeoceanographic changes in the northern South China Sea (ODP Site 1146); radiolarian evidence

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doi: 10.1002/jqs.784
Author(s): Wang Rujian; Clemens, Steven; Huang Baoqi; Chen Muhong
Author Affiliation(s): Primary:
Tongji University, Laboratory of Marine Geology, Shanghai, China
Other:
Brown University, United States
Chinese Academy of Science, China
Volume Title: JQS. Journal of Quaternary Science
Source: JQS. Journal of Quaternary Science, 18(8), p.745-756. Publisher: John Wiley and Sons for the Quaternary Research Association, Chichester, United Kingdom. ISSN: 0267-8179
Note: In English. Includes appendix. 66 refs.; illus., incl. 2 tables, sketch maps
Summary: The abundance and accumulation rates of siliceous microfossils in the northern South China Sea, including radiolarians, diatoms and sponge spicules, increased during most glacial intervals within the past 1100 kyr. Similar trends are observed in the index of thermocline surface radiolarians (TSR), diatom accumulation rates (DAR), charcoal accumulation rates (CAR) and the abundance of radiolarian species Cycladophora davisiana davisiana. Decreasing sea-surface temperature accompanied by increased seasonality since 900 ka is indicated by a decline in the tropical radiolarian assemblage, including Tetrapyle octacantha and Octopyle stenozona, and by an increase in the subtropical assemblage, including Pterocorys zancleus, Peromelissa phalacra and Ommatartuts tetrathalamus tetrathalamus. Rapid increases at about 800 to 700 ka of siliceous microfossils, charcoal, subsurface and intermediate radiolarians, as well as the TSR index and the DAR, imply a fundamental shift in climate and a shoaling thermocline. Although these fundamental changes in the siliceous fauna and flora of the South China Sea take place within the context of a developing 100-kyr cycle, they do not change in step with changing sea-level as indicated by marine δ18O. This is most clearly illustrated by the step-like increase in silica accumulation (radiolaria, diatoms and sponge spicules) at 680 ka. Rather, these fundamental changes probably reflect intensified surface productivity associated with enhanced East Asian winter-monsoon circulation. Abstract Copyright (2003), Wiley Periodicals, Inc.
Year of Publication: 2003
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 24 Surficial Geology, Quaternary Geology; Algae; Assemblages; Cenozoic; Diatoms; Faunal list; Holocene; Invertebrata; Isotope ratios; Isotopes; Leg 184; Magnetostratigraphy; Marine environment; Microfossils; North Pacific; Northwest Pacific; O-18/O-16; ODP Site 1146; Ocean Drilling Program; Oxygen; Pacific Ocean; Paleo-oceanography; Paleoecology; Paleoenvironment; Plantae; Pleistocene; Porifera; Productivity; Protista; Quaternary; Radiolaria; South China Sea; Spicules; Stable isotopes; West Pacific
Coordinates: N192724 N192724 E1161622 E1161622
Record ID: 2004027625
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from John Wiley & Sons, Chichester, United Kingdom