Radiolarian record to paleoecology environment change events over the past 1.2 MaBP in the southern South China Sea

Author(s): Yang Lihong; Chen Muhong; Wang Rujian; Zhen Fan
Author Affiliation(s): Primary:
Chinese Academy of Sciences, South China Sea Institute of Oceanology, Guangzhou, China
Tongji University, China
Volume Title: Chinese Science Bulletin
Source: Chinese Science Bulletin, 47(17), p.1478-1483. Publisher: Science Press, Beijing, China. ISSN: 1001-6538
Note: In English. 18 refs.; illus.
Summary: This note studies the Radiolarian fossil groups since 1.2 MaBP in ODP leg 184 site 1143, the southern South China Sea (SCS). The result shows that radiolarian abundance experienced a significant variation: before 0.9 MaBP it remained at the extremely low level, but increased with low extent between 0.9-0.65 Ma, which corresponded to the Mid-Pleistocene Transition stage, and it increased rapidly after 0.65 MaBP. During the whole process, the average abundance became higher and higher in each stage, and showed regularly periodic fluctuations. The obvious increase after 0.65 MaBP is inferred to result from the enhanced upwelling in this region, which was induced by the intensified monsoon circulation after the "Mid-Pleistocene Transition". An outstanding result of the spectral analyses is that a long oscillation of ∼0.2 Ma cycle was found in the records of radiolarian abundance and complex diversity, which corresponds well to the result of other paleoceanographic indexes. This probably indicated a special cycle characteristic of paleoecological environment evolution in this area. In addition, all of the radiolarian indexes show an obvious boundary in about 0.47 MaBP, indicating the abrupt variation of the community structure and radiolarian abundance level before and after 0.47 MaBP. So we suppose that there existed a distinct change event of oceanic ecology environment during that period.
Year of Publication: 2002
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Cenozoic; Invertebrata; Leg 184; Microfossils; Middle Pleistocene; North Pacific; Northwest Pacific; ODP Site 1143; Ocean Drilling Program; Pacific Ocean; Paleo-oceanography; Paleoecology; Paleoenvironment; Pleistocene; Protista; Quaternary; Radiolaria; Reconstruction; South China Sea; Southern South China Sea; West Pacific
Coordinates: N092143 N092143 E1131707 E1131707
Record ID: 2003014797
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