Coccolith evidence for Quaternary nutricline variations in the southern South China Sea

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doi: 10.1016/j.marmicro.2007.11.008
Author(s): Liu Chuanlian; Wang Pinxian; Tian Jun; Cheng Xinrong
Author Affiliation(s): Primary:
Tongji University, State Key Laboratory of Marine Geology, Shanghai, China
Other:
University of Salamanca, Spain
Volume Title: Quaternary coccolithophore palaeoceanography; International Nannoplankton Association 10th conference
Volume Author(s): Young, Jeremy R., editor; Flores, José-Abel; Cachao, Mario
Source: Marine Micropaleontology, 69(1), p.42-51; 10th International Nannoplankton Association conference, Lisbon, Portugal, Aug. 28-Sept. 4, 2004, edited by Jeremy R. Young, José-Abel Flores and Mario Cachao. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0377-8398 CODEN: MAMIDH
Note: In English. Based on Publisher-supplied data
Summary: Nutricline variations during the last 1560 ka in the southern South China Sea are reconstructed using the relative abundance of the coccolithophore Florisphaera profunda in ODP Site 1143. Nutricline depth shows both long-term large magnitude variation and high frequency glacial-interglacial variation. On the long-term scale, the nutricline experienced four significant changes, which occurred at 900, 480, 250, and 50 ka respectively. According to these changes, five stages could be recognized during the last 1560 ka. From 1560 to 900 ka, the nutricline depth increased gradually. Around 900 ka, the nutricline abruptly shallowed and then remained stable until 480 ka. The nutricline was shallow during the time interval between 480 and 250 ka. At 250 ka, it deepened again and increased gradually until 50 ka. After 50 ka, the nutricline depth decreased gradually to modern values. On the glacial-interglacial scale, the variations in nutricline depth show different patterns before and after 900 ka. Before 900 ka, the nutricline was deep during glacial periods and shallow during interglacials. However, after 900 ka, the nutricline was deep during interglacials and shallow during glacials. Spectral analysis of the relative abundance of F. profunda shows a similar trend. In addition to the eccentricity (113, 76 ka), obliquity (55, 39 ka), and precession (24, 19 ka), we also find a 431 ka cycle. The former three periods reflect glacial-interglacial variations in nutricline, and the period of 431 ka reflects long-term variations in nutricline. We suggested that the variations in nutricline in the southern South China Sea were caused by global and regional climate changes. Glacial-interglacial variations in nutricline are mainly controlled by the East Asian monsoon, and the long-term variations might be related to the global climatic events, such as the mid-Pleistocene Revolution and the mid-Brunhes event. Abstract Copyright (2008) Elsevier, B.V.
Year of Publication: 2008
Research Program: ODP Ocean Drilling Program
Key Words: 24 Surficial Geology, Quaternary Geology; Algae; Cenozoic; Coccolithophoraceae; Florisphaera profunda; Leg 184; Marine environment; Microfossils; North Pacific; Northwest Pacific; Nutriclines; ODP Site 1143; Ocean Drilling Program; Pacific Ocean; Paleoclimatology; Paleoecology; Paleoenvironment; Plantae; Pleistocene; Quaternary; South China Sea; West Pacific
Coordinates: N092143 N092143 E1131707 E1131707
Record ID: 2009022562
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands