Ages and magnetic structures of the South China Sea constrained by deep tow magnetic surveys and IODP Expedition 349
Date
2014-12-27Author
Li, Chun-Feng
Concept link
Xu, Xing
Concept link
Lin, Jian
Concept link
Sun, Zhen
Concept link
Zhu, Jian
Concept link
Yao, Yongjian
Concept link
Zhao, Xixi
Concept link
Liu, Qingsong
Concept link
Kulhanek, Denise K.
Concept link
Wang, Jian
Concept link
Song, Taoran
Concept link
Zhao, Junfeng
Concept link
Qiu, Ning
Concept link
Guan, Yongxian
Concept link
Zhou, Zhiyuan
Concept link
Williams, Trevor
Concept link
Bao, Rui
Concept link
Briais, Anne
Concept link
Brown, Elizabeth A.
Concept link
Chen, Yifeng
Concept link
Clift, Peter D.
Concept link
Colwell, Frederick S.
Concept link
Dadd, Kelsie A.
Concept link
Ding, Weiwei
Concept link
Almeida, Ivan Hernandez
Concept link
Huang, Xiao-Long
Concept link
Hyun, Sangmin
Concept link
Jiang, Tao
Concept link
Koppers, Anthony A. P.
Concept link
Li, Qianyu
Concept link
Liu, Chuanlian
Concept link
Liu, Zhifei
Concept link
Nagai, Renata H.
Concept link
Peleo-Alampay, Alyssa
Concept link
Su, Xin
Concept link
Tejada, Maria Luisa G.
Concept link
Trinh, Hai Son
Concept link
Yeh, Yi-Ching
Concept link
Zhang, Chuanlun
Concept link
Zhang, Fan
Concept link
Zhang, Guo-Liang
Concept link
Metadata
Show full item recordCitable URI
https://hdl.handle.net/1912/7180As published
https://doi.org/10.1002/2014GC005567DOI
10.1002/2014GC005567Keyword
Deep tow magnetic survey; Magnetic anomaly; Crustal evolution; Modeling; International Ocean Discovery Program Expedition 349; South China Sea tectonicsAbstract
Combined analyses of deep tow magnetic anomalies and International Ocean Discovery Program Expedition 349 cores show that initial seafloor spreading started around 33 Ma in the northeastern South China Sea (SCS), but varied slightly by 1–2 Myr along the northern continent-ocean boundary (COB). A southward ridge jump of ∼20 km occurred around 23.6 Ma in the East Subbasin; this timing also slightly varied along the ridge and was coeval to the onset of seafloor spreading in the Southwest Subbasin, which propagated for about 400 km southwestward from ∼23.6 to ∼21.5 Ma. The terminal age of seafloor spreading is ∼15 Ma in the East Subbasin and ∼16 Ma in the Southwest Subbasin. The full spreading rate in the East Subbasin varied largely from ∼20 to ∼80 km/Myr, but mostly decreased with time except for the period between ∼26.0 Ma and the ridge jump (∼23.6 Ma), within which the rate was the fastest at ∼70 km/Myr on average. The spreading rates are not correlated, in most cases, to magnetic anomaly amplitudes that reflect basement magnetization contrasts. Shipboard magnetic measurements reveal at least one magnetic reversal in the top 100 m of basaltic layers, in addition to large vertical intensity variations. These complexities are caused by late-stage lava flows that are magnetized in a different polarity from the primary basaltic layer emplaced during the main phase of crustal accretion. Deep tow magnetic modeling also reveals this smearing in basement magnetizations by incorporating a contamination coefficient of 0.5, which partly alleviates the problem of assuming a magnetic blocking model of constant thickness and uniform magnetization. The primary contribution to magnetic anomalies of the SCS is not in the top 100 m of the igneous basement.
Description
Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 15 (2014): 4958–4983, doi:10.1002/2014GC005567.
Collections
Suggested Citation
Geochemistry, Geophysics, Geosystems 15 (2014): 4958–4983Related items
Showing items related by title, author, creator and subject.
-
The latest spreading periods of the south china sea: new constraints from macrostructure analysis of IODP expedition 349 cores and geophysical data
Sun, Zhen; Ding, Weiwei; Zhao, Xixi; Qiu, Ning; Lin, Jian; Li, Chun‐Feng (American Geophysical Union, 2019-08-29)Macrostructures preserved in deformed rocks are essential for the understanding of their evolution, especially when the deformation is weak and hard to discriminate in regional scale or purely through geophysical data. In ... -
Seismic stratigraphy of the central South China Sea basin and implications for neotectonics
Li, Chun-Feng; Li, Jiabiao; Ding, Weiwei; Franke, Dieter; Yao, Yongjian; Shi, Hesheng; Pang, Xiong; Cao, Ying; Lin, Jian; Kulhanek, Denise K.; Williams, Trevor; Bao, Rui; Briais, Anne; Brown, Elizabeth A.; Chen, Yifeng; Clift, Peter D.; Colwell, Frederick S.; Dadd, Kelsie A.; Hernandez-Almeida, Ivan; Huang, Xiao-Long; Hyun, Sangmin; Jiang, Tao; Koppers, Anthony A. P.; Li, Qianyu; Liu, Chuanlian; Liu, Qingsong; Liu, Zhifei; Nagai, Renata H.; Peleo-Alampay, Alyssa; Su, Xin; Sun, Zhen; Tejada, Maria Luisa G.; Trinh, Hai Son; Yeh, Yi-Ching; Zhang, Chuanlun; Zhang, Fan; Zhang, Guo-Liang; Zhao, Xixi (John Wiley & Sons, 2015-03-16)Coring/logging data and physical property measurements from International Ocean Discovery Program Expedition 349 are integrated with, and correlated to, reflection seismic data to map seismic sequence boundaries and facies ... -
Observational and model studies of the circulation in the Gulf of Tonkin, South China Sea
Ding, Yang; Chen, Changsheng; Beardsley, Robert C.; Bao, Xianwen; Shi, Maochong; Zhang, Yu; Lai, Zhigang; Li, Ruixiang; Lin, Huichan; Viet, Nguyen Trung (John Wiley & Sons, 2013-12-03)Moored current measurements were made at one mooring site in the northern Gulf of Tonkin for about 1 year during 1988–1989. Analyses were performed to examine characteristics and variability of tidal and subtidal flows. ...