40Ar/39Ar ages of seamount trachytes from the South China Sea and implications for the evolution of the northwestern sub-basin

Geoscience Frontiers

Jiabiao Li¹  Xiaohu Li¹  Xing Yu¹  Chunsheng Wang²  Fred Jourdan³ 

[1] Key Laboratory of Submarine Geoscience, State Oceanic Administration, Hangzhou 310012, China;Second Institution of Oceanography, State Oceanic Administration, Hangzhou 310012, China;Western Australian Argon Isotope Facility, Department of Applied Geology and JdL Centre, Curtin University, GPO Box U1987, Perth 6845, WA, Australia;

关键词: 40Ar/39Ar dating;    Seamount trachyte;    Northwest sub-basin;    Expansion history;    South China Sea;   

DOI  :  10.1016/j.gsf.2014.08.003

来源: DOAJ

【 摘 要 】

A chronological study of seamount rocks in the South China Sea basin provides a great opportunity to understand the expansion and evolution history of the sea basin. In this paper, we analyzed the 40Ar/39Ar age of trachytic samples collected from the Shuangfeng seamounts in the northwestern sub-basin of the South China Sea. The two samples yielded plateau ages of 23.80 ± 0.18 and 23.29 ± 0.22 Ma, respectively, which indicate magmatic activity in late Oligocene which helpful constraints the expansion time of the northwest sub-basin. Previous studies suggested that the northwestern sub-basin and southwestern sub-basin have experienced a relatively consistent expansion in the NW–SE direction followed by a late expansion of the eastern sub-basin. We concluded that the expansion of the northwestern sub-basin began prior to ca. 24 Ma, which also implicated magmatic events of a late or stop expansion of the northwestern sub-basin combined with our results of 40Ar/39Ar age data and previous geophysical data.

【 授权许可】

Unknown