Astronomical tuning and magnetostratigraphy of Neogene biogenic reefs in Xisha Islands, South China Sea

作     者：Liang Yi Zhimin Jian Xinyu Liu Youhua Zhu Daojun Zhang Zhenfeng Wang Chenglong Deng 

作者机构：State Key Laboratory of Marine Geology Tongji University Shanghai 200092 China Laboratory for Marine Geology. Qingdao National Laboratory for Marine Science and Technology Qingdao 266061 China China National Offshore Oil Corporation Ltd. Zhanjiang Branch Zhanjiang 524057 China Key Laboratory of Economic Stratigraphy and Palaeogeography Nanjing Institute of Geology and Palaeontology. Chinese Academy of Sciences Nanjing 210008 China State Key Laboratory of Lithospheric Evolution. Institute of Geology and Geophysics. Chinese Academy of Sciences Beijing 100029 China Institutions of Earth Science Chinese Academy of Sciences Beijing 100029 China University of Chinese Academy of Sciences. Beijing 100049 China 

出 版 物：《Science Bulletin》 (科学通报（英文版）)

年 卷 期：2018年第63卷第9期

页      面：564-573页

核心收录：

学科分类：070704[理学-海洋地质] 070903[理学-古生物学与地层学(含：古人类学)] 0709[理学-地质学] 07[理学] 0707[理学-海洋科学] 

基　　金：supported by the National Natural Science Foundation of China(41630965,41690112 and 41621004) the National Programme on Global Change and Air–Sea Interaction of China(GASI–GEOGE–04) the Fundamental Research Funds for the Central Universities 

主　　题：Astronomical tuning Magentostratigraphy Magnetic susceptibility Biogenic reefs Neogene South China Sea 

摘      要：Biogenic reefs are one of two major depositional types in the South China Sea, and are constructed by coral, algae and bryozoa. The West Pacific is a major area of biogenic reef development and plays a critical role in the global carbon cycle. However, the lack of geochronological studies in previous works inhibits our understanding of their contributions. Herein, we conduct a cyclostratigraphic and magnetostratigraphic study on Neogene biogenic reefs using the XK–1 core that was drilled at the Shidao Island,Xisha(Paracel) Islands. The main findings of this study are:(1) the establishment of reliable magentostratigraphy for Ledong, Huangliu, Meishan and Sanya Formations;(2) the magnetic susceptibility variation can be inferred as growth index and tuned to the 405–ka long eccentricity cycle;(3) the astronomical geochronology suggests that the bottom ages for Ledong, Yinggehai, Huangliu, Meishan,and Sanya Formations are 2.2 Ma, 5.7 Ma, 10.4 Ma, 16.6 Ma, and 24.3 Ma, respectively; and (4) Earth s eccentricity and obliquity played predominant roles in biogenic reef establishment on orbital to tectonic timescales. Thus, the reported geochronology offers an opportunity to test the contributions of various factors and hypothesize their roles in the global carbon cycle in future.