摘要
采薇海山位于西北太平洋麦哲伦海山区,是由中国发现、命名并负责资源勘探的重点调查区之一.本文利用大洋27航次在采薇海山北坡MABC-05站获得的箱式沉积物样品,开展了详细的岩石磁学研究.结果显示表层沉积物中的磁性矿物以颗粒较细的、矫顽力较低的磁铁矿为主;利用对数正态分布函数可以区分三个具有不同矫顽力值的磁性颗粒组分,并发现磁性颗粒的矫顽力值变化可以有效指示沉积物埋藏后的早期成岩特征.在参考现代物理海洋过程的基础上,我们推测南极底层水团的演化和太阳辐射的变化可能共同影响了采薇海山区海洋底层环境过程.这一结果为探讨南极气候状况对北太平洋的可能影响,评估海洋上层与底层的相互作用等重要科学问题提供了新途径.
Seamounts constitute some of the most direct evidence about intraplate volcanism,and can profoundly affect physical and biological processes,mesoscale circulation and primary production.Caiwei Guyot locates within the Magellan Seamounts of the Northwest Pacific Ocean,where is one of the key investigation areas discovered,named and responsible for resource exploration by China.In this study,we carried out detailed rock magnetic investigations on a sedimentary sequence obtained from the Caiwei Guyot.The methods include hysteresis loops,isothermal remanent acquisition curves,and first-order reversal curves.It is found that the magnetic minerals in the surface sediments of the Caiwei Guyot are mainly fine-grained magnetite with low coercivity;and three magnetic sub-groups with different coercivity values can be mathematically distinguished by a log-normal distribution function,inferring that the change of the coercivity of the magnetic particles can effectively indicate the intensity of the early diagenesis of the sediments.Referring to the physical ocean process,we speculate that the production changes of the Antarctic bottom water and solar insolation may affect the environmental evolution of ocean bottom.Therefore,we suggest that this result provides new perspective to explore the possible impacts of the Antarctic climate on the North Pacific,and to assess the interactions between the upper and lower parts of the oceans,which both may have directly contributed to global changes.
作者
林震
易亮
王海峰
邓希光
杨继超
付腾飞
于洪军
谢强
邓成龙
LIN Zhen;YI Liang;WANG HaiFeng;DENG XiGuang;YANG JiChao;FU TengFei;YU HongJun;XIE Qiang;DENG ChengLong(Institute of Deep-sea Science and Engineering,Chinese Academy of Sciences,Sanya Hainan 572000,China;University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Marine Geology,Tongji University,Shanghai 200092,China;MNR Key Laboratory of Marine Mineral Resources,Guangzhou Marine Geological Survey,China Geological Survey,Guangzhou 510640,China;National Deep Sea Center of China,Qingdao Shandong 266061,China;MNR Key Laboratory of Marine Sedimentology and Environmental Geology,First Institute of Oceanography,Ministry of Natural Resources,Qingdao Shandong 266061,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)
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2019年第8期3067-3077,共11页
Chinese Journal of Geophysics
基金
国际海域资源调查与开发“十三五”(DY135-E2-1-01,DY135-C1-1-07)
中科院战略性先导科技专项《蛟龙号7000m级海试区地形特征与沉积物古海洋环境研究》(XDB06020206,XDB06020101)
国家自然科学基金(41690112)联合资助
关键词
西北太平洋
采薇海山
岩石磁学
早期成岩作用
深海环境过程
Northwest Pacific
Caiwei Guyot
Rock magnetism
Early diagenesis
Deep-sea environmental changes
