海洋岩石圈磁结构及动力学

Magnetic structure of the oceanic lithosphere and its dynamic implications

古地磁学在20 世纪极大地促进了板块构造理论的诞生和全球大洋钻探计划的发展.对洋壳的磁性研究是这场地学革命的突破点之一.从磁学性质上, 洋壳磁性包括洋壳中所含磁性矿物本身的性质以及这些矿物携带的古地磁信息.从介质性质上, 洋壳包含下部岩石层（包括枕状玄武岩、辉长岩和橄榄岩）和上部沉积物.文章首先总结洋壳的磁性结构,并对其代表的动力学意义进行深入探讨, 主要包括应用磁异常条带进行年代学、地球深部动力学、大洋洋壳的板块运动学以及热点演化等研究, 详细总结了国内相关研究中南海洋壳的磁性研究进展.最后对研究中遇到的相关难点和关键科学问题进行了回顾与展望.

In the last century,paleomagnetism,especially studies on magnetic properties of oceanic crusts,have greatly promoted the development of the plate tectonics theory and the International Ocean Drilling Program. The oceanic crust carries two kinds of magnetic information: magnetic properties of the magnetic assemblage in the oceanic crust,and the paleomagnetic signals carried by these minerals. Generally,the oceanic crust consists of a lower oceanic lithosphere(including pillow basalt,gabbro and peridotite) and overlying marine sediments. This paper summarized the magnetic structure of the oceanic crust,and then discussed relevant dynamic processes including chronological indications of oceanic magnetic anomalies,dynamic processes of the Earth's interior,kinematics of the oceanic crust,and evolution of hotspots. Then,we systematically summarized major progresses of magnetic studies of the South China Sea. Key scientific topics related to magnetic properties of oceanic crusts in future studies were also discussed.