Large tectonic movement of the Japan Arc in late Cenozoic times inferred from paleomagnetism: Review and synthesis
Large tectonic movement of the Japan Arc in late Cenozoic times inferred from paleomagnetism: Review and synthesis
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DOI：
10.1111/j.1440-1738.1996.tb00029.x
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发表时间：
1996-09
期刊：
影响因子：
1.5
通讯作者：
Y. Otofuji
中科院分区：
文献类型：
--
作者：
Y. Otofuji
摘要古地磁研究有助于从构造运动的角度理解新生代日本弧的演化。中新世中期，日本弧从亚洲大陆上裂陷，而包括日本弧在内的东亚大陆则同时向北移动。日本弧的裂陷现象可以用日本西南部和东北部的差异旋转来描述。日本西南部顺时针旋转约45°，日本东北部逆时针旋转约40°。这种差异旋转发生在大约15 Ma。百分之八十的旋转是在180万年的时间里完成的。这些因素使我们提出了日本海演化的一种“双开门"模式，其扩张速率为21 cm/yr，表明日本海地区的软流圈具有较低的粘度。根据日本弧的古地磁数据构建的表观极移路径，预计东亚相对于欧洲的大规模北向运动。在20 ~ 10 Ma之间，东亚可能向北移动了1700 km以上，并伴有10°的轻微顺时针旋转。晚新生代欧亚板块东部处于极端的地球动力学条件下。
Abstract Paleomagnetic studies facilitate an understanding of the evolution of the Japan Arc in Cenozoic times from the perspective of tectonic movement. The Japan Arc rifted from the Asian continent in the middle Miocene, while East Asia, including the Japan Arc, moved northward at the same time. The rifting phenomenon of the Japan Arc is described by differential rotation of Southwest and Northeast Japan. Southwest Japan was rotated clockwise through about 45° and Northeast Japan was rotated counter-clockwise through about 40°. This differential rotation occurred concurrently at about 15 Ma. Eighty percent of the rotation was completed during a period of 1.8 million years. These factors lead us to propose a‘double door’opening mode with a fast spreading rate of 21 cm/yr for the evolution of the Japan Sea, suggesting that the asthenosphere with a low viscosity was injected beneath the Japan Sea area. The large northward motion of East Asia in relation to Europe is expected from the apparent polar wander path constructed from the paleomagnetic data of the Japan Arc. East Asia may have moved northward by more than 1700 km between 20 Ma and 10 Ma accompanied by a slightly clockwise rotation of 10°. The eastern part of the Eurasian plate was subjected to extreme geodynamic conditions in late Cenozoic times.