Jianren Mao, Nanjing Institute of Geology and Mineral Resources (China)
Yutakak Takahashi, Institute of Geology and Geoinformation,AIST( Geological Survey of Japan) (Japan)
Zilong Li, Zhejiang University (China)
Qing Hu, Nanjing Institute of Geology and Mineral Resources (China)
Haimin Ye, Nanjing Institute of Geology and Mineral Resources (China)
Xilin Zhao, Nanjing Institute of Geology and Mineral Resources (China)
Qingtao Zeng, Nanjing Institute of Geology and Mineral Resources (China)
The SE China, South Korea and Japan are part of the trench-arc-basin system of Pacific Ocean continental margin. The SE China is composed of three continental blocks, e.g., Sino-Korean, Yangtze and Cathaysian. The three continents were amalgamated together by continental collision and became part of Eurasia plate during early Mesozoic. The geological evolutional history of South Korean is closely relationship with SE China.
Japan is located at the frontal margin of East Asian mainland, belonging to the one of the most important parts of arc series around the Pacific Ocean. The geological records indicated that, chain islands were derived from gathering of oceans and continents along active continental margin, and collage of terranes coming from the equator of low latitude. Before opening of the Japan Sea as the back-arc basin in the Miocene (15Ma), Japan was once belonged to the part of Asian mainland. Geodynamics model:
(1)The Meso-Cenozoic tectono-magmatic activity in SE China and South Korean might have been divided into four major stages:
I. 250-200Ma stage: Collision and compression of inter-continents between Sino-Korea and Yangtze block, as well as between Sibumasu and Cathaysian plate-Indosinian orogeny (Songrim orogeny in South Korea).
II. 200-80Ma stage: Eurasian active continental margin: Transformation from Tethys ( EW-trend, liner distribution ) to Paleo-Pacific active continental margin (NE-trend, extensive distribution)-Yanshan orogeny in SE China. The Paleo-Pacific plat subduction was lead to the activation of the paleo-tectonics in the inner mainland.There were no magmatic activity during 150-110Ma in South Korea.
III. 60-2Ma stage: Rifting of the Eurasian continental margin due to the opening in South China Sea and East China Sea: The lithosphere thinning affected by Paleo-Pacific geodynamic system-Himalayan movement.
<2Ma stage: the production of huge EW-direction rift zone in South China Sea; the production of NE-direction rift zone due to Japan Sea opening in South Korea. (2) The Meso-Cenozoic tectono-magmatic activity in Japan might have been divided into four major stages:
I. 250-130Ma stage: The production of tectonic formwork in Japan during Late Paleozoic- Early Mesozoic- Yanshan-Hirosima movement. The convergence of ocean-continents along the active continental margin, and collage of terranes coming from low latitude.
II. 130-40Ma stage: Eurasian active continental margin. Cretaceous-Paleogene calc-alkaline granitoids were widely distributed in the NE Japan and the inner zone of the SW Japan, which were consisted of the volcano-intrusive belt accompanying with large scale rhyolites.
III. 25-4Ma stage: The Island arc formation of the tectonic formwork in Japan. Japan can be divided into the NE Japan Arc and the SW Japan Arc by Itoigawa-Shizuoka tectonic line.
. 4Ma-present stage: Modern arc during Quaternary-modern volcanic activities and earthquake.