东北亚中生代火山岩的地球动力学意义

东北亚中生代火山岩可划分为陆内环状火山岩带、纬向火山岩带和陆缘北北东向火山岩带,本文通过对俄罗斯、蒙古、中国东北、日本和朝鲜半岛在内的东北亚中生代火山岩分布图的编制,以及火山岩地球化学对比研究,认为东北亚中生代火山岩是古亚洲洋构造域向太平洋构造域转换时期,深部地幔地球化学过程以及东亚大陆与古太平洋板块相互作用的产物。在晚古生代至早中生代古亚洲构造域的闭合和欧亚大陆形成过程中,古亚洲域冷板块向地幔深部潜入而引发的热地幔柱的上升,是东北亚中生代大地构造演化和岩浆作用的重要控制因素。

GEOMECHANICAL SIGNIFICANCE OF THE MESOZOIC VOLCANICS IN NORTHEAST ASIA

The Mesozoic volcanic in Northeast Asia could be divided into continental circular volcanic belt, latitudinal volcanic belts and NNE trending epicontinental volcanic belt. They were formed by interaction between East Asia continet and Paleo-Pacific plate and by deep geological and geochemical procasses in the mantle during the transitional period of Paleo-Asia to Paleo-Pacific tectonic regines. During the period of the Eurasian continent formation from Late Paleozoic to Early Mesozoic, the subducting of the cold Paleo-Asia plate into the deep mantle caused the rising of hot mantle plumes, which is believed to be the most important factor controlling the Mesozoic tectonic evolution in Noreast Asia.