TECTONIC SIGNIFICANCE OF MESOZOIC VOLCANIC ROCKS IN NORTHEASTERN CHINA
Lin Qiang1, Ge Wenchun1, Sun Deyou1, Wu Fuyuan1, Chong Kwan Won2, Kyung Duck Min3, Myung Shik Jin4, Moon Wonlee2, Chi Soon Kwon5, Sung Hyo Yun6
1. Changchun University of Science and Technology, Changchun, 130026; 2. Kang Won National University, Chunche on, Korea; 3. YOnsei University, Seoul, Korea; 4. Korea Institute of Geology Mining and Materials, Daejeon, Korea; 5. Seoul National University of Education, Seoul, Korea; 6. Pusan National University, Pusan, Korea
Mesozoic volcanic rocks in Northeastern China can be classified into three volcanic belts,i.e. Western Daxinganling ring-like volcanic belt,Southern volcanic belt,and Eastern volcanic belt.They were formed in different tectonic settings during the transforming period of the tectonic regime from the Paleo-Asian to Pacific.Younging from outer to inner part,the Daxinganling ring-like volcanic belt shows a kind of structure of “thermal synclin”,the areal and ring-like distribution,and the geochemical features of highly enriched lithophile elements suggest that the formation of this belt is related to the rising of enriched hot mantle plume that was induced by the reaction between the oceanic lithosphere and the continental mantle during the closing process of Paleo-Asian Ocean.Located at the eastern part of the Indosinian Early Yanshanian tectonic belt in the northern margin of the Northern China Platform,the NEE Southern volcanic belt is the product of lithospheric extension during the transforming period of tectonic domain from Triassic to Early Cretaceous,accompanied by the horizontal development of Mongolian Permian-Triassic hot mantle plume and the continental dispersion.As the inner part of NEE calc-alkaline volcanic belt along the continental margin of Eastern Asia,the Eastern volcanic belt belongs to the Late Jurassic-Early Cretaceous calc-alkaline volcanic belt from Okhotsk,Sikhote Alin to northeastern Japan,and is related to tha oblique subduction of the Farralon-Izanagi and Kula-Pacific oceanic ridges at the Eastern continental marging.