VOLCANIC ROCKS AND FOREDEEP BASIN IN MESOZOIC, THE SOUTHERN NORTH CHINA

Volcanic rocks have been studied with geochemical theory and method in Mesozoic,the southern North China.The rock types include andesite-basalt,andesite,dacite,liparite which are calic-alkalic and alkalic,high-K,high-∑REE and rich in LREE.The forming tectonic environment of volcanic rocks is not related to plate subduction-collision or rifting,but mantle plume after plate subduction-collision.The forming tectonic environment of Hefei and Zhoukou is related to thermo-extension.The tectonic framework is controlled by mantle plume action(140～85 Ma).The space style of tectonic unites is composed of thermal dome-detachment fault-sliding system.The basin is formed in sliding system and the basin type is foredeep.