南华北中生代火山岩与前渊盆地

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

黄泽光 高长林

Huang Zeguang Gao Changlin

同济大学, 海洋地质与地球科学学院, 上海, 200092 2. 中国石油化工股份有限公司, 石油勘探开发研究院, 无锡石油地质研究所, 江苏, 无锡, 214151

School of Oceanic Geology and Geosciences, Tongji University, Shanghai 200092, China 2. Wuxi Research Institute of Petroleum Geology, Research Institute of Petroleum Exploration and Production, SINOPEC, Wuxi, Jiangsu 214151, China

运用地球化学理论和方法对南华北中生代火山岩研究后得知:火山岩的岩石类型为安山玄武岩、安山岩、英安岩、流纹岩类,为碱钙性和碱性,高钾,稀土总量高,富轻稀土;火山岩的形成构造环境既不是板块俯冲碰撞,也不是裂谷作用;火山岩形成于板块俯冲碰撞期后,与地幔柱活动有关;在白垩纪,合肥盆地和周口盆地的形成大地构造环境应是与岩石圈的热伸展有关。构造格局由地幔柱活动—伸展热窿作用(140～85 Ma)所主导,空间上各单元组成热窿核—剥离断裂带—下滑系统配置样式,盆地形成于下滑系统,盆地类型为前渊盆地。

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.

中国石化科技开发项目(P02071)

https://doi.org/10.11781/sysydz200601001