摘要
东北地区中生代火山岩可划分为晚三叠世—早白垩世中期、早白垩世晚期及以后两个大旋回 ,和晚三叠世—中侏罗世、晚侏罗世—早白垩世中期、早白垩世晚期及以后三大期次 .早期火山岩分布局限 ,主要分布于华北板块北缘 (侧 ) ;中期火山活动强烈 ,并逐渐向北东方向迁移 ,是古亚洲洋构造域与滨西太平洋构造域叠加产物 ;晚期火山活动较弱 ,逐渐向东迁移 ,是滨西太平洋板块俯冲作用单一体制环境的产物 .
A detailed study on the regional tectonics,magma activity,paleomagnetism,paleontology and stable isoptope shows that the Mesozoic volcanic rocks in northeast China were formed mainly in the period of late Triassic to late Cretaceous in two different surroundings The volcanic rocks, which were formed in the period of late Triassic to middle Cretaceous(230～120 Ma),were developed in the superimposition of the Paleo asiatic tectonic domain and the marginal Pacific tectonic domain The volcanic rocks,formed since late Cretaceous,were developed in the Cretaceous marginal Pacific tectonic domain That is why the volcanic rocks which were formed in the period of late Triassic to early Cretaceous(230～120 Ma) became newer from south to north, while the volcanic rocks which were formed since late Cretaceous became newer from west to east
基金
原地质矿产部资源与环境科技攻关课题!(编号 950 2 0 0 80 1 )资助
