论文部分内容阅读
中亚造山带作为地球上规模宏伟的造山带之一,是显生宙以来陆壳增生和伸展作用强烈的地区。华北克拉通是世界上最古老的陆块之一,晚中生代以来经历了大规模的伸展作用。中亚造山带与华北克拉通南北相连,悠久的构造演化进程使这一地区成为研究大陆造山及造山后伸展作用的理想场所。本文对新近完成的横过中亚造山带南缘一华北克拉通北缘(洪格尔-怀来)的600 km大地电磁长剖面,进行了严格规范的数据处理、分析和反演,获得了深部电性结构模型,研究了中亚造山带南缘和华北克拉通北缘深部壳幔结构,进而为该区构造演化提供新的依据。沿剖面,上地壳高阻体与分布的花岗岩对应;中、下地壳向北倾斜的高导层与其下方高导体相连,指示出地幔物质上升的通道,该套高导层与高导体可能形成于板块碰撞后的伸展环境,反映出地幔物质的上升作用是碰撞后构造伸展的主要动力。
The Central Asian orogenic belt, one of the magnificent orogenic belts on Earth, is a region where the continental crust has been strongly proliferated and extended since the Phanerozoic. North China Craton is one of the oldest land masses in the world and has undergone a large-scale expansion since the late Mesozoic. The Central Asian orogenic belt is linked to the north and south of the North China Craton. The long process of tectonic evolution makes this area an ideal place for studying the post-orogenic expansion of the mainland. In this paper, a rigorous standardization of data processing, analysis and inversion has been performed on the newly completed 600 km long magnetotelluric long section across the northern margin of the North China Craton (Hangel-Huailai) on the southern margin of the Central Asian orogenic belt Deep electrical structure model to study the deep crust and mantle structure of the southern margin of the Central Asia orogenic belt and the northern margin of North China Craton and thus provide a new basis for the tectonic evolution of the area. Along the section, the upper crust high resistivity body corresponds to the distributed granites. The middle and lower crust northward sloped high-conductivity layer is connected with the high-conductivity conductor below it, which indicates the rising channel of mantle material. The high-conductivity layer and high-conductivity body may form in The extension of the plate after the collision, reflecting the rising role of mantle material is the main driving force after the collision structure.