河南南部的燕山运动

Yanshan Movement in Southern Henan Province

燕山运动是我国东部的一次强烈而重要的构造变动,在河南南部形成了一系列坳陷、断陷,堆积了一套特殊的类磨拉石沉积建造,发育强烈的褶皱和断裂,并有大规模的岩浆喷发和侵入活动,蕴含了丰富的矿产。燕山运动可分早、晚两期5幕,各幕强弱表现不同。早期Ⅰ、Ⅱ幕主要发生在大别山一带,以隆升与小规模岩浆侵入活动为主;晚期Ⅲ幕以火山活动局部发育岩浆侵入活动为特征;Ⅳ幕为断裂、岩浆活动发育,是重要的成矿期;Ⅴ幕使盆地由断陷转入坳陷发育阶段,造成白垩系与三叠系之间普遍不整合或假整合接触。分析认为,燕山期发生的太平洋板块与欧亚板块相互作用及印度板块对中国的推挤,使中国东部始终处于一种以挤压为主局部拉伸的构造应力场中。

Yanshan movement is a strong and significant tectonic event which makes a series of fault depression and accumulating huge quasi-molasse deposit in them,a lot of fold and faults,large amount of magma intrusion and eruption,and abundant mineral resources formation in southern Henan province.Yanshan movement can be subdivided into two periods and five episodes,earlier period contains Ⅰand Ⅱepisode,later period contains Ⅲ,Ⅳ and Ⅴ episode.Each episode has its own character.Small scale magma intrusion and uplift happened in Ⅰand Ⅱepisodes in Dabie Mountain area.Large scale volcanic activity and locally magma intrusion are happened in Ⅲ episode,while lots of fault and magma intrusion associated by important mineral resources formed in Ⅳ eposide.In the Ⅴ episode,the development of basin comes to subsidence stage from fault depression,which makes widespread unconformity or disconformity between Cretaceous and Triassic.The interacting between Pacific plate and Eurasian plate and the pushing of Indian plate against China continent make eastern China at a mainly compressional and locally extensional tectonic stress field in Yanshanian.