中国东部中新生代地质构造发展特征与地震

引言本文讨论范围包括贺兰山、六盘山、龙门山和大雪山一线以东的广大东北、华北和华南地区及台湾省(简称中国东部)。中国东部自前震旦纪结晶基底形成后(其中华南东部是加里东褶皱基底),古生代时期受地中海构造体系和西太平洋构造体系的控制,主要处于一个三面有地槽带围限、内部为地台的发展阶段。随着属于地中海构造体系的天山和蒙古-大兴安岭地槽带、昆仑山-秦岭地槽带和川西-滇西地槽带于古生代至三迭纪期间逐渐褶皱迴返结束地槽生命后,中国东部受西太平洋构造体系的影响便相应地明显起来,成为中国东部中新生代地质构造发展的主导因素。

THE FEATURES OF MESOZOIC AND CENOZOIC TECTONIC DEVELOPMENTS IN EASTERN CHINA AND THEIR RELATIONSHIP TO SEISMICITY

In the light of crustal disturbances, magmatisms and sedimentary characteristics, the tectonic evolution through Mesozoic and Cenozoic times in eastern China may be divided into four stages: in the first one (T3-J21), under the influence of the West Pacific tectonic activities, the differences between the eastern and the western parts in eastern China in the above-mentioned three respects began to develop; in the second (J22-K1), the same differences became more pronounced; in the third (K2-E), owing to the decrease of the effect of the West Pacific tectonic activities, the differences started to develop instead between the southern and the northern parts; and in the fourth (N-Q), the same differences between the southern and northern parts became more prominently and in seismicity as well. Regarding the differences between the eastern and the western parts in eastern China displaying in Mesozoic age, the view that the Pacific plate has westward intensively underthrusted the Asiatic continent is established, but in the Cenozoic the differences between the southern and the northern parts are likely to be related to the isostatic readjustment.