中国大陆东部晚中生代构造活化及其演化过程

与中生代中期造山型构造活化不同．晚中生代期间，中国大陆东部的构造活化表现为规模宏大的断陷盆地系、变质核杂岩、花岗岩浆侵位、火山岩喷发以及沿大型走滑断层的转换伸展为特征的大陆裂陷作用。根据岩浆活动、盆地的充填记录，构造格架和盆地的沉降史分析，可以将裂陷作用划分为两个大的阶段，即由兴安岭群火山喷发为代表的第一阶段和以巴彦花群含煤、油碎屑岩系为代表的断陷盆地形成阶段。盆地沉降史回剥研究表明，裂陷作用第二阶段断陷盆地的发育受控于次一级的幕式构造作用过程。此外．对晚中生代裂陷作用的动力学背景的探讨需要阐明岩石圈的深部过程和构造应力场的反转这个两个重要的问题。

THE LATE MESOZOIC TECTONIC ACTIVATION IN THE EASTERN CHINESE CONTINENT AND ITS EVOLUTION PROCESS

Different from the Middle Mesozoic orogeny-type tectonic activation, the Late Mesozoictectonic activation in the eastern Chinese continent was characterized by continental rifting such as gigantic faulted basin system, metamorphic core complex, volcanic eruption and the transform extension along large scale strike-slip faults. Based on the magmatic activation,filling sequence of basin. tectonic framework and subsidence history of basin, the rifting can be subdivided into two main development stages. The first stage was intensive and widespread volcanic eruption along NNE-trending faults, represented by volcanic rocks of the Xinan'ling Group. The second stage was the development of faulted basin, represented by elastic rocks bearing coal and oil of the Bayanhua Group. The development of faulted basin in the second stage of rifting underwent simultaneously several episodes of rapid subsidence, which show the multiple stretching of the lithosphere. Besides, the two important problems, the deep prooes of lithosphere and the inversion of tectonic stress field, have to be expounded for studying the geodynamic setting of the Late Mesozoic rifting.