华南早中生代从印支期碰撞构造体系向燕山期俯冲构造体....pdf

16 1 ( ( ); ) Vol. 16 No. 1 2009 1 Earth Science Frontiers (China University of Geosciences, Beijing; eking University) Jan. 2009 1 2 2 2 张岳桥 , 徐先兵 , 贾 东 , 舒良树 11 , 100081 21 , 210093 1 2 2 2 Zhang Yueqiao , Xu Xianbing , Jia Dong , Shu Liangshu 11 Inst it ut e of Geomechani cs , Ch inese Acad emy of Geol ogi cal Sci ence s, Beij i ng 100081, Chi na 21 Depar t ment of Ear th Sci ence , N anj ing Univer sit y , N anj ing 210093, Chi na Zhang Yueqiao, Xu Xianbing, Jia Dong, et al. Deformation r ecor d of the change fr om Indosinian collision2related tectonic sys2 tem to Yanshanian subduction2related tectonic system in South China dur ing the Ear ly Meso oic. E a r th Scien ce F r ont ier s, 2009, 16( 1) :2342247 Abstr act: It is commonly accepted that t ectonic regimes underwent a tremendous change, during the Mesozoic, from the Tethys tectonic domain to the acific tectonic domain in South China, although the timing and geolog2 ical effects of such a change have been debated. This paper ident ified two generat ions of superimposed folds that widely develop in Indosinian to early Yanshanian t ectonic layer ( D2J ) in South China, and it is found 122 that the earlier generation of folds is well zonat ed in W2E and the later one is distributed in NNE. Based on the analysis of stratigraphic contact relationship and isotopic dat ing results of Early Mesozoic igneous rocks, it is considered that these two fold generat ions clearly record two phases of Early Mesozoic tectonic compression in South China: the nearly W2E trending fold z