太华群出露于华北中部造山带南段,是研究华北克拉通南缘演化的关键地区,对其研究不仅有助于深入了解华北克拉通古、中元古代构造演化特征,对于华北克拉通东西陆块碰撞时间的厘定也具有重要意义.通过对豫西小秦岭地区太华群深熔作用形成的3类混合岩开展岩相学研究,发现深熔作用对岩石的改造是不均匀的,明显受到了原岩的物质成分、岩石的结构构等性质的制约.通过对岩浆锆石及深熔锆石进行LA-ICP-MS定年,确定小秦岭地区太华群混合岩原岩年龄为早古元古代,深熔作用发生时间约为1.8Ga.研究区混合岩形成于华北克拉通东、西陆块碰撞后的伸展阶段,与区域同时期形成的大量基性岩墙群及A型花岗岩共同记录了华北克拉通在1.8Ga前后发生的大规模伸展拉张事件. Taihua Group is exposed in the southern segment of central orogenic belt in central North China. It is a key area for studying the evolution of the southern margin of North China Craton. It is not only helpful for its study to understand the tectonic and evolutionary features of Paleozoic and Mesoproterozoic in the North China Craton, It is also of great significance to determine the collision time of the East and West continents.Through the study of petrography on the three types of migmatites formed by the Taihua Group in the Xiaoqinling area, western Henan, it is found that the deep melting effect is not uniform to the rock reforming, Obviously affected by the material composition of the original rock and the structural structure of the rock.According to LA-ICP-MS dating of magmatic zircons and zircons, the age of the Taihua Group mixed rocks in the Xiaoqinling Mountains is determined as Early Proterozoic In the Proterozoic, the deep melting occurred about 1.8Ga.The mixed rocks in the study area formed in the extensional stage after the collision of the eastern and western continental blocks of North China Craton, and were recorded together with a large number of basic dykes and A-type granites formed in the same period The North China Craton in 1.8Ga before and after the occurrence of large-scale stretching tension event.