论文部分内容阅读
大陆碰撞造山带的形成和演化是汇聚板块边缘的重要特征,其形成和演化大多经历了复杂的过程.以西大别为例,利用锆石成因矿物学、U-Pb年龄和Hf同位素组成特点等,结合区域地质情况,对造山带的多期演化提供了较为重要的制约.结果得到,浒湾地区洋壳的形成时间约为400～430Ma,稍晚于北秦岭与华北的碰撞时间,可能是碰撞后扬子板块北缘伸展作用形成的边缘盆地.浒湾地区榴辉岩相变质作用峰期发生在约310Ma的石炭纪,浒湾地区洋壳初始抬升时间约为270Ma.新县和红安地区榴辉岩的原岩时代和性质与大别-苏鲁其他地体一致,超高压变质作用也发生在中三叠纪,并经历了多阶段的抬升作用过程,应该是大别-苏鲁造山带的西延部分.因此,秦岭-大别-苏鲁地区是一个典型的多阶段复合型造山带,其聚合过程可能持续了200Ma以上.
The formation and evolution of the continental collision orogenic belt are the important characteristics of the convergent plate margin, and the formation and evolution of the continental collision orogenic belt have undergone a complicated process mostly.With the case of western Dabie, zircon mineralogenic mineralogy, U-Pb age and Hf isotopic compositions , Combined with the regional geological conditions, provides more important constraints on the multi-period evolution of the orogenic belt. As a result, the formation time of the oceanic crust in Ba Bay is about 400 ~ 430Ma, slightly later than that between North Qinling and North China, After the collision, the northern margin of the Yangtze plate formed the extensional margin basin.The eclogite metamorphism in the Huwan area occurred at about 310 Ma in the Carboniferous, and the initial rise time of the oceanic crust in the Bay area was about 270 Ma. The protolith age and nature of the eclogites are consistent with that of the Dabie-Sulu. The UHP metamorphism also took place in the Middle Triassic and experienced multi-stage uplift processes, which should be the Dabie-Sulu orogen Therefore, the Qinling-Dabie-Sulu region is a typical multi-stage composite orogenic belt, and its polymerization process may last more than 200Ma.