苏鲁造山带东段新生代两阶段剥露事件的磷灰石(U-Th)/He热年代学证据

苏鲁造山带位于华北和华南板块之间,是中国东部最显著的陆内造山带之一,约束其新生代剥露过程对于理解中国东部盆山格局分布及其动力学机制具有重要意义.低温热年代学方法由于封闭温度较低,能更准确地约束上地壳地质体的剥露过程.利用磷灰石(U-Th)/He方法,对苏鲁造山带东部的多福山和锯齿山开展研究.磷灰石(U-Th)/He年龄...

Apatite (U-Th)/He Thermochronology Evidence for Two Cenozoic Denudation Events in Eastern Part of Sulu Orogenic Belt

The Sulu orogenic belt, located between the North China and South China plates, is one of the most prominent intracontinental orogenic belt in eastern China. Therefore, the denudation history of Sulu orogenic belt provides significant insight into the basin-mountain evolution in eastern China and their dynamic mechanism. Due to the apatite (U-Th)/He system has low closure temperature (ca. 70 ℃), it can constrain the cooling processes of geological bodies more accurately in the upper crust. In this study, the apatite (U-Th)/He method was used to analyze the exhumation time of rocks on the Duofu and Juchi mountains located in the eastern parts of Sulu orogenic belt. The apatite (U-Th)/He age-elevation relationship and thermal history simulation results show that the exhumation occurred in the Early-Middle Eocene (54-43 Ma) and Oligocene (35-27 Ma) for the Duofu and Juchi mountains, respectively. These cooling episodes were synchronized with the exhumation time of the western part of the Sulu orogenic belt. Combined with the results reported in the region, it is shown that the eastern China was influenced by the Pacific and Indian plates subduction into Eurasia, and the extensive exhumation process occurred in the Early Cenozoic, which established the basin-mountain distribution pattern during this time.