三江地区怒江流域岩石剥露的时空特征及其构造和气候意义

揭示构造和气候在造山带形成演化过程中所起的作用，对理解造山带地貌演化、高原形成的时间和机制等具有重要意义。青藏高原东南缘地貌特征独特、岩石剥露作用强烈，是研究印-亚碰撞过程、高原隆升和地貌演化的关键地区之一。然而，构造作用和气候变化如何控制青藏高原东南缘的岩石剥露和地貌演化存在着广泛的争论。三江地区发育的贯穿整个藏东南的怒江深切峡谷为详细揭示该地区岩石剥露历史提供了理想条件。本项目以8个分布于怒江流域的高程剖面以及河谷底部岩石为研究对象，通过系统的磷灰石和锆石的(U-Th)/He和裂变径迹年代学研究，建立怒江流域岩石剥露的时空样式，运用地貌定量分析和Pecube三维热-动力模拟，并综合前人构造地质和古气候的研究成果，解译构造和气候在塑造高原地貌方面所起的作用，约束高原边界扩展的时间和机制。

Revealing the roles of tectonics and climate in the formation and evolution of orogenic belts is of great significance for understanding the large-scale landscape evolution, the timing and mechanisms of plateau formation. The southeast Tibetan Plateau is one of the key areas to study the processes of India-Asia collision, uplift and landscape evolution of plateau due to its unique geomorphologic features and rapid exhumation. However, how tectonics and climate changes control the exhumation and landscape evolution in southeast Tibetan Plateau is widely debated. The deep gorge of the Nujiang River that traverses through the whole southeast Tibetan Plateau provides an ideal condition for detailed study of exhumation history of the Three Rivers Region. This project plan to collect samples from eight vertical transects distributed in the gorge of Nujiang River and the bottom of the river valley, use apatite and zircon (U-Th)/He and fission track thermochronology to construct the spatial and temporal pattern of exhumation along the Nujiang River, conduct the quantitative morphologic analysis and Pecube 3D thermo-kinematic model and combine previous studies for structural geology and ancient climate to decipher the roles of tectonics and climate in the formation of plateau landform, and then constrain the timing and mechanisms of plateau growth.