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高校地质学报 ›› 2026, Vol. 32 ›› Issue (01): 61-75.DOI: 10.16108/j.issn1006-7493.2025021

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藏南冈底斯带中段晚新生代隆升—剥蚀与地形演化历史:基于三维热运动学模拟的限定

王伟屹,蔡东旭,杨一帆,侯旭东,李广伟*   

  1. 冈底斯造山带的隆升—剥蚀历史及其地貌演化过程是研究青藏高原形成和演变发展的关键问题之一。同时,该区独
    特的地质—地貌演化特征也是解析构造—地表过程—气候三者相互作用共同塑造造山带形貌特征的理想地区。尽管前人在冈底斯带的隆升—剥蚀历史方面取得重要的进展和成果,但多数研究集中于冈底斯带东段地区,绵延上千公里的冈底斯造山带的隆升—剥蚀是否存在空间差异性依旧不清。该研究选取冈底斯中段日喀则地区,基于前人发表的低温热年代学数据,利用三维热运动学模拟方法(Pecube),反演冈底斯带中段晚新生代隆升—剥蚀和地貌演化过程。模拟结果表明,冈底斯中段自近30 Ma以来历经四个剥蚀演化阶段,剥蚀速率总体呈现“慢—快—慢”的趋势,地形起伏呈现“低—高—低”的变化;其中两个相对快速剥蚀阶段为:近27~18 Ma(约0.3 km/Myr)和近18~14 Ma(约0.75 km/Myr),对应此时冈底斯中段维持较高的地形起伏度。渐新世早期,呈现较低的剥蚀速率(0.15 km/Myr),地表地形较平坦,与该阶段青藏高原构造体系转向东西向伸展以及降水量较低相关;渐新世中后期—中新世早期剥蚀速率上升(约0.3 km/Myr),地形起伏显著增大,应受该时期冈底斯逆冲断裂带的强烈活动和亚洲季风系统扩展至高原内部的影响;中中新世冈底斯中段剥蚀速率达到最大(0.75 km/Myr),同时对应地形起伏度达到最大,应与该时期中中新世气候适宜期的湿热气候因素以及大反冲断裂活动加剧雅鲁藏布江溯源侵蚀密切相关;近14~10 Ma至今剥蚀速率和地形起伏再次下降(约0.2 km/Myr),这可能与该阶段喜马拉雅地体隆升导致降水屏障作用增强、亚洲内陆干旱化有关。
  • 出版日期:2026-02-14 发布日期:2026-02-14

Late Cenozoic Exhumation and Topographic Evolutionary History of the Gangdese Belt in Southern Tibet: A Qualification Based on Three-dimensional Thermal Kinematics Simulations

WANG Weiyi,CAI Dongxu,YANG Yifan,HOU Xudong,LI Guangwei*   

  1. The exhumation history of the Gangdese orogenic belt and its geomorphologic evolution process are key issues to
    understand the formation and evolution of the Tibetan Plateau. This region’s unique geological and geomorphological evolution makes it an ideal case study for analyzing the interaction of tectonics, surface processes, and climate in shaping orogenic belts. Despite significant progress in studying the exhumation history of the Gangdese belt, most studies have focused on the eastern part of the belt. The lateral variability in the exhumation of this over 1000-km-long belt remains unclear. In this study, we collected thermochronological ages from the Xigaze area published and applied a 3D thermokinematic model to reconstruct the late Cenozoic exhumation and topographic history of the central Gangdese belt. Our simulation results indicate that since ~30 Ma, the central Gangdese has undergone four exhumation stages. The exhumation rates generally followed a “slow-fast-slow” pattern, while topographic relief showed “low-high-low” changes. Two relatively rapid exhumation phases were identified at ~27-18 Ma (~0.3 km/Myr) and ~18-14 Ma (~0.75 km/Myr), corresponding to periods of sustained high topographic relief(R=1.5-1.7) in the central Gangdese. In the early Oligocene, lower exhumation rates (0.15 km/Myr) were observed, likely due to the tectonic transition of the Tibetan Plateau system to the E-W extension, topographic flattening, and reduced precipitation during this stage. From the mid-late Oligocene to early Miocene, the exhumation rate rose to ~0.3 km/Myr, potentially influenced by intense activity of the Gangdese thrust fault system and the expansion of the Asian monsoon system into the plateau interior. The maximum exhumation rate (0.75 km/Myr) occurred during the middle Miocene, and was closely related to the high topographic relief (R=1.7) in Gangdese and the warm-humid climate of the mid-Miocene Climatic Optimum. From ~14-10 Ma to the present, exhumation rates decreased again (~0.2 km/Myr), associated with enhanced precipitation shielding due to Himalayan terrane uplift, Asian inland drying, and progressive topographic flattening in the Gangdese region. 
  • Online:2026-02-14 Published:2026-02-14

摘要: 冈底斯造山带的隆升—剥蚀历史及其地貌演化过程是研究青藏高原形成和演变发展的关键问题之一。同时,该区独特的地质—地貌演化特征也是解析构造—地表过程—气候三者相互作用共同塑造造山带形貌特征的理想地区。尽管前人在
冈底斯带的隆升—剥蚀历史方面取得重要的进展和成果,但多数研究集中于冈底斯带东段地区,绵延上千公里的冈底斯造山带的隆升—剥蚀是否存在空间差异性依旧不清。该研究选取冈底斯中段日喀则地区,基于前人发表的低温热年代学数据,利用三维热运动学模拟方法(Pecube),反演冈底斯带中段晚新生代隆升—剥蚀和地貌演化过程。模拟结果表明,冈底斯中段自近30 Ma以来历经四个剥蚀演化阶段,剥蚀速率总体呈现“慢—快—慢”的趋势,地形起伏呈现“低—高—低”的变化;其中两个相对快速剥蚀阶段为:近27~18 Ma(约0.3 km/Myr)和近18~14 Ma(约0.75km/Myr),对应此时冈底斯中段维持较高的地形起伏度。渐新世早期,呈现较低的剥蚀速率(0.15 km/Myr),地表地形较平坦,与该阶段青藏高原构造体系转向东西向伸展以及降水量较低相关;渐新世中后期—中新世早期剥蚀速率上升(约0.3 km/Myr),地形起伏显著增大,应受该时期冈底斯逆冲断裂带的强烈活动和亚洲季风系统扩展至高原内部的影响;中中新世冈底斯中段剥蚀速率达到最大(0.75 km/Myr),同时对应地形起伏度达到最大,应与该时期中中新世气候适宜期的湿热气候因素以及大反冲断裂活动加剧雅鲁藏布江溯源侵蚀密切相关;近14~10 Ma至今剥蚀速率和地形起伏再次下降(约0.2 km/Myr),这可能与该阶段喜马拉雅地体隆升导致降水屏障作用增强、亚洲内陆干旱化有关。

关键词: 冈底斯造山带, 低温热年代学, 热运动学模型, 隆升剥蚀

Abstract: The exhumation history of the Gangdese orogenic belt and its geomorphologic evolution process are key issues to
understand the formation and evolution of the Tibetan Plateau. This region’s unique geological and geomorphological evolution makes it an ideal case study for analyzing the interaction of tectonics, surface processes, and climate in shaping orogenic belts. Despite significant progress in studying the exhumation history of the Gangdese belt, most studies have focused on the eastern part of the belt. The lateral variability in the exhumation of this over 1000-km-long belt remains unclear. In this study, we collected thermochronological ages from the Xigaze area published and applied a 3D thermokinematic model to reconstruct the late Cenozoic exhumation and topographic history of the central Gangdese belt. Our simulation results indicate that since ~30 Ma, the central Gangdese has undergone four exhumation stages. The exhumation rates generally followed a “slow-fast-slow” pattern, while topographic relief showed “low-high-low” changes. Two relatively rapid exhumation phases were identified at ~27-18 Ma (~0.3 km/Myr) and ~18-14 Ma (~0.75 km/Myr), corresponding to periods of sustained high topographic relief(R=1.5-1.7) in the central Gangdese. In the early Oligocene, lower exhumation rates (0.15 km/Myr) were observed, likely due to the tectonic transition of the Tibetan Plateau system to the E-W extension, topographic flattening, and reduced precipitation during this stage. From the mid-late Oligocene to early Miocene, the exhumation rate rose to ~0.3 km/Myr, potentially influenced by intense activity of the Gangdese thrust fault system and the expansion of the Asian monsoon system into the plateau interior. The maximum exhumation rate (0.75 km/Myr) occurred during the middle Miocene, and was closely related to the high topographic relief (R=1.7) in Gangdese and the warm-humid climate of the mid-Miocene Climatic Optimum. From ~14-10 Ma to the present, exhumation rates decreased again (~0.2 km/Myr), associated with enhanced precipitation shielding due to Himalayan terrane uplift, Asian inland drying, and progressive topographic flattening in the Gangdese region.

Key words: Gangdese orogenic belt, Low temperature thermochronology, Thermokinematic model, Exhumation

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