陡坎地貌定年理论及其在活动构造与地貌学研究中的应用  

GEOMORPHIC DATING OF SCARPS AND ITS APPLICATION TO ACTIVE TECTONICS AND GEOMORPHOLOGY

作　　者：庞桢辉 徐皓婷 石许华 葛进 李丰 PANG Zhen-hui;XU Hao-ting;SHI Xu-hua;GE Jin;LI Feng(Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province,School of Earth Sciences,Zhejiang University,Hangzhou 310058,China;Research Center for Structures in Oil-and Gas-Bearing Basins,Ministry of Education,Hangzhou 310058,China;Xinjiang Pamir Intracontinental Subduction National Observation and Research Station,Beijing 100029,China)

机构地区：[1]浙江大学,地球科学学院,浙江省地学大数据与地球深部资源重点实验室,杭州310058 [2]教育部含油气盆地构造研究中心,杭州310058 [3]新疆帕米尔陆内俯冲国家野外科学观测研究站,北京100029

出　　处：《地震地质》2024年第2期251-276,共26页Seismology and Geology

基　　金：国家自然科学基金(41972227,41941016,51988101);国家重点研发计划项目(2022YFC3003704);第2次青藏高原综合科学考察研究项目(2019QZKK0708);浙江省钱江人才基金(QJD190202);浙江大学百人计划项目共同资助。

摘　　要：陡坎是构造活动、气候变化和侵蚀过程所产生的一种地貌现象。对陡坎中蕴含的地质信息进行解译,一方面可定量分析其地貌演变过程、重建相应地区的构造演化过程以及相关的地壳运动学过程及动力机制;另一方面也可了解地貌演化过程中构造、侵蚀与气候三者之间的互馈关系。然而,在地质条件欠佳的区域(无良好定年沉积物或人员无法到达),通常难以获得陡坎形成的年代。陡坎地貌定年很好地弥补了研究区的史料记载以及传统测年方法(如放射性碳同位素法、释光法和宇宙成因核素测年等)难以获得测年样品的不足。陡坎地貌定年的理论基础为“陡坎演化在稳定的侵蚀退化阶段可以通过坡面演化模型进行模拟”。不同坡面演化模型的提出及发展对研究构造活动、气候变化与地表剥蚀过程等有着重要意义。文中系统总结了陡坎定年理论及其数学模型,同时介绍了发育于不同地貌类型(活动断层、河流及海岸阶地、冲积扇、地外行星等)下的陡坎研究进展,并以帕米尔东北缘正断层陡坎地貌定年为研究实例,进一步探论并展望了陡坎地貌定年在构造地貌学领域的发展方向。Scarps are typical geomorphic features of tectonics,climatic changes,and erosion processes.On one hand,interpreting geological information encoded in scarps allows for the quantitative constraint of the kinematic and dynamic mechanisms of the active structures.On the other hand,studying the evolution processes of scarps contribute to a better understanding of the couplings among tectonics,erosion,and climate during geomorphic evolution processes.In regions characterized by adverse geological conditions,limited accessibility,and logistical challenges hindering researchers from reaching certain areas,traditional dating methods such as radiocarbon dating,luminescence dating,and cosmogenic nuclide dating often face difficulties in determining the age of scarps.The geomorphic dating method of scarps,however,offers a promising avenue to address the scarcity of chronological samples in research areas where either sample availability is limited or conventional dating techniques are impractical.This paper provides a concise summary of the theoretical evolution of geomorphic dating of scarps.Emphasis is placed on elucidating the slope evolution processes,transport models,and associated computational methodologies integral to this approach.Additionally,the specific applications of these methods in active tectonics and geomorphology are highlighted,accompanied by a case study showcasing their practical implementation.The theoretical foundation of geomorphic dating of scarps posits that the evolution of scarps during stable erosion stages can be simulated through models describing the evolution of slope surfaces over time.In practical dating applications,it is essential to determine the theoretical models and computational methods for the evolution of scarps.This necessitates the integration of measured profiles of the scarp to establish boundary and initial conditions,facilitating the determination of the geomorphic age of the studied scarps.On one hand,the related slope evolution model mainly involves processes such as bedr

关 键 词：活动构造 扩散方程 陡坎地貌定年 数值模拟 坡面演化 构造地貌学 

分 类 号：P542[天文地球—构造地质学] P931.2[天文地球—地质学]