摘要
青藏高原东缘是全球古滑坡最发育的地区之一。基于大量地面调查、遥感解译和年龄测试资料,总结了青藏高原东缘深切河谷区古滑坡的判识方法、主要发育特征、形成时代和分布规律。结果表明,古滑坡具有规模巨大、高位起动、物质组成和结构复杂等特征,其空间分布与地形地貌、岩性组合和活动构造等因素关系密切。古滑坡在区域上受气候变化影响较明显,一般形成于河流强烈下切阶段,与河流阶地具有较好的对应关系,多数已发现的古滑坡与T 2阶地时代相当,时间跨度为40~10 ka,集中分布于30~20 ka。构造活动和地震造成古滑坡在不同区段的分布具有差异性,一般在活动断裂带附近密集发育,现今发现的古滑坡多为这种成因。这些认识对于科学认知古滑坡的形成演化过程和未来巨灾风险预测具有重要的指导作用。
The eastern Tibetan Plateau is a region with the most developed ancient landslides on earth.Based on ground surveys,remote sensing interpretation,and age dating,we summarize here the identification methods and the main developmental characteristics,formation age,and distribution pattern of the ancient landslides on the eastern Tibetan Plateau.The ancient landslides have the characteristics of large scale,high starting point,and complex material composition and structure,and their spatial distribution is closely related to factors such as topography,lithology,and active structure.The ancient landslides are obviously affected by climate change in the region,and are generally formed at the stage of strong river undercuts.They have a good corresponding relationship with river terraces,with the formation ages mostly equivalent to the age of the T 2 terrace.The age span is 40-10 ka,concentrated in 30-20 ka.The distribution patterns of the ancient landslides differ in different areas because of tectonic activities and earthquakes as landslides generally developed intensely near active fault zones.This study will be helpful for understanding the evolution of ancient landslides and for predicting future catastrophe risk.
作者
张永双
刘筱怡
吴瑞安
郭长宝
任三绍
ZHANG Yongshuang;LIU Xiaoyi;WU Rui’an;GUO Changbao;REN Sanshao(Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences,Shijiazhuang 050061,China;Key Laboratory of Quaternary Chronology and Hydro-Environmental Evolution,China Geological Survey,Shijiazhuang 050061,China;Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China)
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2021年第2期94-105,共12页
Earth Science Frontiers
基金
国家自然科学基金项目(41731287,41941017)
国家地质调查专项项目(20190505)。
关键词
古滑坡
河流阶地
活动构造
遥感判识模型
青藏高原东缘
ancient landslide
river terrace
active tectonics
RS cognization model
eastern Tibetan Plateau
