A high-resolution sedimentary archive from landslide-dammed Lake Mengda, north-eastern Tibetan Plateau

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• 作者：Yongbo Wang (1) (2) (3)
  Ulrike Herzschuh (1) (3)
  Xingqi Liu (2)
  Oliver Korup (3)
  Bernhard Diekmann (1)
  
• 关键词：Earthquake ; Landslide ; Natural dam ; Tibetan Plateau
• 刊名：Journal of Paleolimnology
• 出版年：2014
• 出版时间：February 2014
• 年：2014
• 卷：51
• 期：2
• 页码：303-312
• 全文大小：685 KB
• 作者单位：Yongbo Wang (1) (2) (3)
  Ulrike Herzschuh (1) (3)
  Xingqi Liu (2)
  Oliver Korup (3)
  Bernhard Diekmann (1)
  
  1. Alfred Wegener Institute for Polar and Marine Research, Research Unit Potsdam, Telegrafenberg A43, 14473, Potsdam, Germany
  2. State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, People’s Republic of China
  3. Institute of Earth and Environmental Sciences, University of Potsdam, Karl-Liebknecht-Str. 24, 14476, Potsdam, Germany
  
• ISSN：1573-0417

文摘

Lacustrine sediments have been widely used to investigate past climatic and environmental changes on millennial to seasonal time scales. Sedimentary archives of lakes in mountainous regions may also record non-climatic events such as earthquakes. We argue herein that a set of 64 annual laminae couplets reconciles a stratigraphically inconsistent accelerator mass spectrometry (AMS) 14C chronology in a?~4-m-long sediment core from Lake Mengda, in the north-eastern Tibetan Plateau. The laminations suggest the lake was formed by a large landslide, triggered by the 1927 Gulang earthquake (M?=?8.0). The lake sediment sequence can be separated into three units based on lithologic, sedimentary, and isotopic characteristics. Starting from the bottom of the sequence, these are: (1) unweathered, coarse, sandy valley-floor deposits or landslide debris that pre-date the lake, (2) landslide-induced, fine-grained soil or reworked landslide debris with a high organic content, and (3) lacustrine sediments with low organic content and laminations. These annual laminations provide a high-resolution record of anthropogenic and environmental changes during the twentieth century, recording enhanced sediment input associated with two phases of construction activities. The high mean sedimentation rates of up to 4.8?mm?year? underscore the potential for reconstructing such distinct sediment pulses in remote, forested, and seemingly undisturbed mountain catchments.