Earth Science Frontiers ›› 2021, Vol. 28 ›› Issue (2): 1-18.DOI: 10.13745/j.esf.sf.2020.9.7

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A review on the dating techniques for mountain hazards-induced sediments

LAI Zhongping1(), YANG Anna2,3, CONG Lu2,4, LIU Weiming2, WANG Hao5   

  1. 1. Institute of Marine Sciences, Shantou University, Shantou 515063, China
    2. CAS Key Laboratory of Mountain Hazards and Earth Surface Processes, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China
    3. College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China
    4. CAS Key Laboratory of Salt Lake Resource and Chemistry, Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, Xining 810008, China
    5. Institute of Geographic Sciences and Natural Resource Research, Chinese Academy of Sciences, Beijing 100101, China
  • Received:2020-06-15 Revised:2020-08-23 Online:2021-03-25 Published:2021-04-03

Abstract:

Chronology of mountain hazard events is the foundation for understanding hazard mechanisms and making hazard predictions. On the long timescale, the conventional dating methods include OSL, 14C, cosmogenic nuclides, tephrochronometry, etc.; on the short timescale, dendrochronology is normally used, supplemented by lichenometry. The selection of a specific technique depends on the availability of dating materials in the field. In order to enhance the reliability of dating results, cross-checking by different techniques is essential whenever dating materials are available. The field sampling should meet the age determination task for hazard events as well as the chronological requirements, thus researchers carrying out hazard and dating studies should collaborate routinely in the field during sample collection. We summarize here the routines and key points of related dating methods in order to provide some instructions for laboratory work and field trips. In particular, we emphasize the role of OSL and 14C techniques in dating mountain hazard sediments, as they are the most widely used dating methods at present. We suggest replicating dating results for critical sediment layers as an effective and practical way to assess the impact of OSL partial bleaching: If replication provides similar ages within error, the partial bleaching could be minor or negligible. OSL is ideal for dating dammed lake deposits which is the common recorder of mountain hazards. For 14C dating, the saturation age is mostly between 25-35 ka BP regardless of the dating materials, indicating that age falling into this range or beyond should be taken with caution.

Key words: mountain hazards, selection of dating techniques, sampling strategy in the field

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