地震地质 ›› 2024, Vol. 46 ›› Issue (1): 63-80.DOI: 10.3969/j.issn.0253-4967.2024.01.005

• 研究论文 • 上一篇    下一篇

重结晶碳酸盐ESR年代学在碳酸盐岩基岩区断层和滑坡活动性研究中的应用进展

刘春茹(), 袁仁茂*(), 尹功明, 姬昊, 魏传义, 田颖颖, 马玺, 党嘉祥   

  1. 中国地震局地质研究所, 地震动力学国家重点实验室, 北京 100029
  • 收稿日期:2023-03-08 修回日期:2023-06-09 出版日期:2024-02-20 发布日期:2024-03-22
  • 通讯作者: *袁仁茂, 男, 1972年生, 研究员, 主要研究方向为工程地质、 地质灾害、 活断层致灾机理、 工程地震等。 E-mail: yuanrenmao@ies.ac.cn
  • 作者简介:

    刘春茹, 女, 1980年生, 2007年于中国科学院地球化学研究所获地球化学专业博士学位, 研究员, 主要研究方向为第四纪年代学与新构造运动, E-mail:

  • 基金资助:
    国家自然科学基金(U1939201); 国家自然科学基金(42172211); 国家重点研发计划项目(2021YFC3000601); 中国地震局地质研究所基本科研业务专项(IGCEA1908)

APPLICATION PROGRESS OF RECRYSTALLIZED CARBONATE IN THE STUDY OF FAULT AND LANDSLIDE ACTIVITY IN CARBONATE BEDROCK AREA

LIU Chun-ru(), YUAN Ren-mao*(), YIN Gong-ming, JI Hao, WEI Chuan-yi, TIAN Ying-ying, MA Xi, DANG Jia-xiang   

  1. State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029, China
  • Received:2023-03-08 Revised:2023-06-09 Online:2024-02-20 Published:2024-03-22

摘要:

开展发震断层活动历史研究是地震、 滑坡等自然灾害研究和防治的基础, 年代测定一直是断层活动历史研究的热点和难点。在缺乏第四纪沉积物的碳酸盐岩基岩区, 宇生核素暴露测年是确定断层活动历史的主要手段, 但测年结果受曝露面表面风化、 侵蚀和溶蚀作用影响较大。碳酸盐是ESR年代学研究的主要测年矿物之一, 可以测量碳酸盐的结晶年龄。在碳酸盐岩基岩区的大型断层面和滑坡滑动面上, 因高速摩擦生热可形成重结晶碳酸盐, 为ESR测年提供了可靠的测年计时零点, 有望通过ESR测年法获得重结晶碳酸盐的结晶年龄, 即断层和滑坡最近一次的活动时代。以往用于ESR测年的碳酸盐都是自生碳酸盐, 如珊瑚、 石笋、 文石等, 尚未对断层和滑坡滑动面上的重结晶碳酸盐开展过相关研究。因此, 文中介绍了重结晶碳酸盐ESR测年的最新研究, 以丽江-小金河断裂剑川剖面的断层面和小江断裂与则木河断裂交会处的巧家滑坡后缘滑动面上的重结晶碳酸盐为研究对象, 通过微观结构观察、 热退火实验、 光晒退实验及与前人的沉积物14C和光释光测年结果进行比对等, 对将重结晶碳酸盐ESR测年法用于碳酸盐岩基岩区断层和滑坡活动性分析的可行性和可靠性进行分析和论证, 并建立了重结晶碳酸盐ESR测年技术, 该技术可广泛地用于碳酸盐岩基岩区的断层和滑坡活动历史研究。

关键词: ESR测年, 碳酸盐岩, 基岩断层, 滑坡, 重结晶

Abstract:

The research on the activity history of seismogenic faults is the basis for the research and prevention of natural disasters such as earthquakes and landslides. Dating has always been the focus and difficulty of the research on the activity history of fault. However, it is difficult to carry out geochronological surveys for faults and landslides evolution in the carbonated areas due to the lack of suitable dating materials, such as the region of south-eastern Tibet where the main lithology is carbonate bedrock. The exposure dating of cosmogenic nuclides is the main method to determine the activity history of fault. But the cosmic nuclides  36Cl and 14C dating methods still have some limitations, such as the complex generation mode of  36Cl being caused by fission under the action of cosmic rays, neutron capture and meson action, the yield of  36Cl being changed with chemical composition change of dating mineral(the range of 2-171atom/g·a), and so on. More importantly, the rapid rock weathering in the carbonate bedrock area is a big problem. Once exposed, the bedrock will start rapid weathering and erosion and dissolution. Therefore, it is necessary to find new dating materials or dating methods in carbonate bedrock areas, especially in areas with little or no quaternary sediments. When a large landslide moves on the sliding surface of carbonate bedrock, heat is often generated due to high-speed friction, and then the dynamic metamorphism can occur easily on the sliding surface to form recrystallized carbonate, which can be used to determine the active time of faults.

Carbonate is one of the main materials for ESR dating. As early as the 1970s, Ikeya made the first electron spin resonance(ESR)dating study of carbonates using stalactite calcite. After that, many researches on the ESR signal characteristics of carbonate(such as coral, shell, aragonite, stalagmite and etc)were carried out, and the carbonate ESR dating then became one of the main methods in Quaternary chronology and had been widely used. The recrystallized carbonate on the fault friction surface and the sliding surface of the landslide is a newly discovered dating material. Although its main component is calcium carbonate, its origin is different from the carbonate materials commonly used in ESR dating(such as stalagmite, stalactite, etc.), so it is necessary to study its characteristics of ESR dating.

The characteristics of recrystallized carbonate collected from the fault friction surface of Jianchuan section on Lijiang-Xiaojinhe Fault(Yin et al., 2021)and the sliding surface of Qiaojia landslide which is located at the intersection of Xiaojiang Fault and Zemuhe Fault(Liu et al., 2023)have been studied, including microstructure, thermal annealing characteristics, sunlight bleaching characteristics, and compared with the previous dating results of AMS 14C and OSL on sediments. Yin et al.(2021)and Liu et al.(2023)analyzed and demonstrated the feasibility and reliability of the recrystallized carbonate ESR dating method used in the analysis of bedrock fault and landslide activity in the carbonate bedrock area, and established the recrystallized carbonate ESR dating technology.

Therefore, the ESR dating of recrystallized carbonate is an effective dating technology and can be used widely for the studying of activity history of faults and landslides in carbonate bedrock areas. This paper introduced the latest research progress of recrystallized carbonate ESR dating in the Carbonate rock area of southwest China by Yin et al.(2021)and Liu et al.(2023). In this paper, the requirements for sample collection and the range of dating were proposed which provide technical support for dating of key geological samples for research on fault and landslide activity history, engineering exploration, active structure, and seismic risk assessment in Carbonate rock bedrock area.

Key words: ESR dating, carbonate rock, bedrock fault, landslide, recrystallization