地震地质 ›› 2011, Vol. 33 ›› Issue (2): 383-390.DOI: 10.3969/j.issn.0253-4967.2011.02.011

• 年代学 • 上一篇    下一篇

沉积速率摇摆匹配法限定古地震事件日历年龄

尹金辉, 陈杰, 卢演俦, 郑勇刚   

  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:2009-10-19 修回日期:2010-11-17 出版日期:2011-06-29 发布日期:2011-12-17
  • 作者简介:尹金辉,男,1969年生,2006年在中国地震局地质研究所获得构造地质学专业博士学位,副研究员,主要从事地质灾害事件与第四纪地质年代学研究工作,电话: 62009015,E-mail: yjhdzs@ies.ac.cn。
  • 基金资助:

    中国地震局地质研究所基本科研业务专项(DF-IGCEA0607115)和地震科学联合基金(A07026)共同资助。

THE CALENDAR DATE OF PALEO-EARTHQUAKE EVENT ESTIMATED BY DEPTH-AGE WIGGLE MATCH

YIN Jin-hui, CHEN Jie, LU Yan-chou, ZHENG Yong-gang   

  1. State Key Laboratory of Earthquake Dynamics,Institute of Geology, China Earthquake Administration,Beijing 100029,China
  • Received:2009-10-19 Revised:2010-11-17 Online:2011-06-29 Published:2011-12-17

摘要:

尝试运用沉积速率摇摆匹配方法来获得淤泥质泥炭系列样品的日历年龄,并与单个14 C年代、时序已知系列14 C年代的日历年龄进行对比。结果表明: 在采样厚度较小的情况下,沉积速率摇摆匹配方法可以获得较小的日历年龄区间,具有一定的优越性; 在采样数量足够多的情况下,系列14 C年代贝叶斯校正也可以获得理想的日历年龄区间。综合不同方法获得的结果,推测发生在海原断裂带石卡关沟的古地震事件最大概率日历年龄区间为1 340~1 114cal a BP(2σ)。

关键词: 海原断裂, 古地震事件, 贝叶斯分析, 沉积速率摇摆匹配

Abstract:

This paper presents a comparison of the calendar range of individual paleoearthquake calculated by conventional calibration,Bayesian analysis of series of peat samples as well as depth-age wiggle matching.The results suggest that: (1)The Bayesian analysis provides an excellent means to enhance chronological resolution when applied to a series of radiocarbon dates from sections with clear stratigraphic relationships.Such application can assess systematic errors when combined with independent chronological information,and determine the optimum chronological information for specific events and contexts.(2)The calendar ranges of series of samples collected from the same peat but different sampling thickness were compared with that of depth-age wiggle matching.The result shows that the chronological resolution by depth-age wiggle matching for the peat sample with thickness less than 2cm could achieve less than 100a.Therefore,the condition to obtain a high resolution calendar age is to have 5~6 samples with 0.5~2cm sampling thickness each and the interval of samples is 0.5~1cm.(3)The calendar range of paleoearthquakes constrained by the Markov chain Monte Carlo(MCMC)Bayesian analysis model,which constructs the order of samples according to their position in the strata with series of radiocarbon dates,was compared with calendar range by the conventional method.The results show that Bayesian analysis could obtain high-precision calendar dates for closely spaced samples.(4)Therefore,the calendar interval of the paleoearthquake event on the middle segment of Huaiyuan Fault was inferred as 1340~1114cal a BP(2σ)by the above systematical comparsion.

Key words: Haiyuan Fault, paleoearthquake event, Bayesian analysis, depth-age wiggle match

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