青海玉树断裂带地震落石的地震地质意义.pdf

第33卷第4期
地质通报
Vo1. 33. No4
2014年4月
GEOLOGICAL BULLETIN OF CHINA
Apr.,2014
青海玉树断裂带地震落石的地震地质意义
田婷婷2,吴中海2,马志邦3,冯卉2,尼玛次仁,蒋瑶2,张绪教,张铎26
TIAN Ting-ting", WU Zhong hai MA Zhibang, FENG Hui, NIMA Ci-ren',
JIANG Yao", ZHANG Xu-jiao, ZHANG Duos
1.中国地质大学(北京)地球科学与资源学院,北京100083;
2.中国地质科学院地质力学研究所,北京100081;
3.中国科学院地质与地球物理研究所,北京100029
4.西藏地质调查院一分院,西藏堆龙徳庆851400;
5.首都师范大学资源环境与旅游学院,北京100048
College of Earth Science and Resources, China University of Geosciences, Beijing 100083, China,
2. Institude of Geomechanics, Chinese Academy of Geologcal Sciences, Beijing 100081, China
3. Institude of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
4. First I, Tibet Institue of Geological Su Duilongdegng851400, ibet, China
5. Colege of Resource Enuironment and Tourism, Captial Normal University, Beijing 100048, China
摘要:2010年青海玉树Ms7.1级大地震引发了一系列次生地质灾害,其中地震落石是除地震滑坡外沿断裂带及其邻侧最常见
的现象。对玉树震区落石的调查发现,该区多处存在非常典型的多期地震落石分布现象,指示该区地震落石的发育与其他古
地震现象类似,具有多期性和一定的原地复发性。实地调查表明,该区地震落石分布的主要特征为:多集中发育在活动断裂带
附近的陡峭基岩斜坡下方,分布零散,且滚动較远,并常与古地震滑坡相伴生。初步获得的8个地震落石钙膜U系测年结果分
布在距今6030±300aBP、4720土210aBP、3530土490~3560土280aBP、2010±160aBP、1090士70aBP、760土20aBP和230土20aBP年
龄段,与该区古地震探槽和滑坡反映的地震事件比较吻合,进一步揭示玉树断裂带附近在全新世中晚期发生过多期可导致地
表产生地震落石的事件。同时也说明,地震落石及其钙膜测年是特别值得进一步探索的潜在古地震研究方法或途径。
关键词:玉树断裂带;地震落石;U系测年;古地震事件;地震灾害
中图分类号:P315.9:P315.2文献标志码:A文章编号:1671-2552(2014)04-0567-11
Tian T T, Wu Z H, Ma Z B, Jiang Y, Zhang X J. A tentative iscussion on the seismic and geolo cal significance of the seis
mic rockfall along the Yushu faulted zone in Qinghai Province. Geological Bulletin of China, 2014, 33(4) 567-577
Abstract: In 2010, Ms 7. 1 carthquake in Yushu, Qinghai Province triggered a series of secondary geological disasters, in addition to
the earthquake landslide, distribution of seismic rock all alon the fault zone and its adjacent side is extremely common. By the inves
tigation of rockfalls in Yushu area, the survey indicated in a number of typical rockfall zone, in addition to the fresh rockfalls formed
in the 2010 earthquake, there are still a lot of early seismic rockfalls scattered, which suggests that the development of seismic rockfall
is similar to paleo-earthquake activity, with multi-period and a certain number of in-situ recurrent. The typical seismic rockfall sur
vey found that the distribution characteristics of rockfall is mainly: general concentrated distribution below steep rock slopes near the
active fault belt, scattered distibution, rolling far awa and often accompanied by paleo-earthquake landslide. Preliminary U series
dating result of& seismic rockall alcium membrane distributed in 6030*00a BP, 4720t210a BP, 3530490-3560*280a BP
收稿日期:2013-11-20;修订日期:2014-01-27
资助项目:中国地质调查局项目(编号:121201112063)、中国地质科学院地质力学研究所基本科研业务费项目(编号: DZLXJK201202)
和国家自然科学基金项目(批准号:4117100
作者简介:田婷婷(1986-),女,在读硕士生,从事第四纪年代学与活动构造研究。E-mai:wing815@126.com
通讯作者:中海(1974-),男,博士,研究员,从事第四纪地质和活动构造研究。E- mail: wzhh448 @sina.om