甘孜—玉树断裂带古地震研究
发布时间：2018-12-12 09:50
【摘要】：甘孜-玉树断裂带位于隆升与侵蚀作用均较为强烈的青藏高原东北部,为玛尼-玉树-鲜水河断裂系的中段,其与断裂系中的鲜水河断裂、则木河断裂、安宁河断裂、小江断裂和大凉山断裂一起构成了顺时针旋转的青藏高原南东地块的北部边界。本文在对甘孜-玉树断裂带遥感资料进行解释和分析的基础上,开展了野外地质调查、微地形测量和古地震槽勘探等工作,结合前人的研究成果,对甘孜玉树断裂带在古地震事件、重复间隔、滑动速率等方面进行了分析,获得了以下几点认识:(1)在构造地貌的研究方面,通过野外地质调查、遥感影像解释和微地形测量,发现断裂带上有大量的断层地貌,比如河流冲沟的错切、阶地的断错、以及积水槽谷的受错切封闭等,这些断错地貌沿断层分布,形成长近300km的形变带。(2)在古地震事件的研究方面,立足于在断裂沿线地区所开挖的10个探槽剖面,结合地层的沉积特征和14C样品的测年结果,分析区域沉积环境以及古地震的发震时代。分析发现,5000a以来,甘孜-玉树断裂带的南东段在存在三次古地震事件,时间分别为(1000±30)a BP、(3750±30)a BP、(1050±30)a BP,该段最近一次古地震离逝时间接近于(1000±30)a BP;断裂带中段因缺乏相关地层的年代数据,仅能根据历史文献记载,判定一次古地震事件,最近一次古地震时间为AD(1320±65);北西段探槽资料较为丰富,下拉村组合探槽共揭示7次古地震事件,该段最近一次古地震离逝时间为AD1896。岔来村探槽共揭示5次古地震事件,该段最近一次古地震离逝时间为距今(1765±30)aBP。查乌扣探槽共揭示9次古地震事件,该段最近一次古地震离逝时间为距今(1045±415)aBP。(3)在滑动速率的估算中,通过选取甘孜-玉树断裂的位错变形数据和年代资料,计算出了13个地点的滑动速率。排除人为因素影响明显的采集点,得到晚第四纪以来甘孜-玉树断裂的左旋滑动速率为6.5±2.5、7.2±0.7、8.8±1.2、10.9±2.0、11.3±1.8、12.8±1.7和13.9±1.4mm/a等结果,其中12~14mm/a的滑动速率是利用下阶地面的地面采集点获得的年代数据来代替阶地坎被位错的年代,因此,测得的速率值会偏大许多。横跨该断裂的GPS速度剖面表明,该断裂滑动速率为6.6±1.5mm/a。根据综合分析,认为晚第四纪以来8.9mm/a的整体滑动速率较为接近断裂带整体的滑动情况。(4)在古地震复发间隔方面,结合由探槽资料和滑动速率分析分别获得的古地震复发间隔数据,分析认为,5000a以来,得出了甘孜—玉树断裂在甘孜段的大震平均复发间隔为(2725±30)a,邓柯-错阿段的大震平均复发间隔为4968a,邓柯-巴塘段的大震平均复发间隔为(1282±220)a,巴塘盆地段的大震平均复发间隔为(3555±460)a。
[Abstract]:The Ganzi-Yushu fault zone is located in the northeast of Qinghai-Xizang Plateau, which is characterized by strong uplift and erosion, and is the middle part of the Mani-Yushu Xianshuihe fault system, which is associated with the Xianshuihe fault, the Muhe fault and the Anning River fault in the fault system. The Xiaojiang fault and the Daliangshan fault together form the northern boundary of the south east block of the Qinghai-Tibet Plateau which rotates clockwise. Based on the interpretation and analysis of remote sensing data in the Ganzi-Yushu fault zone, field geological survey, microtopography survey and paleoseismic trough exploration are carried out in this paper. Based on the analysis of paleoearthquake events, repetition intervals and slip rates in the Ganzi Yushu fault zone, the following conclusions have been obtained: (1) in the study of tectonic landforms, field geological surveys have been carried out. Remote sensing image interpretation and microtopographic survey show that there are a large number of fault landforms in the fault zone, such as the fault of river gully, the fault of terrace, and the block of water trough valley. These fault landforms are distributed along the fault. Forming a deformation zone near 300km. (2) in the study of paleoearthquake events, based on 10 trench sections excavated along the fault line, combined with the sedimentary characteristics of the strata and the dating results of 14C samples, The regional sedimentary environment and the seismogenic age of paleoearthquakes are analyzed. It is found that there are three paleoearthquakes in the eastern section of the Ganzi-Yushu fault zone since 5000 years, the time of which is (1000 卤30) a BP, (, 3750 卤30) a BP, (, 1050 卤30) a BP, respectively). The last paleoearthquake is close to (1000 卤30) a BP;). Due to the lack of age data of relevant strata in the middle part of the fault zone, only a paleoearthquake event can be determined according to the historical documents. The last paleoearthquake time is AD (1320 卤65). The north west section is rich in data. The Dachaocun assemblage trough reveals 7 paleoearthquakes. The last paleoearthquake in this section is AD1896.. A total of 5 paleoearthquake events were revealed in Chalaicun grooves. The last paleo-earthquake in this segment was (1765 卤30) aBP.. A total of 9 paleoearthquake events were revealed by Chawukuan trench. The last paleo-earthquake passing time was (1045 卤415) aBP. (3). In the estimation of slip rate, the dislocation deformation data and age data of Ganzi-Yushu fault were selected. The sliding rate of 13 sites was calculated. The results of left-lateral slip rate of Ganzi-Yushu fault since late Quaternary are 6.5 卤2.5 卤7.2 卤0.710. 8 卤1. 2 卤2. 0 10. 3 卤1. 8 卤1. 8 卤1. 8 卤1. 7 and 13. 9 卤1.4mm/a. The slip rate of 12~14mm/a is to use the age data obtained from the ground sampling points of the lower terrace to replace the age when the terraces are dislocated, so the measured rate value will be much larger. The GPS velocity profile across the fault shows that the slip rate of the fault is 6.6 卤1.5mm / a. According to the comprehensive analysis, it is considered that the overall slip rate of 8.9mm/a since the late Quaternary is closer to that of the whole fault zone. (4) in terms of the recurrence interval of paleoearthquakes, Based on the recrudescence interval data of paleoearthquakes obtained from trough data and slip rate analysis, it is concluded that the average recurrence interval of large earthquakes in the Ganzi-Yushu fault section is (2725 卤30) a since 5000 years ago. The average recurrence interval of large earthquakes in Dengke-Kaoa segment is 4968 a, that of large earthquakes in Dengke-Batang section is (1282 卤220a) a, and that of large earthquakes in Batang basin is (3555 卤460A) a.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P315.2
本文编号：2374357
[Abstract]:The Ganzi-Yushu fault zone is located in the northeast of Qinghai-Xizang Plateau, which is characterized by strong uplift and erosion, and is the middle part of the Mani-Yushu Xianshuihe fault system, which is associated with the Xianshuihe fault, the Muhe fault and the Anning River fault in the fault system. The Xiaojiang fault and the Daliangshan fault together form the northern boundary of the south east block of the Qinghai-Tibet Plateau which rotates clockwise. Based on the interpretation and analysis of remote sensing data in the Ganzi-Yushu fault zone, field geological survey, microtopography survey and paleoseismic trough exploration are carried out in this paper. Based on the analysis of paleoearthquake events, repetition intervals and slip rates in the Ganzi Yushu fault zone, the following conclusions have been obtained: (1) in the study of tectonic landforms, field geological surveys have been carried out. Remote sensing image interpretation and microtopographic survey show that there are a large number of fault landforms in the fault zone, such as the fault of river gully, the fault of terrace, and the block of water trough valley. These fault landforms are distributed along the fault. Forming a deformation zone near 300km. (2) in the study of paleoearthquake events, based on 10 trench sections excavated along the fault line, combined with the sedimentary characteristics of the strata and the dating results of 14C samples, The regional sedimentary environment and the seismogenic age of paleoearthquakes are analyzed. It is found that there are three paleoearthquakes in the eastern section of the Ganzi-Yushu fault zone since 5000 years, the time of which is (1000 卤30) a BP, (, 3750 卤30) a BP, (, 1050 卤30) a BP, respectively). The last paleoearthquake is close to (1000 卤30) a BP;). Due to the lack of age data of relevant strata in the middle part of the fault zone, only a paleoearthquake event can be determined according to the historical documents. The last paleoearthquake time is AD (1320 卤65). The north west section is rich in data. The Dachaocun assemblage trough reveals 7 paleoearthquakes. The last paleoearthquake in this section is AD1896.. A total of 5 paleoearthquake events were revealed in Chalaicun grooves. The last paleo-earthquake in this segment was (1765 卤30) aBP.. A total of 9 paleoearthquake events were revealed by Chawukuan trench. The last paleo-earthquake passing time was (1045 卤415) aBP. (3). In the estimation of slip rate, the dislocation deformation data and age data of Ganzi-Yushu fault were selected. The sliding rate of 13 sites was calculated. The results of left-lateral slip rate of Ganzi-Yushu fault since late Quaternary are 6.5 卤2.5 卤7.2 卤0.710. 8 卤1. 2 卤2. 0 10. 3 卤1. 8 卤1. 8 卤1. 8 卤1. 7 and 13. 9 卤1.4mm/a. The slip rate of 12~14mm/a is to use the age data obtained from the ground sampling points of the lower terrace to replace the age when the terraces are dislocated, so the measured rate value will be much larger. The GPS velocity profile across the fault shows that the slip rate of the fault is 6.6 卤1.5mm / a. According to the comprehensive analysis, it is considered that the overall slip rate of 8.9mm/a since the late Quaternary is closer to that of the whole fault zone. (4) in terms of the recurrence interval of paleoearthquakes, Based on the recrudescence interval data of paleoearthquakes obtained from trough data and slip rate analysis, it is concluded that the average recurrence interval of large earthquakes in the Ganzi-Yushu fault section is (2725 卤30) a since 5000 years ago. The average recurrence interval of large earthquakes in Dengke-Kaoa segment is 4968 a, that of large earthquakes in Dengke-Batang section is (1282 卤220a) a, and that of large earthquakes in Batang basin is (3555 卤460A) a.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P315.2
【参考文献】
相关期刊论文 前10条
1 黄学猛;田坤;杜义;何仲太;雷惊昊;马保起;谢富仁;;玉树巴塘断裂晚第四纪滑动速率及其构造意义[J];北京大学学报(自然科学版);2015年01期
2 吴中海;周春景;冯卉;张克旗;李家存;叶培盛;李跃华;田婷婷;;青海玉树地区活动断裂与地震[J];地质通报;2014年04期
3 李安;石峰;杨晓平;徐锡伟;;甘孜-玉树断裂带东南段古地震复发规律[J];中国科学:地球科学;2013年07期
4 闻学泽;杜方;张培震;龙锋;;巴颜喀拉块体北和东边界大地震序列的关联性与2008年汶川地震[J];地球物理学报;2011年03期
5 张培震;徐锡伟;闻学泽;冉勇康;;2008年汶川8．0级地震发震断裂的滑动速率、复发周期和构造成因[J];地球物理学报;2008年04期
6 田勤俭;任治坤;张军龙;;则木河断裂带大箐梁子附近古地震组合探槽研究[J];地震地质;2008年02期
7 刘静;徐锡伟;李岩峰;冉勇康;;以海原断裂甘肃老虎山段为例浅析 走滑断裂古地震记录的完整性——兼论古地震研究中的若干问题[J];地质通报;2007年06期
8 尹金辉;郑勇刚;刘粤霞;卢演俦;;系列~(14)C样品贝叶斯法日历年龄校正研究进展[J];地球科学进展;2007年03期
9 彭华;马秀敏;白嘉启;杜德平;;甘孜玉树断裂带第四纪活动特征[J];地质力学学报;2006年03期
10 李勇;P.A.ALLEN;周荣军;A.L.DENSMORE;M.A.ELLIS;;青藏高原东缘中新生代龙门山前陆盆地动力学及其与大陆碰撞作用的耦合关系[J];地质学报;2006年08期
相关博士学位论文 前1条
1 冉勇康;我国几个典型地点的古地震细研究和大地震重复行为探讨[D];中国地震局地质研究所;1997年
相关硕士学位论文 前2条
1 王腾文;甘孜—玉树断裂北西段活动性及其构造地貌研究[D];成都理工大学;2016年
2 马超;川滇块体内主干断裂活动性及微地貌研究[D];成都理工大学;2013年
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