四川青川县乔庄镇城区活动断裂探测与评价
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摘要
青川县乔庄镇主城区坐落于乔庄河Ⅰ级河流阶地面上,平武-青川断裂分为3支呈隐伏状穿过主城区,地表未见明显的断裂新活动形迹。2008年5月12日发生的汶川MS8.0级地震,对青川县乔庄镇造成了比较严重的破坏,出现了沿平武-青川主干断裂通过位置震害显著加重的条带状异常现象,但未见明显的地表破裂。本文在地面地质调查、浅层地球物理勘探和探槽开挖验证结果的基础上,对平武-青川断裂在乔庄镇主城区的通过位置进行了重新定位,定位结果与前人研究结果存在一定的差异。结合地表调查发现的零星地表破裂和探槽下部砂砾石层出现的小尺度变形及位错现象分析,乔庄镇条带状震害加重异常现象应是平武-青川断裂在汶川地震时发生的近地表错动所致。由此联系到汶川地震的余震条带与平武-青川断裂乔庄以东段基本重合的事实,平武-青川断裂的活动性应是下一步研究工作的方向。
Qiaozhuang town of Qingchuan county is located on the terrace I of the Qiaozhuang river,where Pingwu-Qingchuan fault consists of three buried fault segments,crossing the main area of Qiaozhuang town.There are not new active evidence of the fault found on the ground.On May 12 of 2008,the Wenchuan earthquake caused serious damages to the city zone of Qiaozhuang town.The damages,along the main fault zone of the Qingchuan fault,are more serious and engendered a abnormal damage belt.However,there is no obvious surface rupture caused in the ground.Through geological investigation,shallow geophysical exploration and trenching,the segments of Pingwu-Qingchuan fault in the city zone were repositioned.Through some surface rupture and the slight deformation and offset of the sand-gravel layer under the trench,we proposed that the abnormal damage belt in Qiaozhuang town was due to the near-surface offset of the Pingwu-Qingchuan fault caused by the Wenchuan earthquake.This is consistent with the fact that the aftershock belt of the Wenchuan earthquake extend to the eastern segment of Pingwu-Qingchuan fault.Therefore,more work should be done for the new activity of Pingwu-Qingchuan fault in the future.
Qiaozhuang town of Qingchuan county is located on the terrace I of the Qiaozhuang river,where Pingwu-Qingchuan fault consists of three buried fault segments,crossing the main area of Qiaozhuang town.There are not new active evidence of the fault found on the ground.On May 12 of 2008,the Wenchuan earthquake caused serious damages to the city zone of Qiaozhuang town.The damages,along the main fault zone of the Qingchuan fault,are more serious and engendered a abnormal damage belt.However,there is no obvious surface rupture caused in the ground.Through geological investigation,shallow geophysical exploration and trenching,the segments of Pingwu-Qingchuan fault in the city zone were repositioned.Through some surface rupture and the slight deformation and offset of the sand-gravel layer under the trench,we proposed that the abnormal damage belt in Qiaozhuang town was due to the near-surface offset of the Pingwu-Qingchuan fault caused by the Wenchuan earthquake.This is consistent with the fact that the aftershock belt of the Wenchuan earthquake extend to the eastern segment of Pingwu-Qingchuan fault.Therefore,more work should be done for the new activity of Pingwu-Qingchuan fault in the future.
引文
2中国建筑西南勘察设计研究院有限公司,2009.青川县人民政府青川县城重建项目乔庄镇勘察报告(内部报告).
1浙江省城乡规划设计研究院,2008.四川省青川县城镇体系规划(内部报告).
1中国地震局地质研究所,四川省地震局工程地震研究院,2006.821厂址地震安全性评价报告(内部报告).
地质部四川省地质局,1966.中华人民共和国地质图广元幅,1:20万,I-48-X X XI V.
樊春,王二七,王刚等,2008.龙门山断裂带北段晚新近纪以来的右行走滑运动及其构造变换研究——以青川断裂为例.地质科学,43(3):417—433.
李志强,袁一凡,李晓丽等,2008.汶川MS8.0特大地震破坏特征初步研究.地震地质,30(4):855—876.
冉勇康,陈立春,陈桂华等,2008.汶川MS8.0地震发震断裂大地震原地重复现象初析.地震地质,30(3):630—643.
四川省测绘局编制,2001.四川省地图集.成都地图出版社,145.
四川省地质矿产局,1993.中华人民共和国地质图青川县幅,1:5万,I-48-127-A.
田勤俭,刁桂苓,郝平等,2009.汶川8.0级地震及余震破裂的地质构造特征.地震,29(1):141—148.
王卫民,赵连锋,李娟等,2008.四川汶川8.0级地震震源过程.地球物理学报,51(5):1403—1410.
徐锡伟,闻学泽,叶建青等,2008.汶川MS8.0地震地表破裂带及其发震构造.地震地质,30(3):597—629.
杨晓平,冯希杰,戈天勇等,2008.龙门山断裂带北段第四纪活动的地质地貌证据.地震地质,30(3):644—657.
中国地震局汶川地震现场指挥部,2009.汶川8.0级地震图集.北京:地震出版社.
周荣军,黄润秋,雷建成等,2008.四川汶川8.0级地震地表破裂与震害特点.岩土力学与工程学报,27(11):2173—2183.
张勇,许力生,陈运泰,2008.2008年汶川大地震震源机制的时空变化.地球物理学报,52(2):379—389.
张季生,高锐,曾令森等,2009.龙门山及邻区重、磁异常特征及与地震关系的研究.地球物理学报,52(2):572—578.
1浙江省城乡规划设计研究院,2008.四川省青川县城镇体系规划(内部报告).
1中国地震局地质研究所,四川省地震局工程地震研究院,2006.821厂址地震安全性评价报告(内部报告).
地质部四川省地质局,1966.中华人民共和国地质图广元幅,1:20万,I-48-X X XI V.
樊春,王二七,王刚等,2008.龙门山断裂带北段晚新近纪以来的右行走滑运动及其构造变换研究——以青川断裂为例.地质科学,43(3):417—433.
李志强,袁一凡,李晓丽等,2008.汶川MS8.0特大地震破坏特征初步研究.地震地质,30(4):855—876.
冉勇康,陈立春,陈桂华等,2008.汶川MS8.0地震发震断裂大地震原地重复现象初析.地震地质,30(3):630—643.
四川省测绘局编制,2001.四川省地图集.成都地图出版社,145.
四川省地质矿产局,1993.中华人民共和国地质图青川县幅,1:5万,I-48-127-A.
田勤俭,刁桂苓,郝平等,2009.汶川8.0级地震及余震破裂的地质构造特征.地震,29(1):141—148.
王卫民,赵连锋,李娟等,2008.四川汶川8.0级地震震源过程.地球物理学报,51(5):1403—1410.
徐锡伟,闻学泽,叶建青等,2008.汶川MS8.0地震地表破裂带及其发震构造.地震地质,30(3):597—629.
杨晓平,冯希杰,戈天勇等,2008.龙门山断裂带北段第四纪活动的地质地貌证据.地震地质,30(3):644—657.
中国地震局汶川地震现场指挥部,2009.汶川8.0级地震图集.北京:地震出版社.
周荣军,黄润秋,雷建成等,2008.四川汶川8.0级地震地表破裂与震害特点.岩土力学与工程学报,27(11):2173—2183.
张勇,许力生,陈运泰,2008.2008年汶川大地震震源机制的时空变化.地球物理学报,52(2):379—389.
张季生,高锐,曾令森等,2009.龙门山及邻区重、磁异常特征及与地震关系的研究.地球物理学报,52(2):572—578.
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