临泽断裂新活动特征初步研究
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摘要
临泽断裂在地貌上可见3条断层陡坎,总体走向NNW,最长约8 km,东侧和中间陡坎主体倾向E,西侧陡坎倾向W。①利用差分GPS对3条断层陡坎进行了详细的测量,发现临泽断层陡坎较低,局部发育多级断层陡坎,坡角较缓,高度几十厘米至1米多;②在临泽断裂上选取4个探槽剖面进行古地震分析、样品采集和年代测试,发现东侧和中间的断层陡坎为正断层所控制,西侧的断层陡坎为逆断层所控制;③探槽开挖揭露出晚更新世晚期以来,临泽断裂上发生过4次古地震事件,时间分别为(8 895±125)a B.P.之前、(7 245±75)a B.P.～(6 190±20)a B.P.、(5120±20)a B.P.～(4.8±0.5)ka和(2 550±50)a B.P.～(2 326±64)a;④全新世以来可以确定3次事件,较早一次事件与榆木山北缘断裂上较早一次古地震事件时间比较吻合,说明临泽断裂可能是榆木山断裂向河西走廊内部继续活动的延伸;最后一次古地震事件的离逝时间约为2 500 a,表明临泽断裂全新世活动一直比较强烈。
The Linze fault includes three fault scarps,of which the middle and east scarps facing east,while the west scarp facing west,mainly striking NNW direction with the length up to 8 km,have been discovered. ①Three fault scarp are measured in detail by differential GPS. The profiles show that the Linze fault scarps are much lower,and multi-level fault scarp are locally developed,with gentle slope angle and a height from tens of centimeters to one meter. ② Four trench profiles on Linze fault are selected for paleoseismic analysis,sample collection and dating. It is found that the fault scarps in the east and middle are controlled by normal faults,while the fault scarps in the west are controlled by reverse faults. ③Since late Late Pleistocene,four rupture events happened respectively before(8 895±125) a B.P.,(7 245±75) a B.P.～(6 190±20) a B.P.,(5 120±20) a B.P.～(4.8±0.5) ka and(2 550±50) a B. P.～(2 326±64) a. ④Three events can be identified since Holocene. The earlier one coincides with the earlier paleoearthquake event on the northern margin fault of Yumushan,which indicates that Linze fault may be the extension of Yumushan fault to the Hexi Corridor. The last paleoearthquake event elapsed about 2 500 a,which indicates that the Linze fault is active during Holocene.
The Linze fault includes three fault scarps,of which the middle and east scarps facing east,while the west scarp facing west,mainly striking NNW direction with the length up to 8 km,have been discovered. ①Three fault scarp are measured in detail by differential GPS. The profiles show that the Linze fault scarps are much lower,and multi-level fault scarp are locally developed,with gentle slope angle and a height from tens of centimeters to one meter. ② Four trench profiles on Linze fault are selected for paleoseismic analysis,sample collection and dating. It is found that the fault scarps in the east and middle are controlled by normal faults,while the fault scarps in the west are controlled by reverse faults. ③Since late Late Pleistocene,four rupture events happened respectively before(8 895±125) a B.P.,(7 245±75) a B.P.～(6 190±20) a B.P.,(5 120±20) a B.P.～(4.8±0.5) ka and(2 550±50) a B. P.～(2 326±64) a. ④Three events can be identified since Holocene. The earlier one coincides with the earlier paleoearthquake event on the northern margin fault of Yumushan,which indicates that Linze fault may be the extension of Yumushan fault to the Hexi Corridor. The last paleoearthquake event elapsed about 2 500 a,which indicates that the Linze fault is active during Holocene.
引文
陈柏林,王春宇,宫红良,等.2007.关于河西走廊盆地榆木山北缘断裂晚第四纪活动特征的新认识[J].地质通报,26(8):976-983.
国家地震局地质研究所,国家地震局兰州地震研究所.1993.祁连山-河西走廊活动断裂系[M].北京:地震出版社.
金卿,何文贵,史志刚,等.2011.榆木山北缘断裂古地震特征研究[J].地震地质,33(2):347-355.
金卿.2011.榆木山断裂带晚第四纪构造活动与大震危险性评价[D].兰州:中国地震局兰州地震研究所.
李有利,李保俊,杨景春.1995.甘肃张掖黑河口断层晚更新世晚期以来的活动[J].北京大学学报(自然科学版),31(3):351-357.
李有利,杨景春,李保俊,等.1997.河西走廊榆木山边缘断层构造地貌研究[J].地质力学学报,3(4):20-26.
李玉龙,邢成起.1988.河西走廊地质构造基本特征以及榆木山北麓与黑河口上龙王活断层研究[J].西北地震学报,10(2):35-47.
刘栋梁,宋春晖,方小敏,等.2012.榆木山地区玉门砾石磁性地层及其对青藏高原东北部变形隆升意义[J].地质学报,86(6):898-905.
潘宏勋,葛肖虹,刘俊来.2000.对祁连山北缘榆木山隆起的质疑[J].长春科技大学学报,30(1):9-13.
庞炜.2015.祁连山前逆冲断裂带古地震识别的关键技术研究[D].兰州:中国地震局兰州地震研究所.
冉永康,李志义,尤惠川,等.1988.河西走廊黑河口断层上的古地震及年代研究[J].地震地质,10(4):118-126.
袁道阳,张培震,刘百篪,等.2004.青藏高原东北缘晚第四纪活动构造的几何图像与构造转换[J].地质学报,78(2):270-278.
张培震,郑德文,尹功明,等.2006.有关青藏高原东北缘晚新生代扩展与隆升的讨论[J].地质通报,26(1):5-13.
郑文俊,袁道阳,张培震,等.2016.青藏高原东北缘活动构造几何图像、运动转换与高原扩展[J].第四纪研究,36(4):775-788.
郑文俊.2009.河西走廊及其邻区活动构造图像及构造变形模式[D].北京:中国地震局地质研究所.
Gaudemer Y,Tapponnier P,Meyer B,et al.1995.Partitioning of crustal slip between linked,active faults in the eastern Qilian Shan,and evidence for a major seismic gap,the‘Tianzhu gap’,on the western Haiyuan Fault,Gansu(China)[J].Geophysical Journal International,120(3);599-645.
Palumbo L,Hetzel R,Tao M X,et al.2009.Deciphering the rate of mountain growth during topographic presteady state:An example from the NE margin of the Tibetan Plateau[J].TECTONICS,28(TC4017):1-18.
Tapponnier P,Meyer B,Avouac J P,et al.1990.Active thrusting and folding in the Qilian Shan,and decoupling between upper crust and mantle in northeastern Tibet[J].Earth and Planetary Science Letters,97(3-4):382-403.
Xu X W,Yeats R,Yu G H.2010.Five short historical earthquake surface ruptures near the Silk Road,Gansu Province China[J].Bull Seism Soc Am,100(2):541-561.
国家地震局地质研究所,国家地震局兰州地震研究所.1993.祁连山-河西走廊活动断裂系[M].北京:地震出版社.
金卿,何文贵,史志刚,等.2011.榆木山北缘断裂古地震特征研究[J].地震地质,33(2):347-355.
金卿.2011.榆木山断裂带晚第四纪构造活动与大震危险性评价[D].兰州:中国地震局兰州地震研究所.
李有利,李保俊,杨景春.1995.甘肃张掖黑河口断层晚更新世晚期以来的活动[J].北京大学学报(自然科学版),31(3):351-357.
李有利,杨景春,李保俊,等.1997.河西走廊榆木山边缘断层构造地貌研究[J].地质力学学报,3(4):20-26.
李玉龙,邢成起.1988.河西走廊地质构造基本特征以及榆木山北麓与黑河口上龙王活断层研究[J].西北地震学报,10(2):35-47.
刘栋梁,宋春晖,方小敏,等.2012.榆木山地区玉门砾石磁性地层及其对青藏高原东北部变形隆升意义[J].地质学报,86(6):898-905.
潘宏勋,葛肖虹,刘俊来.2000.对祁连山北缘榆木山隆起的质疑[J].长春科技大学学报,30(1):9-13.
庞炜.2015.祁连山前逆冲断裂带古地震识别的关键技术研究[D].兰州:中国地震局兰州地震研究所.
冉永康,李志义,尤惠川,等.1988.河西走廊黑河口断层上的古地震及年代研究[J].地震地质,10(4):118-126.
袁道阳,张培震,刘百篪,等.2004.青藏高原东北缘晚第四纪活动构造的几何图像与构造转换[J].地质学报,78(2):270-278.
张培震,郑德文,尹功明,等.2006.有关青藏高原东北缘晚新生代扩展与隆升的讨论[J].地质通报,26(1):5-13.
郑文俊,袁道阳,张培震,等.2016.青藏高原东北缘活动构造几何图像、运动转换与高原扩展[J].第四纪研究,36(4):775-788.
郑文俊.2009.河西走廊及其邻区活动构造图像及构造变形模式[D].北京:中国地震局地质研究所.
Gaudemer Y,Tapponnier P,Meyer B,et al.1995.Partitioning of crustal slip between linked,active faults in the eastern Qilian Shan,and evidence for a major seismic gap,the‘Tianzhu gap’,on the western Haiyuan Fault,Gansu(China)[J].Geophysical Journal International,120(3);599-645.
Palumbo L,Hetzel R,Tao M X,et al.2009.Deciphering the rate of mountain growth during topographic presteady state:An example from the NE margin of the Tibetan Plateau[J].TECTONICS,28(TC4017):1-18.
Tapponnier P,Meyer B,Avouac J P,et al.1990.Active thrusting and folding in the Qilian Shan,and decoupling between upper crust and mantle in northeastern Tibet[J].Earth and Planetary Science Letters,97(3-4):382-403.
Xu X W,Yeats R,Yu G H.2010.Five short historical earthquake surface ruptures near the Silk Road,Gansu Province China[J].Bull Seism Soc Am,100(2):541-561.
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