嘉峪关断层中段的新活动特征
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摘要
嘉峪关断层是河西走廊盆地内部的一条重要断层,断层走向NNW向,晚第四纪以来新活动特征以挤压逆冲为主兼具有右旋走滑特征。通过野外地质调查,在嘉峪关城楼北关园子山嘉峪关断层大陡坎西侧0.5km处的Ⅲ级阶地面上,新发现一段长约1.6km保存完好的小断层陡坎,坎高0.5～2m,且有冲沟发生右旋位错现象。经探槽开挖和热释光测年确认,嘉峪关断层全新世有古地震活动。据断错地貌的差分GPS测量和测年结果,得到断裂晚第四纪晚期以来的平均滑动速率为0.52～0.56mm/a。
The Jiayuguan fault is an important one in the Hexi Corridor Basin.The strike of the fault is NNW,and the main recent active characteristics since Late Quaternary include squeeze and thrust with right-lateral strike-slip.In the field investigation,we found that there was a new small fault scarp on the third terrace which is located in 0.5km west of the large scarp of the Jiayuguan fault at Yuanzi hill north to the Jiayuguan Castle.The small fault scarp retains intact,and its length is about 1.6km and height is 0.5-2m.We also found that right-lateral phenomena occurred when the gullies crossed the small scarp.Through the trench excavation and TL dating,we confirmed that the paleoearthquakes had occurred along the Jiayuguan fault in Holocene.Using the differential GPS measurement and dating to the dislocated landform,we obtained that the average slip rate of the fault is 0.52-0.56mm /a since the late Quaternary.
The Jiayuguan fault is an important one in the Hexi Corridor Basin.The strike of the fault is NNW,and the main recent active characteristics since Late Quaternary include squeeze and thrust with right-lateral strike-slip.In the field investigation,we found that there was a new small fault scarp on the third terrace which is located in 0.5km west of the large scarp of the Jiayuguan fault at Yuanzi hill north to the Jiayuguan Castle.The small fault scarp retains intact,and its length is about 1.6km and height is 0.5-2m.We also found that right-lateral phenomena occurred when the gullies crossed the small scarp.Through the trench excavation and TL dating,we confirmed that the paleoearthquakes had occurred along the Jiayuguan fault in Holocene.Using the differential GPS measurement and dating to the dislocated landform,we obtained that the average slip rate of the fault is 0.52-0.56mm /a since the late Quaternary.
引文
[1]玉门石油管理局,1956,石油地质勘探(内部资料)
[1]甘肃省地质局,1996,1/20万泉幅地质图及说明书。
陈柏林,刘建生,张永双等,2007,嘉峪关断裂晚第四纪新构造活动特征,地质力学学报,13(1),78～85。
国家地震局地质研究所等,1993,祁连山-河西走廊活动断层系,北京:地震出版社。
国家地震局兰州地震研究所等,1993,甘肃省地震危险区划研究,兰州:兰州大学出版社。
李玉龙,1984,嘉峪关断层的性质和活动时期,兰州大学学报(自然科学版),20(2),118～123。
李有利,谭利华,段烽军等,2000,甘肃酒泉盆地河流地貌与新构造运动,干旱区地理,23(4),304～309。
向宏发、虢顺民,1991,河西走廊玉门-嘉峪关地区活动断层的初步研究,现代地壳运动研究(5),地震出版社。
杨景春、谭利华、李有利等,1998,祁连山北麓河流阶地与新构造演化,第四纪研究,3,229～237。
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,北京:博士学位论文,中国地震局地质研究所。
[1]甘肃省地质局,1996,1/20万泉幅地质图及说明书。
陈柏林,刘建生,张永双等,2007,嘉峪关断裂晚第四纪新构造活动特征,地质力学学报,13(1),78～85。
国家地震局地质研究所等,1993,祁连山-河西走廊活动断层系,北京:地震出版社。
国家地震局兰州地震研究所等,1993,甘肃省地震危险区划研究,兰州:兰州大学出版社。
李玉龙,1984,嘉峪关断层的性质和活动时期,兰州大学学报(自然科学版),20(2),118～123。
李有利,谭利华,段烽军等,2000,甘肃酒泉盆地河流地貌与新构造运动,干旱区地理,23(4),304～309。
向宏发、虢顺民,1991,河西走廊玉门-嘉峪关地区活动断层的初步研究,现代地壳运动研究(5),地震出版社。
杨景春、谭利华、李有利等,1998,祁连山北麓河流阶地与新构造演化,第四纪研究,3,229～237。
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,北京:博士学位论文,中国地震局地质研究所。
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