冷龙岭断裂系活动性与2016年门源6.4级地震构造研究
发布时间：2018-11-10 08:00
【摘要】：2016年1月21日门源MS6.4级地震发生在祁连-海原断裂带冷龙岭断裂北侧.此次地震邻近冷龙岭断裂发生,震中距祁连山北缘断裂带民乐-大马营断裂和皇城-双塔断裂较远,地震破裂面近北西向,与两条断裂的走向呈一定角度相交.震源机制解显示此次地震为逆冲型地震,与冷龙岭断裂逆-走滑运动性质略有差异.在野外地质填图的基础上,采用构造地貌分析、探槽开挖和~(14)C定年技术等研究方法,揭示冷龙岭断裂全新世活动明显,可能表现为特征滑动行为,地震震级为M_W7.3~7.5;断裂倾角较陡,倾向北北东,构造样式上表现为花状构造;最新一次地震事件的形成时间晚于1815~1065a BP.冷龙岭北侧断裂是冷龙岭断裂西北端一条伴生断裂,受到冷龙岭断裂左旋剪切在端部持续的构造推挤作用,相应发生弯曲,产生向外的构造旋转作用,偏离优势破裂方位,活动性相应减弱,在地表表现为一条晚第四纪变形不明显的逆断裂,与断裂整体呈北东向微突出的弧形形态和晚第四纪以来没有断错地表的地质地貌迹象相协调,但此类断裂在深部仍可能发生破裂,产生中强地震.断裂几何学特征和运动性质与震源机制解揭示的断层节面2产状和运动性质以及余震和地震烈度的分布特征较为吻合.冷龙岭北侧断裂作为门源M_S6.4级地震发震构造较为恰当.冷龙岭北侧断裂此次的逆冲运动也为冷龙岭断裂下一次的运动腾出空间.在冷龙岭北侧断裂历史演化过程中,冷龙岭断裂和冷龙岭北侧断裂对局部地形地貌产生构造抬升作用.
[Abstract]:The Mengyuan MS6.4 earthquake occurred on January 21, 2016, on the northern side of the Lenglongling fault in the Qilian Haiyuan fault zone. The earthquake occurred near the Lenglongling fault, and the epicenter was far from the Minle-Daimaying and Huangcheng-Shuangta faults in the northern margin of Qilian Mountains, and the seismic fracture surface was near the NW direction, which intersected with the strike of the two faults at a certain angle. The focal mechanism solution shows that the earthquake is a thrust-type earthquake, which is slightly different from that of the Lenglongling fault in the nature of anti-strike-slip movement. On the basis of field geological mapping, by using structural geomorphology analysis, trench excavation and ~ (14) C dating technique, it is revealed that the Holocene activity of Lenglongling fault is obvious, which may be characterized by sliding behavior. The magnitude of the earthquake is Mushi W7.3 and 7.5; The dip angle of the fault is steeper, inclining to the north, north and east, and the latest earthquake event occurred later than 1815 ~ 1065a BP.. The northern Lenglongling fault is an associated fault at the northwest end of the Lenglongling fault, which is subjected to the continuous tectonic pushing and squeezing at the end of the left lateral shear of the Lenglongling fault, resulting in a corresponding bending, resulting in outward tectonic rotation and deviation from the dominant fracture direction. The activity is weakened correspondingly, and it shows a reverse fault in late Quaternary, which is not obvious deformation in the late Quaternary, which is in harmony with the arc shape of the whole fault in the north east direction and the geological and geomorphologic sign of no fault surface since the late Quaternary. However, such faults may still be ruptured in the deep, resulting in moderate earthquakes. The geometries and motion properties of the faults are in good agreement with the occurrence and movement characteristics of the fault joint plane 2 and the distribution characteristics of aftershocks and seismic intensity revealed by the focal mechanism solution. The northern Lengling fault is a suitable seismogenic structure for the Mengyuan M_S6.4 earthquake. The thrust movement of the northern side of the Lenglongling fault also makes room for the next movement of the Lenglongling fault. During the historical evolution of the northern Lenglongling fault, the Lenglongling fault and the northern Lenglongling fault caused tectonic uplift to the local topography and geomorphology.
【作者单位】： 中国地震局地质研究所活动构造与火山重点实验室;中国地震局地壳应力研究所地壳动力学重点实验室;中国地质大学地球科学与资源学院;中国地震局地震预测研究所;中国地震台网中心;
【基金】：地震行业科研专项项目(编号:201408023) 中国地震局地壳应力研究所基本科研业务专项项目(编号:ZDJ2015-16)资助
【分类号】：P315.2
本文编号：2321874
[Abstract]:The Mengyuan MS6.4 earthquake occurred on January 21, 2016, on the northern side of the Lenglongling fault in the Qilian Haiyuan fault zone. The earthquake occurred near the Lenglongling fault, and the epicenter was far from the Minle-Daimaying and Huangcheng-Shuangta faults in the northern margin of Qilian Mountains, and the seismic fracture surface was near the NW direction, which intersected with the strike of the two faults at a certain angle. The focal mechanism solution shows that the earthquake is a thrust-type earthquake, which is slightly different from that of the Lenglongling fault in the nature of anti-strike-slip movement. On the basis of field geological mapping, by using structural geomorphology analysis, trench excavation and ~ (14) C dating technique, it is revealed that the Holocene activity of Lenglongling fault is obvious, which may be characterized by sliding behavior. The magnitude of the earthquake is Mushi W7.3 and 7.5; The dip angle of the fault is steeper, inclining to the north, north and east, and the latest earthquake event occurred later than 1815 ~ 1065a BP.. The northern Lenglongling fault is an associated fault at the northwest end of the Lenglongling fault, which is subjected to the continuous tectonic pushing and squeezing at the end of the left lateral shear of the Lenglongling fault, resulting in a corresponding bending, resulting in outward tectonic rotation and deviation from the dominant fracture direction. The activity is weakened correspondingly, and it shows a reverse fault in late Quaternary, which is not obvious deformation in the late Quaternary, which is in harmony with the arc shape of the whole fault in the north east direction and the geological and geomorphologic sign of no fault surface since the late Quaternary. However, such faults may still be ruptured in the deep, resulting in moderate earthquakes. The geometries and motion properties of the faults are in good agreement with the occurrence and movement characteristics of the fault joint plane 2 and the distribution characteristics of aftershocks and seismic intensity revealed by the focal mechanism solution. The northern Lengling fault is a suitable seismogenic structure for the Mengyuan M_S6.4 earthquake. The thrust movement of the northern side of the Lenglongling fault also makes room for the next movement of the Lenglongling fault. During the historical evolution of the northern Lenglongling fault, the Lenglongling fault and the northern Lenglongling fault caused tectonic uplift to the local topography and geomorphology.
【作者单位】： 中国地震局地质研究所活动构造与火山重点实验室;中国地震局地壳应力研究所地壳动力学重点实验室;中国地质大学地球科学与资源学院;中国地震局地震预测研究所;中国地震台网中心;
【基金】：地震行业科研专项项目(编号:201408023) 中国地震局地壳应力研究所基本科研业务专项项目(编号:ZDJ2015-16)资助
【分类号】：P315.2
【相似文献】
相关会议论文 前1条
1 刘百篪;袁道阳;何文贵;杨明;;冷龙岭活断裂的古地震特征与1540年甘肃中部强震[A];中国地震学会第七次学术大会论文摘要集[C];1998年
，本文编号：2321874
本文链接：https://www.wllwen.com/kejilunwen/diqiudizhi/2321874.html
