玛多—甘德断裂甘德段晚第四纪活动特征
|
摘要
玛多—甘德断裂是巴颜喀拉块体内部的一条活动断裂。通过野外调查发现,在玛多-甘德断裂的甘德段保留有一条较好的地震地表破裂带。破裂带整体走向NW向,长约为50 km。野外获得的最大左旋水平位移7.6 m,最大垂直位移4 m。沿破裂带有大量地震活动的遗迹,地表破裂类型十分丰富。通过对各种地质地貌现象的调查与分析,认为该破裂带形成时代较新。断裂带在地貌上发育有线性排列的垭口、断层三角面、断层陡坎、断层泉、断错水系、山脊扭错、断塞塘、鼓包等现象。根据野外考察并结合现有资料分析,该破裂带可能是该区域内历史上一次较为强烈地震的产物。据此推断,巴颜喀拉块体内部的玛多—甘德断裂晚第四纪以来可能有过强烈的活动并至今活跃。
Maduo-Gande fault is an active fault within the Bayan Har block.According to our field investigation,there was an earthquake rupture zone on the Gande segment of Maduo-Gande fault zone.We found that the length of the rupture zone is about 50 km,with the general trend of NW.The maximum sinistral-horizontal dislocation is about 7.6 m and the maximum vertical dislocation is about 4m.A large number of earthquake traces were found along the rupture zone and the surface rupture phenomena were also various.It is believed that the rupture zone with the formation of a relatively new era through the field investigation and analysis on the geological and geomorphological phenomena.A series of linear arranged pass,fault triangles,fault scarps,fault springs,gullies dislocation,ridges twisted,sag-ponds,pressure ridges,et al.exist along the fault.Based on the field investigation and the materials available,we believe that the rupture zone is due to a strong earthquake in the history of this area.And it is inferred that the Maduo-Gande fault in the Bayan Har block had intense activities since late quaternary and may still be active nowadays.
Maduo-Gande fault is an active fault within the Bayan Har block.According to our field investigation,there was an earthquake rupture zone on the Gande segment of Maduo-Gande fault zone.We found that the length of the rupture zone is about 50 km,with the general trend of NW.The maximum sinistral-horizontal dislocation is about 7.6 m and the maximum vertical dislocation is about 4m.A large number of earthquake traces were found along the rupture zone and the surface rupture phenomena were also various.It is believed that the rupture zone with the formation of a relatively new era through the field investigation and analysis on the geological and geomorphological phenomena.A series of linear arranged pass,fault triangles,fault scarps,fault springs,gullies dislocation,ridges twisted,sag-ponds,pressure ridges,et al.exist along the fault.Based on the field investigation and the materials available,we believe that the rupture zone is due to a strong earthquake in the history of this area.And it is inferred that the Maduo-Gande fault in the Bayan Har block had intense activities since late quaternary and may still be active nowadays.
引文
[1]青海省地震局,中国地震局地壳应力研究所.东昆仑活动断裂带[M].北京:地震出版社,1999.
[2]任金卫,汪一鹏,吴章明,等.青藏高原北部东昆仑断裂带第四纪活动特征和滑动速率[A].中国地震局地质研究所编.活动断裂研究[C].北京:地震出版社,1999.147-163.
[3]Van der Woerd J,Ryerson F,Tapponnier P,et al.Uniform slip-rate along the Kunlun Fault:impli-cation for seismic behavior and large-scale tectonics[J].Geophysical Research Letters,2000,27(16):2 353-2 356.
[4]Kirby E,Harkins N,Wang E,et al.Slip rate gradients along the eastern Kunlun fault[J].Tecton-ics,2007,26:TC2010.
[5]闻学泽,徐锡伟,郑荣章,等.甘孜—玉树断裂的平均滑动速率与近代大地震破裂[J].中国科学(D辑),2003,33(z):199-208.
[6]徐锡伟,闻学泽,郑荣章,等.川滇地区活动块体最新构造变动样式及其动力来源[J].中国科学(D辑),2003,33(z):151-162.
[7]李传友,宋方敏,冉勇康.龙门山断裂带晚第四纪活动性讨论[J].地震地质,2004,26(2):248-258.
[8]马保起,苏刚,侯治华,等.利用岷江阶地的变形估算龙门山断裂带中段晚第四纪滑动速率[J].地震地质,2005,27(2):234-242.
[9]Arne D B,Wilson W C,Chen S,et al.Differential exhumation in response to episodic thrusting a-long the eastern margin of the Tibetan Plateau[J].Tectonophysics,1997,280:239-256.
[10]Kirby E,Reiners P W,Korl M A,et al.Late Cenozoic evolution of the eastern margin of the Tibet-an Plateau:inference from40Ar/39Ar and(U-Th)/He thermochronology[J].Tectonics,2002,21:1-20.
[11]戴华光.1947年青海达日73/4级地震[J].西北地震学报,1983,5(3):71-77.
[12]田勤俭.8.1级大地震—考察地震地表破裂带[J].中国减灾杂志,2002,(2):4-7.
[13]邓起东,于贵华,叶文华.地震地表破裂参数与震级关系的研究[A].中国地震局地质研究所编.活动断裂研究[C].北京:地震出版社,1992.247-264.
[14]何宏林,宋方敏,杨晓平,等.郯庐断裂带莒县胡家孟晏地震破裂带的发现[J].地震地质,2004,26(4):630-637.
[2]任金卫,汪一鹏,吴章明,等.青藏高原北部东昆仑断裂带第四纪活动特征和滑动速率[A].中国地震局地质研究所编.活动断裂研究[C].北京:地震出版社,1999.147-163.
[3]Van der Woerd J,Ryerson F,Tapponnier P,et al.Uniform slip-rate along the Kunlun Fault:impli-cation for seismic behavior and large-scale tectonics[J].Geophysical Research Letters,2000,27(16):2 353-2 356.
[4]Kirby E,Harkins N,Wang E,et al.Slip rate gradients along the eastern Kunlun fault[J].Tecton-ics,2007,26:TC2010.
[5]闻学泽,徐锡伟,郑荣章,等.甘孜—玉树断裂的平均滑动速率与近代大地震破裂[J].中国科学(D辑),2003,33(z):199-208.
[6]徐锡伟,闻学泽,郑荣章,等.川滇地区活动块体最新构造变动样式及其动力来源[J].中国科学(D辑),2003,33(z):151-162.
[7]李传友,宋方敏,冉勇康.龙门山断裂带晚第四纪活动性讨论[J].地震地质,2004,26(2):248-258.
[8]马保起,苏刚,侯治华,等.利用岷江阶地的变形估算龙门山断裂带中段晚第四纪滑动速率[J].地震地质,2005,27(2):234-242.
[9]Arne D B,Wilson W C,Chen S,et al.Differential exhumation in response to episodic thrusting a-long the eastern margin of the Tibetan Plateau[J].Tectonophysics,1997,280:239-256.
[10]Kirby E,Reiners P W,Korl M A,et al.Late Cenozoic evolution of the eastern margin of the Tibet-an Plateau:inference from40Ar/39Ar and(U-Th)/He thermochronology[J].Tectonics,2002,21:1-20.
[11]戴华光.1947年青海达日73/4级地震[J].西北地震学报,1983,5(3):71-77.
[12]田勤俭.8.1级大地震—考察地震地表破裂带[J].中国减灾杂志,2002,(2):4-7.
[13]邓起东,于贵华,叶文华.地震地表破裂参数与震级关系的研究[A].中国地震局地质研究所编.活动断裂研究[C].北京:地震出版社,1992.247-264.
[14]何宏林,宋方敏,杨晓平,等.郯庐断裂带莒县胡家孟晏地震破裂带的发现[J].地震地质,2004,26(4):630-637.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心