The 1994 Sefidabeh earthquakes in eastern Iran: blind thrusting and bedding-plane slip on a growing anticline, and active tectonics of the Sistan suture zone

被引:83
作者
Berberian, M
Jackson, JA
Qorashi, M
Talebian, M
Khatib, M
Priestley, K
机构
[1] Najarian Associates, Eatontown, NJ 07724 USA
[2] Univ Cambridge, Dept Earth Sci, Bullard Labs, Cambridge CB3 0EZ, England
[3] Geol Survey Iran, Tehran, Iran
[4] Birjand Univ, Dept Geol, Birjand, Iran
关键词
active tectonics; bedding-plane slip; blind thrusting; earthquakes; eastern Iran;
D O I
10.1046/j.1365-246x.2000.00158.x
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
In 1994 a sequence of five earthquakes with M-w 5.5-6.2 occurred in the Sistan belt of eastern Iran, all of them involving motion on blind thrusts with centroid depths of 5-10 km. Coseismic ruptures at the surface involved bedding-plane slip on a growing hanging-wall anticline displaying geomorphological evidence of uplift and lateral propagation. The 1994 earthquakes were associated with a NW-trending thrust system that splays off the northern termination of a major N-S right-lateral strike-slip fault. Elevation changes along the anticline ridge suggest that displacement on the underlying thrust dies out to the NW, away from its intersection with the strike-slip fault. This is a common fault configuration in eastern Iran and accommodates oblique NE-SW shortening across the N-S deforming zone, probably by anticlockwise rotations about a vertical axis. This style of fault kinematics may be transitional to a more evolved state that involves partitioning of the strike-slip and convergent motion onto separate subparallel faults.
引用
收藏
页码:283 / 299
页数:17
相关论文
共 59 条
[1]   ACTIVE DEFORMATION IN THE NEW-GUINEA FOLD-AND-THRUST BELT - SEISMOLOGICAL EVIDENCE FOR STRIKE-SLIP FAULTING AND BASEMENT-INVOLVED THRUSTING [J].
ABERS, G ;
MCCAFFREY, R .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS, 1988, 93 (B11) :13332-13354
[2]  
Ambraseys N.N., 1982, HIST PERSIAN EARTHQU
[3]  
[Anonymous], AM GEOPHYS UNION GEO
[4]   Field examples of strike-slip fault terminations in Mongolia and their tectonic significance [J].
Bayasgalan, A ;
Jackson, J ;
Ritz, JF ;
Carretier, S .
TECTONICS, 1999, 18 (03) :394-411
[5]   The 1997 May 10 Zirkuh (Qa'enat) earthquake (Mw 7.2):: faulting along the Sistan suture zone of eastern Iran [J].
Berberian, M ;
Jackson, JA ;
Qorashi, M ;
Khatib, MM ;
Priestley, K ;
Talebian, T ;
Ghafuri-Ashtiani, M .
GEOPHYSICAL JOURNAL INTERNATIONAL, 1999, 136 (03) :671-694
[6]  
Berberian M, 1999, B SEISMOL SOC AM, V89, P120
[7]   EVALUATION OF THE INSTRUMENTAL AND RELOCATED EPICENTERS OF IRANIAN EARTHQUAKES [J].
BERBERIAN, M .
GEOPHYSICAL JOURNAL OF THE ROYAL ASTRONOMICAL SOCIETY, 1979, 58 (03) :625-630
[8]  
BERBERIAN M, 1979, B SEISMOL SOC AM, V69, P1861
[9]   TOWARDS A PALEOGEOGRAPHY AND TECTONIC EVOLUTION OF IRAN [J].
BERBERIAN, M ;
KING, GCP .
CANADIAN JOURNAL OF EARTH SCIENCES, 1981, 18 (02) :210-265
[10]  
Boudiaf A, 1998, TERRA NOVA, V10, P236