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
[11]  
*BUILD HOUS RES CT, 1994, 5 BUILD HOUS RES CTR
[12]   QUATERNARY FOLD DEFORMATION ASSOCIATED WITH BLIND THRUST FAULTING, LOS-ANGELES BASIN, CALIFORNIA [J].
BULLARD, TF ;
LETTIS, WR .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 1993, 98 (B5) :8349-8369
[13]   GREAT THRUST EARTHQUAKES AND ASEISMIC SLIP ALONG THE PLATE BOUNDARY OF THE MAKRAN SUBDUCTION ZONE [J].
BYRNE, DE ;
SYKES, LR ;
DAVIS, DM .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 1992, 97 (B1) :449-478
[14]  
Camp V. E., 1982, LITHOS, V3, P221
[15]   DISPLACEMENT LENGTH SCALING RELATIONSHIP FOR FAULTS - DATA SYNTHESIS AND DISCUSSION [J].
COWIE, PA ;
SCHOLZ, CH .
JOURNAL OF STRUCTURAL GEOLOGY, 1992, 14 (10) :1149-1156
[16]   GROWTH OF FAULTS BY ACCUMULATION OF SEISMIC SLIP [J].
COWIE, PA ;
SCHOLZ, CH .
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 1992, 97 (B7) :11085-11095
[17]  
Engdahl ER, 1998, B SEISMOL SOC AM, V88, P722
[18]   ROTATION OF STRIKE SLIP FAULTS IN SISTAN, SOUTHEAST-IRAN [J].
FREUND, R .
JOURNAL OF GEOLOGY, 1970, 78 (02) :188-&
[19]   The structural evolution of active fault and fold systems in central Otago, New Zealand: Evidence revealed by drainage patterns [J].
Jackson, J ;
Norris, R ;
Youngson, J .
JOURNAL OF STRUCTURAL GEOLOGY, 1996, 18 (2-3) :217-&
[20]   DRAINAGE SYSTEMS AND THE DEVELOPMENT OF NORMAL FAULTS - AN EXAMPLE FROM PLEASANT VALLEY, NEVADA [J].
JACKSON, J ;
LEEDER, M .
JOURNAL OF STRUCTURAL GEOLOGY, 1994, 16 (08) :1041-1059