We have investigated gravity anomalies around the Niigata plain, which is a sedimentary basin in central Japan bounded by mountains, to examine the continuity of subsurface fault structures of a large fault zone—the eastern boundary fault zone of the Niigata plain (EBFZNP). The features of the Bouguer anomaly and its first horizontal and vertical derivatives clearly illustrate the EBFZNP. The s...

the nnw-trending dena fault, with 140 km length, cuts the major structures of zagros fold-thrust belt in borujen region. the fault has divided the region in two zones, in which different structural, andmorphological features as well assedimentation and seismtectonic characteristics have developed. this study presents a new interpretation for the kinematics of dena fault based on field evidence....

Triaxial experiments show that samples of fault gouge deform distinctly differently than those from the adjacent fault damage zone (e.g., Chester and Logan, 1986). Rock samples in the damage zone follow a characteristic elastic-brittle behavior, whereas fault gouge readily compacts and deforms in a more ductile manner. In order to explain the apparent weakness of large plate bounding faults suc...

Introduction: Quaternary basalts are one of the last signs of magmatism in Iran, some of which are related to deep fractures and active faults in the Quaternary. Quaternary basalts of Tabas are very important due to their high expansion and location in eastern Iran, and are located 140 km south east of Tabas city and according to the proposed divisions are part of the Lut zone. The aim of this...

Earthquake dynamics are strongly affected by fault zone structure and fault surface geometry. Here we investigate the interplay of bulk deformation and surface topography using detailed structural analysis of a fault zone near Klamath Falls, Oregon combined with LiDAR measurements of the fault surface. We find that the fault zone has a layered damage architecture. Slip primarily occurs inside a...

[1] The Uganik Thrust is a fossil out-of-sequence thrust fault which was active over a period of 3 Ma during the early Tertiary until activity ceased with the subduction of the Kula-Farallon spreading ridge at 57 Ma. During this period the fault experienced at least 1 km of throw and developed a strongly asymmetric damage zone. The brittle damage zone in the footwall of the fault acted as a con...

The evolution of fault slip through time may yield insight into the geodynamics of deforming lithosphere. Precise determination of temporal variations in fault slip is often hindered, however, by a dearth of markers of varying age from which to reconstruct fault slip. Here we determine slip rates across the White Mountain Fault Zone over the past ca. 0.8 Ma from displaced alluvial deposits pres...

[1] We used dense linear seismic arrays across and along the San Andreas Fault (SAF) at Parkfield, California to record fault zone trapped waves generated by explosions and microearthquakes in 2002. Prominent trapped waves appeared at stations close to the SAF main fault trace while some energy was trapped in the north strand at the array site. Observations and 3-D finitedifference simulations ...

Damage to fault-zone rocks during fault slip results in the formation of a channel of low seismic-wave velocities. Within such channels guided seismic waves, denoted by Fg, can propagate. Here we show with core samples, well logs and Fg-waves that such a channel is crossed by the SAFOD (San Andreas Fault Observatory at Depth) borehole at a depth of 2.7 km near Parkfield, California, USA. This l...