Pulse-Like Rupture Induced by Three-Dimensional Fault Zone Flower Structures

Three-dimensional P wave velocity models under the Zipingpu reservoir in Longmenshan fault zone are obtained with a resolution of 2 km in the horizontal direction and 1 km in depth. We used a total of 8589 P wave arrival times from 1014 local earthquakes recorded by both the Zipingpu reservoir network and temporary stations deployed in the area. The 3-D velocity images at shallow depth show the low-velocity regions have strong correlation with the surface trace of the Zipingpu reservoir. According to the extension of those low-velocity regions, the infiltration depth directly from the Zipingpu reservoir itself is limited to 3.5 km depth, while the infiltration depth downwards along the Beichuan-Yingxiu fault in the study area is about 5.5 km depth. Results show the low-velocity region in the east part of the study area is related to the Proterozoic sedimentary rocks. The Guanxian-Anxian fault is well delineated by obvious velocity contrast and may mark the border between the Tibetan Plateau in the west and the Sichuan basin in the east.

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Numerical Analyses on the Stability of a Deep Coalmine Roadway Passing through a Fault Zone: A Case Study of the Gugui Coalfield in China

Energies ◽

10.3390/en14082114 ◽

2021 ◽

Vol 14 (8) ◽

pp. 2114

Author(s):

Yongshui Kang ◽

Congcong Hou ◽

Jingyi Liu ◽

Zhi Geng ◽

Jianben Chen ◽

...

Keyword(s):

Fault Zone ◽

Distinct Element ◽

Three Dimensional ◽

Tectonic Stress ◽

Three Dimensional Model ◽

Support Strategy ◽

Failure Theory ◽

Calculation Results ◽

Pass Through ◽

The Stability

Massive deformation often occurs when deep coalmine roadways pass through a fault zone due to the poor integrity of rock mass and high tectonic stress. To study deformation characteristics of the surrounding rock in the fault zone of a coalmine, a roadway passing through the FD1041 fault zone in China’s Gugui coalfield was investigated in this research. The geo-stress characteristics of this fault zone were analyzed based on the Mohr failure theory. Furthermore, a three-dimensional model for the experimental roadway in the FD1041 fault zone was built and calculated by a numerical program based on the distinct element method. Stability conditions of the roadway, using several types of support methods, were calculated and compared. Calculation results indicated that pre-grouting provides favorable conditions for the stability of a roadway in a fault zone. Finally, an optimized support strategy was proposed and implemented in the experimental roadway. Monitored results demonstrated that the optimized support strategy is appropriate for this fault zone.

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Three-dimensional characterization of a crustal-scale fault zone: The Pusteria and Sprechenstein fault system (Eastern Alps)

Journal of Structural Geology ◽

10.1016/j.jsg.2010.06.003 ◽

2010 ◽

Vol 32 (12) ◽

pp. 2022-2041 ◽

Cited By ~ 27

Author(s):

Andrea Bistacchi ◽

Matteo Massironi ◽

Luca Menegon

Keyword(s):

Fault Zone ◽

Three Dimensional ◽

Eastern Alps ◽

Fault System

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Three-dimensional records of surface displacement on the Superstition Hills fault zone associated with the earthquakes of 24 November 1987

Bulletin of the Seismological Society of America ◽

10.1785/bssa0790020376 ◽

1989 ◽

Vol 79 (2) ◽

pp. 376-389

Author(s):

Robert V. Sharp ◽

John L. Saxton

Keyword(s):

Fault Zone ◽

Power Law ◽

Main Shock ◽

Three Dimensional ◽

Surface Displacement ◽

Displacement Component ◽

Observation Data ◽

Fault Movement ◽

Remarkable Agreement ◽

Observation Period

Abstract Seven quadrilaterals, constructed at broadly distributed points on surface breaks within the Superstition Hills fault zone, were repeatedly remeasured after the pair of 24 November 1987 earthquakes to monitor the growing surface displacement. Changes in the dimensions of the quadrilaterals are recalculated to right-lateral and extensional components at millimeter resolution, and vertical components of change are resolved at 0.2 mm precision. The displacement component data for four of the seven quadrilaterals record the complete fault movement with respect to an October 1986 base. These data fit with remarkable agreement the power law U ( t ) = U f ( B t 1 + B t ) c , where U(t) is a displacement component at time t after the second main shock and Uf, B, and c are constants. This power law permits estimation of the final displacement, Uf, from the data obtained within the period of observation. Data from one quadrilateral, located near the epicenter of the second main shock and northeast-trending conjugate faults, allow that about 5 cm of right-lateral slip may have been associated with the first main shock there. Data from the other quadrilaterals confirm that the surface faulting on most of the Superstition Hills fault zone did initiate at the time of the second main shock of the 1987 earthquakes. The three-dimensional motion vectors all describe nearly linear trajectories throughout the observation period, and they indicate smooth shearing on their respective fault surfaces. The inclination of the shear surfaces is generally nearly vertical, except near the south end of the Superstition Hills fault zone where two strands dip northeastward at about 70°. Surface displacement on these strands is right reverse. Another kind of deformation, superimposed on the fault displacements, has been recorded at all quadrilateral sites. It consists of a northwest-southeast contraction or component of contraction that ranged from 0 to 0.1 per cent of the quadrilateral lengths between November 1987 and April 1988.

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Mesozoic salt tectonics in the Toulon Belt, Eastern Provence : Inversion of a salt-rich fault zone

10.5194/egusphere-egu21-3233 ◽

2021 ◽

Author(s):

Vincent Wicker ◽

Mary Ford

Keyword(s):

Fault Zone ◽

Early Cretaceous ◽

Late Cretaceous ◽

Three Dimensional ◽

Complex Salt ◽

Salt Diapir ◽

Lateral Migration ◽

Northern Flank ◽

Northern Margin ◽

Thickness Variations

<p>Detailed structural and stratigraphic field mapping is used to reconstruct the Jurassic to Late Cretaceous diapiric and tectonic evolution of the Toulon Fault Zone, eastern Beausset Syncline and Toulon Belt, southern France, which represents the easternmost vestige of the Pyrenean orogen in Provence. This complex salt-rich area records a complete history from Jurassic-early Cretaceous subsidence and Aptian-Albian oblique rifting to Late Cretaceous Pyrenean-Proven&#231;al shortening. Halokinetic sequences and geometries were preserved principally on the northern flank of the Mont Caume salt diapir sourced from the Upper Triassic Keuper unit. Our field observations are best explained by a model where halokinetic activity interacted with regional deviatoric stresses from early-Jurassic to Santonian/Campanian times. Halokinetic wedges of Jurassic and Early Cretaceous carbonates thin toward the diapir, recording early salt mobilisation. Inverted relics of Apto-Albian rift depocenters are aligned along the northern margin of the Toulon Belt and the adjacent Bandol belt that lies to the west.&#160; The Turonian-Coniacian Revest depocenter developed due to localized strong asymmetrical growth of the Mont Caume diapir. The three-dimensional form and growth of the diapir controlled lateral migration of the Revest depocenter, thickness variations, progressive unconformities, and the westward increase in stratal overturning of a flap. A component of N-S compression with related accelerated halokinetic activity can explain our observations and can be considered as the earliest expression of N-S convergence in the Provencal fold belt.&#160; Further west, the overturned Beausset klippe can be interpreted as the remnant of a megaflap on the northern flank of the Bandol diapir. The Toulon belt salt structures are excellent field analogues to others observed in the external Alps and Pyrenees.</p>

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Structure Evolution of Qinjiatun-Qindong Fault System in Lishu Subbasin

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.734-737.170 ◽

2013 ◽

Vol 734-737 ◽

pp. 170-177

Author(s):

Shao Dong Qu ◽

Chi Yang Liu ◽

Li Jun Song ◽

Hui Deng ◽

Long Zhang ◽

...

Keyword(s):

Fault Zone ◽

Structure Analysis ◽

Late Cretaceous ◽

Seismic Data ◽

Three Dimensional ◽

Strike Slip ◽

Fault System ◽

Structure Evolution ◽

Active Stage ◽

Regional Stress

Three-dimensional(3-D) seismic data and structure analysis of the Lishu subasin in Songliao basin indicates that Qinjiatun fault zone is composed of two faults: East-Qin and West-Qin fault. This fault system initially formed at Huoshiling stage, peaked at Shahezi stage and faded dramatically from Yingcheng stage. The Qinjiatun fault was important in controlling strata thickness and distribution of the Huoshiling formation. Qindong fault, a typical strike-slip fault, developed relatively later, cutting the Qinjiatun fault, The major active stage was in Denglouku-Quantou stage, and weakened in the end of late Cretaceous. Qinjiatun fault zone was reversed at Denglouku stage when the regional stress went compressive, generating a structure nose that was potentially beneficial for hydrocarbon to accumulate. The strike-slip Qindong fault became active relatively later, cutting through the previous strata and proving pathways for both accumulation and effusion of hydrocarbon.

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On: “Three‐dimensional imaging of steeply dipping structure near the San Andreas fault, Parkfield, California” by John N. Louie, Robert W. Clayton, and Ronan J. LeBras, (GEOPHYSICS, 53, 176–185, February 1988).

Geophysics ◽

10.1190/1.1442416 ◽

1988 ◽

Vol 53 (10) ◽

pp. 1364-1365 ◽

Cited By ~ 2

Author(s):

J. H. McBride

Keyword(s):

Survey Data ◽

Fault Zone ◽

Complex Terrain ◽

San Andreas Fault ◽

Three Dimensional ◽

Migration Process ◽

Prestack Migration ◽

San Andreas ◽

Survey Line ◽

Lateral Heterogeneities

Louie et al. (1988) apply to COCORP survey data a prestack migration process, which they describe, to image better reflections associated with structure in the upper 5 km of the San Andreas fault zone near Parkfield, California. They demonstrate the usefulness of this approach in an area along the survey where, as they point out, the CMP-stacking process may be particularly troublesome. While the authors were sensitive to the extreme lateral heterogeneities in and about the fault zone, the crooked survey line, and the complex terrain in which the survey was mounted (McBride and Brown, 1986), I suspect they were nevertheless a little too zealous in discounting, in this case, the value of conventional stacking applied and interpreted judiciously. Moreover, Louie et al. imply that their approach yields previously unobtained results; however, this is not the case.

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