Early Pleistocene initiation of the San Felipe fault zone, SW Salton Trough, during reorganization of the San Andreas fault system

2009 ◽  
Vol 121 (5-6) ◽  
pp. 663-687 ◽  
Author(s):  
A. N. Steely ◽  
S. U. Janecke ◽  
R. J. Dorsey ◽  
G. J. Axen
Keyword(s):  
Fault Zone ◽  
San Andreas Fault ◽  
Early Pleistocene ◽  
Fault System ◽  
San Andreas ◽  
Salton Trough ◽  
San Andreas Fault System

Active displacement on the Calaveras fault zone at Hollister, California

1971 ◽  
Vol 61 (2) ◽  
pp. 399-416
Author(s):  
Thomas H. Rogers ◽  
Robert D. Nason
Keyword(s):  
San Francisco ◽  
Fault Zone ◽  
Active Fault ◽  
San Andreas Fault ◽  
Fault System ◽  
Fault Creep ◽  
San Andreas ◽  
San Andreas Fault System ◽  
Fault Trace ◽  
Fault Displacement

abstract The Calaveras fault zone, which is a major branch of the San Andreas fault system in northern California, passes through the City of Hollister 160 km (100 miles) southeast of San Francisco. Active fault displacement (fault creep slippage) has occurred in and near Hollister along a fault trace within the Calaveras fault zone. Various man-made structures crossing the fault trace have been deformed and gradually offset in a right-lateral sense. The amount of offset varies directly with age of the structure. The maximum offset is 33 cm (13 in) of a sidewalk constructed in the period 1909 to 1914. Offsets on dated structures indicate displacement rates of approximately 2 mm/yr (0.08 in/yr) from 1909 to 1925 and 6 mm/yr (0.24 in/yr) from 1925 to 1967. Data obtained from periodic measurement of specially designed survey lines and instruments have indicated a displacement rate of 9 mm/yr (0.4 in/yr) since May 1967. Displacements of the survey lines are not associated with local earthquake events. Rates of active fault displacement vary with time and position along the Calaveras and San Andreas fault zones in the Hollister area. The pattern of this variation suggests that active displacement on the San Andreas fault zone may be transferring northeastward to the Calaveras fault zone.

The San Andreas Fault Zone Drilling Project: Scientific Objectives and Technological Challenges

1995 ◽  
Vol 117 (4) ◽  
pp. 263-270 ◽  
Author(s):  
S. H. Hickman ◽  
L. W. Younker ◽  
M. D. Zoback ◽  
G. A. Cooper
Keyword(s):  
Fault Zone ◽  
San Andreas Fault ◽  
Fractured Rock ◽  
Fluid Pressure ◽  
Plate Boundary ◽  
Fault System ◽  
Earthquake Activity ◽  
Scientific Drilling ◽  
San Andreas ◽  
San Andreas Fault System

We are leading a new international initiative to conduct scientific drilling within the San Andreas fault zone at depths of up to 10 km. This project is motivated by the need to understand the physical and chemical processes operating within the fault zone and to answer fundamental questions about earthquake generation along major plate-boundary faults. Through a comprehensive program of coring, fluid sampling, downhole measurements, laboratory experimentation, and long-term monitoring, we hope to obtain critical information on the structure, composition, mechanical behavior and physical state of the San Andreas fault system at depths comparable to the nucleation zones of great earthquakes. The drilling, sampling and observational requirements needed to ensure the success of this project are stringent. These include: 1) drilling stable vertical holes to depths of about 9 km in fractured rock at temperatures of up to 300°C; 2) continuous coring and completion of inclined holes branched off these vertical boreholes to intersect the fault at depths of 3, 6, and 9 km; 3) conducting sophisticated borehole geophysical measurements and fluid/rock sampling at high temperatures and pressures; and 4) instrumenting some or all of these inclined core holes for continuous monitoring of earthquake activity, fluid pressure, deformation and other parameters for periods of up to several decades. For all of these tasks, because of the overpressured clay-rich formations anticipated within the fault zone at depth, we expect to encounter difficult drilling, coring and hole-completion conditions in the region of greatest scientific interest.

High Geologic Slip Rates since Early Pleistocene Initiation of the San Jacinto and San Felipe Fault Zones in the San Andreas Fault System: Southern California, USA

2011 ◽  
Author(s):  
Susanne U. Janecke ◽  
Rebecca J. Dorsey ◽  
David Forand ◽  
Alexander N. Steely ◽  
Stefan M. Kirby ◽  
...  
Keyword(s):  
Southern California ◽  
San Andreas Fault ◽  
Fault Zones ◽  
Early Pleistocene ◽  
Fault System ◽  
Slip Rates ◽  
San Andreas ◽  
San Andreas Fault System
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