Kinematics of rotating panels of E-W faults in the San Andreas system: what can we tell from geodesy?

John P. Platt, & Thorsten W. Becker

Published June 2013, SCEC Contribution #1531

Panels of E-W-trending sinistral and/or reverse faults occur within the San Andreas system, commonly associated with paleomagnetic evidence for clockwise vertical-axis rotations. The panels cut across the trend of active dextral faults, posing questions as to how displacement is transferred across them. Geodetic data show that they lie within an overall dextral shear field, and the data are commonly interpreted to indicate little or no slip on the E-W faults, nor any significant rate of rotation. We model these panels as rotating by bookshelf slip in a dextral shear field, and show that a combination of sinistral slip and rotation can produce the observed velocity field. This allows prediction of rates of slip, rotation, fault-parallel extension, and fault-normal shortening within the panel. We illustrate the method using the Garlock fault and the western Transverse Ranges as examples.

Citation
Platt, J. P., & Becker, T. W. (2013). Kinematics of rotating panels of E-W faults in the San Andreas system: what can we tell from geodesy?. Geophysical Journal International, 194(3), 1295–1301. doi: 10.1093/gji/ggt189.