image: New GSA Special Paper 475 presents five new displacement estimates for the San Jacinto fault zone using offset successions of crystalline rocks; distinctive marker beds in the late Cenozoic basin fill; analysis of strike-slip-related fault-bend folds; quantification of strain in folds at the tips of dextral faults; and gravity, magnetic and geomorphic data sets. view more
Credit: Geological Society of America
Boulder, CO, USA - Gaining insight into the San Jacinto right-lateral strike-slip fault zone is crucial for understanding the plate-boundary dynamics, regional slip partitioning, and seismic hazards within Southern California's San Andreas fault system, yet conclusions about its age and average slip rate remain controversial. Authors from the U.S. and Utah Geological Surveys, Utah State University, University of Oregon, Fugro William Lettis & Associates, Western Washington University, and ExxonMobil combine their expertise to present five new estimates of displacement.
The authors develop these five estimates using offset successions of crystalline rocks; distinctive marker beds in the late Cenozoic basin fill; analysis of strike-slip-related fault-bend folds; quantification of strain in folds at the tips of dextral faults; and gravity, magnetic, and geomorphic data sets With these estimates, this synthesis of prior and new detailed studies in the western Salton Trough documents initiation of structural segments of the San Jacinto fault zone at or slightly before the 1.07 Ma base of the Jaramillo subchron.
Individual copies of the volume may be purchased through the Geological Society of America online bookstore, http://rock.geosociety.org/Bookstore/default.asp?oID=0&catID=9&pID=SPE475, or by contacting GSA Sales and Service, gsaservice@geosociety.org.
Book editors of earth science journals/publications may request a review copy by contacting Jeanette Hammann, jhammann@geosociety.org.
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
by Susanne U. Janecke, Rebecca J. Dorsey, David Forand, Alexander N. Steely, Stefan M. Kirby, Andrew T. Lutz, Bernard A. Housen, Benjamin Belgarde, Victoria E. Langenheim, and Tammy M. Rittenour
Geological Society of America Special Paper 475
SPE475, 48 p., $40.00; Member price $28.00
ISBN 978-0-8137-2475-1