SCEC Award Number 14107 View PDF
Proposal Category Collaborative Proposal (Special Fault Study Area)
Proposal Title QUATERNARY FAULT SLIP BEHAVIOR OF THE MISSION CREEK FAULT OF THE SOUTHERN SAN ANDREAS FAULT ZONE IN THE SAN GORGONIO PASS, CA Part II ‰ÛÒ Constraining Sedimentary Provenance and Displacements of Pleistocene Alluvial Fans
Investigator(s)
Name Organization
Julie Fosdick Indiana University Kimberly Blisniuk University of California, Berkeley
Other Participants Louis Wersen
SCEC Priorities 1a, 4a, 4c SCEC Groups SoSAFE, Geology, USR
Report Due Date 03/15/2015 Date Report Submitted N/A
Project Abstract
 The objective of our study is to provide precise, accurate fault slip rates on the southern San Andreas fault zone (SAFZ), more specifically the Mission Creek fault strand, as it enters the San Gorgonio Pass (Fig. 1) on the timescale of 104 to 105 years. These data are needed to evaluate our alternative earthquake rupture model that supports the potential for a SAFZ earthquake rupture through the San Gorgonio Pass on the relatively narrow dominantly strike-slip Mission Creek fault strand, rather than the diffuse zone of deformation of the Banning fault strand. To evaluate this model we are presently

(1) re-evaulating the slip rate history of the Mission Creek fault strand of the SAFZ by determining its long-term and short-term slip rate through detailed field mapping and dating of landforms and deposits offset along the fault strand;
(2) conducting a sedimentary provenance study of mid-Quaternary to late Quaternary alluvial deposits and their potentially displaced source-drainages and
(3) developing, validating, and applying the novel technique of 36Cl/10Be burial dating to determine the age of offset alluvial deposits in the 200 ka – 1 Ma age range.
Intellectual Merit Our investigation addresses two long-term science priorities for SCEC4; namely, improving our understanding of (1) stress transfer from plate motion to crustal faults and (2) the structural evolution of fault zones and fault systems. Additional information on slip rates will, help test and refine kinematic and mechanical models of fault slip in California in the San Gorgonio Pass region.
Broader Impacts This proposal provided funding for two young early career scientists, Kimberly Blisniuk and Julie Fosdick, and a graduate student.
Exemplary Figure Figure 1. Location of the study area, (A) the southern San Andreas fault zone in the San Gorgonio Pass and northern Coachella Valley, showing the location of the Mission Creek, Banning and Garnet Hill fault strands.