Progress towards a comprehensive incremental slip rate and paleo-earthquake age and displacement record for the central Garlock fault

James F. Dolan, Sally F. McGill, Ed J. Rhodes, & Thomas M. Crane

Published August 15, 2016, SCEC Contribution #6964, 2016 SCEC Annual Meeting Poster #101

As part of our ongoing studies of the incremental slip-rate and paleo-earthquake age and displacement record of the Garlock fault, we present new slip rate results from our Pilot Knob Valley (PKV) site along the east-central part of the fault. These incremental rate data are based on geologic mapping and lidar terrain analysis of several progressive offsets of fluvial terrace risers that we have dated with the robust new post-IR IRSL luminescence geochronometer. Our preliminary interpretation of the new data is that they generally confirm our earlier incremental slip rate record from farther west along the Garlock fault, with a very rapid slip rate over the past ca. 2 ka preceded by a lull in earthquake activity and an absence of slip for a several-thousand-year-long period during the early late to late mid-Holocene. Slightly different offset measurements between the west-central (Christmas Canyon West & El Paso Peaks) sites and the new east-central PKV site leave open the possibility that, while the fault exhibited the same general pattern of millennia-long, alternating fast and zero slip rate periods, the actual number of earthquakes and their displacements may have been different between the two areas, with the east-central site perhaps experiencing more and/or larger-displacement events. This suggestion needs to be confirmed with additional data, however, and should be considered preliminary.

Key Words
Garlock fault, fault slip rates, strain transient, fault-system behavior

Citation
Dolan, J. F., McGill, S. F., Rhodes, E. J., & Crane, T. M. (2016, 08). Progress towards a comprehensive incremental slip rate and paleo-earthquake age and displacement record for the central Garlock fault. Poster Presentation at 2016 SCEC Annual Meeting.

Related Projects & Working Groups
Earthquake Geology