The timing, tempo, and processes of punctuated deformation in strike-slip fault systems are challenging to resolve in the rock record. Faults in the Mecca Hills, adjacent to the southernmost San Andreas Fault, California, accommodate active deformation and exhumation in the Plio-Pleistocene sedimentary rocks and underlying crystalline basement. We document the spatiotemporal patterns of San Andreas Fault-related deformation as recorded in crystalline basement rocks of the Mecca Hills using fault microstructural observations, geochemical data, and hematite (n =24) and apatite (n =44) (U–Th)/He (hematite He, apatite He) thermochronometry data. Reproducible mean hematite He dates from minor hematite-coated fault surfaces in the Painted Canyon Fault damage zone range from ∼0.7–0.4 Ma and are younger than ∼1.2 Ma apatite He dates from adjacent crystalline basement host rock. These data reveal concomitant Pleistocene pulses of fault slip, fluid flow, and synkinematic hematite mineralization. Hematite textures, crystal morphology, and hematite He data patterns imply some damage zone deformation occurred via cyclic crack-seal and creep processes. Apatite He data from crystalline basement define distinct date-eU patterns and indicate cooling across discrete fault blocks in the Mecca Hills. Uniform ∼1.2 Ma apatite He dates regardless of eU are located exclusively between the Painted Canyon and Platform faults. Outside of this fault block, samples yield individual apatite He dates from ∼30–1 Ma that define a positive apatite He date-eU correlation. These patterns reveal focused exhumation away from the main trace of the San Andreas Fault at ∼1.2 Ma. Low-temperature thermochronometry of fault-related rocks provides an unprecedented window into the 105–106-yr record of San Andreas Fault-related deformation in the Mecca Hills and documents hematite deformation mechanisms that may be operative in other strike-slip faults world-wide.©2017 Elsevier B.V. All rights reserved.1. IntroductionEstablishing the spatiotemporal patterns of deformation in fault systems is critical for informing fault zone evolution, the geody-namic processes that shape modern fault systems, and the seis-mic hazards of active faults (e.g., Fialko, 2006; Dolan et al., 2007;Pérouse and Wernicke, 2016). Punctuated exhumation and asso-ciated deformation processes may be a key characteristic of fault zone dynamics in strike-slip fault systems, particularly in trans-pressional regimes (e.g., Frost and Rose, 1996; Dolan et al., 2007). In the southernmost San Andreas Fault (SAF) system, extensive but spatially-isolated, rapid exhumation of discrete fault blocks has been documented over greater than million-year timescales (e.g., *Corresponding author.E-mail address:amy.moser@aggiemail.usu.edu(A.C. Moser).Spotila et al., 2001, 2007; Niemi et al., 2013). Identifying shorter-duration (105–106-yr) deformation pulses and deformation mech-anisms is challenging, but is needed to bridge long-term structural and geologic histories with geodetic and paleoseismic datasets.The Mecca Hills lie adjacent to and northeast of the south-ernmost SAF. Active deformation and exhumation in this area results from transpression on the Coachella section of the SAF (Fig. 1; Dibblee, 1954; Sylvester and Smith, 1976). The geology of the Mecca Hills is well established (Sylvester and Smith, 1976;McNabb et al., in press); geodetic data constrain modern-day asymmetric strain rates across the southernmost San Andreas Fault, as well as creep localization on discrete structures in the Mecca Hills (Fialko, 2006; Lindsey and Fialko, 2013; Lindsey et al., 2014). Prior work in the Mecca Hills focuses on the Late Pliocene to Pleistocene sedimentary record of basin development and de-formation (Sylvester and Smith, 1976; McNabb et al., in press). A suite of dextral and dextral-normal faults sub-parallel to the http://dx.doi.org/10.1016/j.epsl.2017.07.0390012-821X/©2017 Elsevier B.V. All rights reserved.