Hematite fault rock thermochronometry and textures inform fault zone processes

摘要: Abstract Minerals on fault surfaces record fluid-rock interaction, strain, and/or heat during slip. Fault-hosted hematite is amenable to (U–Th)/He (He) thermochronometry. Hematite He dates reflect fault-related processes or exhumation, depending growth above below the grain-size controlled closure temperature and that promote open system behavior. Deconvolving these phenomena requires multi-scale textural characterization constraints ambient thermal history from conventional Two examples of this approach include investigations hematite-coated exhumed damage zones in seismically active Wasatch zone (WFZ), UT, Painted Canyon (PCF) paralleling southern San Andreas fault, Mecca Hills, CA. WFZ mirrors preserve sub-μm-scale polygonal grain textures data patterns that, together with host-rock apatite data, are consistent localized friction-generated heat, loss, recrystallization seismicity