Preliminary geologic map of the Red Bluff 1:100,000 Quadrangle, California

Review of Late Jurassic-early Miocene sedimentation and plate-tectonic evolution of northern California: illuminating example of an accretionary margin

“…To the south, Wright and Wyld (2007) interpreted the NWtrending Cold Fork-Elder Creek fault zone as an important discontinuity defining several hundred kms of dextral slip. Judging by geologic field relations documented by Blake et al (1999), the Cold Fork-Elder Creek fault zone and subparallel structures truncate the Oak Flat-Sulphur Spring faults. Thus, oceanward relative displacement of the Klamath Mountains salient along the Oak Flat-Sulphur Spring fault zone apparently was mainly completed in Valanginian-Hauterivian time, prior to the right-lateral motion described by Wright and Wyld-which therefore represents Barremian and younger offset.…”

“…1 annealing of the pluton rather than the time of its emplacement. Geologic mapping by Blake et al (1999) documented Hauterivian GVG strata resting with angular unconformity on exhumed, eroded Shasta Bally rocks, supporting a Valanginian or older age for the intrusive (SB locates the plutonon Fig. 1).…”

“…Geologic relationships among units of the Klamath Mountains province, the Franciscan Complex, and the GVG in the vicinity of the Yolla Bolly triple junction (Jones and Irwin 1971;Sliter et al 1984;Blake et al 1999) include several important fault systems. In addition to the major terrane bounding, NW-trending South Fork and Coast Range faults, Blake et al (1999) mapped numerous transverse breaks transecting GVG stratigraphic units in this area.…”

“…In addition to the major terrane bounding, NW-trending South Fork and Coast Range faults, Blake et al (1999) mapped numerous transverse breaks transecting GVG stratigraphic units in this area. Significant faults include, from north to south, the Oak Flat, Sulphur Spring, Cold Fork, and Elder Creek structures.…”

“…Shasta Bally pluton = SB. The South Fork and Coast Range faults juxtapose rocks of the Franciscan Complex against those of the Klamath province and the GVG respectively (e.g., Blake et al 1999). Labeled fault zones: Oak Flat-Sulphur Spring = OF-SS; Cold Fork-Elder Creek = CF-EC; on-land and offshore segments of the Nacimiento, = N and N?…”