Intra-arc strike-slip fault exposed at batholithic levels in the southern Sierra Nevada, California

Journal Article · Thu Mar 01 00:00:00 EST 1990 · Geology; (USA)

DOI:https://doi.org/10.1130/0091-7613(1990)018<0255:IASSFE>2.3.CO;2· OSTI ID:6314619

Busby-Spera, C J ^[1]; Saleeby, J B ^[2]

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1. Univ. of California, Santa Barbara (USA)
2. California Institute of Technology, Pasadena (USA)

The Kern Canyon fault is a major north-trending fault that is continuous for a distance of 140 km in the southern Sierra Nevada, California. Previous geologic mapping and geochronological work along the northern third of the fault indicate that dextral offset occurred sometime after 80 Ma and before 3.5 Ma; this offset was interpreted to be the result of Cenozoic basin-and-range extension. Our new results from the central third of the fault (Kernville-Lake Isabella region) indicate an earlier right-lateral movement history, contemporaneous with emplacement of the largest plutons in the Sierra Nevada. The older structure is termed the proto-Kern Canyon fault zone. The Cenozoic fault trace is a narrow zone of brittle deformation, whereas the Cretaceous fault zone is a broad zone of ductile deformation. U-Pb zircon geochronology on plutonic and metavolcanic rocks involved int he ductile deformation, as well as a pluton that postdates ductile deformation, demonstrate that the proto-Kern Canyon fault zone was active at 85 Ma, and may have begun to move as early as 105 Ma. Longitudinal strike-slip faults are common in modern magmatic arcs where convergence is oblique. The proto-Kern Canyon fault zone may have originated in response to a moderate northward component in subduction of the Farallon plate or perhaps a strong northward component for the Kula plate.

• OSTI ID: 6314619
• Journal Information: Geology; (USA), Vol. 18:3; ISSN 0091-7613
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CALIFORNIA
GEOLOGIC FAULTS
TECTONICS
AGE ESTIMATION
CENOZOIC ERA
DEFORMATION
GEOLOGIC HISTORY
LEAD ISOTOPES
MOUNTAINS
PLUTONIC ROCKS
SLIP
SUBDUCTION ZONES
URANIUM ISOTOPES
VOLCANIC ROCKS
ZIRCON
ACTINIDE ISOTOPES
FEDERAL REGION IX
GEOLOGIC AGES
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
IGNEOUS ROCKS
ISOTOPES
MINERALS
NORTH AMERICA
OXYGEN COMPOUNDS
ROCKS
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
USA
ZIRCONIUM COMPOUNDS
ZIRCONIUM SILICATES
580000* - Geosciences