Strike-Slip Tectonics
Strike-Slip Tectonics
Strike-Slip Faults• Faults with strike-slip motion where movement is parallel
to the strike of the fault; fault dip near vertical
• Right- and left-lateral motion
• Include: transform faults, tear faults, transcurrent faults
Transform faults
Length of transform is a function ofspreading or subduction rates
Strike-Slip Faults
Amount of slip on transform can exceedthe length of the transform fault
Incipienttransformdevelopingduring rifting
Strike-Slip Faults
Transcurrent fault: die out alongtheir length Tear fault: form in the thrust sheet
over a lateral ramp in the footwall
Strike-Slip Fault Systems
San Andreas fault zone
Alpine fault, New Zealand
Commonly, transpression ortranstension strain alongstrike-slip faults
Strike-Slip Fault SystemsStrike-slip fault zones are wide and complex (Basin and Rangeextension is part of the strike-slip zone in western U.S.)
Stepover along a strike-slip fault
compression
extension
Strike-Slip Fault Systems
Physical model of strike-slip fault development
Maximum stress is oriented at an angle to fault strike (notparallel to strike!)
Strain along a strike-slip faultand the structures that form
Transpression and Transtension
Transpression =positive flower structure
Transtension =negative flower structure
Bend in fault strike createstranstension
Bend in fault strike creates transpression
Transpression and Transtension
Transverse Ranges, CA:zone of transpression
Strike-Slip Fault Cross Section
Different rock types form atdifferent depths in the fault zone
Tectonic Settings of Continental Strike-Slip Faults
Oblique collision and lateral escape
Lateral escape of Turkey to westas Arabian plate moves north
Himalayas
Tectonic Settings of Continental Strike-Slip Faults
Garlock fault (left-lateral) accommodates extension of Basinand Range
SAFOD
Drilling began June 2002:by August 2005, intersectionof San Andreas fault