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