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Outline: Outline: Normal Fault Systems and KinematicsNormal Fault Systems and Kinematics
• Planar Faults and Block Rotation
• Detachment Faulting
• Fault Linkage
• Kinematics of Normal Faulting
Development of Continental Rift into Ocean Basin
Upwelling of hot mantleThins, weakens, and cracks the lithosphere
Development of Continental Rift into Ocean BasinRift ValleyEarly graben formation prior to continental splitting. This stage may be associated with domal uplift caused by uprise of hot upper mantle material - uplift may be connected with underlying mantle hotspots.
Development of Continental Rift into Ocean BasinYoung ocean basinLast about 50 my after the onset of seafloor spreading, while the thermal effects are still dominant.
Characterized by rapid regional subsidence of the outer shelf and slope, but some graben formation may persist. Example: Red Sea.
Development of Continental Rift into Ocean Basin
Mature Ocean basinSubdued regional subsidence may continue. Example: most of the present Atlantic continental margins.
East African Rift SegmentationEast African Rift Segmentation
9 mm/a (GPS)
16 mm/a (GPS)
Basin and Range Normal Fault BlocksBasin and Range Normal Fault Blocks
Rio Grande Rio Grande RiftRift
Segmentation Segmentation
Death ValleyDeath ValleyFault Zone Fault Zone
Fault StepoverFault Stepover
Closeup of StepoverCloseup of Stepover
Planar Normal Faults and Block RotationPlanar Normal Faults and Block Rotation
Planar Normal Faults and Block RotationPlanar Normal Faults and Block Rotation
Domino Block ExampleDomino Block Example
Domino Block ExampleDomino Block Example
Detachment FaultDetachment Fault
Detachment FaultDetachment Fault
Detachment FaultDetachment Fault
Soft-Linked SystemsSoft-Linked Systems
Kinematics of Normal FaultingKinematics of Normal Faulting
• Domino, Bookshelf-Style Normal Faulting
• Listric Normal Faulting with Reverse Drag
• Imbricate Listric Normal Faulting
• Inversion
Domino-Style Normal FaultingDomino-Style Normal Faulting
Domino-Style Normal Faulting (bookshelf faulting)Domino-Style Normal Faulting (bookshelf faulting)
Occurs above Detachment faultsOccurs above Detachment faults
Listric-Planar Normal Fault SystemListric-Planar Normal Fault System
???
Listric-Planar Normal Fault SystemListric-Planar Normal Fault System
L
Listric Normal Faulting with Reverse DragListric Normal Faulting with Reverse Drag
Listric Normal Faulting with RolloverListric Normal Faulting with Rollover
Occurs due to space problem with curved detachmentOccurs due to space problem with curved detachment
Imbricate Listric Normal FaultingImbricate Listric Normal Faulting
Synthetic faults also accommodate collapse of HW blockSynthetic faults also accommodate collapse of HW block
Imbricate Listric Normal FaultingImbricate Listric Normal Faulting
““Meatslices common in large displacement systemsMeatslices common in large displacement systems
InversionInversion
• Normal faulting
• Syn-tectonic deposition of B
• Post-tectonic deposition of C
InversionInversion
• Normal faulting
• Syn-tectonic deposition of B
• Post-tectonic deposition of C
• Thrust faulting
• Deformation of B and folding of C
ReferencesReferences
Slides 1, 20, 21Slides 1, 20, 21Twiss, R. J. and E. M. Moores, Structural Geology, W. H. Freeman & Co., New York, 532 p., Twiss, R. J. and E. M. Moores, Structural Geology, W. H. Freeman & Co., New York, 532 p., 1992.1992.
Slides 3-6Slides 3-6http://earth.http://earth.leedsleeds.ac..ac.uk/faults/normal/dominouk/faults/normal/domino..htmhtm
Slides 7-9Slides 7-9http://earth.http://earth.leedsleeds.ac.uk/faults/normal/detachment1..ac.uk/faults/normal/detachment1.htmhtm
Slide 10Slide 10http://earth.leeds.ac.uk/faults/soft/softnormal.http://earth.leeds.ac.uk/faults/soft/softnormal.htmhtm
Slides 12-19Slides 12-19Davis. G. H. and S. J. Reynolds, Structural Geology of Rocks and Regions, 2nd ed., John Davis. G. H. and S. J. Reynolds, Structural Geology of Rocks and Regions, 2nd ed., John Wiley & Sons, New York, 776 p., 1996.Wiley & Sons, New York, 776 p., 1996.
