Outline: Normal 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 mantle Thins, weakens, and cracks the lithosphere

Development of Continental Rift into Ocean Basin Rift Valley Early 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 Basin Young ocean basin Last 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 basin Subdued regional subsidence may continue. Example: most of the present Atlantic continental margins.

East African Rift Segmentation 9 mm/a (GPS) 16 mm/a (GPS)

Basin and Range Normal Fault Blocks

Rio Grande Rift Segmentation

Death Valley Fault Zone Fault Stepover

Closeup of Stepover

Planar Normal Faults and Block Rotation

Domino Block Example

Detachment Fault

Soft-Linked Systems

Kinematics of Normal Faulting Domino, Bookshelf-Style Normal Faulting Listric Normal Faulting with Reverse Drag Imbricate Listric Normal Faulting Inversion

Domino-Style Normal Faulting

Domino-Style Normal Faulting (bookshelf faulting) Occurs above Detachment faults

Listric-Planar Normal Fault System ???

Listric-Planar Normal Fault System L

Listric Normal Faulting with Reverse Drag

Listric Normal Faulting with Rollover Occurs due to space problem with curved detachment

Imbricate Listric Normal Faulting Synthetic faults also accommodate collapse of HW block

Imbricate Listric Normal Faulting “Meatslices common in large displacement systems

Inversion Normal faulting Syn-tectonic deposition of B Post-tectonic deposition of C

Inversion Normal faulting Syn-tectonic deposition of B Post-tectonic deposition of C Thrust faulting Deformation of B and folding of C

References Slides 1, 20, 21 Twiss, R. J. and E. M. Moores, Structural Geology, W. H. Freeman & Co., New York, 532 p., Slides Slides Slide 10 Slides Davis. G. H. and S. J. Reynolds, Structural Geology of Rocks and Regions, 2nd ed., John Wiley & Sons, New York, 776 p., 1996.