structural geology deformation of rocks produces: folds, joints, faults deformation of rocks...

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  • Slide 1
  • Structural Geology Deformation of rocks produces: folds, joints, faults Deformation of rocks produces: folds, joints, faults
  • Slide 2
  • Monocline - southeastern Utah
  • Slide 3
  • Northeastern California - note tilted layers
  • Slide 4
  • http://faculty.uaeu.ac.ae/~afarrag/physical%20geology/GEODE1.jpg
  • Slide 5
  • Wasatch Front NE of Salt Lake City, UT
  • Slide 6
  • Types of Stresses Compressive rocks are squeezed Tensile rocks are pulled apart Shear rocks are sheared Compressive rocks are squeezed Tensile rocks are pulled apart Shear rocks are sheared
  • Slide 7
  • Responses to Stress Folding - produced by compressive stress on ductile rocks Joints, Faults - produced by any type of stress on brittle rocks Folding - produced by compressive stress on ductile rocks Joints, Faults - produced by any type of stress on brittle rocks
  • Slide 8
  • Folding Anticlines - where layers are warped upward Synclines - where layers are warped downward Compression of ductile rocks produces alternating anticlines and synclines Anticlines - where layers are warped upward Synclines - where layers are warped downward Compression of ductile rocks produces alternating anticlines and synclines http://piru.alexandria.ucsb.edu/~geog3/concept_illus/1015_ex1.jpg http://myweb.cwpost.liu.edu/vdivener/notes/faults_folds.gif
  • Slide 9
  • Strongly Folded Rock Note quartzite layer folded back on itself - Baraboo, WI
  • Slide 10
  • Joints Fractures in rock along which no movement has occurred - can form in response to any type of stress Often promote mechanical weathering since they provide access for water Fractures in rock along which no movement has occurred - can form in response to any type of stress Often promote mechanical weathering since they provide access for water Yellowstone Natl Park, WY Devils Postpile Natl Mon, CA
  • Slide 11
  • Faults Fractures in rock along which movement has occurred Different styles reflect different stresses Fractures in rock along which movement has occurred Different styles reflect different stresses Canyonlands Natl Park, UT Merrimac Valley, NH
  • Slide 12
  • Dip-slip Faults Best seen in cross- section view (vertical offsets) Normal Faults - upper block slides down (tensional stress) Reverse Faults - upper block is pushed up (compressional stress) Best seen in cross- section view (vertical offsets) Normal Faults - upper block slides down (tensional stress) Reverse Faults - upper block is pushed up (compressional stress) http://northonline.northseattle.edu/gel101tb/images/fault2.jpg
  • Slide 13
  • Faulting in Esker - near White River Jct., VT (??)
  • Slide 14
  • Strike-slip Faults Result from shear stresses - best seen in map view (horizontal offsets) Right-lateral vs. left-lateral Result from shear stresses - best seen in map view (horizontal offsets) Right-lateral vs. left-lateral http://epod.usra.edu/archive/images/carrizoplain.jpg
  • Slide 15
  • http://soconnell.web.wesleyan.edu/courses/ees106/field_trips/ct_tectonics/images/CT_bedrockgeology_fault_enh.gif Bedrock Geology of Connecticut
  • Slide 16
  • http://z.about.com/d/geology/1/0/B/J/massgeomap.png Bedrock Geologic Map of Massachusetts Features to Note: 1.N-S striping: compression from E-W 2.NE-SW striping in E 3.Cape consists of recent glacial sediment

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