GLG510 Advanced Structural Geology

Announcements Syllabus Schedule Weekly lecture notes Links

Lecture Notes

DateTopic
Week 1:
1/20 & 1/22
Introduction to Advanced Structural Geology
Discussion of Pollard and Fletcher Chapter 1: Introduction and motivations (powerpoint; right click and save)
Week 2:
1/29
Anatomy of orogenic belts (powerpoint; right click and save)
Anatomy of The Alps (powerpoint; right click and save)
Week 3:
2/3 & 2/5
Overview of the Cordillera anatomy and history (powerpoint; right click and save)
Read: Atwater and Stock, 1998, Pacific-North America Plate Tectonics of the Negoene Southwestern United States: An update, in, Integrated Earth and Environmental Evolution of the Southwestern United States: The Clarence A. Hall, Jr. Volume By Wallace Gary Ernst, Clemens Arvid Nelson, Geological Society of America, 1998, ISBN 0966586905, 9780966586909
And review of various illustrations on Tanya Atwater pages
Also:
PacHist_Big.mov
Pac-NoAm_Intro_Big.mov
Pac-NoAm_Tech_Big.mov
TransRanges_Big.mov

Discussion of geologic maps of Arizona and California
Discussion of New Departures in Structural Geology and Tectonics edited by David Pollard.
Weeks 4 and 5:
2/10 & 2/12 & 2/17
Take note of this on line resource about the San Andreas Fault: U.S. Geological Survey, Professional Paper 1515 titled The San Andreas Fault System, California. Discussion of New Departures in Structural Geology and Tectonics edited by David Pollard.
Short clarification on Rheology
Coordinate systems, displacements, and rotations
Reading for Thursday: U.S. Geological Survey, Professional Paper 1515 titled The San Andreas Fault System, California.: review Chapter 3 and read Chapter 7.
Long and short term deformation along the San Andreas Fault
Week 6:
2/24 and 2/26
Take note of this on line resource about the San Andreas Fault: U.S. Geological Survey, Professional Paper 1515 titled The San Andreas Fault System, California. Long and short term deformation along the San Andreas Fault
Exercise on strike-slip dislocations
Postseismic/viscoelastic effects
Dixon, T. H., Norabuena, E., Hotaling, L., 2003, Paleoseismology and Global Positioning System: Earthquake-cycle effects and geodetic versus geologic fault slip rates in the Eastern California shear zone, Geology; January 2003; v. 31; no. 1; p. 5558.
Field trip to Saguaro East National Monument and Catalina Fault zone, 3/1/2009
  1. Assignment
  2. Driving map
  3. Mapping:
    Overview aerial photograph
    Eastern portion base map on aerial photography
    Eastern portion base map on topography
    Western portion base map on aerial photography
    Western portion base map on topography
  4. Compilation:
    Simple geology with profile location on contours
    Topographic profile. Blue dots are at intersections with Catalina and Javalina Faults
  5. References:
    Chapter 9 (shear zones) and portions of chapter 6 on fault rocks from Davis and Reynolds, 1996, Structural geology of rocks and regions
    Spencer, J. E., and Reynolds, S. J., 1989, Middle tertiary tectonics of Arizona and adjacent areas, in Jenney, J. P., and Reynolds, S. J., Geologic evolution of Arizona: Tucson, Arizona Geological Society digest 17, p. 539-574.
  6. Catalina Highway tour:
    GM terrain map of Catalinas
    Naruk, S. J., and Bykerk-Kaufmann, A., Late Cretaceous and Tertiary Deformation of the Santa Catalina Metamorphic Core Complex, Arizona, field trip guide
Week 7:
3/3 and 3/5
Catalina fault field trip discussion
Orientations of structural features
also handed out Chapter 1 (Structural Planes) by D. M. Ragan (in press).
Force, tractions, and stress
Faults and stress
Week 8:
3/17
South Mountains field trip
Week 9:
3/21, 22, 24, 26
Mecca Hills field trip
Fold analysis and cross sections
Week 10:
3/31 & 4/2
Faults and Stress II
Week 11:
4/7
Faults and Stress II Continued
Week 12:
4/16
Vectors
Week 13:
4/21 & 4/23
Vectors
Vectors, cross product
3D stress
Spherical distributions
Summary for 3D stress resolution to traction components

Matlab code for 3D stress:
Main script to run it all: southmountainssolutionwithmeasurementsFunctions.m
Stress functions: buildrotationmatrix2.m resolvestresses.m
Helper functions: degrees.m (degrees from radians) dir_cosines_to_plunge_trend.m plunge_trend_to_dir_cosines.m
Stereonet functions: primitive1.m greatcircle.m plotdiamond.m plotpoint.m plotpointcolor.m

All above files zipped: resolvestresses.zip--unzip and make sure they are all in the same directory
Week 14:
4/28
3D Dislocations
Okada, 1992
Coulomb 3: Graphic-rich deformation and stress change software
Week 15:
5/5
Coulomb 3: Graphic-rich deformation and stress change software
Stress transfer animations from USGS
Static stress transfer
Assignment:
Part 1: Displacement field variation as a function of variable fault geometry. Choose a simple fault geometry of interest and use Coulomb to compute the horizontal and vertical displacement fields. Vary aspects of the geometry including dip, length, and depth to the top and bottom. Vary the Youngs modulus. How does the orientation and magnitude of the displacement vectors change as you vary these parameters (compute them for 0 depth)? Illustrate your answer with representative graphics.

Part 2: Coulomb stress variation. Choose a simple fault geometry of interest and use Coulomb to compute the following:
  • Shear, normal, and CFF plot for one specified fault orientation case to show how CFF is built
  • Change the friction along the receiver faults and change the relative magnitude and orientation of the remote stresses. How do these changes map into changing CFF for optimally oriented faults?
Part 3: Looking at the Bombay Beach Earthquake sequence: http://www.scsn.org/2009bombaybeach.html: This image shows that the "ladder rungs" of the left lateral faults in the Salton Sea are about 4 km long (see red dots). Build a simple Coulomb model that simulates the effect of the M4.7 event (assume that it had a 0.5 m left lateral slip, measure the strike from the map, and assume that it slipped over a patch that was active from 5 km to 10 km depth).
  • Compute the vertical and horizontal displacements due to the event. If there were a GPS receiver about 2 km NE from the end of the fault, what displacement would it have measured?
  • Compute the CFF along the faults oriented parallel to San Andreas fault (N45W). Compute the CFF at a depth of 10km. Use a friction of 0.1. If the nearest that the San Andreas Fault comes to the fault is about 4 km, what is the maximum delta CFF? Assuming that the loading rate is about 1 bar per decade, and that the recurrence interval for major earthquakes along this portion of the San Andreas Fault is about 250 years, compute the shear stress change along the San Andreas Fault orientation and estimate the maximum proportional advance in earthquake timing due to this event.

GLG510 Advanced Structural Geology


Last modified: May 5, 2009