GLG310 Structural Geology
Today’s plan
• Continue Force, Stress, and Strength
(Chapter 3) [continue reading Chapter 3]
• Be sure to cross reference the lecture and
the textbook
• Stretch a bit into faults and stress
12 March 2016
GLG310 Structural Geology
Classification of
faults
12 March 2016
Fracture
12 March 2016
GLG310 Structural Geology
Andersonian Faulting
Theory
• Key assumptions:
– Earth’s surface is a free surface (so it has no
shear tractions acting along it). Therefore, s1,
s2, s3 must be either parallel or perpendicular
to it.
– A fault will slip in the direction of maximum
resolved shear traction
12 March 2016
By E. M. Anderson
(1st ed. 1942, 2nd ed. 1951)
Andersonian Faulting
Theory
Andersonian
Faulting
Theory
Rowland and
Duebendorfer
12 March 2016
GLG510 Advanced Structural
Andersonian Faulting
Theory
-Engelder, 1993, Stress regimes in the lithosphere, Princeton Univ. Press
Relative stress magnitudes and faulting regimes
(from Reservoir Geomechanics by Zoback--http://www.amazon.com/ReservoirGeomechanics-Mark-D-Zoback/dp/0521770696)
12 March 2016
GLG310 Structural Geology
12 March 2016
World Stress Map
http://www.world-stress-map.org/
12 March 2016
http://www.world-stress-map.org/
North America Stress Map