ESS 211
2011
OUTLINE OF TOPICS SEQUENTIALLY COVERED IN SECOND HALF
(COWAN)
November 7 – December 9
Faults: classification & nomenclature; slip; separation
Folds: fold axis; hinge; axial plane or axial surface; nomenclature
Unconformities: definition; how to distinguish from faults
Friction and the Coulomb equation as a condition for shear fracture (= faults)
Amonton’s Law
Coulomb equation
Graph of Coulomb equation & fracture lines
Concept of strength: Coulomb materials become stronger with depth
Fluid pressure & effective normal stress: effect on strength
Extension fractures and tensile strength in a Coulomb context
Reverse faults and thrusts: definitions
Making a thin-skinned fold-thrust belt in a stratigraphic layercake: flats, ramps,
décollements; window and klippe defined
Normal faults & faulting. Basin and Range tectonic province. Topographic
expression of normal faulting (horst-graben & half-graben styles) in arid regions.
GPS present-day velocities in Basin and Range province and California
Home experiment: making a wedge with rice or barley
Accretionary or orogenic wedges: at subduction zones (oceanic or continental
crust consumed)
Critically tapered wedges: evolution; effects of changing parameters such as
alpha, beta, strength, fluid pressure. The Cascadia-Olympics wedge as an
example of a steady-state critical wedge
Strike-slip and transform faulting. Concept of transfer faults. San Andreas fault:
plate-tectonic setting, present-day activity and seismic history; GPS velocities in
western California
Earthquakes: nucleation, rupture propagation, definition (moment: energy
released), relationship to faulting
Present-day intra-continental deformation: examples from Anatolia and Asia;
seismotectonics [earthquakes and faults] in southern California