Earthquakes
Explain why are earthquakes concentrated in the upper 15 km of the continental crust?
Given that plate motions are very slow, why do violent and rapid displacements of the earth's surface occur during an earthquake?
What was the significance of the San Francisco Earthquake of 1906?
What is the relationship between faults and earthquakes?
Why are earthquakes episodic?
What is the relationship between earthquake magnitude and number of earthquakes? Why is this useful?
What is the significance of the different seismic waves?
How can seismologists tell what type of fault caused a given earthquake?
What controls the intensity of ground shaking during an earthquake?
Restoration of the normal faults in the Basin and Range shows that the area has undergone 100% extension in the last 30 million years. How is this magnitude of extension accommodated in the lower crust of the Basin and Range?
Make a schematic cross section of a portion of the Basin and Range to the base of the crust. Label the types of structures present at different depths and the deformation mechanisms that are active at different crustal levels.
Where is the highest seismic risk found in the USA? In the eastern USA?
Draw a schematic crustal strength profile for the crust.
Discuss the physical parameters that control the variation of rock strength with depth.
Know how to interpret the results of a uniaxial deformation experiment and how these experiments are carried out (see homework)
What is elastic deformation? Give Geological examples.
What is plastic deformation? Give Geological examples.
What is the difference between viscous behavior and plastic behavior?
What is ductile behavior?
What are the effects of Temperature, Confining pressure, and Strain Rate on yield strength? On strain?
Know how to use the elastic stress-strain equation
-exx= (1/E) [sxx -n (syy-szz)]
Define:
Young’s modulus
Poisson’s Ratio
Ultimate yield strength
What are dislocations and what role do they play in plastic deformation?
What is pressure-solution and how does it account for diffusional mass transfer?
Know all the geometric elements of a fold, and know how to plot them on a map or cross section:
Fold limbs
Fold hinge
Fold axes
Axial plane
Etc
Know how to describe the geometry of a set of folds, using the proper terminology (recumbent, upright, plunging, inclined, etc)
Recognize anticlines and synclines in map view based on stratigraphic ages.
Distiguish between parallel and similar folds and know where they most commonly occur.
What is fold vergence and what it its kinematic significance?
What happens when an area is folded more than once? What patterns result?
What is the relationship between parasitic folds and the first order folds that contain them?
Understand the folding mechanisms;
Bending, buckling, flexural slip, shear folding
Using strain ellipses, show the distribution of strain through a single buckled layer.
Using strain ellipses, show the distribution of strain through a multi-layer undergoing flexural-slip folding .
What is the relationship between layer thickness, rheological contrast and fold wavelenth? You don’t need to remember the Biot-Ramberg equation, but you do need to be able to interpret a set of folds in this terms)
Define:
Rock fabric
Cleavage
Foliation
Lineation
S-tectonite
L-tectonite
Schsitosity
Crenulation cleavage
What are the mechanisms of cleavage formation?
What is the geometric relationship between cleavage orientation and stress?
What is the geometric relationship between cleavage orientation and folds?
This sketch represents a ductile shear zone. Draw how cleavage would be oriented within the shear zone. Explain why this should be so using the strain ellipse to illustrate your answer.
Structures in Petroleum exploration
Draw examples of all the common types of hydrocarbon trap. Label clearly the reservoir rock, the seal and where the oil accumulation would be located.
What types of traps can be expected in extensional tectonic settings? … in compressional? …in strike slip? ….in passive margins?
What are the geological elements needed for an oil deposits to exist.
What is the role of salt in the formation of petroleum traps?
How are oil deposits found? Describe the steps of the process.
Explain the basics of the seismic reflection method.
What drives the movement of salt diapirs?
What are the possible geometries of salt diapirs?
What happens when salt withdraws from an area?
From Lab:
Stereonets
What are the uses of stereonets?
How is a tilted planar bed of known strike and dip plotted on a stereonet?
How is a lineation, of known trend and plunge, plotted on the stereonet?