Physical Geology - GEOL 117 1999 3rd Exam - Earth structure and resources- Practice version

This is a practice exam from Fall of 99. The actual exam will have the same format, but will naturally not cover the exact same material. My suggestion is to go through this exam after you have studied the material in order to identify portions of the material covered that you might want to study more. From year to year the exact content of the course varies a bit. There may be a question or two asked in this test which we did not study . Hwever, most of the material should look familiar.

Matching: Choose the answer that best matches. (2 pts. each)

 ____ P waves a) southern supercontinent which had a large ice-cap, dispersed some 150 Ma
 ____ S waves b) example of a subduction-arc complex, a convergent plate boundary
 ____diamond anvil c) glassy fault rock representing frictional melting during sudden slip.
 ____ shadow zone d) oxygen poor conditions in which decay is slow, e.g. bottom swamp waters
____ Andes e) fabric created in rock during deformation and reflecting the strain.
 ____ San Andreas f) waxy organic material in rocks that serves as a good oil source rock
____ Iceland g) distribution of forces inside a body that cause internal deformation.
 ____Gondwanaland h) travels through solid and liquid, an elastic deformation, fastest
 ____pseudotachylite i) example of a seafloor spreading center emergent because of hotspot overprint
____ foliation j) area of maximum seepage of rainfall and recharge of Ogallala High Plains aquifer
  ____ stress k) allows high experimental P to be reached so can model deep interior changes
 ____ kerogen l) geologic unit at depth that can serve as a groundwater resource.
 ____ euxinic m) travels only through solid, an elastic deformation, slower.
 ____ SandHills n) example of a transcurrent plate boundary with abundant strike-slip faults.
 ____ aquifer o) due to blockage or refraction of seismic waves at core/mantle interface
  p) sudden euphoria released by completion of geologic assessment tool

Diagrammatic, fill-in-the blank and other such questions:

1) Number the following in order of descending depth (1 the shallowest):

Circle the one which represents a seismic velocity decrease with depth. Put a box around the one which is the deepest level we have earthquakes originate at. Put an X through the one that represents the base of the crust. Put a check through the one that results from a small bit of partial melt. (4 pts.) 1 bonus point for the depth to the Moho, LVZ and core/mantle boundary.

2) Use the schematic diagram below of seismic waves penetrating layers in the earth to complete the following (4 pts.): a) Circle the area(s) where refraction is occurring. b) Put a box around the area(s) where reflection is occurring. c) Which layer has the greater seismic velocity? ______ d) By repeating this process with many shot sources and many geophones an image of the interior of the earth known as a ___________________________________ can be built up.

3) The earth's magnetic field is generated in the __________ _____________ which is composed of ____________________________. Convection patterns create a _________________ effect, which produces the magnetic field. Periodically the pattern breaks down and a new pattern of flow and a new magnetic field develops in a process known as a ________________ ____________________ . (4 pts.)

4) What do meteorites tell us about the interior of the earth. (3 pts.)



5) Use the map diagram of a plate boundary segmented by letters into different portions to answer the following (4 pts.). Segments can be referred to as AB, BC, CD, DE, EF, FG. The pattern gives this away but as a help the interior plate is moving left with respect to the surrounding plate.

6) This is a diagram you have seen before of a type of plate boundary. Use it to do the following:

7) Define NRM.


8) Collisional mountain belts have a long and complex history. For example, the Himalayas have been forming over a period of 40 million years. Put the following processes that shape mountain belts in a reasonable geologic order starting with 1 as the earliest in the progression.

Which large scale process that is found in response to India colliding with Asia is not mentioned in the above?


Which of the above orogenic processes is due to the strength of the rocks supporting the mountainous relief?

___________________________ (4pts.)

9) Typically, how fast do plates move with respect to each other? ________________

What new technology allows us to actually monitor crustal motion from year to year? __________________ (3pts.)

10) Approximately what depth in typically continental crust is the brittle-ductile transition? ___________

What controls the depth to this transition zone? _______________ (3 pts.)

Faults that are moving below this zone move in a creep, chaotic, or stick-slip mode (circle the right one?)

11) List three examples of tensile brittle failure features on the earth. (3 pts.)




12) List three factors that influence deformation behavior and indicate how they affect the rock strength (3 pts.).

 factor   affect on strength

13) Draw a picture of what a fold might look like in the deep, soupy migmatite bowels of a mountain belt. (3 pts.)







14) What are the three geologic features/processes necessary for an oil field to form? (3 pts.)

a) ____________________________________

b) _____________________________________

c) ____________________________________

Put a box around the one that needs to develop first. Circle the one that requires some sort of seal. Put an x next to the one that requires carbon be taken out of the biosphere and stored in the lithosphere.

15) Name the geologic concentration process that forms these type of ore deposits: (3 pts.)

Massive sulfide deposits forming at ridges______________________________

Bauxite ore forming in tropical soils ________________________________

Gold in river gravels ________________________________

16) Use the cross section diagram below and Darcy's law given here to answer the following:

Q = k A (h / l) (4 pts.)

17) Use the cross section diagrams below to answer questions about hydraulic properties of rock.(4 pts.)


18) List three factors that determine the magniture of fracture permeability of a geologic unit. (3 pts.)




19) List four specific ways in which geologic knowledge is useful in environmental decision making? (4 pts.)




20) Create a question that you think may provide some new insight into some of the geology that we have discussed in this second part of the course, but which was not asked in the above questions. You need not answer the question you create.These are not bonus points. (4 pts.)


Best wishes for the future and have a good holiday break!