SO461 Geological Oceanography

Fall 2004, Test 2

Definitions: answer with no more than a single sentence.  You should be complete and show you clearly understand the term.  Note that you need only answer 8.

Short Answer: The questions should be answered with several sentences (no more than a short paragraph). You must answer four questions.

Longer Answer: These should clearly indicate understanding of the procedures and concepts involved.

Note that on both the definitions and short answer you have a choice of which questions to answer.

The exam is open book, which includes any notes permanently written in the book.  No other references or calculators are allowed.

 Budget your time.  If you try to look up everything in the text book, you will run out of time. 

Definitions. Define 8 of these terms. 

1.      Andean mountain belt:

2.      Blueschist:

3.      Craton:

4.      Gneiss:

5.      Marble:

6.      Orogeny:

7.      Rift valley:

8.      Stage pole:

9.      Transpression:

10.  VLBI:

Short Answer.  Answer 4 of the 5 questions in this section.  You do not have to use complete sentences, but must clearly indicate that you understand the concepts involved.

1. The map below shows some of the major earthquakes in southeast Asia (India is just to the west of this map).   What kinds of faults are here, and can you relate them to the development of the Himalayas?

2.  The San Andreas is a right lateral fault that strikes northwest-southest.  Draw a sketch map to illustrate what this means.  Then draw another sketch to show how the motion would vary along a transform fault and a strike-slip fault with the same geometry.

3.  Sketch a destructive plate boundary.

• Show where two different kind of metamorphic rock would form, and name them.
• Show where two different kind of igneous rock would form, and name them.

4.  Differentiate a subbottom profiler from a side scan sonar.

5.  How and why are the MAR and EPR different?

Longer Answer.  Answer all of these questions.

 The diagram below shows three plates (A, B, and C), and the velocities (mm/yr) in an absolute hot spot model.

• What kind of boundaries are depicted, and how do you know?
• Compute the relative velocity between each pair of plates.  Insure that your method is clear; you can estimate the numbers.

This diagram shows magnetic anomaly profiles over suspected ridges.

• Locate any likely ridges, and indicate how you picked those locations.
• Identify three anomalies on each profile, using the names indicated on the time scale below.
• Which profile has the faster spreading rates, and how can you tell?
• Where is the oldest crust on these profiles, and how can you tell?

Explain the diagram below. 

• What does it show, and why do marine geologists use it?
• Can you estimate the water depth north (to the right) of the Gorda Escarpment?
• What are the units on the vertical scale, and why are these units used?

 The map below shows the earthquakes in a region, without the land.  The graph below shows the earthquakes by depth within the small box on the map.

• Is there a plate boundary here?  If so, what kind of boundary, and how could you tell?  If not, what is happening here?
• What kinds of faults would you predict here, and why?