SO461 Geological Oceanography

Fall 2003, Test 2







10 @ 3points



Short answer

4 @ 10 points



Longer answer

2 @ 15 points








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 10 of the 12.

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


Answers in Red represent selected key points, and not necessarily a complete answer.


Definitions. Define 10 of these 13 terms. 


1.      Andean mountain belt:

2.      Aulacogen:

3.      Backstripping:

4.      Beta

5.      Blueschist:

6.      Craton:

7.      Gneiss:

8.      Indentation tectonics:

9.      Orogeny:

10.  Rift valley:

11.  Total reconstruction pole:

12.  Transtension: creation of a basin

13.  VLBI: used for plate motions


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.  Discuss the thermal impact of stretching the crust, and how a thick geosyncline can accumulate as a result.


·     Text   p7 notes concept is outdated, but applies at passive margins which result from stretching

·      Tex:  Fig.10-11, middle stage of the plate margin shows a geosyncline without naming it


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.


4.  Describe how suspect terranes form, the features in today’s oceans might become the suspect terranes of the future, and how suspect terranes complicate the simple model of the Wilson cycle.


5.  How do ridges vary with plate spreading rates?


Longer Answer.  Answer both of these questions.


The map below shows two plates (A and B), and the velocities (mm/yr) between the two plates at two locations (V-A is the velocity of plate A, and V-A the velocity of plate B).




Longer Answer.  Answer both of these questions.


The diagram below shows the distribution of earthquakes at a plate boundary.