SO461 Geological Oceanography

Fall 2014 Test 1

 

Definitions

4 @ 5 points

20

 

Diagrams

4 @ 15 points

60

 

Short answer

2 @ 10 points

20

 

Total

 

100

 

 

Authorized reference:

  1. You may use one 3x 5 card, personally hand written on both sides, during the exam. You will turn it in with the exam.
  2. Calculators will not be allowed. For the calculations, you may set it up and leave the answer in terms of a sum, product, or quotient, or you can make reason simplifications to get a rough idea of the answer.

 

Diagrams: These should clearly indicate understanding of the procedures and concepts involved, and should be well thought out with appropriate terms and details to support your answer. You must answer four of the five questions.

 

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

 

Budget your time. Do not leave anything blank, and note that I am looking for an understanding of the important concepts and appropriate use of terminology.

 

Do not talk about the exam to any students in the course who have not completed the exam. This applies in particular to the student in medical quarantine.

 

All work on this exam is individual. You may not any materials (books, notes, computers) other than your personal3x5 note cared, and you may not use IM, texting, talking, or any other means to communicate with other individuals. If you are caught with an electronic device that is not turned off and inaccessible you will get a 0 on the exam.


 

 

Definitions: Answer 4 of the 5, for 5 points each. Indicate why each is important.

 

         Mineral:

         Quartz:

         Regression or Transgression, depending on version:

         Steno:

         William Smith


 

 

Answer 4 of the 5 questions on the next 5 pages, for 15 points each question. Each has a figure or table.

 


Figure 1. Geoid anomalies from the TOPEX/Poseidon altimeter.

 

How is the geoid anomaly computed?

 

 

 

What does the altimeter actually measure that enables it compute the geoid?

 

 

 

How can the altimeter measure something else that would be of interest to oceanographers rather than geologists?

 

 

 

 

The three profiles have different vertical and horizontal scales. What do you think is causing each anomaly and why do you think this?

 

A:

 

 

B:

 

 

C:

 


 


Figure 2. Topographic profiles across two submarine features labelled A and B. The horizontal and vertical scales are different.

 

Which feature is actually steeper? Why dont we use the same scale for the horizontal and vertical axes?

 

 

What is the difference between the two features, and what fundamental relationship do they represent?

 

 

Can you make any inferences about the ages of the features, and the rest of the profiles? Why or why not?

 


 


Figure 3. Drilling results from two sites on ODP Leg 190.

 

 

One of the sites has some anomalies in the data. Which site is it, what are the anomalies, and what could have caused them?

 

   

What happens at 600 m Depth mbsf at site 1174?

 

  

Which site do you think will have a better record of the Pleistocene Ice Age (12,000 years to 2.6 million years ago? Why would this be the case?

 


 

 

 


Figure 4. Profiles drawn on two different continental margins. Note sea level shown on each.  These are on the east and west sides of South America.

 

 

How should a geologist select locations profiles like to insure they best show the relevant features? Why?

  

How do these two margins differ?

 


 


 

Table 1. Sediment recovered at IODP site 2015, in sequence from top to bottom of the hole.

Sediment type

 

Environment

Glacial sediments

 

 

Diatom oozes

 

 

Abyssal red clay

 

 

Radiolarian ooze

 

 

Abyssal red clay

 

 

Calcareous ooze

 

 

MORB

 

 

 

Indicate something about the depositional environment for each layer in the space provided.

 

Is there any way this collection of sediments could be found at a single location? Why or why not?

 


 

 Answer2 of these 3 questions, for 10 points each.

 

 

What happens to density, porosity, and sound velocity during sediment lithification? Why?

 

 

What three geologic conditions are required for petroleum? Indicate why each is important.

 

 

Why do oceanographic processes like upwelling affect sediment thickness? Where would we find these accumulations?