Geology 50413
Global Tectonics and Basin Analysis Geology

COURSE OBJECTIVE: An examination of the rock cycle viewed from the perspective of plate tectonics. A focus on the development of sedimentary basins, from both an academic and a commercial viewpoint. Three hours of lecture per week.

PRINCIPAL SKILLS/KNOWLEDGE BASE REQUIRED: Prerequisite: permission of the instructor. A basic understanding of petrology, stratigraphy and structure, an ability to conceptualize and synthesize on a large scale and an ability to write competently are essential.

COURSE OUTLINE:

1. Historical review: the two basic paradigms of geological thought. Review of the rock cycle,continental drift, sea floor spreading and plate tectonics.
2. Plate motion, heat and loading, compression, tension and shear.
3. The Wilson Cycle: basin development in
   1. rifts and aulacogens
   2. mature oceans
   3. closing oceans
   4. post-orogenic settings
   5. intercratonic settings
4. Sedimentary facies; basic controls; hydrodynamic and chemical.
5. Deposition, depositional rates, preservation rates. Environmental stability and evolution.
6. Unconformity
7. Climate
8. Cycles
9. Diagenesis; physical, chemical and organic
10. Specific case study: the Southern Oklahoma aulacogen

PROJECTS:

1. Wilson Cycle synoptic presentation - 20%
2. Time-Subsidence curves, isopachs and maturity - 25%
3. Giant oil field evaluation - 25%
4. Final: take home essays - 30%

Important note: In each of the projects and essays, you are expected to work with me on an individual or group basis. Plan accordingly.

CLASS PROJECTS FOR BASIN ANALYSIS:

• WILSON CYCLE

  Construct a flow chart which integrates basin development during the various stages of the Wilson Cycle, i.e., the initial rifting of a continent, following through to young ocean development, mature ocean formation, ocean closure, orogeny and post orogenic developments. Integrate such factors as subsidence rates and geothermal gradients into your synopsis.

  For each basin type indicate:

  1. Likely facies and structural styles
  2. Source rock and reservoir rock potential with respect to oil and gas.
  3. Other likely economic targets.

  I can give you some pointers with regard to sources.
  
  

• BASIN SUBSIDENCE CURVES

  For this exercise you are required to work in pairs. Your first task is to select an area of the crust that will allow you to generate information pertaining to the age, thickness and lithology of the various sedimentary rocks present. Where available information as to local geothermal gradients should be used: if not use a generic world-wide average. The impact of unconformities must also be known. In general a more complete picture can be obtained for basins in North America, Europe and Australasia.

  One of the most useful methods in analyzing selected basin histories is to develop a time subsidence curve i.e, a plot of geologic time against sedimentary thickness. Allied to these curves are time - sediment entrapment sections, showing the spatial impact of uplift and unconformity, isopach maps and conventional geologic cross sections. When integrated correctly these techniques area useful method of summarizing basin development. In particular they can be used to evaluate the imprint of geothermal effects (especiallym maturation), diagenetic changes and metamorphic imprints.

  Work is due by November 26 without exception and is to be presented as a series of maps and curves accompanied by a short (c. 500) word synoptic report. Draw comparisons where appropriate. In each case the curves are to chart time from c. 2 billion years ago to the present.

• ENTREPENEURIAL OILFIELD STUDY

  You will working in groups of three for this project. Imagine that you are representing a major oil company and that I am an obscenely rich investor. However, I am only willing to support one group and thus you are in competition with each other. Select a hydrocarbon prospect and develop a presentation which will knock my socks off and convince me that you are the company my money is safest with. AAPG Giant Oilfield studies and other of their publications are a major source of data.

  During the last class meeting each group will have thirty minutes to convince me that I should give you my money. Obviously you will have to be as inventive as possible in this exercise.

• TAKE HOME FINAL

  You are to write an illustrated essay of at least 1,500 words on one of the following topics:

  1. The imprint of climate on the sedimentary record.
  2. The evolution of southern Texas since the Mesozoic.
  3. The importance of understanding unconformities.
  4. Syntectonic sedimentation.
  5. The evolution of the oilfields of California.
  6. Why is there so much oil in Saudi Arabia?

This page created 8-20-02 by Sara Donaldson
Last revised 8-31-02
© 2002, Nowell Donovan
Maintained by Sara Donaldson