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Basin Classification Schemes (taken from Chapter 1 of Allen and Allen) OUTLINE
INTRODUCTION
Zones of pronounced subsidence where sediment can accumulate. The larger the thickness of sediments and longer the accumulation has taken place, the more interesting to the oil companies the basin becomes.
Basin can be classified according to many priorities of the individual. A classification scheme should create "order from the chaos", and highlight patterns that are useful for our geologic objectives.
A modified Dickinson's (1974) classification scheme is still relevant based on:
If one is interested in HOW Basins are formed then it is very natural that we break up the basin types according to their mechanism of formation. If on the other hand one is interested in WHERE they are to be found with respect to PLATE TECTONIC boundaries we might also get a hint about the mechanism of formation. Fossil basins may no longer be in the plate tectonic setting in which they were originally formed.
For the basin you have chosen to write a proposal in this class write an essay (1 page or 300 words at most, including figures). In the essay you will classify your basin according to Kingston et al., (1983a) scheme (4-5 sentences). If you wish you may read the original paper to get a detailed understanding of their classification scheme. This scheme was devised to help predict hydrocarbon potential. Write a brief sentence or two about your opinion of this classification scheme? Does it help you? Does it make it moredifficult to understand the basin? Please justify your answer with a reason. Think honestly and write clearly in your own words.
Kingston, D.R. Dishroon,C.P. and Williams,P.A. (1983) Global basin classification. Bull AM. Assoc. Petrol. Geol. 67, 2175-2193 (A copy of this paper will be available for xeroxing outside my office. Please borrow and return ASAP so everyone can use it. A copy of the main table is given as a handout as well). There is also a *.pdf file of this paper available from my website.
Based only on the composition, which affects density, and short-term rigidity (and hence seismic velocities) the shallow portions of the earth (0-80 km) can have one of three flavors: oceanic composition, i.e. gabbroic melt and all its cooling derivatives- mafic rocks, density ~ 2,800 kg/m3, vaverage Vp=5km/s continental composition, i.e. granitic melt and all its cooling derivatives - felsic rocks, density ~ 2,700 kg/m3, average Vp = 6.5 km/s mantle i.e. peridotitie and high temepratures and pressures, density = 3,300 kg/m3, average Vp=8.1 km/s Although the above rock types have a different composition
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