Re: dinosaurs/petroleum

["King, Norm" <nking.ucs@smtp.usi.edu>]

Chris Nedin already answered some of the questions from Christine Mills
(5/6/96; 6:53p) about dinosaurs possibly being a source for petroleum.

A number of years ago, a major oil company (Texaco??) ran some 
commercials using animation to show how difficult it is to find oil, as 
underground dinosaurs (sauropods) kept dodging the drill bit, cutely 
croaking the whole time.  So the Geo Metro folks aren't the first.

Christine said:

>I always believed petroleum was formed from ancient marine
>creatures...

That is correct--marine algae, in fact.

>Is there a certain time period that all petroleum dates from?

No.  Oil is forming today.  It has apparently been forming at least since 
the Cambrian.  There are biomarker hints that there may have been 
Precambrian oil deposits at one time.  That's why major oil companies 
occasionally drill into Precambrian deposits--in Iowa, Illinois, and 
Kentucky recently (like, in the last decade), for example.

This one I'm not certain about, but I believe it is true that significant 
amounts of oil generation have not occurred in terrestrial deposits of 
any age.  In any case, terrestrial vegetation is prone to produce natural 
gas rather than liquid hydrocarbons.  There are significant Pleistocene 
(and older) gas reservoirs in the Gulf Coast region, because the 
Mississippi has been dumping so much particulate vegetal matter into the 
Gulf.

Tell people that these commercials with the incorrect information in them 
are run simply because they are cute, hence thought to be effective (the 
end justifies the means!).  Having marine bacteria alter gobs of dead 
algal tissue just wouldn't have the same appeal.

*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Norman R. King                                       tel:  (812) 464-1794
Department of Geosciences                            fax:  (812) 464-1960
University of Southern Indiana
8600 University Blvd.
Evansville, IN 47712                      e-mail:  nking.ucs@smtp.usi.edu