For what it is worth:
Early in my life I spent ten years in oil exploration.   I sat on many oil
wells in the Uinta Basin of Utah.   On every hole we retorted the oil shale
of every ten feet in depth.  I have a piece of core with fish scales in it,
about three million years old.   The geologist identified them as shark
scales.   To me they look more like scales from a snake.

Anyway, being interested in oil (it was a very exciting life) I have more or
less followed it.   In my humble opinion, for whatever it is worth, I
believe much of it was done by bacteria.  Oil has been produced that way but
not economically, it takes a long time, but what is a couple of million
years in the life of the earth.

Food for thought:  In the sea vents bacteria, live off of Hydrogen Sulfide -
Very poisonous.   In  leaching piles of gold ore, utilizing Cyanide for
leaching.  and in Modesto,CA The water supply contains bacteria that lives
on Silicon Dioxide (sand).  It is problematic to the people that live there
but it is kept a secrete from them.  So they don't complain.

Gene Sandburg

How far down were those fish scales?
Why were all those dinosaurs up there on the north slope? Surely there
was no food.

Paul Lamar
 --

Paul,

Surely you jest:)  Pole shifts and migration of landmasses.  Used to be a
lush vegetation up at North slope.

Doug in Japan

Not jesting.
I doubt that. The axis of the earth would need to shift 90 degrees in the
age of the dinosaurs. The physics of that becomes mind boggling. Try turning
a spinning gyroscope 90 degrees. The current pole would be the tropics and the current
equator would be the pole. If that was the case then why do we find lots of oil
near the equator and in the artic? Frankly I think the dead dinosaurs theory is wrong
since it was formulated in 1757 long before they discovered oil a mile down or more and
all over the globe. The dead dinosaurs theory has been repeated so many times
in so many books it has become gospel. Up until the Russians questioned the
theory in the 1950s did anybody challenged it.

A parallel between the way diamonds are formed and oil is formed has been
suggested.

Paul Lamar