"Isoprenoids:
Pristane and phytane are the two predominant isoprenoids found in petroleum products. They are, in essence, "chemical fossils" from the hydrolysis of chlorophyll and tend to degrade after the straight chain aliphatics. "
The implication is that petroleum contains traces of biotic chemicals, obviating abiotic origins. Other sites mention isotopic ratios as proof of non-abiotic origin.
Perhaps the whole question is a false dichotomy. 'Organic' chemistry appears throughout the solar system, even in places we assume have no life. There may be biotic and abiotic origins to our subterranean hydrocarbon deposits.
Personally, I believe that the petroleum company geologists must have the best appreciation for this murky field. Their corporations have spent more and conducted more surveys and tests than all the universities and governments combined. Unless they are lying I trust their assessment.
(Are they lying?)
Which would you think more valuable?
1. A finite quantity of material currently in use by almost all of mankind.
2. An infinite quantity of the same material.
Shouldn't we find millions of tiny pockets of oil wherever we find a fossil? If not, it seems more likely that we would find many pools or lakes of oil on the surface rather than seeing oil travel and pool in a central location deep underground by sinking below heavier water.
With us becoming partners with Russia now and Bush being an oil man, amybe that will allow more information to be shared so we can find out more about what Russia knows and is still finding out from their basement drilling. They're #2 behind Saudi Arabia and have lots of unreleased data collected by excellent scientists.
Also found this blurb from a 1997 a Toledo Blade article:
"...Millions of Americans learned in grade school that oil deposits originated in the age of dinosaurs, when vegetation in lush forests was buried and subjected to high heat and pressure. Those extreme conditions supposedly transformed the hydrocarbons in vegetation into the hydrocarbons of petroleum.
"That's nonsense," snapped Thomas Gold, a scientist at Cornell University. "There's not a shred of evidence from chemistry, geology, or any other science to support it. It has no place in textbooks and school classrooms."
Petroleum originating from plant matter decayed by bacteria, similar to bacteria that decay backyard garden-compost piles, would resemble a microbial product. Instead, petroleum is chemically similar to a pure hydrocarbon that has been contaminated with microbial material. That contamination, he argues, occurred as petroleum seeped upward through rock now known to contain enormous amounts of bacterial life. In moving upward, petroleum also collected helium, explaining why oil wells are such a rich source of helium. "This is the only possible explanation," Gold said. "The association of helium with petroleum has not been accounted for in any other way."
Gold also presented evidence that oil and gas deposits on Earth are primordial. That means they came with the planet. They were part of the original raw material that formed the sun and planets, and deposited deep below Earth's surface when the planet formed 4.5 billion years ago."