which fossils are used to date the oil reserves of the gulf of mexico in the united states?

Answer 1

http://www.publicaffairs.noaa.gov/oceanreport/oilandgas.html

Stratigic Petroleum

Answer 2

I wasn't going to answer this, as I have no great knowledge of Gulf of Mexico geology, but answers like Chas_Chas makes me see red... (since when have fossils ever been dated by rocks?!?!?)

OK - generally speaking the younger Tertiary (Neogene and Palaeogene) oil and gas bearing rocks are nicely dated by small planktonic fossils like foraminifera, algae etc. Remember that the the fossils are in the rocks, not in the oil! These fossils are well-preserved, small, easily identified by micropalaeontologists and are not destroyed by the drill bit that pulverizes the rock! Because of rapid evolution, certain species can be accurately tied in with precise geological intervals. It's proven and it works! Geologists use this technique everywhere to correlate rocks, and the oil finding rates speak for themselves! The age is of course relative, but can be reasonably accurately calibrated by radiometric techniques (K-Ar, etc). Palynology (pollen grains) is also a well-used technique. In the UK, older strata in the Cretaceous and Jurassic are zoned according to ammonites.

Now Carbon 14. This is never used as a dating technique in oil and gas bearing rocks. Carbon 14 simply has too short a half life; i.e. the rocks are far, far too old for the technique to be applicable. Now solid carbon, in particular coal and charcoal (both of which are common in the geological record) is microporous and highly adsorbative. The reason that it is often found to contain C14 is that it has been contaminated by atmospheric C14 on exposure to air! Simple as that! No need to invoke any ill-informed pseudo-biblical explanations.

Answer 3

Do you mean fossils in surrounding rock?
No fossils in oil itself.

Lot of assumptions involved in dating the rock/oil. Typically involving circular reasoning. The rocks are dated by fossils, and fossils are dated by rocks - but all based on uniformitarian assumptions that the world is billions of years old.

Interestingly there is evidence which is problematic for this viewpoint. For example all coal deposits (allegedly millions of years old) contain carbon 14. This has a half life of about 5700 years and there would be none left to measure after about 50000 years.

Answer 4

Mainly planktic foraminifera and calcareous nannofossils. They're unbeatable in the Neogene.