It would be difficult to age crude oil because it depends where you get the crude from and crude oil moves around underground and becomes a blend of ages.
Most oil is from Jurassic and Cretaceous organic material
Crude oil is the organic remains of things that lived between 5 and 200+ million years ago. The age can be determined by the level of the organic compound oleanane
(flowering plants) and hopane
(bacteria). Because oleanane
is associated with angiosperms, the higher the concentrations of oleanane
the younger the crude (evolution of plants means further back you go, the less pollon).
No oleanane
would suggest the crude is more than 160 million years old.
A little oleanane
would make it 65~160 million years old.
A high concentration of oleanane
would make it relatively young, between 5~65 million years old.