Where does crude oil come from?

I have a gcse tomorrow and i was wondering where crude oil came from. I said the earths crust and my friend said the sea, please can you tell me which is right.. Thanks :)

2 Responses to “Where does crude oil come from?”

  1. Calvin W Says:

    They drill into the crust, wherever it may be. But I’d would like to go into this deeper with you. Contrary to what you are told, it is formed by an abiotic synthesis of hydrocarbons in the earth’s MANTLE. After this, it seeps up to the bedrock part of the crust and pools up. It is not the remains of ancient animals formed under heat and pressure blah blah blah. A Russian scientist by the name of Proskurowski recently went to the " Lost City sea vents" and found hydrocarbons( which might I add are naturally produced constantly) containing carbon-13 isotopes formed in the –>mantle<– , not from junk pooled on the ocean floor. Carbon 13 is entirely abiotic, and the assumption of it being formed by an animal is absurd. Not to mention a Cornell physicist found some microorganisms in one of his oil drills, that originate from the mantle.

  2. bdwolfhound Says:

    Your friend is half right. Crude comes from UNDER the sea. The only way you get it from the sea itself is if there’s a tanker accident ! You on the other hand are 100% right. Crude oil (so-called because it has yet to be refined) consists of a complex mixture of hydrocarbons of various molecular weights, and other organic compounds, that is found in geologic formations beneath the earth’s surface. See: