---
title: "Crude Oil — AP Environmental Science Definition & Exam Guide"
description: "Crude oil is a liquid fossil fuel made of hydrocarbons from ancient marine organisms. Learn how APES tests it in Topic 6.3, from tar sands to oil spills."
canonical: "https://fiveable.me/ap-enviro/key-terms/crude-oil"
type: "key-term"
subject: "AP Environmental Science"
---

# Crude Oil — AP Environmental Science Definition & Exam Guide

## Definition

Crude oil refers to a fossil fuel that is formed from the remains of ancient marine organisms. It is a thick, dark liquid composed mainly of hydrocarbons.

## Related Study Guides

- [6.3 Fuel Types and Uses](/ap-enviro/unit-6/fuel-types-uses/study-guide/gSCAb3LVL5rkRp2HrqFp)

## Review

### Related Terms

- [Non-renewable energy](/ap-enviro/key-terms/non-renewable-energy): Energy derived from sources that cannot be replenished in a short period, like crude oil.
- Tar sands: Also known as oil sands, tar sands are deposits of sand or clay mixed with water and bitumen (a thick form of petroleum). They require extensive processing to extract usable oil.
- Fossil fuels: A general term for non-renewable energy sources such as coal, natural gas, and crude oil.