Oil
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| The word petroleum is used today to refer to both oil and gas. It is derived from Latin petra, meaning "rock," and oleum, meaning "oil"--thus, oil from rock. Crude oil is composed mainly of hydrocarbons, with small amounts of sulfur and other substances. Whereas coal was created from dead vegetation buried close to where it grew, oil and gas formed primarily from transported ancient organic matter buried in fine sediment in deep basins. |
Figure 4 Click on image to see layers. |
