Crude oil ranges in color from almost clear to green, amber, brown or black. It may flow like water or creep like molasses. The plankton died and drifted downward, mixing with sediments of mud and silt. As the centuries passed, layers of sediment covered the decaying animals and plants, burying them deeper and deeper. The pressure and temperature rose, transforming the plankton into oil.
Oil is critical for the U.S. economy and the conveniences of our everyday lives.
It is the source of 38 percent of America's total energy, including 97 percent of our transportation fuels. Oil and its sister fuel, natural gas, provide the building blocks of a myriad of products. As computers, cellular phones, pagers and fax machines, they allow us to communicate more efficiently. In these and many other ways, they enhance our lives.