9781422285596

14 Natural Gas

in British Columbia and Alberta south and east to Utah and Colorado; the US heartland around Kansas, Oklahoma, and Texas; the eastern Midwest from the Great Lakes south to Tennessee; and the Gulf Coast and northern Gulf of Mexico. Natural gas and petroleum oil formation have been going on for more than 1,000 million years. Much of the natural gas used today is from 400 to 250 million years ago, and from 180 to 15 million years ago. For example, the huge Marcellus Shale natural gas reserves date back to 390–380 million years ago.

Exposed shale outside Marcellus, New York.