Everyone could hear the earsplitting whir of the drill. Workers in clothes covered with mud and muck climbed around the drill rig in Clarksburg, West Virginia on Wednesday, carefully feeding a new pipe into the well or steering the sharp drill bit. The 126 foot tall rig muscled its way through layers of dirt and rock to release the natural gas found in the Marcellus Shale formation.
Natural gas often is contained in shale, a marine sedimentary rock. The Marcellus formation, which runs from Pennsylvania through western Maryland and into West Virginia, is one of the largest shale fields in the world, formed almost 400 million years ago as layers of dead plants and animals built up.