Question

can someone give me an overview of the Marcellus Shale

Answer 1

The short answer is that it's a mega-huge deposit of natural gas that runs under Pennsylvania, parts of Ohio, New York, and West Virginia. Geologists have known about it for a long time but like any fossil fuel, the difficulty has always been in just how to get to it because it's so deep underground. But because technology has gotten better, it's now much more possible to get at the massive reserves there.

You can read more about it here:
http://www.pioga.org/marcellus-shale/