The New York Times reports that the shale-gas frenzy has spread from Texas, Oklahoma and Arkansas to Pennsylvania.  Triggered by the success of horizontal exploration in the Barnett Formation underneath Fort Worth and thereabouts, new drilling technology and spiking natural gas prices, energy companies like Chesapeake Energy, a big player in the Fayetteville shale, are madly gathering leases across Pennsylvania, where for a hundred years gas has been known to exist in the deep rock. The Marcellus Formation spreads from upstate New York to Ohio and south to West Virginia and may have 50 trillion cubic feet of recoverable gas. Oh, and Pennsylvania doesn’t have a severance tax — yet. See, they will all pick up their rigs in Arkansas and head east to avoid the tax, we’ll soon hear.