Pa. Marcellus Shale wells are most productive in U.S. https: aspwv1970-01-01T00:00:00-05:00January 1st, 1970|Twitter| Pa. Marcellus Shale wells are most productive in U.S. https://t.co/qXFLll3Nrr via @oronline #Fracking Share This Story, Choose Your Platform! FacebookTwitterRedditLinkedInWhatsAppTumblrPinterestVkEmail