Michael H. Trippi Debra K. Higley William A. Rouse Frank T. Dulong Timothy R. Klett Tracey J. Mercier Michael E. Brownfield Heidi M. Leathers-Miller Thomas M. Finn Kristen R. Marra Phuong A. Le Cheryl A. Woodall Christopher J. Schenk Catherine B. Enomoto 2018 <p>Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered, technically recoverable continuous resources of 10.7 trillion cubic feet of natural gas in Upper Devonian shales of the Appalachian Basin Province.</p> application/pdf 10.3133/fs20183018 en U.S. Geological Survey Assessment of undiscovered continuous gas resources in Upper Devonian Shales of the Appalachian Basin Province, 2017 reports