Tracey J. Mercier Phuong A. Le Andrea D. Cicero Ronald M. Drake II Sarah E. Gelman Jane S. Hearon Benjamin G. Johnson Jenny H. Lagesse Heidi M. Leathers-Miller Kira K. Timm Christopher J. Schenk 2025 <p>Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean conventional resources of 3.3 billion barrels of oil and 80.3 trillion cubic feet of gas in the Zagros Fold Belt of Iran, Iraq, Syria, and Turkey.</p> application/pdf 10.3133/fs20243048 en U.S. Geological Survey Assessment of undiscovered conventional oil and gas resources of the Zagros Fold Belt of Iran, Iraq, Syria, and Turkey, 2023 reports