Ronald R. Charpentier Troy A. Cook Timothy R. Klett Janet K. Pitman Richard M. Pollastro Christopher J. Schenk Marilyn E. Tennyson Michael E. Brownfield 2010 Four geologic provinces located along the northwest and west-central coast of Africa recently were assessed for undiscovered oil, natural gas, and natural gas liquids resources as part of the U.S. Geological Survey's (USGS) World Oil and Gas Assessment. Using a geology-based assessment methodology, the USGS estimated mean volumes of 71.7 billion barrels of oil, 187.2 trillion cubic feet of natural gas, and 10.9 billion barrels of natural gas liquids. application/pdf 10.3133/fs20103006 en U.S. Geological Survey Assessment of undiscovered oil and gas resources of four west Africa geologic provinces reports