Michael E. Brownfield Ronald R. Charpentier Troy A. Cook Timothy R. Klett Mark A. Kirschbaum Janet K. Pitman Richard M. Pollastro Marilyn E. Tennyson Christopher J. Schenk 2012 Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 126 billion barrels of oil and 679 trillion cubic feet of undiscovered natural gas in 31 geologic provinces of South America and the Caribbean. application/pdf 10.3133/fs20123046 en U.S. Geological Survey Assessment of undiscovered conventional oil and gas resources of South America and the Caribbean, 2012 reports