Predictions of Oil or Gas Potential by Near-Surface Geochemistry

V.T. Jones and R.J. Drozd The American Association of Petroleum Geologists Bulletin V.67, No. 6 (June 1983), P.932-952

Figure 7.  Typical soil-gas histograms for propane/methane ratio (C3/C1) x 1,000- over dry-gas, condensate, and oil-producing basins surveyed