Light Hydrocarbons for Petroleum and Gas Prospecting
V.T. Jones, III, M.D. Matthews and D.M. Richers
Geochemical Remote Sensing of the Subsurface.  Edited by M.Hale
Handbook of Exploration Geochemistry, Vol. 7 (G.J.S. Govett, Editor)
©1999 Elsevier Science B.V. All rights reserved
Preprint

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TABLE 5-III

Literature review of methane/ethane ratios diagnostic of biogenic origin

Reference	Diagnostic of biogenic origin
Davis and Squires, 1954	C1/C2 > 500
Reitsema et al., 1978	C1/C2 > 500
Frank et al., 1970	C1/(C2+C3) > 1000
Bernard et al., 1976	C1/(C2+C3) > 1000; dC^13 -50%
Sackett, 1977	C1/(C2+C3) > 1000; dC^13 -50%