TY - RPRT TI - Molecular carbon isotopic evidence for the origin of geothermal hydrocarbons AU - D.J. Des Marais AU - J.H. Donchin AU - N.L. Nehring AU - A.H. Truesdell PY - 1981 DO - 10.1038/292826a0 UR - https://pubs.usgs.gov/publication/70011851 ID - 70011851 ER -