title: Gas formation. Formation temperatures of thermogenic and biogenic methane.
abstract: Methane is an important greenhouse gas and energy resource generated dominantly by methanogens at low temperatures and through the breakdown of organic molecules at high temperatures. However, methane-formation temperatures in nature are often poorly constrained. We measured formation temperatures of thermogenic and biogenic methane using a "clumped isotope" technique. Thermogenic gases yield formation temperatures between 157° and 221°C, within the nominal gas window, and biogenic gases yield formation temperatures consistent with their comparatively lower-temperature formational environments (<50°C). In systems where gases have migrated and other proxies for gas-generation temperature yield ambiguous results, methane clumped-isotope temperatures distinguish among and allow for independent tests of possible gas-formation models.
authors: Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA. dstolper@caltech.edu.
authors: D A
authors: DA
authors: Stolper
authors: ExxonMobil Upstream Research Company, Houston, TX, USA.
authors: M
authors: M
authors: Lawson
authors: ExxonMobil Upstream Research Company, Houston, TX, USA.
authors: C L
authors: CL
authors: Davis
authors: Division of Geochemistry, Petrobras Research and Development Center (CENPES), Rio de Janeiro, RJ, Brazil.
authors: A A
authors: AA
authors: Ferreira
authors: Division of Geochemistry, Petrobras Research and Development Center (CENPES), Rio de Janeiro, RJ, Brazil.
authors: E V
authors: EV
authors: Santos Neto
authors: U.S. Geological Survey, Denver Federal Center, Denver, CO, USA.
authors: G S
authors: GS
authors: Ellis
authors: U.S. Geological Survey, Denver Federal Center, Denver, CO, USA.
authors: M D
authors: MD
authors: Lewan
authors: Department of Geology, Amherst College, Amherst, MA, USA.
authors: A M
authors: AM
authors: Martini
authors: Power, Environmental, and Energy Research Institute, Covina, CA, USA.
authors: Y
authors: Y
authors: Tang
authors: GasConsult International Inc, Berkeley, CA, USA.
authors: M
authors: M
authors: Schoell
authors: Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
authors: A L
authors: AL
authors: Sessions
authors: Division of Geological and Planetary Sciences, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
authors: J M
authors: JM
authors: Eiler
mesh_terms: D001673:Biodegradation, Environmental; D002247:Carbon Isotopes; D019605:Euryarchaeota / Q000378:metabolism*; D005740:Gases; D006358:Hot Temperature; D008697:Methane / Q000096:biosynthesis* / Q000737:chemistry*; D008962:Models, Theoretical; D061329:Oil and Gas Fields / Q000382:microbiology; D010578:Petroleum / Q000378:metabolism; D013696:Temperature
chemical_list: D002247:Carbon Isotopes; D005740:Gases; D010578:Petroleum; D008697:Methane