Geoffrey S Ellis
Biography
Geoffrey Ellis is a petroleum geochemist with the Energy Resources Program (ERP) of the US Geological Survey. He received an A.B. in Geological Sciences from Cornell University, an M.Sc. in Geochemistry from the Colorado School of Mines, and a Ph.D. in Marine Geology and Geophysics from the Rosenstiel School of Marine and Atmospheric Science at the University of Miami. Prior to joining the ERP he worked as a staff scientist in the Division of Chemistry and Chemical Engineering at the California Institute of Technology, a research chemist in the Water Resources Division of the USGS, and as a consultant in environmental and resource exploration geochemistry. His research interests include organic-inorganic interactions in petroleum systems, gas isotope geochemistry, and the controls on sedimentary organic geochemistry in aquatic environments.
Selected Publications
Tang, Y., Huang, Y., Ellis, G.S., Wang, Y., Kralert, P.G., Gillaizeau, B., Ma, Q., and Hwang, R., 2005, A kinetic model for thermally induced hydrogen and carbon isotope fractionation of individual n-alkanes in crude oil: Geochimica et Cosmochimica Acta, v. 69, no. 18, p. 4505-4520.
Cohen, A.S., Lezzar, K.E., Cole, J., Dettman, D., Ellis, G.S., Gonneea, M.E., Plisnier, P.-D., Langenberg, V., Blaauw, M., and Zilifi, D., 2006, Late Holocene linkages between decade–century scale climate variability and productivity at Lake Tanganyika, Africa: Journal of Paleolimnology, v. 36, no. 2, p. 189-209.
Zhang, T., Ellis, G.S., Wang, K.-s., Walters, C.C., Kelemen, S.R., Gillaizeau, B., and Tang, Y., 2007, Effect of hydrocarbon type on thermochemical sulfate reduction: Organic Geochemistry, v. 38, no. 6, p. 897-910.
Amrani, A., Zhang, T., Ma, Q., Ellis, G.S., and Tang, Y., 2008, The role of labile sulfur compounds in thermochemical sulfate reduction: Geochimica et Cosmochimica Acta, v. 72, no. 12, p. 2960-2972.
Kelemen, S.R., Walters, C.C., Kwiatek, P.J., Afeworki, M., Sansone, M., Freund, H., Pottorf, R.J., Machel, H.G., Zhang, T., Ellis, G.S., Tang, Y., and Peters, K.E., 2008, Distinguishing solid bitumens formed by thermochemical sulfate reduction and thermal chemical alteration: Organic Geochemistry, v. 39, no. 8, p. 1137-1143.
Ma, Q., Ellis, G.S., Amrani, A., Zhang, T., and Tang, Y., 2008, Theoretical study on the reactivity of sulfate species with hydrocarbons: Geochimica et Cosmochimica Acta, v. 72, no. 18, p. 4565-4576.
Zhang, T., Amrani, A., Ellis, G.S., Ma, Q., and Tang, Y., 2008, Experimental investigation on thermochemical sulfate reduction by H2S initiation: Geochimica et Cosmochimica Acta, v. 72, no. 14, p. 3518-3530.
Zhang, T., Ellis, G.S., Walters, C.C., Kelemen, S.R., Wang, K.-s., and Tang, Y., 2008, Geochemical signatures of thermochemical sulfate reduction in controlled hydrous pyrolysis experiments: Organic Geochemistry, v. 39, no. 3, p. 308-328.
Houseknecht, D.W., Coleman, J.L., Milici, R.C., Garrity, C.P., Rouse, W.A., Fulk, B.R., Paxton, S.T., Abbott, M.M., Mars, J.C., Cook, T.A., Schenk, C.J., Charpentier, R.R., Klett, T.R., Pollastro, R.M., and Ellis, G.S., 2010, Assessment of undiscovered natural gas resources of the Arkoma Basin Province and geologically related areas: Reston, VA, US Geological Survey, p. 4.
Higley, D.K., Gaswirth, S.B., Abbott, M.M., Charpentier, R.R., Cook, T.A., Ellis, G.S., Gianoutsos, N.J., Hatch, J.R., Klett, T.R., Nelson, P.H., Pawlewicz, M.J., Pearson, O.N., Pollastro, R.M., and Schenk, C.J., 2011, Assessment of undiscovered oil and gas resources of the Anadarko Basin Province of Oklahoma, Kansas, Texas, and Colorado, 2010: U. S. Geological Survey Fact Sheet, p. 2.
McGlue, M.M., Silva, A., Corradini, F.A., Zani, H., Trees, M.A., Ellis, G.S., Parolin, M., Swarzenski, P.W., Cohen, A.S., and Assine, M.L., 2011, Limnogeology in Brazil’s “forgotten wilderness”: a synthesis from the large floodplain lakes of the Pantanal: Journal of Paleolimnology, v. 46, no. 2, p. 273-289.
Ni, Y., Ma, Q., Ellis, G.S., Dai, J., Katz, B., Zhang, S., and Tang, Y., 2011, Fundamental studies on kinetic isotope effect (KIE) of hydrogen isotope fractionation in natural gas systems: Geochimica et Cosmochimica Acta, v. 75, no. 10, p. 2696-2707.
McGlue, M.M., Ellis, G.S., Cohen, A.S., and Swarzenski, P.W., 2012, Playa-lake sedimentation and organic matter accumulation in an Andean piggyback basin: the recent record from the Cuenca de Pozuelos, North-west Argentina: Sedimentology, v. 59, no. 4, p. 1237-1256.
McGlue, M.M., Silva, A., Corradini, F.A., Zani, H., Trees, M.A., Ellis, G.S., Parolin, M., Swarzenski, P.W., Cohen, A.S., and Assine, M.L., 2012, Erratum to: Limnogeology in Brazil’s ‘‘forgotten wilderness’’: a synthesis from the large floodplain lakes of the Pantanal: Journal of Paleolimnology, v. 47, no. 1, p. 165-166.
McGlue, M.M., Silva, A., Zani, H., Corradini, F.A., Parolin, M., Abel, E.J., Cohen, A.S., Assine, M.L., Ellis, G.S., Trees, M.A., Kuerten, S., Gradella, F.d.S., and Rasbold, G.G., 2012, Lacustrine records of Holocene flood pulse dynamics in the Upper Paraguay River watershed (Pantanal wetlands, Brazil): Quaternary Research, v. 78, no. 2, p. 285-294.
Zhang, T., Ellis, G.S., Ma, Q., Amrani, A., and Tang, Y., 2012, Kinetics of uncatalyzed thermochemical sulfate reduction by sulfur-free paraffin: Geochimica et Cosmochimica Acta, v. 96, p. 1-17.
Zhang, T., Ellis, G.S., Ruppel, S.C., Milliken, K., and Yang, R., 2012, Effect of organic-matter type and thermal maturity on methane adsorption in shale-gas systems: Organic Geochemistry, v. 47, no. 0, p. 120-131.
Fishman, N.S., Ellis, G.S., Paxton, S.T., Boehlke, A.R., and Egenhoff, S.O., 2013, Gas storage in the Upper Devonian-Lower Mississippian Woodford Shale, Arbuckle Mountains, Oklahoma—how much of a role do the cherts play?, in Chatelier, J.-Y., and Jarvie, D.M., eds., Critical assessments of shale resource plays: AAPG Memoir 103: Tulsa, OK, American Association of Petroleum Geologists, p. 81-107.
McGlue, M.M., Cohen, A.S., Ellis, G.S., and Kowler, A.L., 2013, Late Quaternary stratigraphy, sedimentology and geochemistry of an underfilled lake basin in the Puna plateau (northwest Argentina): Basin Research, v. 25, no. 6, p. 638-658.
Ellis, G.S., 2014, Geochemistry of natural gases of the Anadarko Basin, in Higley, D.K., ed., Petroleum systems and assessment of undiscovered oil and gas in the Anadarko Basin Province, Colorado, Kansas, Oklahoma, and Texas—USGS Province 58: U.S. Geological Survey Digital Data Series DDS–69–EE: Reston, VA, US Geological Survey, p. 31.
Higley, D.K., Gaswirth, S.B., Abbott, M.M., Charpentier, R.R., Cook, T.A., Ellis, G.S., Gianoutsos, N.J., Hatch, J.R., Klett, T.R., Nelson, P.H., Pawlewicz, M.J., Pearson, O.N., Pollastro, R.M., and Schenk, C.J., 2014, Assessment of undiscovered oil and gas resources of the Anadarko Basin Province of Oklahoma, Kansas, Texas, and Colorado, in Higley, D.K., ed., Petroleum systems and assessment of undiscovered oil and gas in the Anadarko Basin Province, Colorado, Kansas, Oklahoma, and Texas—USGS Province 58: U.S. Geological Survey Digital Data Series DDS–69–EE: Reston, VA, US Geological Survey, p. 1-3.
Ivory, S.J., McGlue, M.M., Ellis, G.S., Lézine, A.-M., Cohen, A.S., and Vincens, A., 2014, Vegetation Controls on Weathering Intensity during the Last Deglacial Transition in Southeast Africa: Plos One, v. 9, no. 11, p. e112855.
Li, M., Wang, T.G., Shi, S., Liu, K., and Ellis, G.S., 2014, Benzo[b]naphthothiophenes and alkyl dibenzothiophenes: Molecular tracers for oil migration distances: Marine and Petroleum Geology, v. 57, no. 0, p. 403-417.
Xia, X., Ellis, G.S., Ma, Q., and Tang, Y., 2014, Compositional and stable carbon isotopic fractionation during non-autocatalytic thermochemical sulfate reduction by gaseous hydrocarbons: Geochimica et Cosmochimica Acta, v. 139, no. 0, p. 472-486.
Cohen, A., McGlue, M.M., Ellis, G.S., Zani, H., Swarzenski, P.W., Assine, M.L., and Silva, A., 2015, Lake formation, characteristics, and evolution in retroarc deposystems: A synthesis of the modern Andean orogen and its associated basins, in DeCelles, P.G., Ducea, M.N., Carrapa, B., and Kapp, P.A., eds., Geodynamics of a Cordilleran Orogenic System: The Central Andes of Argentina and Northern Chile: Geological Society of America Memoir 212: Boulder, CO, The Geological Society of America, p. 309-335.
Ellis, G.S., Katz, B.J., Scholz, C.A., and Swart, P.K., 2015, Organic sedimentation in modern lacustrine systems: A case study from Lake Malawi, East Africa, in Larsen, D., Egenhoff, S.O., and Fishman, N.S., eds., Paying Attention to Mudrocks: Priceless!: Boulder, CO, The Geological Society of America.
Gvirtzman, Z., Said-Ahmad, W., Ellis, G.S., Hill, R.J., Moldowan, J.M., Wei, Z., and Amrani, A., 2015, Compound-specific sulfur isotope analysis of thiadiamondoids of oils from the Smackover Formation, USA: Geochimica et Cosmochimica Acta, v. 167, p. 144-161.
Hu, H., Zhang, T., Wiggins-Camacho, J.D., Ellis, G.S., Lewan, M.D., and Zhang, X., 2015, Experimental investigation of changes in methane adsorption of bitumen-free Woodford Shale with thermal maturation induced by hydrous pyrolysis: Marine and Petroleum Geology, v. 59, no. 0, p. 114-128.
Li, M., and Ellis, G.S., 2015, Qualitative and Quantitative Analysis of Dibenzofuran, Alkyldibenzofurans, and Benzo[b]naphthofurans in Crude Oils and Source Rock Extracts: Energy & Fuels, v. 29, no. 3, p. 1421-1430.
McGlue, M.M., Ellis, G.S., and Cohen, A.S., 2015, Modern muds of Laguna Mar Chiquita (Argentina): Particle size and organic matter geochemical trends from a large saline lake in the thick-skinned Andean foreland: Geological Society of America Special Papers, v. 515.
Meshoulam, A., Ellis, G.S., Said Ahmad, W., Deev, A., Sessions, A.L., Tang, Y., Adkins, J.F., Liu, J., Gilhooly III, W.P., Aizenshtat, Z., and Amrani, A., 2016, Study of thermochemical sulfate reduction mechanism using compound specific sulfur isotope analysis: Geochimica et Cosmochimica Acta, v. 188, p. 73-92.
Ellis, G.S., Said-Ahmad, W., Lillis, P.G., Shawar, L., and Amrani, A., 2017, Effects of thermal maturation and thermochemical sulfate reduction on compound-specific sulfur isotopic compositions of organosulfur compounds in Phosphoria oils from the Bighorn Basin, USA: Organic Geochemistry, v. 103, p. 63-78.
Ivory, S.J., McGlue, M.M., Ellis, G.S., Boehlke, A., Lézine, A.-M., Vincens, A., and Cohen, A.S., 2017, East African weathering dynamics controlled by vegetation-climate feedbacks: Geology, v. 45, no. 9, p. 823-826.
Li, Y., Zhang, T., Ellis, G.S., and Shao, D., 2017, Depositional environment and organic matter accumulation of Upper Ordovician–Lower Silurian marine shale in the Upper Yangtze Platform, South China: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 466, p. 252-264.
Piasecki, A., Sessions, A., Lawson, M., Ferreira, A.A., Santos Neto, E.V., Ellis, G.S., Lewan, M.D., and Eiler, J.M., 2018, Position-specific 13C distributions within propane from experiments and natural gas samples: Geochimica et Cosmochimica Acta, v. 220, p. 110-124.
Science and Products
Kinetics of elemental sulfur reduction by petroleum hydrocarbons and the implications for hydrocarbon thermal chemical alteration
Although sulfur-containing compounds are known to play a significant role in the diagenic and catagenic processes that generate oil and gas, relatively little is known about the kinetics of reactions between elemental S and petroleum hydrocarbons. To investigate this subject, a series of closed-system pyrolysis experiments using paraffin, a low-...
Ellis, Geoffrey S.; Zhang, Tongwei; Kralert, Paul G.; Tang, Yongchun Experimental investigation of the role of rock fabric in gas generation and expulsion during thermal maturation: Anhydrous closed-system pyrolysis of a bitumen-rich Eagle Ford Shale
Gold-tube pyrolysis experiments were conducted on miniature core plugs and powdered rock from a bitumen-rich sample of Eagle Ford Shale to investigate the role of rock fabric in gas generation and expulsion during thermal maturation. The samples were isothermally heated at 130, 300, 310, 333, 367, 400, and 425 °C for 72 h under a confining...
Shao, Deyong; Ellis, Geoffrey S.; Li, Yanfang; Zhang, Tongwei Equilibrium and non-equilibrium controls on the abundances of clumped isotopologues of methane during thermogenic formation in laboratory experiments: Implications for the chemistry of pyrolysis and the origins of natural gases
Multiply isotopically substituted molecules (‘clumped’ isotopologues) can be used as geothermometers because their proportions at isotopic equilibrium relative to a random distribution of isotopes amongst all isotopologues are functions of temperature. This has allowed measurements of clumped-isotope abundances to be used to constrain formation...
Shuai, Yanhua; Douglas, Peter M.J.; Zhang, Shuichang; Stolper, Daniel A.; Ellis, Geoffrey S.; Lawson, Michael; Lewan, Michael; Formolo, Michael; Mi, Jingkui; He, Kun; Hu, Guoyi; Eiler, John M. Position-specific 13C distributions within propane from experiments and natural gas samples
Site-specific carbon isotope measurements of organic compounds potentially recover information that is lost in a conventional, ‘bulk’ isotopic analysis. Such measurements are useful because isotopically fractionating processes may have distinct effects at different molecular sites, and thermodynamically equilibrated populations of molecules tend...
Piasecki, Alison; Sessions, Alex L.; Lawson, Michael; Ferreira, A.A.; Santos Neto, E. V.; Ellis, Geoffrey S.; Lewan, Michael; Eilers, J.M. Experimental investigation on thermochemical sulfate reduction in the presence of 1-pentanethiol at 200 and 250 °C: Implications for in situ TSR processes occurring in some MVT deposits
Organic sulfur compounds are ubiquitous in natural oil and gas fields and moderate-low temperature sulfide ore deposits. Previous studies have shown that organic sulfur compounds are important in enhancing the rates of thermochemical sulfate reduction (TSR) reactions, but the details of these reaction mechanisms remain unclear. In order to assess...
Yuan, Shunda; Ellis, Geoffrey S.; Chou, I-Ming; Burruss, Robert East African weathering dynamics controlled by vegetation-climate feedbacks
Tropical weathering has important linkages to global biogeochemistry and landscape evolution in the East African rift. We disentangle the influences of climate and terrestrial vegetation on chemical weathering intensity and erosion at Lake Malawi using a long sediment record. Fossil pollen, microcharcoal, particle size, and mineralogy data affirm...
Ivory, Sarah J.; McGlue, Michael M.; Ellis, Geoffrey S.; Boehlke, Adam; Lézine, Anne-Marie; Vincens, Annie; Cohen, Andrew S. Depositional environment and organic matter accumulation of Upper Ordovician–Lower Silurian marine shale in the Upper Yangtze Platform, South China
The main controlling factors of organic matter accumulation in the Upper Ordovician Wufeng–Lower Silurian Longmaxi Formations are complex and remain highly controversial. This study investigates the vertical variation of total organic carbon (TOC) content as well as major and trace element concentrations of four Ordovician–Silurian transition...
Li, Yangfang; Zhang, Tongwei; Ellis, Geoffrey S.; Shao, Deyong Effects of thermal maturation and thermochemical sulfate reduction on compound-specific sulfur isotopic compositions of organosulfur compounds in Phosphoria oils from the Bighorn Basin, USA
Compound-specific sulfur isotope analysis was applied to a suite of 18 crude oils generated from the Permian Phosphoria Formation in the Bighorn Basin, western USA. These oils were generated at various levels of thermal maturity and some experienced thermochemical sulfate reduction (TSR). This is the first study to examine the effects of thermal...
Ellis, Geoffrey S.; Said-Ahamed, Ward; Lillis, Paul G.; Shawar, Lubna; Amrani, Alon Study of thermochemical sulfate reduction mechanism using compound specific sulfur isotope analysis
The sulfur isotopic fractionation associated with the formation of organic sulfur compounds (OSCs) during thermochemical sulfate reduction (TSR) was studied using gold-tube pyrolysis experiments to simulate TSR. The reactants used included n-hexadecane (n-C16) as a model organic compound with sulfate, sulfite, or elemental sulfur as the...
Meshoulam, Alexander; Ellis, Geoffrey S.; Ahmad, Ward Said ; Deev, Andrei; Sessions, Alex L.; Tang, Yongchun; Adkins, Jess F.; Liu, Jinzhong; Gilhooly, William P.; Aizenshtat, Zeev; Amrani, Alon Compound-specific sulfur isotope analysis of thiadiamondoids of oils from the Smackover Formation, USA
Thiadiamondoids (TDs) are diamond-like compounds with a sulfide bond located within the cage structure. These compounds were suggested as a molecular proxy for the occurrence and extent of thermochemical sulfate reduction (TSR). Compound-specific sulfur-isotope analysis of TDs may create a multi-parameter system, based on molecular and δ34S...
Zvi Gvirtzman; Ward Said-Ahmad; Ellis, Geoffrey S.; Ronald J. Hill; J. Michael Moldowan; Zhibin Wei; Alon Amrani Organic sedimentation in modern lacustrine systems: A case study from Lake Malawi, East Africa
This study examines the relationship between depositional environment and sedimentary organic geochemistry in Lake Malawi, East Africa, and evaluates the relative significance of the various processes that control sedimentary organic matter (OM) in lacustrine systems. Total organic carbon (TOC) concentrations in recent sediments from Lake Malawi...
Ellis, Geoffrey S.; Barry J. Katz; Christopher A. Scholz; Peter K. Swart Qualitative and quantitative analysis of Dibenzofuran, Alkyldibenzofurans, and Benzo[b]naphthofurans in crude oils and source rock extracts
Dibenzofuran (DBF), its alkylated homologues, and benzo[b]naphthofurans (BNFs) are common oxygen-heterocyclic aromatic compounds in crude oils and source rock extracts. A series of positional isomers of alkyldibenzofuran and benzo[b]naphthofuran were identified in mass chromatograms by comparison with internal standards and standard retention...
Meijun Li; Ellis, Geoffrey S.