Research Article| February 01, 2001 Thermogenic vent gas and gas hydrate in the Gulf of Mexico slope: Is gas hydrate decomposition significant? Roger Sassen; Roger Sassen 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845, USA Search for other works by this author on: GSW Google Scholar Stephen T. Sweet; Stephen T. Sweet 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845, USA Search for other works by this author on: GSW Google Scholar Alexei V. Milkov; Alexei V. Milkov 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845, USA Search for other works by this author on: GSW Google Scholar Debra A. DeFreitas; Debra A. DeFreitas 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845, USA Search for other works by this author on: GSW Google Scholar Mahlon C. Kennicutt, II Mahlon C. Kennicutt, II 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845, USA Search for other works by this author on: GSW Google Scholar Geology (2001) 29 (2): 107–110. https://doi.org/10.1130/0091-7613(2001)029<0107:TVGAGH>2.0.CO;2 Article history received: 23 Jun 2000 rev-recd: 24 Oct 2000 accepted: 01 Nov 2000 first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Roger Sassen, Stephen T. Sweet, Alexei V. Milkov, Debra A. DeFreitas, Mahlon C. Kennicutt; Thermogenic vent gas and gas hydrate in the Gulf of Mexico slope: Is gas hydrate decomposition significant?. Geology 2001;; 29 (2): 107–110. doi: https://doi.org/10.1130/0091-7613(2001)029<0107:TVGAGH>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Samples of vent gas and gas hydrate on the Gulf of Mexico slope were collected by research submersible (∼540 m water depth) and by piston coring (∼1060–1070 m water depth). Although gas hydrate that crops out is transiently unstable, the larger volume of structure II gas hydrate in the gulf is stable or increasing in volume because gas from the subsurface petroleum system is venting prolifically within the gas hydrate stability zone. Vent gas from gas hydrate shows no meaningful molecular evidence of gas hydrate decomposition. Gas hydrate fabrics, mainly vein fillings, are typical of ongoing crystallization. Once crystallized, most hydrocarbons are protected from bacteria within the crystal lattice of gas hydrate. A leaky petroleum system is proposed to be the main source of thermogenic greenhouse gases in the central gulf. Stable gas hydrate sequesters large volumes of greenhouse gases, suggesting that gas hydrate may not be a significant factor in models of climate change at present. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Research Article| September 01, 1998 Bacterial methane oxidation in sea-floor gas hydrate: Significance to life in extreme environments Roger Sassen; Roger Sassen 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Search for other works by this author on: GSW Google Scholar Ian R. MacDonald; Ian R. MacDonald 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Search for other works by this author on: GSW Google Scholar Norman L. Guinasso, Jr; Norman L. Guinasso, Jr 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Search for other works by this author on: GSW Google Scholar Samantha Joye; Samantha Joye 2Department of Marine Sciences, University of Georgia, Athens, Georgia 30506 Search for other works by this author on: GSW Google Scholar Adolfo G. Requejo; Adolfo G. Requejo 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Search for other works by this author on: GSW Google Scholar Stephen T. Sweet; Stephen T. Sweet 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Search for other works by this author on: GSW Google Scholar Javier Alcalá-Herrera; Javier Alcalá-Herrera 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Search for other works by this author on: GSW Google Scholar Debra A. DeFreitas; Debra A. DeFreitas 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Search for other works by this author on: GSW Google Scholar David R. Schink David R. Schink 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Search for other works by this author on: GSW Google Scholar Author and Article Information Roger Sassen 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Ian R. MacDonald 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Norman L. Guinasso, Jr 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Samantha Joye 2Department of Marine Sciences, University of Georgia, Athens, Georgia 30506 Adolfo G. Requejo 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Stephen T. Sweet 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Javier Alcalá-Herrera 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Debra A. DeFreitas 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 David R. Schink 1Geochemical and Environmental Research Group, Texas A&M University, College Station, Texas 77845 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1998) 26 (9): 851–854. https://doi.org/10.1130/0091-7613(1998)026<0851:BMOISF>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Roger Sassen, Ian R. MacDonald, Norman L. Guinasso, Samantha Joye, Adolfo G. Requejo, Stephen T. Sweet, Javier Alcalá-Herrera, Debra A. DeFreitas, David R. Schink; Bacterial methane oxidation in sea-floor gas hydrate: Significance to life in extreme environments. Geology 1998;; 26 (9): 851–854. doi: https://doi.org/10.1130/0091-7613(1998)026<0851:BMOISF>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Samples of thermogenic hydrocarbon gases, from vents and gas hydrate mounds within a sea-floor chemosynthetic community on the Gulf of Mexico continental slope at about 540 m depth, were collected by research submersible. Our study area is characterized by low water temperature (mean =7 °C), high pressure (about 5400 kPa), and abundant structure II gas hydrate. Bacterial oxidation of hydrate-bound methane (CH4) is indicated by three isotopic properties of gas hydrate samples. Relative to the vent gas from which the gas hydrate formed, (1) methane-bound methane is enriched in 13C by as much as 3.8‰ PDB (Peedee belemnite), (2) hydrate-bound methane is enriched in deuterium (D) by as much as 37‰ SMOW (standard mean ocean water), and (3) hydrate-bound carbon dioxide (CO2) is depleted in 13C by as much as 22.4‰ PDB. Hydrate-associated authigenic carbonate rock is also depleted in 13C. Bacterial oxidation of methane is a driving force in chemosynthetic communities, and in the concomitant precipitation of authigenic carbonate rock that modifies sea-floor geology. Bacterial oxidation of hydrate-bound methane expands the potential boundaries of life in extreme environments. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
