Torres, Marta E. and Kastner, Miriam (2009): Data report; Clues about carbon cycling in methane-bearing sediments using stable isotopes of the dissolved inorganic carbon, IODP Expedition 311

IODP 311
IODP 311 U1325
IODP 311 U1326
IODP 311 U1327
IODP 311 U1329


Torres, Marta E.
Oregon State University, College of Oceanic and Atmospheric Sciences, Corvallis, OR, United States

Kastner, Miriam
U. S. Geological Survey, United States

Data report; Clues about carbon cycling in methane-bearing sediments using stable isotopes of the dissolved inorganic carbon, IODP Expedition 311
In: Riedel, Michael, Collett, Timothy S., Malone, Mitchell J., Guerin, Gilles, Akiba, Fumio, Blanc-Valleron, Marie-Madeleine, Ellis, Michelle, Hashimoto, Yoshitaka, Heuer, Verena, Higashi, Yosuke, Holland, Melanie, Jackson, Peter D., Kaneko, Masanori, Kastner, Miriam, Kim, Ji-Hoon, Kitajima, Hiroko, Long, Philip E., Malinverno, Alberto, Myers, Greg, Palekar, Leena D., Pohlman, John, Schultheiss, Peter, Teichert, Barbara, Torres, Marta E., Trehu, Anne M., Wang Jiasheng, Wortmann, Ulrich G., Yoshioka, Hideyoshi, Proceedings of the Integrated Ocean Drilling Program; Cascadia margin gas hydrates; Expedition 311 of the riserless drilling platform; Balboa, Panama, to Victoria, British Columbia (Canada); Sites U1325-U1329, 28 August-28 October 2005
IODP Management International, Washington, DC, United States
The isotopic characterization of carbon in the dissolved inorganic carbon (DIC) pool is fundamental for a wide array of scientific studies directly related to gas hydrate research. Here we present the DIC data from pore fluid samples recovered from the northern Cascadia accretionary margin during Integrated Ocean Drilling Program (IODP) Expedition 311. Comparison of these results with data obtained from offshore central Cascadia during Ocean Drilling Program Leg 204 provides clues on carbon cycling processes that control methane inventories and fluxes. Microbial methane production preferentially incorporates the light carbon isotope. As sediment ages, more of the original CO (sub 2) is converted to methane, leaving behind an isotopically heavier residual DIC. This DIC is progressively enriched in (super 13) C below 200 meters below seafloor with increasing distance from the deformation front. In the shallower sections, minima in downcore (super 13) C (sub DIC) profiles coincide with the sulfate-methane transition (SMT) zone. Here the (super 13) C (sub DIC) values provide information on the metabolic pathways that consume sulfate and reveal that anaerobic oxidation of methane (AOM) is not the dominant reaction at all sites drilled. There appears to be no simple correlation between the extent of AOM, depth of the SMT, and thickness of the gas hydrate occurrence zone along the transect drilled in northern Cascadia.
Coverage:Geographic coordinates:
West:-127.0300East: -126.4100

Economic geology, geology of energy sources; Isotope geochemistry; aliphatic hydrocarbons; alkanes; biochemistry; biogenic processes; boreholes; C-13/C-12; carbon; carbon cycle; carbonates; Cascadia subduction zone; cores; dissolved materials; drilling; East Pacific; Expedition 311; gas hydrates; genesis; geochemical cycle; geochemistry; hydrocarbons; inorganic materials; Integrated Ocean Drilling Program; IODP Site 1325; IODP Site 1326; IODP Site 1327; IODP Site 1329; isotope ratios; isotopes; marine drilling; marine sediments; methane; natural gas; North Pacific; Northeast Pacific; organic carbon; organic compounds; oxidation; Pacific Ocean; petroleum; pore water; reduction; sediments; stable isotopes;