Sedimentology and gas hydrates of IODP Expedition 311 samples ...

• Main Authors: Torres, Marta E, Tréhu, Anne M, Cespedes, N, Kastner, Miriam, Wortmann, Ulrich G, Kim, Jung-Hyun, Long, Philip E, Malinverno, Alberto, Pohlman, John W, Riedel, Michael, Collett, Tim S
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2008
• Subjects: Drilling/drill rig; Exp311; Joides Resolution; Integrated Ocean Drilling Program / International Ocean Discovery Program IODP; Methane hydrate
• Online Access: https://dx.doi.org/10.1594/pangaea.716589; https://doi.pangaea.de/10.1594/PANGAEA.716589

Expedition 311 of the Integrated Ocean Drilling Program (IODP) to northern Cascadia recovered gas-hydrate bearing sediments along a SW-NE transect from the first ridge of the accretionary margin to the eastward limit of gas-hydrate stability. In this study we contrast the gas gas-hydrate distribution from two sites drilled ~ 8 km apart in different tectonic settings. At Site U1325, drilled on a depositional basin with nearly horizontal sedimentary sequences, the gas-hydrate distribution shows a trend of increasing saturation toward the base of gas-hydrate stability, consistent with several model simulations in the literature. Site U1326 was drilled on an uplifted ridge characterized by faulting, which has likely experienced some mass wasting events. Here the gas hydrate does not show a clear depth-distribution trend, the highest gas-hydrate saturation occurs well within the gas-hydrate stability zone at the shallow depth of ~ 49 mbsf. Sediments at both sites are characterized by abundant coarse-grained ... : Supplement to: Torres, Marta E; Tréhu, Anne M; Cespedes, N; Kastner, Miriam; Wortmann, Ulrich G; Kim, Jung-Hyun; Long, Philip E; Malinverno, Alberto; Pohlman, John W; Riedel, Michael; Collett, Tim S (2008): Methane hydrate formation in turbidite sediments of northern Cascadia, IODP Expedition 311. Earth and Planetary Science Letters, 271(1-4), 170-180 ...