Field Evaluation of Sediment Structure and Content Relative to Associated Hydrates

• Main Author: Coffin, Richard B.
• Other Authors: NAVAL RESEARCH LAB WASHINGTON DC
• Format: Text
• Language: English
• Published: 2003
• Subjects: Physical and Dynamic Oceanography; *HYDRATES; *SEDIMENTS; COMPRESSION; DATA BASES; SIMULATORS; THICKNESS; COASTAL REGIONS; STRUCTURAL PROPERTIES; DEFORMATION; MOTION; GASES; DEPOSITS; VERTICAL ORIENTATION; MIGRATION; SALTS; NORWAY; DISSOCIATION; NORWEGIAN SEA; BASINS(GEOGRAPHIC); RESERVOIRS; GREENLAND SEA; TECTONICS; MUD; SHALLOW DEPTH; MEXICO GULF; CONDUITS; HAAKON-MOSBY MUD VOLCANO; CASCADIA MARGIN; Norwegian Sea; Greenland; Norway; Greenland Sea
• Online Access: http://www.dtic.mil/docs/citations/ADA411720; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA411720

The goal of the first year in the program is to initiate sample analysis of hydrates and sediments to provide a database that will contribute to the development of a hydrate dissociation simulator. This work was conducted primarily on samples previously taken in the Cascadia Margin (CM) and Gulf of Mexico (GOM). In addition there is some comparison with data from samples taken in 1998 on the Haakon-Mosby Mud Volcano (HMMV) in the Norwegian-Greenland Sea. Comparison of these sites will provide a broad range of in-situ data for development of the simulator. The HMMV is a cold seep off the coast of Norway with an active mud flow. Cascadia Margin is an accretionary prism of a subduction zone. The structure of this region has resulted in a recent tectonic compression and deformation. Hydrates in this region are found in silty clays and clayey silts interbedded with fine sand turbidites. The sample region in the Gulf of Mexico is a salt basin that formed from Late Triassic rifting of the Pangea super continent, and flooding by a thick salt deposit during middle Jurassic marine incursions; Thermogenic petroleum and gas deposits were produced from Miocene to Pleistocene reservoirs in the region. In this region over pressured fracture zones that surround moving salt diapirs and sheets provide active conduits for vertical migration from deep reservoirs to shallow pools and the surface. In this system hydrates are present in organic rich silty clays. To contribute to the development of the simulator, data from analysis of the samples provide information on the range of sediment structure and characteristics of the sediments, between these distinctly different regions. This will assist in understanding the range in dissociation behaviors and modeling the process.