Integrated Ocean Drilling Program Expedition 301 preliminary report; Juan de Fuca hydrogeology; the hydrogeologic architecture of basaltic oceanic crust; compartmentalization, anisotropy, microbiology, and crustal-scale properties on the eastern flank of Juan de Fuca Ridge, eastern Pacific Ocean; 27 June-20 August 2004

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doi: 10.2204/iodp.pr.301.2004
Author(s): Fisher, Andrew T.; Urabe, Tetsuro; Klaus, Adam; Bartetzko, Anne C. M.; Becker, Keir; Coggon, Rosalind; Dumont, Marion; Engelen, Bert; Goto, Shusaku; Hawkins, Lisa; Heuer, Verena; Hulme, Samuel Mark; Hutnak, Michael; Inagaki, Fumio; Iturrino, Gerardo J.; Kiyokawa, Shoichi; Lever, Mark Alexander; Nakagawa, Satoshi; Nielsen, Mark Edward; Noguchi, Takuroh; Rice, Jonathan; Sager, William W.; Sakaguchi, Masumi; Steinsbu, Bjorn Olav; Tsuji, Takeshi; Wheat, Charles Geoffrey
Integrated Ocean Drilling Program, Expedition 301 Scientists, College Station, TX
Author Affiliation(s): Primary:
University of California-Santa Cruz, Earth Sciences Department, Santa Cruz, CA, United States
Other:
University of Tokyo, Japan
Integrated Ocean Drilling Program, United States
Universität Bremen, Federal Republic of Germany
Rosenstiel School of Marine and Atmospheric Science, United States
University of Southampton, United Kingdom
Stockholm University, Sweden
Carl von Ossietzky Universität Oldenburg, Federal Republic of Germany
Kyoto University, Japan
Western Washington University, United States
San Jose State University, United States
Japan Agency of Marine-Earth Science and Technology, Japan
Lamont-Doherty Earth Observatory, United States
Kyushu University, Japan
University of North Carolina at Chapel Hill, United States
Oregon State University, United States
University of Ryukyus, Japan
Green Mountain Union High School, United States
Kochi University, Japan
University of Bergen, Norway
Monterey Bay Aquarium Research Institute, United States
Source: Preliminary Report (Integrated Ocean Drilling Program), Vol.301, 121p. Publisher: IODP Management International, College Station, TX, United States. ISSN: 1932-9423
Note: In English. 37 refs.
Summary: Integrated Ocean Drilling Program Expedition 301 is the first part of a two-expedition, multidisciplinary program to evaluate the formation-scale hydrogeologic properties within oceanic crust; determine how fluid pathways are distributed within an active hydrothermal system; establish linkages between fluid circulation, alteration, and microbiological processes; and determine relations between seismic and hydrologic anisotropy. During Expedition 301, we replaced one existing borehole observatory penetrating the upper oceanic crust on the eastern flank of the Juan de Fuca Ridge and established two new observatories penetrating to depths as great as 583 meters below seafloor or 318 m into basement. We sampled sediments, basalt, fluids, and microbial samples; collected wireline logs; and conducted hydrogeologic tests in two basement holes. Shore-based studies will help us to learn where microbiological communities live in the crust and how these communities cycle carbon, alter rocks, and are influenced by fluid flow paths. During a follow-up expedition, we will conduct the first multidimensional, cross-hole experiments attempted in the oceanic crust, including linked hydrologic, microbiological, seismic, and tracer components. After completion of drillship operations, we will initiate multiyear tests using the new network of subseafloor observatories, allowing us to examine a much larger volume of the crustal aquifer system than has been tested previously. By monitoring, sampling, and testing within multiple depth intervals, we can evaluate the extent to which oceanic crust is connected vertically and horizontally; the influence of these connections on fluid, solute, heat, and microbiological processes; and the importance of scaling on hydrologic properties. This work is helping us to understand the nature of permeable pathways, the depth extent of circulation, the importance of permeability anisotropy, and the significance of hydrogeologic barriers in the crust.
Year of Publication: 2004
Research Program: IODP Integrated Ocean Drilling Program
ODP Ocean Drilling Program
Key Words: 18 Geophysics, Solid-Earth; 20 Geophysics, Applied; Basalts; Basement; Boreholes; C-14; Carbon; Continental margin; Cores; Crust; Drilling; East Pacific; Expedition 301; Flows; Fluid phase; Geochemistry; Geomicrobiology; Geophysical methods; Geophysical profiles; Geophysical surveys; Ground water; IODP Site U1301; Igneous rocks; Integrated Ocean Drilling Program; Isotopes; Juan de Fuca Ridge; Leg 168; Marine drilling; Marine sediments; Microorganisms; Mid-ocean ridge basalts; North Pacific; Northeast Pacific; ODP Site 1026; Ocean Drilling Program; Oceanic crust; Pacific Coast; Pacific Ocean; Pore water; Radioactive isotopes; Sediments; Seismic methods; Seismic profiles; Seismic stratigraphy; Slug tests; Surveys; Tracers; United States; Volcanic rocks; Washington; Well logs
Coordinates: N474556 N474556 W1274526 W1274526
N474500 N474600 W1274600 W1274600
Record ID: 2008016929
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