Deep Seismic Reflection Studies in the Pacific Northwest U.S. Data Visualization Disc

From its inception in May of 1982, the U.S. Department of Energy Deep Source Gas project has investigated the possibility
that significant quantities of hydrocarbons, natural gas in
particular, may be generated during and following convergent
plate tectonic sediment subduction.  Sediment subduction is
believed to have been an important process during the past 180
million years along the western margin of North America.  Several
years of regional geological, and limited geochemical
investigations led to the theory that some portion of these
subducted sedimentary units may have been left in place in the
upper crust of the continental plate margin of this region.  The
potential for these, in part, deeply buried rocks to generate
petroleum, and to contain important quantities of natural gas at
drillable depths, was at the heart of this effort.  Along with
Gas Hydrates, the Deep Source Gas program of the Morgantown
Energy Technology Center was structured under the heading of
Speculative Gas Resources being investigated in frontier areas of
the U.S.

Following an initial reconnaissance geophysical effort in the Pacific Northwest and Alaska, which included the use of
magnetotellurics (MT), gravity, and magnetics information, an
important high conductivity MT anomaly was identified in
southwest Washington.  This feature later identified as the
Southern Washington Cascades Conductor, or SWCC, was of
sufficient areal extent to warrant further study for its
potential as a deeply buried subduction system with significant
sedimentary section.  Approximately 238 kilometers of 1024
channel deep seismic reflection data were collected in 1988, 1989
and 1990 across the SWCC anomaly in six seismic lines.  At this
time approximately half of the data has been analyzed and
released in the following publications:  U.S. Geological Survey,
Open File Report 91-119 entitled "Are Hydrocarbon Source Rocks
Hidden Beneath the Volcanic Flows in the Southern Washington
Cascades?" by W. D. Stanley, W. J. Gwilliam, G. V. Latham, and J.

K. Westhusing, 41 p., 12 figs.;  American Association of
Petroleum Geologists 1990 Annual Convention, San Francisco,
abstract entitled "Deep Seismic Surveys of a Dormant Subduction
Zone in the Pacific Northwest United States", by W. J. Gwilliam,
W. D. Stanley, G. V. Latham and J. K. Westhusing;  U.S.
Department of Energy, Morgantown Energy Technology Center
Proceedings of the 1990 Natural Gas Research and Development
Contractors Review Meeting, entitled "Exploration For Deep Source
Hydrocarbons in Subduction Terrain of the Pacific Northwest" by
Keith Westhusing and Steve Krehbiel, 22 p. 18 figs., available
through the National Technical Information Service (NTIS)
Publication No.DE9100203035;  U.S. Department of Energy
Morgantown Energy Technology Center Proceedings of the 1992
Natural Gas Research and Development Contractors Review Meeting,
abstract, entitled "Deep Source Gas Seismic Survey - Washington
State" by Steven C. Krehbiel, Mary Rafalowski-Guide and Mark H.
Thomas, available through NTIS Publication No. DE92001278;
American Association of Petroleum Geologists Bulletin vol. 76,
no. 10, October 1992 paper entitled "The Southern Washington
Cascades Conductor-A Previously Unrecognized Thick Sedimentary
Sequence?" by W. D. Stanley, W. J. Gwilliam, Gary Latham, and
Keith Westhusing, 16 p., 11 figs.

Tags: 1994, AAPG, Classification, DOE, Data Series DDS-16, Deep Source Gas, Exploratory, Gas, Geochemistry, Geology, METC, MT, Morgantown Energy Technology Center, Oil, SEG-Y format seismic data, Types, UNIX, USGS, Washington, Well Data, geochemical, hydrocarbons, location, magnetotellurics, natural gas, petroleum, subduction, velocity