A marine seismic refraction study, conducted in August 1976 by personnel
from Oregon State University and the University of Connecticut between Cape
Simpson and Prudhoe Bay, Alaska, provides data for analysis which yields a
subsurface structural and geological cross-section of the area.
The results suggest that the structural homocline which dips to the
east southeast on land extends to the offshore region as well. Correlation
of geologic data from wells drilled on land with the refraction data permits
tentative identification of geologic sequences on the basis of their seismic
velocity. This study correlates 1.60 to 1.65 km/s layers to Quaternary sediments,
1.82 to 2.51 km/s layers to Tertiary strata, 2.91 to 3.40 km/s layers to
Mesozoic formations to the east and 2.99 to 4.43 km/s to Early Mesozoic
formations to the west. Velocities of 5.28 to 6.08 km/s are associated with
probable argillite and phyllite of the Pre-Mississippian basement. At greater
depths, refractors with velocities of 6.40 to 7.07 km/s are related to crystalline
material which may be silicic or mafic. No seismic velocities typical
of the upper mantle are present on the record sections, but a minimum depth
calculation places the Mohorovicic discontinuity deeper than 20 km. Although
the observed crustal velocities are ambiguous towards theories of the origin
of the Canada Basin and the tectonic history of the northern Alaska margin,
they tend to favor the orocline-Rift theory of Carey (1955) over a subduction
margin. / Graduation date: 1979
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/29228 |
| Date | 12 January 1979 |
| Creators | Bee, Michel |
| Contributors | Johnson, Stephen H. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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