Basement Geophysical Interpretation of the National Petroleum Reserve Alaska (NPRA), Northern Alaska
R. W. Saltus1, T. L. Hudson2, and J. D. Phillips1
1U.S. Geol
Survey, Denver, CO
2Applied Geology, Sequim, WA
To produce maps of the thickness and inferred geophysical properties
of the crust beneath the Ellesmerian rocks in NPRA we combine
information from 1. total field aeromagnetic data, 2. terraced pseudogravity
transform of magnetic data, 3. isostatic residual
gravity, 4.
basement
residual
gravity (based on geologic-stripping using seismic
depth and velocity interpretations), 5. terraced basement gravity, 6.
inferred Moho depth (from gravity inversion), 7. basement thickness
(from both gravity and seismic interpretation), 8. Ellesmerian section
thickness (from seismic interpretation), 9. basement depth (from
seismic interpretation), 10. basement structure (interpreted from
seismic data), and 11. limited well penetrations. Sialic crust characteristic
of the Barrow Arch is thinned and modified to the south.
Crustal physical properties indicate that dense and magnetic rocks
make up a significant proportion of the crust in the southern part of
NPRA.
AAPG Search and Discovery Article #90904©2001 AAPG Pacific Section Meeting, Universal City, California