A deep source-receiver seismic refraction experiment was conducted
on the upper part of the Monterey Deep Sea Fan. The aim of this thesis is
to construct the velocity structure of the upper Monterey Fan and to examine
the lateral seismic velocity variations among the upper, middle and lower
fan subunits....
The processes responsible for transporting and depositing thick
sections of coarse-grained terrigenous clastics on the abyssal floor
and for forming associated sedimentary structures are still conjectural.
Many workers attribute coarse deep-sea sediments and their
probable lithified equivalent, the graywackes of flysch deposits to
some type of density movement.
Deductions concerning...
Changes in sea level during the past 20,000 years are recorded
in sediments taken from the continental shelf off the Rogue River,
Oregon. Sea level has risen approximately 125 m. during the
Holocene (Curray, 1965) and the general transgression has been
interrupted by several stillstands and minor regressions.
Box core...
Holocene hemipelagic deposition of terrigenous silts and clays
dominates sedimentation on most of the Oregon and Washington continental
slope. The sources of these sediments, the mechanisms causing sediment
dispersal, and the relative contributions of the various continental
sources to the marine deposits have been investigated using quantitative
mineral and geochemical...
A study of sedimentary structures and sediment texture of
beach and continental shelf sediments provides a basis for the interpretation
of the recent history of sedimentation on the Oregon continental
shelf. The texture of various sediment types suggests that
coastal rivers supply a considerable quantity of very fine sand in...
An analysis of the amounts of calcium carbonate, organic carbon,
quartz, and the rates of sediment accumulation in hemipelagic sediments
off Oregon has revealed that the accumulation rates of the total
sediment, organic carbon, and quartz were at least twice as high in
the late Pleistocene as they were during...
A structure map was constructed of the continental shelf between
Cape Blanco and Coos Bay, Oregon, exclusively from an interpretation
of approximately 700 km of continuous seismic profiles.
At least ten discernible seismic units were mapped on the bases of
acoustic appearance, lateral continuity, angular unconformities, and
faults. The offshore...
Recent organic-rich deposits on the Peru continental margin
occur along the upper slope (100-450 m) between about ll°S and 16°S
and along the lower continental slope (>2000 m). The upper slope
deposits reflect high biological production in response to coastal
upwelling, but preservation of organic matter is enhanced by the...
Sediments on the inner portion of the Oregon continental shelf
consist of clean, well-sorted, detrital sand. This sand has an average
median diameter of 2.53Φ (. 173 mm) and is both positively and
negatively skewed. Deposits with median diameters in the coarse
sand and gravel classes occur at depths of...