The continental margin off southern Oregon, which includes the
shelf and slope from Cape Blanco to the Oregon-California border,
exhibits a distinctive marginal-plateau structural pattern which divides
the margin into the continental shelf, the upper continental slope and
its associated benches, and the lower continental slope. Lutum transport
and deposition...
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...
The distribution of surface sediments on the northern Oregon
continental shell is characterized by a nearshore sandy facies and an
outer shelf muddy facies, separated by a mid-shelf zone of mixed
sand and mud. Currents which have been measured at 130 centimeters
above the bottom indicate that the distribution of...
Detailed surveys of several segments of the Peru Trench show
that the region between 6° to 10⁰ S is an area of recent deformation.
Seismic reflection records across the axis of the trench show faulting,
uplift, and tilting of the sedimentary fill and the acoustic basement.
Uplift of the acoustic...
In order to determine whether the sediments found on the landward
wall of the Peru Trench are accreted Nazca Plate sediments,
the clay mineralogy and organic carbon contents of 52 surface
samples were submitted to factor analysis. Q-mode factor analysis
resolved the data from the Nazca Plate and Peru continental...
Detailed bathymetric survey data were collected along the Peruvian
continental margin and were compiled by the author and other
investigators to construct a new bathymetric map for the area between
6° to 18°S latitude. Based on this map and individual bathymetric
profiles, the continental shelf topography is essentially flat. Four...
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...
Surveyor Deep-Sea Channel extends for approximately 700 km
over the northern Alaskan Abyssal Plain. It originates near the base
of the continental slope opposite Dry Bay and Alsek Strath and terminates
in the Aleutian Trench south of Kodiak Island. East of Giacomini
Seamount, the axial gradient of the channel is...
Extensive new trackline coverage of the Chile Trench between 23°S and 34°S, including more than 60 bathymetric and seismic reflection profiles across the trench axis, allows a much more detailed study of the tectonics and sedimentation of this feature than previously possible. Sediment distribution along the axis shows a remarkable...
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...
Sedimentation rate could become a new exploration tool for evaluating
the source rock potential of sedimentary basins in frontier regions.
Petroleum source rocks are defined on the basis of total organic carbon
by weight percent. An analysis of Deep Sea Drilling Project (DSDP)
cores indicates that there exists quantitative relationships...
Cores taken from the ridge areas of the Gorda-Juan de Fuca
plate have a sedimentation rate that is appropriate for the study of
late Quaternary stratigraphy. An analysis of the clay and silt
mineralogy of the cores using X-ray diffraction methods and by
noting changes in the foraminiferan-radiolarian abundances in...
The portion of the East Pacific Rise (EPR) between 5° and 12°S
can be subdivided into three areas by fracture zones that offset the
rise axis at about 6.5°S and 9°S. In all three regions, the spreading
axis of the EPR is defined by a topographic block 300 to 350...
