We have mapped a recently active left-lateral strike-slip fault (the Wecoma fault) on the floor of Cascadia Basin west of the Oregon convergent margin, using SeaMARC I sidescan sonar, Seabeam bathymetry and multichannel seismic and magnetic data. The fault intersects the base of the continental slope at 45°10’N and extends...
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...
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...
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...