Marine sediments exceptionally rich in organic carbon, known as black shales, occur globally but intermittently in well correlated Cretaceous successions. The presence of black shales indicates that sporadic, ocean-wide interruption of normal respiration of marine organic matter during oxygen-deficient conditions has occurred. Submarine volcanism on a massive scale, related to...
The thermal regime of a postulated descending lithospheric slab
is calculated. The gravity anomaly associated with such a structure
is large in amplitude and long in wavelengh. Observed free-air
gravity anomalies in the Pacific Northwest do not indicate a gravitational
effect due to a descending slab.
Two hypothetical compensation models...
Power spectral analysis using the maximum entropy method is
applied to the estimation of depth to the source of magnetic anomalies.
The method assumes that the source is two-dimensional and has a
magnetization with random intensity. The predictive ability of the
maximum entropy technique permits analysis of short segments of...
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...
Submarine volcanic eruptions and intrusions construct new oceanic crust and build long chains of volcanic islands and vast submarine plateaus. Magmatic events are a primary agent for the transfer of heat, chemicals, and even microbes from the crust to the ocean, but the processes that control these transfers are poorly...
The Carnegie Ridge is a linear, aseismic, submarine ridge
lying between the Galapagos Islands and the coast of South America.
A 2300 meter deep saddle near 86°W. longitude divides the ridge into
western and eastern segments. Surface ship, near bottom, and grain
size studies from the saddle have been used...
South Pacific intraplate volcanoes have been active since the Early Cretaceous. Their HIMU-EMI-EMII mantle sources can be traced back into the West Pacific Seamount Province (WPSP) using plate tectonic reconstructions, implying that these distinctive components are enduring features within the Earth's mantle for, at least, the last 120 Myr. These...