The Caribbean Plateau is an oceanic large igneous province (CLIP). A widely accepted model for LIP petrogenesis proposes that these large bodies of igneous rock are formed by decompression melting associated with upwelling mantle plume heads during the initiation of hotspot activity. According to this classical model, petrogenesis occurs over...
The Curaçao Lava Formation (CLF) records the magmatic and tectonic processes that formed the Caribbean Large Igneous Province (CLIP). A model of the petrogenesis of the CLF was developed using new geochemical and geochronological data. These data include major element compositions obtained using X-ray fluorescence spectroscopy (XRF), trace element concentrations...
Variability in the terrigenous (land-derived) fraction of marine sediments,
including pollen and rock fragments, reflects the effects of regional climate change on
continentally derived runoff, ice extent, vegetation and ocean circulation. The transport of
this continental material to the seafloor must be understood in order to interpret the
terrigenous sediment...
The Pacific Ocean basin is home to a set of hotspots diverse in their eruption
rate, duration of volcanism, and basalt chemistry. Pacific hotspots are found in a
spectrum of distinct plate tectonic settings, from near a spreading ridge to intraplate.
Cobb hotspot, which resulted in formation of the Cobb-Eickelberg...
The Cretaceous was a period of extreme climatic conditions accompanied
by major perturbations in ocean-atmosphere biogeochemical cycles. One of the
most intriguing features is the sporadic interruption of normal marine pelagic
sediment deposition by organic rich sediments deposited during oxygen-deficient
conditions (ocean anoxic events OAEs). A current model for the...
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...
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RobertA. Duncan
Marine sediments exceptionally rich in organic carbon, known as
Understanding continental crust formation and modification is a fundamental and longstanding geologic problem. Influx of mantle-derived basaltic magma and partial melting of the crust are two ways to drive crustal differentiation. This process results in a low density upper crust and denser, more refractory lower crust, creating significant and vastly...
In the equatorial Pacific Ocean, earthquakes are used as an indicator of tectonic stress for normal faults in the Galapagos Spreading Center, transform faults along the East Pacific Rise and thrust faults in the Middle American subduction zone. Linkages between seafloor tectonic processes and oceanographic and lunar conditions were explored...
Wave energy has a promising future, especially for the Pacific Northwest, and Oregon, pioneering the way to meet Oregon’s goal of 25% renewable energy by 2025. The project represents a significant ability to harness the untapped potential energy of ocean waves, and maintains the potential to replace standard power sources...
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RobertDuncan
Abstract Body
Wave energy has a promising future, especially for the
The Eyjafjöll Volcanic System, in southern Iceland, is a member of the
Southeastern Volcanic Zone (SEVZ), a segment of the Mid-Atlantic Ridge. The
SEVZ is a well-exposed (subaerial) propagating rift, analogous to the
volcano-tectonic structures that accommodate the growth of ocean floor
spreading ridge segments. Eyjafjöll represents 780 Ka of...
This research focuses on the development of new techniques to explore terrestrial-ocean climate linkages along the Pacific Northwest-northeast Pacific Ocean margin. This is done by investigating river response to climate change and by unraveling this history preserved in continental margin sediments. A significant component of this work centers on developing...
The material in this paper is divided into the following four chapters for convenience. Chapter 1 explains, how the idea of fault testing changed from testing the machine instructions to testing the hardware in logic circuits. Chapters 2, 3 and 4 present the different approaches considered, namely:
1. Path sensitizing...
Quantification and comparison of morphological changes over the last ~300 y in Oregon salt marshes provide valuable insights into the tectonic, hydroclimatic, and anthropogenic processes shaping this important intertidal zone. Understanding of the rates and drivers of salt marsh change contextualizes intertidal habitats within the sediment routing system (i.e., source...
Quantification of contemporary sediment and carbon accumulation within Oregon tidal saline wetlands will: (1) fill a critical knowledge gap, and (2) naturally test without complicating variables whether sea level rise or sediment supply primarily control wetland growth. Here we measure vertical accretion rates and carbon burial rates in three Oregon...