Basaltic volcanism provides a window into the Earth’s mantle. Seeing through this window requires seeing through the processes of magma genesis and evolution that distort the view. Radiogenic isotope ratios, and to a lesser extent incompatible elements and stable isotope ratios, allow us to see through these distortions and infer...
Two studies concerning low molecular weight organic acids in soils were conducted. In the first study, anion exclusion chromatography was used to separate and identify 12 common organic acids, and the accuracy, precision and detection limits of the method were determined. The method was found to be sensitive and accurate...
A comprehensive, joint Soviet-American study of the chemistry of Lake Baikal, the world’s deepest (1,632 m) lake, was carried out in July 1988. In this paper, we report the major, minor, and preliminary trace element concentrations for three profiles obtained at or near the deepest and central part of the...
This thesis investigates the influence of early diagenesis on trace metal and
molybdenum isotope behavior in marine and lacustrine environments. Chapter one is a
synthesis of previous research in all the marine environments investigated, providing an
essential geochemical context for interpreting the observed behavior of Mo in these settings.
Chapter...
Volatile hydrophobic compounds (HOCs) brought into soil and sediment
systems represent a serious threat to the environment. Dissolved
organic carbon (DOC) may exert an important influence over the total
aqueous solubility and mobility of organic pollutants through their
incorporation into micelles or the formation of soluble complexes.
To date, however,...
Determination of the source and fate of natural (higher plant lipids, marine
lipids, etc.) and anthropogenically (e.g., petroleum, coal emissions) derived
hydrocarbons and oxygenated compounds in the environment was accomplished
using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS)
to characterize or identify molecular biomarkers to be utilized as tracers....
Marine microorganisms play a significant role in the cycling of nutrients in the open ocean through production, consumption, and degradation of organic matter (OM). Carbon (C), nitrogen (N), and phosphorus (P) are essential ingredients in every known recipe for life. However, the cycling of each of these elements proceeds at...
The Easter Seamount Chain and Nazca Ridge are two of the most conspicuous volcanic features on the Nazca plate. Many questions about their nature and origin have remained unresolved because of a lack of geochronological and geochemical data for large portions of both chains. New ⁴⁰Ar⁻³⁹Ar incremental heating age determinations...
This study was initiated to characterize the distribution of Fe-Mn nodules and to elucidate trends of Fe, Mn, and P relative to the intensity of the annual cycles of reduction and oxidation. Nodules were enriched in Fe, Mn, and P relative to the soil matrix making them an integral part...
Geophysical and biogeochemical processes associated with fluid venting from active and passive continental margins will receive significant scientific and economic attention
into the next century and are of major societal relevance. An important unknown among these interrelated processes is the role played by methane gas hydrates, at and below the...
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...
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3. Isotopic (O, Sr, Nd, Pb, Hf) Geochemistry of Age-progressive Rhyolites
from the
The adsorption of natural organic matter (NOM) to the surfaces of natural colloids
and engineered nanoparticles is known to strongly influence, and in some cases control,
their surface properties and aggregation behavior. As a result, the understanding of
nanoparticle fate, transport and toxicity in natural systems must include a fundamental...
This study focuses on one widespread characteristic of poor soil quality: hydrophobic soil. Previous research has produced conclusive evidence to show that soil hydrophobicity is affected by soil organic matter (SOM) and soil water content (WC). Hydrophobicity that responds to changes in WC is a unique form of surface hydrophobicity...
The investigation described in this project will test the hypothesis that fluxes of carbon, barium, manganese, iron and uranium associated with fluid seepage at the San Clemente fracture zone significantly affect the geochemical budgets for these elements, and ultimately result in anomalously high benthic fluxes throughout the San Clemente basin.
Sources of polar/water-soluble organic compounds conjunctly with apolar biomarkers were characterized in natural organic matter. This multi-biomarker approach was accomplished by a simple analytical method consisting of extraction with dichloromethane:methanol (2:1, v/v), silylation and analysis by gaschromatography- mass spectrometry (GC-MS). Polar and apolar biomarkers, derived mainly from higher plants and...
Soil organic matter (SOM) is the terrestrial biosphere's largest pool of organic carbon (C) and is an integral part of C cycling globally. Soil organic matter composition typically can be traced directly back to the type of detrital inputs; however, the stabilization of SOM results as a combination of chemical...
Manual and automatic solvent extraction techniques were used
to concentrate organic material from natural waters. Field and
laboratory extractions were compared to determine the most probable
method and best solvents for efficient concentration of organic
material from estuarine and sea waters.
The large scale extraction processes utilizing extractors made
from...
The need for field and laboratory studies of the physical and
chemical behavior of environmentally significant organic molecules often
poses problems because of the toxicity of the chemical and the difficulty
of detecting it at environmentally significant concentrations.
Two dysprosium tracers, dysprosium (III) trisacetylacetonate trihydrate
and dysprosium(III) trisdibenzoylmethane monohydrate, were...
Uranium adsorption to Hanford sediment was studied for various pH, total inorganic carbon concentrations, and total U(VI) concentrations. Both batch and transport studies were done in an attempt to understand the adsorptive trend of U(VI) on Hanford sediment, and the changes in adsorption as both pH and total inorganic carbon...
A provenance study of crypto-crystalline silicates was performed at the Cooper's Ferry archaeological site in west-central Idaho on the Columbia Plateau. In this research, the author used instrumental neutron activation analysis as well as portable x-ray fluorescence to examine and characterize the geochemistry of 300 geologic samples of crypto-crystalline silicates...
Twenty seven modern (top 1-2cm) sediment samples from multicores retrieved from throughout coastal SE Alaska were analyzed for their organic matter content and the source composition. Total organic carbon (TOC) as well as biogenic silica (bioSi), and calcium carbonate (CaCO3) content were analyzed to evaluate the organic matter content and...
Oxidized intervals of five organic‐rich Madeira Abyssal Plain (MAP) turbidites deposited during the Miocene, Pliocene, and Pleistocene all displayed comparable major loss of total organic carbon (TOC) (84 ± 3.1%) accompanied by a negative isotopic (δ¹³C) shift ranging from −0.3 to −2.9‰. Major but significantly lower loss of total nitrogen...
Wildfire greatly impacts the composition and quantity of organic carbon stocks within watersheds. Most methods used to measure the contributions of fire altered organic carbon–i.e. pyrogenic organic carbon (Py-OC) in natural samples are designed to quantify specific fractions such as black carbon or polyaromatic hydrocarbons. In contrast, the CuO oxidation...
Dissolved organic matter (DOM) is a critical component of the carbon cycle linking terrestrial and aquatic ecosystems. Although many factors influence DOM fluxes and quality in rivers, controls on DOM compositions in catchments of the western U.S. are poorly understood. UV and fluorescent spectroscopy is a simpler, faster, and less...
Sediments associated with hydrothermal venting, methane seepage and large organic falls such as whale, wood and plant detritus create deep-sea networks of soft-sediment habitats fueled, at least in part, by the oxidation of reduced chemicals. Biological studies at deep-sea vents, seeps and organic falls have looked at macrofaunal taxa, but...
The use of semi-volatile organic compounds (SOCs) as molecular markers to identify the contributions of regional and long-range atmospheric transport, as well as current and historic sources, and contaminant deposition in remote ecosystems of the Western U.S. was investigated. Trans-Pacific air masses influenced by Siberian biomass burning events had elevated...
Globally, the forestry sector is the second largest contributor of greenhouse gases, and sustainable forest management is a major target of international environmental policy. However, there is the assumption underlying many policy recommendations that an increase in above-ground carbon stocks correspond to long term increases in ecosystem carbon stocks, the...
Outcrops of old strata at the shelf edge resulting from erosive gravity‐driven flows
have been globally described on continental margins. The reexposure of old strata allows
for the reintroduction of aged organic carbon (OC), sequestered in marine sediments for
thousands of years, into the modern carbon cycle. This pool of...
Water samples along the Washington, Oregon and California coastline were collected using high resolution sampling and analyzed to determine particulate organic carbon and nitrogen concentrations. Over 28 days during August 2011, nearly 1500 samples were collected aboard the R/V Wecoma (W1108C) using a semi-automated filtration system. Additional subsurface samples were...
High-temperature combustion oxidation measurements of nonvolatile dissolved organic carbon (DOC) have been determined for pore waters from sediments of Middle Valley, Ocean Drilling Program Leg 139, as well as for overlying and near-bottom seawater. The DOC values in the interstitial waters are generally greater than those in the overlying water...
Columbia River sediment was irradiated with ultraviolet light to
determine if organic material could be removed without altering the
sorptive properties of the hydrous oxides of iron and manganese.
A laboratory preparation of Zn-65 spiked hydrous ferric oxide
was subjected to ultraviolet irradiation in order to assess the photochemical
effect...
Organic aerosols are important atmospheric components, and their formation and sources represent important aspects of urban air quality and health effects. Asia, including India, is the largest global source of aerosol particles due to regional natural advection (e.g. desert and soil dust) and anthropogenic activities (e.g. emissions from traffic, industry...
Intimate associations with reactive metal species permanently protect soil organic matter (SOM) from microbial access and oxidation, contributing to the build-up of organic carbon (C) stocks in soils. It is increasingly recognized, however, that such associations can be reversible and that reactive metal species might even facilitate the oxidation of...
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...
Understanding the processes controlling organic matter (OM) stocks in upland soils, and the ability to management them, is crucial for maintaining soil fertility and carbon (C) storage as well as projecting change with time. OM inputs are balanced by the mineralization (oxidation) rate, with the difference determining whether the system...
More than 30,000 potential Superfund sites have been identified. Heavy metals are contaminants at many of these Superfund sites. The average cost of cleanup a single-typical Superfund site currently stands at $20 million, and it is expected that the cost may escalate to $50 million within the next decade. Problems...
Contaminant transport in ground water is an important environmental process that
affects a host of natural systems. Transport of contaminants is affected by many
processes, including aqueous complexation, adsorption, and redox reactions. One of the
most important components of an aquifer that controls transport is iron-oxide. In this
study, the...
The pentacyclic tritcrpene 17β(H), 21β(H)-hop-22(29)-ene (diploptence) occurs in sediments throughout the Columbia River drainage basin and off the southern coast of Washington state in concentrations comparable to long-chain plantwax n-alkanes. The same relationship is evident for diploptene and long-chain n-alkanes in soils from the Willamette Valley. Microorganisms indigenous to soils...
Although an inordinate fraction of the global sediment flux to the ocean occurs in tropical mountainous river margins, little is known regarding the sources and fate of organic matter in these systems. To address these knowledge gaps, the distribution and composition of organic matter in sediments from the Fly River...
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...
As part of the International Polar Year research program, we conducted a survey of surface marine sediments from box cores along a section extending from the Bering Sea to Davis Strait via the Canadian Archipelago. We used bulk elemental and isotopic compositions, together with biomarkers and principal components analysis, to...
Factors influencing soil organic matter (SOM) stabilization and dissolved organic carbon (DOC) content in complex terrain, where vegetation, climate, and topography vary over the scale of a few meters, are not well understood. We examined the spatial correlations of lidar and geographic information system-derived landscape topography, empirically measured soil characteristics,...
Soils are a globally significant carbon (C) pool and have the potential to respond to elevated CO2 and environmental changes through positive feedback cycles that enhance the turnover of soil organic matter (SOM). Understanding the mechanisms governing the turnover of SOM is particularly important for modeling the fate of C...
Propolis is a gummy material produced by honey bees to protect their hives and currently has drawn the attention of researchers due to its broad clinical use. It has been reported, based only on observations, that honey bees also collect other non-vegetation substances such as paint or asphalt/tar to make...
Models of ecosystem carbon (C) balance generally assume a strong relationship between net primary productivity (NPP), litter inputs, and soil C accumulation, but there is little direct evidence for such a coupled relationship. Using a unique 50-year detrital manipulation experiment in a in a mixed deciduous forest and restored prairie...
We investigated the export of particulate organic matter (POM) to the ocean by two contrasting small, mountainous rivers, the Umpqua and Eel Rivers, by collecting suspended sediment samples over a range of discharges and analyzing them for a variety of constituents, including organic carbon, nitrogen, biomarkers with distinct biochemical sources,...
Total organic carbon, total nitrogen, microbial respiration and enzyme
activity (β-glucosidase) were measured on several horizons of a Dayton silt loam
(fine, montmorillonitic, mesic, Typic Albaqualf) soil cropped to annual ryegrass
under two straw residue management systems. The study evaluated the effects
of annual burning of straw residues or annual...
The relationship between carbon burial and sedimentation in reservoirs is unknown, exposing gaps in our fundamental understanding of the transport, processing, and deposition of sediment and organic matter in fluvial and lacustrine systems and contributing to uncertainty in our understanding of the net impact of dams to the global carbon...
Frontier research of non-aqueous actinide clusters is discussed. Since the inception of the uranyl peroxide clusters over the last decade, they have only been synthesized and characterized as solid crystals and in aqueous solution. This thesis provides thorough characterization of aqueous uranyl clusters and the first demonstration of uranyl cluster...
Soils contain the largest pool of carbon that is actively cycling on human timescales, leading many to view soils as a natural climate solution with multiple co-benefits. The field of soil science is rapidly evolving, but without a unified understanding of soil carbon dynamics. This dissertation leverages two distinct long-term...
Carbonate nodules and associated sediments from Ocean Drilling Program Leg 139 sites of the Middle Valley, Juan de Fuca Ridge, were studied using a combination of inorganic and organic geochemical techniques. The mineralogy and stable isotopic compositions defined three types of nodules, reflecting the conditions of carbonate precipitation. Nodule ingrowth...
The production of carbon and export to deep ocean sediments is linked to carbon partitioning between the ocean and atmosphere and is a key driver of climate change over the glacial-interglacial transition. Yet conflicting reconstructions create barriers to understanding changes to the carbon system over this important climate transition. Production...
Aerosol sampling for major oxygenated organic compounds (dicarboxylic acids, fatty acids, and levoglucosan) was conducted from 15 March to 19 April 2001 on board the National Oceanic and Atmospheric Administration R/V Ronald H. Brown over the western North Pacific, the East China Sea, and the Sea of Japan, as part...
Previous projects in the Gulf of Lion have investigated the path of terrigenous material
in the Rhone deltaic system, the continental shelf and the nearby canyon heads. This
study focuses on the slope region of the Gulf of Lion to further describe particulate
exchanges with ocean’s interior through submarine canyons....
The organic compound tracers of atmospheric particulate matter, as well as organic carbon (OC) and elemental carbon (EC), have been characterized for samples acquired during the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) from Gosan, Jeju Island, Korea, from Sapporo, Japan, and from Chichi-jima Island in the western North Pacific,...
Total organic carbon (TOC) content of marine sediments represents residual carbon, originally derived from terrestrial and marine sources, which has survived seafloor and shallow subseafloor diagenesis. Ultimately, its preservation below the sulfate reduction zone in marine sediments drives methanogenesis. Within the gas hydrate stability zone (GHSZ), methane production along continental...
The organic content of the Columbia River suspended particulate matter (SPM) results from the input of autochthonous (phytoplankton) and allochthonous (terrestrial vascular plants) production. The contribution of these two sources appears seasonal and responds to factors such as rainfall, runoff, river flow, light and nutrients availability. While numerous studies have...
Deeply weathered soils in tropical rainforests and savannas are classified as Ferralsols according to the World References Bases for Soil Resources (WRB). Ferralsols are most nearly akin to the Oxisols order defined in the US Soil Taxonomy. The acidity, low cation exchange capacity, and strong phosphorus retention by the oxidic...
The perhumid coastal temperate rainforests of southeast Alaska contain an abundance of soil organic carbon (SOC) that has accumulated in a wet, cool climate where forest fire disturbance is minimal and organic matter decomposition rates are low. Coastal temperate rainforests are supported by carbon-rich soils that provide ecosystem services including...
Fusarium spp. frequent conifer nursery soils yet are rarely recovered from coniferous forest soils. Experiments were performed to determine what influence humic-rich organic amendments and volatiles from soil, ectomycorrhizal fungi and ectomycorrhizae have on the populations of several physiologic and taxonomic microbial groups potentially related to this phenomenon. A comparative...
The primary objective of this study was to evaluate the rates of nitrate removal for a nitrate containing, low organic carbon wastewater interacting with four different carbon-containing solid substrates (alder woodchips, corn silage, manure and woodchip biochar). Batch systems were tested for nitrate removal, and systems with a combination of...
The specific objectives of this dissertation are to determine subsurface flow
behaviors across different antecedent wetness conditions from a top-down perspective
and to mechanistically assess the hydrological controls on DOC and N transport at the
hillslope and catchment scale. The study area is a small catchment where hillslopes
issue directly...
The Arctic has long been considered to be a pristine environment, far
from population centers and pollution sources. The detection of synthetic
organochlorine compounds in various elements of the Arctic food web has confirmed
the global dispersion of pollutants, particularly of persistent compounds such as
organochlorines and heavy metals. Levels...
This study investigates the relationship between total and ionic copper in samples taken from the Tualatin River and wastewater treatment facilities (WWTFs) that discharge into the Tualatin River. Copper speciation was analyzed by determining conditional stability constants and densities of copper binding ligands on the dissolved organic matter (DOM) in...
It is often perceived that late maturity of grape gives a more complex aroma
profile to Pinot noir wine, however, there is little understanding of the basic flavor
chemistry of grape maturity on wine aroma. The aroma contributing compounds in
Pinot noir were first identified by aroma extract dilution analysis...
Atmospheric particulate matter, collected over the polluted east Asia/Pacific region in spring 2001 during research flights with the National Center for Atmospheric Research (NCAR) C-130 aircraft, was analyzed for different types of organic compounds using capillary gas chromatography–mass spectrometry. More than 70 organic species were detected in the aerosols and...
Forest fires contribute a significant amount of CO₂ to the atmosphere each year, and CO₂ emissions from fires are likely to increase under projected conditions of global climate change. In addition to volatilizing aboveground biomass and litter layers, forest fires have a profound effect on belowground carbon (C) pools and...
Small, mountainous river systems have been increasingly studied due to their importance as sources of fluvial sediment and organic matter to the coastal ocean. Thus far, studies of small, mountainous river systems have focused on rivers with very high sediment loads. The well-studied Eel River dispersal system in northern California...
This project determined how the presence of environmental biofilms on sand, granular activated carbon and biochar affected the sorption capacity and desorption quantity of copper, zinc, nutrients and organic carbon from stormwater. These contaminants have harmful and toxic environmental impacts on aquatic life, can lead to eutrophication of surface waters,...
This study investigated complete reductive dechlorination of chlorinated aliphatic hydrocarbons (CAHs) over a broad range of concentrations. Tetrabutoxysilane (TBOS), as a slow-release anaerobic substrate, was studied for enhanced reductive dechlorination of tetrachioroethylene (PCE) present as a dense non-aqueous liquid (DNAPL). Four different site-mixed cultures were used in the study: Site-300...
Streams and rivers play a critical role in global carbon (C) cycling by processing, storing, and transporting C. Headwater streams which make up more than 95% of the length of streams and rivers worldwide have disproportionate influence on fluvial C dynamics. The hyporheic zone (HZ) of headwater streams is a...
Transition metal and rare earth element (REE) data are presented
for various sedimentary materials from two Manganese Nodule
Program (MANOP) sites in the eastern tropical Pacific. These data
constrain the sources of elemental supply to the seafloor and the
processes that control ferromanganese nodule genesis. Investigation
of elemental partitioning between...
Isotopic analyses of dissolved molybdenum are presented for sediment pore waters from a reducing
sedimentary basin and for fluids from a low-temperature ridge flank hydrothermal system. δ⁹⁸/⁹⁵Mo in
these fluids range from 0.8 to 3.5%₀ (relative to a laboratory standard), demonstrating that marine
sedimentary reactions significantly fractionate Mo isotopes. Within...
Assessments of climate change over time scales that exceed the last 100 years require robust integration of high-quality instrument records with high-resolution paleoclimate proxy data. In this study, we show that the recent biogenic sediments accumulating in two temperate ice-free fjords in Southeast Alaska preserve evidence of North Pacific Ocean...
Benthic incubation chambers have been deployed in a variety of geochemical environments that provide a comprehensive geochemical framework from which to address issues related to Ba geochemistry and the use of Ba as a paleoproxy. First order budgets for barium show that in the equatorial Pacific, present rates of Ba...
Marine sediments are one of the largest habitats for microbial life on earth. These microorganisms play critical roles in biogeochemical cycling both within the subsurface and between the sediment and water columns. However, microbial communities in sediments are highly heterogeneous and the factors defining microbial community structure and metabolic function...
Dating pelagic clay can be a challenge due to its slow sedimentation rate, post-depositional alteration, and lack of biogenic deposition. Co-based dating techniques have the potential to create age models in pelagic clay under the assumption that the flux of non-detrital Co to the seafloor is spatially and temporally constant,...
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age models of pelagic clay in the South
Pacific Gyre. Geochemistry, Geophysics, Geosystems, 16(8
Sequence stratigraphic analysis of the southern Tyee basin, Oregon Coast Range, reveals
that the lower to middle Eocene forearc and subduction zone strata comprise four depositional
sequences. Sequence I (lower Umpqua Group) represents a partially subducted accretionary
wedge. Sequence II (upper Umpqua Group) is a deltaic sequence that filled irregular...
Sequence stratigraphic analysis of the southern Tyee basin, Oregon Coast Range, reveals
that the lower to middle Eocene forearc and subduction zone strata comprise four depositional
sequences. Sequence I (lower Umpqua Group) represents a partially subducted accretionary
wedge. Sequence II (upper Umpqua Group) is a deltaic sequence that filled irregular...
Sequence stratigraphic analysis of the southern Tyee basin, Oregon Coast Range, reveals
that the lower to middle Eocene forearc and subduction zone strata comprise four depositional
sequences. Sequence I (lower Umpqua Group) represents a partially subducted accretionary
wedge. Sequence II (upper Umpqua Group) is a deltaic sequence that filled irregular...
Sequence stratigraphic analysis of the southern Tyee basin, Oregon Coast Range, reveals
that the lower to middle Eocene forearc and subduction zone strata comprise four depositional
sequences. Sequence I (lower Umpqua Group) represents a partially subducted accretionary
wedge. Sequence II (upper Umpqua Group) is a deltaic sequence that filled irregular...
Sequence stratigraphic analysis of the southern Tyee basin, Oregon Coast Range, reveals
that the lower to middle Eocene forearc and subduction zone strata comprise four depositional
sequences. Sequence I (lower Umpqua Group) represents a partially subducted accretionary
wedge. Sequence II (upper Umpqua Group) is a deltaic sequence that filled irregular...
Sequence stratigraphic analysis of the southern Tyee basin, Oregon Coast Range, reveals
that the lower to middle Eocene forearc and subduction zone strata comprise four depositional
sequences. Sequence I (lower Umpqua Group) represents a partially subducted accretionary
wedge. Sequence II (upper Umpqua Group) is a deltaic sequence that filled irregular...
Sequence stratigraphic analysis of the southern Tyee basin, Oregon Coast Range, reveals
that the lower to middle Eocene forearc and subduction zone strata comprise four depositional
sequences. Sequence I (lower Umpqua Group) represents a partially subducted accretionary
wedge. Sequence II (upper Umpqua Group) is a deltaic sequence that filled irregular...
Sequence stratigraphic analysis of the southern Tyee basin, Oregon Coast Range, reveals
that the lower to middle Eocene forearc and subduction zone strata comprise four depositional
sequences. Sequence I (lower Umpqua Group) represents a partially subducted accretionary
wedge. Sequence II (upper Umpqua Group) is a deltaic sequence that filled irregular...
Sequence stratigraphic analysis of the southern Tyee basin, Oregon Coast Range, reveals
that the lower to middle Eocene forearc and subduction zone strata comprise four depositional
sequences. Sequence I (lower Umpqua Group) represents a partially subducted accretionary
wedge. Sequence II (upper Umpqua Group) is a deltaic sequence that filled irregular...
Sequence stratigraphic analysis of the southern Tyee basin, Oregon Coast Range, reveals
that the lower to middle Eocene forearc and subduction zone strata comprise four depositional
sequences. Sequence I (lower Umpqua Group) represents a partially subducted accretionary
wedge. Sequence II (upper Umpqua Group) is a deltaic sequence that filled irregular...
Sequence stratigraphic analysis of the southern Tyee basin, Oregon Coast Range, reveals
that the lower to middle Eocene forearc and subduction zone strata comprise four depositional
sequences. Sequence I (lower Umpqua Group) represents a partially subducted accretionary
wedge. Sequence II (upper Umpqua Group) is a deltaic sequence that filled irregular...
Sequence stratigraphic analysis of the southern Tyee basin, Oregon Coast Range, reveals
that the lower to middle Eocene forearc and subduction zone strata comprise four depositional
sequences. Sequence I (lower Umpqua Group) represents a partially subducted accretionary
wedge. Sequence II (upper Umpqua Group) is a deltaic sequence that filled irregular...