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Publications
Publications (51)
Sedimentological and geochemical analyses of gravity and piston cores retrieved from Lake Quinault, Washington, reveal an ~4000-year flood-dominated depositional record. Individual flood event layers are identified by combining core stratigraphy, sedimentology, and the ratio of incoherent to coherently scattered x-ray radiation (inc/coh) from µXRF...
Lake Crescent, a 180-m-deep, glacially carved lake located on the Olympic Peninsula in western Washington, overlies the Lake Creek-Boundary Creek fault zone, a system of structures with at least 56 km of late Pleistocene to Holocene surface rupture. Investigation of the lake’s sediment, including a reflection seismic survey and analysis of piston c...
The damming of rivers has created hotspots for organic carbon sequestration and methane production on a global scale as the reservoirs intercept fluvial suspended and dissolved loads. To better understand how the C-biogeochemistry of a reservoir responds to watershed processes and evolves over time, Lake Decatur, located in the Intensively Managed...
Investigation of Lake Quinault in western Washington, including a reflection seismic survey, analysis of piston cores, and preliminary mapping in the steep, landslide-prone Quinault River catchment upstream of the lake, reveals evidence for three episodes of earthquake disturbance in the past 3000 yr. These earthquakes triggered failures on the lak...
A fundamental goal of the Earth Science community is to understand how perturbations on Earth's surface are preserved in the stratigraphic record. Recent Source to Sink (S2S) studies of the Waipaoa Sedimentary System (WSS), New Zealand, are synthesized herein to provide a holistic perspective of the processes that generate, transport and preserve s...
Purpose
We employ a geochemical-fingerprinting approach to estimate the source of suspended sediments collected from tributaries entering Falls Lake, a 50-km2 drinking water reservoir on the Neuse River, North Carolina, USA. Many of the major tributaries to the lake are on North Carolina’s 303(d) list for impaired streams, and in 2008, the lake was...
a b s t r a c t Sedimentary processes on the inner Mekong Shelf were investigated by examining the characteristics of sediments sampled in gravity cores at 15 locations, including grain size, clay mineralogy, sediment accu-mulation rates, and the elemental and stable carbon isotopic composition of organic matter (atomic C/N ratios and d 13 C). Delt...
Lateral movement of carbon and other materials across landscapes is
punctuated with periods of storage and reaction. Though we understand
basic principles concerning transport and storage effects on the nature
of some materials, an adequate understanding is lacking of the
cumulative impacts of those processes as material migrates across the
biogeoc...
The Waipaoa sedimentary system of New Zealand offers an opportunity to study the impacts of tectonic, climatic and anthropogenic forcings on the export of organic carbon from land and its preservation in the seabed. The dominant sources of organic carbon from the watershed are sedimentary rocks, aged soils, and flora. Marine C is added to sediment...
The composition of particulate organic carbon in sedimentary systems can provide information concerning sources of materials and their history. The NSF-MARGINS Source to Sink study of the Waipaoa Sedimentary System in New Zealand provides a platform to calibrate the particulate organic carbon sedimentary record by linking chemical characteristics t...
The rivers that drain active, collisional margins of the southwest Pacific deliver up to 35% of particulate organic carbon (POC) to the world ocean, and are a key component of the global organic carbon flux. However, knowledge of the fate of terrestrial POC in the ocean is both limited and necessary for quantifying terrestrial and coastal ocean car...
In the Waipaoa watershed on the North Island of New Zealand, as in many small mountainous watersheds around the world, high sediment yields are accommodated by the weathering and mass wasting of bedrock as well as of its mantle of soil and vegetation. Investigation of both the contemporary Waipaoa system and the sedimentary record preserved in adja...
The significant contribution of small mountainous river systems to the global fluvial sediment supply motivates investigation into the processes that influence the composition of the organic carbon that they carry. Organic matter preserved in continental margin sediments originates from terrestrial sources, such as kerogen and fresh and aged soil c...
The sedimentology and stratigraphy of river-fed continental margins reflect a diverse range of tectonic, climatic and hydrodynamic conditions that moderate the supply, transport and accumulation of terrigenous sediment in the coastal ocean. This paper describes a study of the modern and late Holocene northern California shelf and slope. The aim is...
Microfossils from Cretaceous coal-bearing strata can be used to establish key stratigraphic surfaces that mark marine flooding events with intermediate-frequency (fourth-order) and high-frequency (fifth-order) periodicities. We document several examples of this cyclicity from the transgressive and regressive facies at the land–sea transition of the...
The stable isotopic composition of organic matter in continental margin sediments provides a useful, long- term record of environmental change. The Waipaoa River watershed, New Zealand, represents a system of interest due to its very large sediment supply and well known, relatively recent history of anthropogenic disturbance. Three cores taken by t...
The significant contribution of short mountainous river systems, including the Waiapu River on New Zealand's East Cape, to the global fluvial sediment supply necessitates further investigation into the processes that influence the character and composition of organic carbon associated with these high sediment discharge systems. Organic matter prese...
To assess the role that erosion processes play in governing the character of particulate organic carbon (POC) discharged from small mountainous and upland rivers, a suite of watersheds from Oregon, California, and New Zealand was investigated. The rivers share similar geology, tectonic setting, and climate, but have sediment yields that range over...
To assess the role that erosion processes play in governing the character of particulate organic carbon (POC) discharged from small mountainous and upland rivers, a suite of watersheds from Oregon, California, and New Zealand was investigated. The rivers share similar geology, tectonic setting, and climate, but have sediment yields that range over...
The Tropic Shale and correlative Tununk Shale Member of the Mancos Shale accumulated during Cenomanian-Turonian time, within prodeltaic environments near the western margin of the Western Interior Seaway of North America. Stratigraphical and sedimentological analysis has revealed a detailed history of relative sea level change in the thick, fine gr...
The conglomeratic sandstone of the Sandstone of Floras Lake, a coarse-grained sequence deposited in a high-energy, storm-wave-dominated, shallow-marine environment. The features of the unit suggest deposition on a shoreface in proximity to a fluvial source. Distinguishing characteristics include amalgamated hummocky-stratified sandstone, low-angle...
The modern Eel River shelf and analogous Pleistocene Rio Dell Formation in northern California provide an ideal opportunity to combine the advantages of studying a modern environment with those of studying an ancient sequence, and thereby enables further understanding of muddy-shelf processes. The modern shelf is the site of accumulation of a thick...
The burial of organic carbon (OC) on continental margins is strongly coupled to the supply and accumulation of inorganic mineral particles. It follows that carbon burial on the margins should be impacted by changes in riverine sediment delivery, yet these impacts have not been well documented. In this study, an ∼2000-year record of sedimentation an...
Deltas sequester nearly half of the organic carbon (OC) buried in the marine environment. The composition of the buried organic matter reflects both watershed and seabed processes. A conceptual model is presented that describes the evolution of particulate organic carbon (POC) as it travels from its terrestrial source to its burial at sea. Alterati...
The cycle of organic carbon burial and exhumation moderates atmospheric chemistry and global climate over geologic timescales. The burial of organic carbon occurs predominantly at sea in association with clay-sized particles derived from the erosion of uplifted continental rocks. It follows that the history of the fine-grained particles on land may...
Microfossils from Cretaceous coal-bearing strata can be used to establish key stratigraphic surfaces that mark marine flooding events with intermediate-frequency (fourth-order) and high-frequency (fifth-order) periodicities. We document several examples of this cyclicity from the transgressive and regressive facies at the land–sea transition of the...
Previous investigations of the factors governing organic carbon burial on continental margins have pointed toward the important, apparently protective association of carbon with mineral particles. These studies have also revealed dramatic transformations of carbon-particle relationships at the land-sea interface. Riverine particles in some settings...
The 1995 flood of the Eel River in northern California provided an opportunity to follow the short-term history of riverine particulate matter on a continental shelf. Particulate organic carbon, including both vascular plant debris and soil carbon, was utilized as a tracer of the distribution and modification of the shelf flood deposit. These compo...
Lower-middle Turonian strata of the Tropic Shale and correlative Tununk Shale Member of the Mancos Shale accumulated in muddy prodeltaic environments near the western margin of the Cretaceous Western Interior Seaway. These fine-grained rocks are well exposed in outcrops along the southern margin of the Kaiparowits Plateau and in the Henry Mountains...
A study was designed to investigate the relationship between depletion of benthic oxygen and 4th-order sea-level change within the Cretaceous Western Interior Seaway of North America. Three 4th-order sea-level change cycles were studied in strata belonging to the Tropic Shale and the Tununk Shale Member of the Mancos Shale in Utah. These sedimentar...
The influence of seamount-intensified flows on the structure of infaunal assemblages was examined at two sand-covered sites located 2.3 km apart atop the summit plain of Fieberling Guyot (32°27.6N 127° 48.0W). Both sites experience strong, tidal bottom currents with flows exceeding 20 cm/s on a daily basis (4 mab). Estimates of shear velocity (u*)...
In Phanerozoic fine-grained marine sedimentary deposits, preservation of
physical lamination is commonly presumed to record anoxic benthic
conditions. Lamination may also be preserved, however, in oxygen-rich
settings where sediment influx is rapid and, as a consequence, high
levels of turbidity and fluid substrates inhibit colonization by benthic...
The Rio Dell Formation was deposited in a tectonically active area during a time of fluctuating eustatic sea-level. Detailed intepretation of Rio Dell shelf sediments, facilitated by comparison to the nearby, analogous, modern Eel River shelf, has proved a vital tool for decoding the record of these influences. -from Authors
Thesis (Ph. D.)--University of Washington, 1987. Vita ... Includes bibliographical references (leaves [238]-253). Photocopy.
The composition of particulate organic carbon in sedimentary systems provides information concerning sources of materials and their history. The NSF-MARGINS Source to Sink study of the Waipaoa system in New Zealand provides a platform to calibrate the particulate organic carbon (POC) sedimentary record by linking chemical characteristics to terrest...
