Index Catalog // ScholarsArchive@OSU

The Geology, Geochronology, and Geochemistry of the Miocene Volcanic Rocks at the Inmaculada Ag-Au Mine, Southern Peru

Creator:: Cuellar Quispe, Juan Carlos
Abstract:: The Inmaculada Mine is located in the Miocene belt of epithermal deposits that extends from southern Peru to northern Chile and Bolivia. This belt is known for its silver-rich epithermal veins that have been worked since colonial times. The Inmaculada Mine belongs to a mining district that includes, from north...
Resource Type:: Masters Thesis

Exploring the Magnetic Properties of Specific Grain-Sizes to Understand Marine Depositional Systems: A Case Study from the Eirik Ridge South of Greenland over the Last Glacial Cycle

Creator:: Freiberg, Benjamin T.
Abstract:: Disentangling sediment source from sediment transport is a fundamental marine geologic challenge critical to the interpretation of any sedimentary record. The Eirik Ridge, a sediment drift south of Greenland, receives terrigenous sediment primarily from subglacial erosion of south Greenland’s Precambrian bedrock and Paleogene volcanics that outcrop in east Greenland and...
Resource Type:: Masters Thesis

The Nature of Sulfate Saturation in Oxidized Arc Magmas: Implications for Magmatic Sulfur Budgets

Creator:: Hutchinson, Michael C.
Abstract:: This dissertation is concerned with the behavior of sulfur in intermediate-silicic arc magmas associated with subduction at convergent margins. In particular it focusses on oxidized, sulfur-rich magmas, the conditions at which they might reach sulfate saturation, and implications of sulfate saturation. It is divided into an investigation of natural samples...
Resource Type:: Dissertation

Late Holocene Earthquake History Recorded in Alluvial Fan Sequences, Panamint Valley, Eastern California

Creator:: Sethanant, Israporn
Abstract:: The Panamint Valley fault zone (PVFZ) is an active, dextral-oblique normal fault that partially accommodates dextral shear across the Eastern California Shear Zone (ECSZ). The fault system has a complex geometry, characterized by a relatively high-angle dextral oblique normal fault in the south and a low-angle detachment system that accommodates...
Resource Type:: Masters Thesis

Magnetotelluric Constraints on Lithospheric Properties in the Southeastern United States

Creator:: Murphy, Benjamin S.
Abstract:: By inverting EarthScope long-period magnetotelluric (MT) data from the southeastern United States (SEUS), we obtain electrical conductivity images that provides key insights into the geodynamics of this region. Significantly, we resolve a highly electrically resistive block that extends to mantle depths beneath the modern Piedmont and Coastal Plain physiographic provinces....
Resource Type:: Dissertation

Timing and Composition of Volcanism at Harrat Ithnayn, Western Saudi Arabia

Creator:: Alhejji, Suhail
Abstract:: Western Saudi Arabia hosts a number of young volcanic fields, known as “Harrats”. Harrats cover a significant proportion of western Saudi Arabia and are associated with significant volcanic hazards. However, the ultimate cause of volcanic activity remains unclear. Younger volcanism (<12 Ma) is clearly represented by the north-south-trending region known...
Resource Type:: Masters Thesis

Petrological Forensics of the Mount Sinabung, Sumatra, Indonesia Magma Reservoir before May 2016 Dome Collapse

Creator:: Bowers, Jade M.
Abstract:: Mount Sinabung, Sumatra, Indonesia initiated eruptive activity in 2010 with the addition of a magmatic component in 2013, after a 3 year period of quiescence. Observations of magmatic activity began with phreatomagmatic eruption starting July 2013 closely followed by extrusion of andesitic lava in December 2013. Lava effusion has persisted...
Resource Type:: Masters Thesis

Creating a Predictive Model of Cinder Cone Evolution in Central Oregon

Creator:: Das-Toke, Shyam P.
Abstract:: Cinder cones are useful geomorphic features for geological analysis because they generally have known initial states and follow a similar pattern of degradation as they are exposed to erosive processes. This is largely because cinder cones are produced by monogenetic eruptions. Characterizing large cinder cone fields in terms of age...
Resource Type:: Masters Thesis

North Atlantic Climate and Cryosphere Variability Over the Past 20,000 Years

Creator:: Sinclair, Gaylen
Abstract:: Reconstructing the sensitivity of past climate to forcings, and of ancient glaciers and ice sheets to this climate, can allow us to better understand the range of climate and cryosphere behavior we may see in the coming centuries. The Arctic is a region of particular importance due to its well-documented...
Resource Type:: Dissertation

Role of the Sisters Fault Zone in the Separation of Siletzia from the Cascadia Backarc

Creator:: Mark-Moser, MacKenzie
Abstract:: Oblique subduction of the Juan de Fuca plate beneath the North American plate characterizes the tectonic setting of the Pacific Northwest. North American plate deformation at the latitude of central Oregon consists of the clockwise-rotation of the Siletzia block in the forearc and the extensional Basin and Range province in...
Resource Type:: Masters Thesis

Geomorphic Evidence for Differential Rock Uplift Across the Southern Cascadia Forearc

Creator:: von Dassow, Wesley
Abstract:: The nature of upper plate deformation along the Cascadia subduction zone (CSZ) is poorly understood. Systematic covariation among topographic relief, geodetically determined uplift rates, decadal to millennial erosion rates, and the frequency of episodic tremor and slip (ETS) along the Cascadia forearc suggest a genetic association between forearc topography and...
Resource Type:: Masters Thesis

The Effects of the Flow Regime on Stream Channel Form and Processes

Creator:: Hempel, Laura A.
Abstract:: Numerous studies have explored how alluvial channel size and morphology are adjusted to different sediment and flow conditions, yet we still know very little about how and to what degree the flow regime controls channel form and processes. We use the term ‘channel form’ to refer to the size and...
Resource Type:: Dissertation

Evidence for Strengthening Hadley Cells and a Westward Expansion of the Walker Circulation from Assimilation of Paleoclimate Proxy Data

Creator:: Horlick, Kaleb A.
Abstract:: A synthesis of over 2000 paleoclimate proxy records is performed via a data assimilation framework that expands upon previous efforts by implementing a suite of physically-based proxy system models, and which provides the first example of an observationally independent, multi-seasonal (DJFM, JJAS) paleoclimate reanalysis. This methodology is contrasted against previous...
Resource Type:: Masters Thesis

An Experimental and Analytical Investigation of the Parameters that Influence Measured CO₂ in Plagioclase-Hosted Melt Inclusions in MORBs

Creator:: Drignon, Melissa J.
Abstract:: To understand the processes that lead to the formation of the oceanic crust, one must know the composition and the depth at which primary melts originate. Towards this end, this dissertation focuses on plagioclase-hosted melt inclusions from plagioclase ultraphyric basalts (PUBs). Plagioclase is usually considered to be the second phase,...
Resource Type:: Video and Dissertation

Controls on Process and Form in Alluvial and Bedrock Meandering Rivers

Creator:: Zunka, John P. P.
Abstract:: Bedrock meandering rivers are sinuous channels that pair steep bedrock outside banks with lower gradient slip-off slopes on the inside of bends. These rivers have the potential to record information on climatic and tectonic “external” forcings in their morphology (e.g., longitudinal profiles, strath terraces, channel and valley dimensions). However, geology...
Resource Type:: Dissertation

Petrogenesis of the Steens Basalt : Variation in Source Contributions and Effects of Crustal Passage During the Onset of Columbia River Flood Basalt Volcanism

Creator:: Moore, Nicole E.
Abstract:: Continental flood basalts represent short-lived but immense blasts of mafic magma to the continental crust. The youngest and smallest continental flood basalt worldwide, the Columbia River Basalt, initiated with the eruption of the most mafic member, the Steens Basalt (~16.9 Ma). The Steens Basalt is exposed in southeast Oregon, southwest...
Resource Type:: Dataset and Dissertation

Resurgent Uplift of Samosir Island in Toba Caldera, Indonesia : Insights from Lake Sediment Paleomagnetism and C-14 Age Determination

Creator:: Solada, Katharine
Abstract:: Around 74 ka, a supervolcano, Toba Caldera in Sumatra, Indonesia erupted, producing the Youngest Toba Tuff and its associated caldera. After this catastrophic eruption, a lake filled the caldera, sedimentation within the lake occurred, and the process known as resurgence began. Today, the resurgent dome, Samosir Island, is uplifted 700...
Resource Type:: Masters Thesis

Effects of estuary characteristics and tsunami waveforms on transported sand sheets

Creator:: Armstrong, Emma M.
Abstract:: The details of the 1700 Cascadia Subdction Zone earthquake and tsunami can be better constrained using data from tsunami sand sheets, provided knowledge of the waveform, estuary geometry and bed roughness controls on the deposition pattern of the sand sheet. In this study, we use the hydrodynamic and sediment transport...
Resource Type:: Undergraduate Thesis

A stratigraphic approach to characterize the deposition and storage of organic matter in reservoir sediments

Creator:: Stratton Garvin, Laurel E.
Abstract:: 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...
Resource Type:: Dissertation

From the Shoreface to the Foredunes : Coastal Morphodynamics Across the Land-Sea Interface

Creator:: Cohn, Nicholas T.
Abstract:: Coastal flooding and erosion are major concerns for low lying coastal communities -- particularly in light of accelerated sea level rise and climate change. To improve quantitative understanding of the physical drivers of both flooding and coastal landscape change, this dissertation explores coastal morphodynamics bridging the land-sea interface on modally...
Resource Type:: Dissertation
Date Created:

An Evaluation of the Complex Age Progression along the Cook-Austral Islands Using High-resolution ⁴⁰Ar/³⁹Ar Incremental Heating Ages

Creator:: Rose, Joanna
Abstract:: The Cook-Austral island chain has been the center of debate for many years. Contrary to the classical hotspot hypothesis, this volcanic island chain does not exhibit a linear age progression with a single node of active volcanism, but instead shows evidence of young volcanism at several points along the chain....
Resource Type:: Masters Thesis

Investigating Timescales of Resurgence at Large Calderas: Post-74 ka Activity at Toba Caldera, Sumatra, Indonesia

Creator:: Mucek, Adonara E.
Abstract:: The Toba Caldera Complex is the youngest resurgent caldera in the last 100 kyrs, formed from four overlapping eruptions starting 1.2 Myrs ago. The last caldera-forming eruption, the Youngest Toba Tuff eruption, occurred ~74 kyrs ago, emitting 2800 km3 of ash and pumice into the atmosphere and forming the caldera...
Resource Type:: Dissertation

The Deschutes Formation: evidence of extension-enhanced explosivity in the early High Cascades

Creator:: Pitcher, Bradley W.
Abstract:: The eruptive history of the Quaternary Cascades arc has been relatively well characterized. However, much less is known about the frequency and sizes of explosive eruptions produced by earlier stages of the arc. The Late Neogene Deschutes Formation of Central Oregon preserves a remarkable record of heightened pyroclastic activity during...
Resource Type:: Dissertation

Groundwater Flow Modeling at Santa Susana Field Laboratory

Creator:: Gardner, Gerrit T.
Abstract:: Understanding groundwater flow in faulted and fractured rock is an important frontier in the field of environmental remediation and in the management of water resources. One example of a site where this is particularly evident is the Santa Susana Field Laboratory (SSFL) in Ventura County, CA where environmental remediation activities...
Resource Type:: Masters Thesis

Intrusion Sequence and Hydrothermal Fluid Evolution of Encuentro Porphyry Cu-Mo-Au deposit, Northern Chile

Creator:: Osorio C., Jaime
Abstract:: This dissertation is divided into two major chapters. The first chapter covers the geologyof the Encuentro deposit with emphasis in the intrusion sequence, vein mineral assemblages and distribution, and age of mineralization. The data used for this section includes field mapping, petrography, elemental analysis of biotite, and isotopic geochronology. The...
Resource Type:: Masters Thesis

Geochemical and Geostatisical Analyses of Quaternary Climate Variability over Millennial-to-Orbital Timescales

Creator:: Barth, Aaron M.
Abstract:: The goal of dissertation research was to use geochemical, statistical and geological methods to constrain and understand climate variability over several different time scales. Specifically, I have addressed three questions regarding past climate change: (1) how does the record of Irish cirque glaciers constrain the dimensions of the Irish Ice...
Resource Type:: Dissertation

Signatures in the Subsurface - Big & Small Data Approaches for the Spatio-Temporal Analysis of Geologic Properties & Uncertainty Reduction

Creator:: Rose, Kelly Kathleen
Abstract:: Despite more than two centuries of exploration, including more than six million deep wellbores with depths exceeding 40,000 feet in some parts of the world, our ability to constrain subsurface processes and properties remains limited. Characteristics of the subsurface vary and can be analyzed on a variety of spatial scales....
Resource Type:: Dissertation

Crystal Records of the Origin, Evolution, and Thermal Histories of Magmas

Creator:: Bradshaw, Richard W., 1985-
Abstract:: In volcanic systems, magma is generally stored in the shallow crust prior to eruption. The conditions of this storage directly impact whether the magma eventually erupts, or crystallizes within the crust to form a pluton. In this dissertation I present four studies that investigate the storage conditions of a number...
Resource Type:: Dissertation

New Insights into Mantle Dynamics from Helium Isotopes and Argon Geochronology

Creator:: Konrad, Kevin
Abstract:: Earth’s mantle extends to nearly 3000 km depth, comprises >80 % of Earth’s total volume, and has the largest influence on the primordial and radiogenic heat budget. Despite its importance, the structure and composition of the mantle is still debated. There are three primary models for Earth’s mantle structure that...
Resource Type:: Dissertation

Ocean Temperature Variability during the Late Pleistocene

Creator:: Hoffman, Jeremy Scott
Abstract:: This dissertation explores one overarching question relevant to the paleoclimate of the latest Pleistocene glacial cycle (approximately the last 130,000 years): “How did spatial and temporal evolution of ocean temperature, both at the surface and interior, relate to other parts of the climate system in the late Pleistocene?” Results from...
Resource Type:: Dissertation

Structural Evolution, Vein Orientation, and Paragenesis of the Botija Porphyry Cu-Mo-(Au) Deposit, Colón, Panamá

Creator:: Sepp, Michael D.
Abstract:: The Botija Cu-Mo-Au porphyry deposit is located in the Cobre Panamá mining district, which contains several deposits with a global measure and indicated and inferred resource of 14.8 MT of Cu. These deposits are associated with the Cerro Petaquilla batholith, which has U/Pb zircon ages of 26-33 Ma (Whattam et...
Resource Type:: Masters Thesis

Quaternary Landscape Evolution and the Surface Expression of Plume-Lithosphere Interactions in the Greater Yellowstone Area

Creator:: Guerrero, Eduardo Francisco
Abstract:: Numerous investigations demonstrate that mantle convective processes such as upwelling affect the surface topography of the overriding plate. The surface expression of mantle flow has been coined ‘transient topography’. Transient topography in the North American plate is thought to result from a mantle thermal anomaly beneath the Yellowstone volcanic center,...
Resource Type:: Dissertation

Late Cenozoic Climate, Ice-sheet and Earth-surface Evolution Derived from Terrestrial and Marine Sedimentary Archives

Creator:: Bill, Nicholas S.
Abstract:: The goals of this dissertation are centered on understanding changes in Earth surface and climate systems through the use of geologic proxies as records of past changes in these systems. Specifically, this dissertation (1) establishes a new chronology for retreat of the Ross Sea sector of the West Antarctic Ice...
Resource Type:: Dissertation

Application of Cosmogenic Nuclides and Argon Geochronology to Paleoclimate, Paleomagnetism, and Paleohydrology

Creator:: Balbas, Andrea M.
Abstract:: This dissertation uses argon geochronology and cosmogenic nuclide surface exposure dating methods to address three research questions. The first question concerns a geomagnetic instability recorded in lava flows on the island of Floreana in the Galapagos Archipelago. Changes in the Earth’s magnetic field (intensity and orientation) occur frequently throughout geologic...
Resource Type:: Dissertation

Ar-Ar Age Correlation of the Elkhorn Mountain Volcanics and Base Metal Mineralization in the Ratio Mountain Quadrangle, Montana

Creator:: Horton, Thomas
Abstract:: The Ratio Mountain Quadrangle is located in Southwest Montana, East of the city of Butte. This quadrangle features two major geologic units; the Elkhorn Mountain Volcanics, a series of several ignimbrites of varying composition, and the Boulder Batholith, a large granite pluton that rose through the EMV. Previous studies in...
Resource Type:: Research Paper

Late Pleistocene Slip Rate along the Panamint Valley Fault System, Eastern California

Creator:: Choi, Na Hyung
Abstract:: The Eastern California Shear Zone (ECSZ) is a broad zone of dextral shear inboard of the North American - Pacific plate boundary. Despite decades of study, the significance of a mismatch between geodetic velocities and geologic fault slip rates across the ECSZ remains incompletely understood. Geodetically determined interseismic strain across...
Resource Type:: Masters Thesis

Reconstructing the Physical Record of a Four-Million-Year Volcanic System : Geochemistry, Thermobarometry, and Geologic Map of the Mount Jefferson Area, Oregon

Creator:: DiGiulio, Jennifer
Abstract:: Volcanic and sedimentary deposits of the Mount Jefferson area (MJA) record a fourmillion-year history of arc-related volcanism related to the subduction of the Juan de Fuca plate beneath North America. 171 mapped stratigraphic units over an area of 150 km² reveal four periods of volcanic activity resulting in diverse composition...
Resource Type:: Masters Thesis

The Hampton Tuff, High Lava Plains, Oregon : Implications for Westward Migrating Silicic Volcanism

Creator:: Sanville, Henri J.
Abstract:: The Hampton Tuff is a 3.9 ± .02 Ma (2σ) ignimbrite sheet from the High Lava Plains of central Oregon. The majority of known outcrops exist to the north, within ~22 mi (~35 km) of the Frederick Butte Volcanic Center, the proposed source of the tuff. Thickness of the tuff...
Resource Type:: Masters Thesis

Local Seismicity Recorded by ChilePEPPER : Implications for Dynamic Accretionary Prism Response and Long-term Prism Evolution

Creator:: de Moor, Alexander
Abstract:: To investigate the dynamic response of the outer accretionary wedge updip from the patch of greatest slip during the Mw8.8 2010 Maule earthquake, 10 Ocean Bottom Seismometers (OBS) were deployed from May 2012 to March 2013 in a small array with an inter-instrument spacing of ~10 km. Nine instruments were...
Resource Type:: Masters Thesis

The Geology and Geochemistry of the Haquira East Porphyry Copper Deposit of Southern Peru : Insights on the Timing, Temperature and Lifespan of the Magmatic-hydrothermal Alteration and Mineralization

Creator:: Cernuschi Rodilosso, Federico
Abstract:: This dissertation is informally divided into three major sections. In the first section (Chapter 2) I use data from field mapping, isotopic geochronology, whole rock geochemistry and trace element concentrations in zircons to examine the petrology, geochemistry and ages of the Haquira East porphyry copper deposit of southern Peru. In...
Resource Type:: Dissertation

Insights into the Geochemical Evolution of the Youngest Toba Tuff (Sumatra, Indonesia) Magma Chamber Through the Lens of Zircon-hosted Melt Inclusions

Creator:: Lerner, Allan
Abstract:: Supervolcanic eruptions are among the most catastrophic phenomena on Earth, erupting 100s-1000s of cubic kilometers of magma, and producing devastating local effects and global climate perturbations. The largest supervolcanic eruption of the last 28 Ma was the 74 ka Youngest Toba Tuff (YTT) eruption from Sumatra, Indonesia, which erupted 2,800...
Resource Type:: Masters Thesis

Geochemistry of Plutonic Rocks of the Western Cascades, Washington & Oregon : Relationship to Crustal Segmentation and Ore Genesis

Creator:: Utevsky, Elinor S.
Abstract:: The volcanic (~45-10 Ma) and plutonic rocks (~37-12 Ma) comprising the Western Cascades extend from northernmost California to southern British Columbia and are ancestral to modern arc magmatism. The ancestral arc hosts a series of small plutons that are locally associated with porphyry (Cu-Mo) and epithermal (Au) ore deposits. Three...
Resource Type:: Masters Thesis

Upper-Crustal Magma Evolution at Intermediate Arc Systems : Uranium-Series Zircon Chronochemistry of the Unzen Volcanic Complex, Southwestern Japan

Creator:: Murphy, Bethany S.
Abstract:: Crystal-rich (40-50 vol.%) intermediate lava has been the primary eruptive product of several recent hazardous eruptions: Mt. Pinatubo, Philippines (1991), Soufriere Hills, Montserrat (1995-present), and Unzen, Japan (1990-1995). Despite this association with such devastating eruptions, the formation, timing, and evacuation of such magma is not well understood: do such eruptions...
Resource Type:: Masters Thesis

The geology, geochronology, and geochemistry of the Kaskanak Batholith, and other late Cretaceous to Eocene magmatism at the Pebble porphyry Cu-Au-Mo deposit, SW Alaska

Creator:: Olson, Nansen H.
Abstract:: The Pebble porphyry Cu-Au-Mo deposit in Alaska is one of the world's largest Cu-Au mineral resources. Late Cretaceous magmatic evolution in the Pebble district culminated with the intrusion of the Kaskanak Batholith and associated porphyry copper-gold-molybdenum mineralization. The Kaskanak Batholith is a multiphase granodiorite intrusion with an estimated footprint of...
Resource Type:: Masters Thesis

Fault behavior over geomorphic time scales in the Pakistan Himalaya, Kashmir Himalaya, and California

Creator:: Madugo, Christopher Lee Madden
Abstract:: The state of the knowledge for fault behavior in the northwest Himalaya and California varies dramatically. In the Pakistan and Kashmir Himalaya, few data constrain the role that individual active faults play in accommodating Indo-Eurasian convergence and the relative earthquake hazard across the region. By contrast, the San Andreas fault...
Resource Type:: Dissertation

Crustal architecture and magma dynamics in a large continental magmatic system : a case study of the Purico-Chascon Volcanic Complex, Northern Chile

Creator:: Burns, Dale H.
Abstract:: The ~1 Myr history of the Purico-Chascon volcanic complex (PCVC) records significant changes in the production and storage of magmas in the crust. At ~1 Ma activity at the PCVC initiated with the eruption of a large 80-100 km³ crystal-rich dacite ignimbrite with restricted whole rock ⁸⁷Sr/⁸⁶Sr isotope ratios between...
Resource Type:: Dissertation

Understanding large resurgent calderas and associated magma systems : the Pastos Grandes Caldera Complex, southwest Bolivia

Creator:: Kaiser, Jason Frederick, 1985-
Abstract:: The Pastos Grandes Caldera Complex (PGCC) in southwest Bolivia has produced two large-volume (≥800 km³ DRE) dacite ignimbrites from a nested caldera source over a period of 5.5 Myr. In addition to the large-volume ignimbrites, a small-volume ignimbrite shield and post-climactic lavas define this composite system. Based on detailed field...
Resource Type:: Dissertation

Augmenting and interpreting ice core greenhouse gas records

Creator:: Rosen, Julia L.
Abstract:: The three studies that comprise this dissertation seek to answer significant questions in paleoclimatology through unconventional applications of ice core greenhouse gas data. These studies involve different gases and span the interval of time between the Last Glacial Maximum and the Industrial Revolution, but are united by their nontraditional use...
Resource Type:: Dissertation

Volatile mobility of trace metals in volcanic systems

Creator:: Loewen, Matthew W.
Abstract:: Semi-volatile trace metals like Li, Cu, Mo, Sn, In, and Pb have the potential to track mobility of a volatile phase in volcanic systems. In this dissertation four studies are presented that either directly investigate or are motivated by observations of trace metal behavior in volcanic systems. A common tool...
Resource Type:: Dissertation

Biotic alteration of oceanic basalt glass

Creator:: Drinnan, Megan R.
Abstract:: The subsurface microbial biosphere in the igneous oceanic crust has implications for global geochemical cycling, early life on Earth, and the search for life on Mars. Microscopic evidence of a subsurface microbial ecosystem includes biotic alteration textures associated with basaltic glass. The exact conditions in the basaltic layer that make...
Resource Type:: Masters Thesis

Submarine earthquakes, volcanic eruptions and ambient noise in the Northeast Pacific

Creator:: Haxel, Joseph H.
Abstract:: Passive hydrophone technologies and a variety of acoustic methods are applied in the deep-ocean and shallow water coastal environments of the northeast Pacific. A catalog derived from U.S. Navy regional hydrophone array recordings of acoustic T- phases from seafloor earthquakes is examined, describing space/time patterns through empirical orthogonal function analysis...
Resource Type:: Dissertation

Carbon cycle variability during the last millennium and last deglaciation

Creator:: Bauska, Thomas K.
Abstract:: The exchange of carbon on earth is one of the fundamental processes that sustains life and regulates climate. Since the onset of the Industrial Revolution, the burning of fossil fuels and anthropogenic land conversion have altered the carbon cycle, increasing carbon dioxide in the atmosphere to levels that are unprecedented...
Resource Type:: Dissertation

Structural geology of the Mount Polley Cu-Au district, south-central British Columbia

Creator:: Wafforn, Stephanie R.
Abstract:: The Mount Polley copper-gold deposit is one of a series of porphyry copper deposits that occur in a belt of accreted Mesozoic age island arc terranes in the Canadian Cordillera. The deposit comprises three breccia-hosted Cu-Au ore zones that are associated with a series of monzodiorite to monzonite intrusions emplaced...
Resource Type:: Masters Thesis

Magmatic processes beneath mid-ocean ridges : insights from mineral and glass chemistry in plagioclase ultraphyric basalts

Creator:: Lange, Amy E.
Abstract:: Prior to eruption at mid-ocean ridges, melts must travel through >6 km of crust from their origin in the mantle. The final composition of the melts is dependent on both the melting conditions and magmatic processes within the crust. While mid-ocean ridge basalt (MORB) glasses are commonly used to infer...
Resource Type:: Dissertation

Debris flows in glaciated catchments : a case study on Mount Rainier, Washington

Creator:: Legg, Nicholas T.
Abstract:: Debris flows, which occur in mountain settings worldwide, have been particularly damaging in the glaciated basins flanking the stratovolcanoes in the Cascade Range of the northwestern United States. This thesis contains two manuscripts that respectively investigate the (1) initiation processes of debris flows in these glaciated catchments, and (2) debris...
Resource Type:: Masters Thesis

The late holocene atmospheric methane budget reconstructed from ice cores

Creator:: Mitchell, Logan E.
Abstract:: Ice cores are considered the gold standard for recording past climate and biogeochemical changes. However, gas records derived from ice core analysis have until now been largely limited to centennial and longer timescales because sufficient temporal resolution and analytical precision have been lacking, except during rare times when atmospheric concentrations...
Resource Type:: Dissertation

Trace element characteristics of zircon : a means of assessing mineralization potential of intrusions in northern Nevada

Creator:: Farmer, Lucian P.
Abstract:: Oxidized hydrous intermediate composition magmas are responsible for porphyry copper (Cu ±Mo ±Au) deposits and epithermal Au ore deposits formed globally in the shallow crust (Sillitoe, 2010; Seedorff et al., 2005). Recently, zircon geochemistry has been used to characterize both productive and barren intrusions associated with porphyry Cu-Au ore deposits....
Resource Type:: Masters Thesis

Structural and volcanic evolution of the Glass Buttes area, High Lava Plains, Oregon

Creator:: Boschmann, Darrick E.
Abstract:: The Glass Buttes volcanic complex is a cluster of bimodal (basalt-rhyolite), Miocene to Pleistocene age lava flows and domes located in Oregon's High Lava Plains province, a broad region of Cenozoic bimodal volcanism in south-central Oregon. The High Lava Plains is deformed by northwest-striking faults of the Brothers Fault Zone,...
Resource Type:: Masters Thesis

Regional scale sandbar variability : observations from the U.S. Pacific Northwest

Creator:: Di Leonardo, Diana R.
Abstract:: Understanding sandbar dynamics and variability is integral to developing a predictive capacity for nearshore flows, sediment transport, morphological change, and ultimately for determining coastline exposure to damaging storm waves. Along the high-energy U.S. Pacific Northwest (PNW) coast, sandbars typically dominate the bathymetry of the active zone. Here we report on...
Resource Type:: Masters Thesis

The provenance and trace element signatures of MORB anorthitic plagioclase

Creator:: Burleigh, Andrew W.
Abstract:: In an attempt to understand the phase equilibria and petrogenesis of MORB anorthitic plagioclase, Cr-spinel commonly hosted within anorthitic plagioclase has been investigated petrographically and compositionally. Based on spinel-anorthite relationships from three samples of plagioclase ultra-phyric basalt (PUB; Southeast Indian Ridge, Axial Seamount and West Valley Segment, Juan de Fuca...
Resource Type:: Masters Thesis

Helium isotope variations in peridotite, gabbro and basalt from the Kane Oceanic Core Complex

Creator:: Konrad, Kevin
Abstract:: The Kane Oceanic Core Complex (OCC) is a valuable window into crustal architecture and chemical composition of the lithosphere beneath a slow-spreading ocean ridge. A suite of > 30 samples (comprised of whole rocks, mineral separates and basalt glasses) has been analyzed for ³He/⁴He isotope ratios and He concentrations. Gas...
Resource Type:: Masters Thesis

Early high Cascade silicic volcanism : analysis of the McKenzie Canyon and Lower Bridge tuff

Creator:: Eungard, Daniel W.
Abstract:: Silicic volcanism in the central Oregon Cascade range has decreased in both the size and frequency of eruptions from its initiation at ~40 Ma to present. The reasons for this reduction in silicic volcanism are poorly constrained. Studies of the petrogenesis of these magmas have the potential for addressing this...
Resource Type:: Masters Thesis

The Cerro Guacha caldera complex : an upper Miocene-Pliocene polycyclic volcano-tectonic structure in the Altiplano Puna Volcanic Complex of the Central Andes of Bolivia

Creator:: Iriarte, Rodrigo
Abstract:: Four multicyclic complex calderas and smaller ignimbrite shields located within the Altiplano Puna Volcanic Complex of the Central Andes (APVC) erupted 13000 km³ of magma within the last 11 Ma. One of the largest and most complex of these is the Cerro Guacha Caldera. Ar-Ar age determinations and paleomagnetic directions...
Resource Type:: Masters Thesis

Timescales of large silicic magma systems : investigating the magmatic history of ignimbrite eruptions in the Altiplano-Puna Volcanic Complex of the Central Andes through U-Pb zircon dating

Creator:: Kern, Jamie M.
Abstract:: The Altiplano-Puna Volcanic Complex in the Central Andes is one of the youngest large silicic volcanic fields (LSVFs) in the world, erupting over 13,000 km³ of material during multiple supereruptions from 11 to 1 Ma. Understanding the timescales over which magma is stored in the crust prior to eruption is...
Resource Type:: Masters Thesis

Quantification of the temperature, pressure and compositional dependence of trace element partitioning : an experimental and theoretical study

Creator:: Cunningham, Jennifer Lynn
Abstract:: The thermodynamic history of the Earth is preserved in the trace element record created through igneous processes. The ability to interpret that record depends on the accuracy and precision of numerical models that connect igneous processes with their geochemical consequences. This project answers three major questions concerning the relationship between...
Resource Type:: Masters Thesis

Search Constraints

Search Results

Limit your search