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Full-Text Articles in Earth Sciences

High Throughput Petrochronology And Sedimentary Provenance Analysis By Automated Phase Mapping And Laicpms, Pieter Vermeesch, Martin Rittner, Ethan Petrou, Jenny Omma, Chris Mattinson, Eduardo Garzanti Nov 2017

High Throughput Petrochronology And Sedimentary Provenance Analysis By Automated Phase Mapping And Laicpms, Pieter Vermeesch, Martin Rittner, Ethan Petrou, Jenny Omma, Chris Mattinson, Eduardo Garzanti

All Faculty Scholarship for the College of the Sciences

The first step in most geochronological studies is to extract dateable minerals from the host rock, which is time consuming, removes textural context, and increases the chance for sample cross contamination. We here present a new method to rapidly perform in situ analyses by coupling a fast scanning electron microscope (SEM) with Energy Dispersive X-ray Spectrometer (EDS) to a Laser Ablation Inductively Coupled Plasma Mass Spectrometer (LAICPMS) instrument. Given a polished hand specimen, a petrographic thin section, or a grain mount, Automated Phase Mapping (APM) by SEM/EDS produces chemical and mineralogical maps from which the X-Y coordinates of the datable …


Exploring The Historical Earthquakes Preceding The Giant 1960 Chile Earthquake In A Time-Dependent Seismogenic Zone, Marco Cisternas, Matias Carvajal, Robert Wesson, Lisa L. Ely, Nicolás Gorigoitia Nov 2017

Exploring The Historical Earthquakes Preceding The Giant 1960 Chile Earthquake In A Time-Dependent Seismogenic Zone, Marco Cisternas, Matias Carvajal, Robert Wesson, Lisa L. Ely, Nicolás Gorigoitia

All Faculty Scholarship for the College of the Sciences

New documentary findings and available paleoseismological evidence provide both new insights into the historical seismic sequence that ended with the giant 1960 south‐central Chile earthquake and relevant information about the region’s seismogenic zone. According to the few available written records, this region was previously struck by earthquakes of varying size in 1575, 1737, and 1837. We expanded the existing compilations of the effects of the two latter using unpublished first‐hand accounts found in archives in Chile, Peru, Spain, and New England. We further investigated their sources by comparing the newly unearthed historical data and available paleoseismological evidence with the effects …


Bedrock Geology Of Dfdp-2b, Central Alpine Fault, New Zealand, Virginia Gail Toy, Angela Halfpenny Oct 2017

Bedrock Geology Of Dfdp-2b, Central Alpine Fault, New Zealand, Virginia Gail Toy, Angela Halfpenny

All Faculty Scholarship for the College of the Sciences

During the second phase of the Alpine Fault, Deep Fault Drilling Project (DFDP) in the Whataroa River, South Westland, New Zealand, bedrock was encountered in the DFDP-2B borehole from 238.5–893.2 m Measured Depth (MD). Continuous sampling and meso- to microscale characterisation of whole rock cuttings established that, in sequence, the borehole sampled amphibolite facies, Torlesse Composite Terrane-derived schists, protomylonites and mylonites, terminating 200–400 m above an Alpine Fault Principal Slip Zone (PSZ) with a maximum dip of 62°. The most diagnostic structural features of increasing PSZ proximity were the occurrence of shear bands and reduction in mean quartz grain sizes. …


The Uppermost Mantle Seismic Velocity And Viscosity Structure Of Central West Antarctica, J. P. O'Donnell, K. Selway, A. A. Nyblade, R. A. Brazier, D. A. Wiens, S. Anandakrishnan, R. C. Aster, Audrey D. Huerta, T. Wilson, J. Paul Winberry Aug 2017

The Uppermost Mantle Seismic Velocity And Viscosity Structure Of Central West Antarctica, J. P. O'Donnell, K. Selway, A. A. Nyblade, R. A. Brazier, D. A. Wiens, S. Anandakrishnan, R. C. Aster, Audrey D. Huerta, T. Wilson, J. Paul Winberry

All Faculty Scholarship for the College of the Sciences

Accurately monitoring and predicting the evolution of the West Antarctic Ice Sheet via secular changes in the Earth's gravity field requires knowledge of the underlying upper mantle viscosity structure. Published seismic models show the West Antarctic lithosphere to be ∼70–100 km thick and underlain by a low velocity zone extending to at least ∼200 km. Mantle viscosity is dependent on factors including temperature, grain size, the hydrogen content of olivine, the presence of partial melt and applied stress. As seismic wave propagation is particularly sensitive to thermal variations, seismic velocity provides a means of gauging mantle temperature. In 2012, a …


Origin Of Primitive Ocean Island Basalts By Crustal Gabbro Assimilation And Multiple Recharge Of Plume-Derived Melts, Anastassia Y. Borisova, Wendy A. Bohrson, Michel Grégoire Jul 2017

Origin Of Primitive Ocean Island Basalts By Crustal Gabbro Assimilation And Multiple Recharge Of Plume-Derived Melts, Anastassia Y. Borisova, Wendy A. Bohrson, Michel Grégoire

All Faculty Scholarship for the College of the Sciences

Chemical Geodynamics relies on a paradigm that the isotopic composition of ocean island basalt (OIB) represents equilibrium with its primary mantle sources. However, the discovery of huge isotopic heterogeneity within olivine‐hosted melt inclusions in primitive basalts from Kerguelen, Iceland, Hawaii and South Pacific Polynesia islands implies open‐system behavior of OIBs, where during magma residence and transport, basaltic melts are contaminated by surrounding lithosphere. To constrain the processes of crustal assimilation by OIBs, we employed the Magma Chamber Simulator (MCS), an energy‐constrained thermodynamic model of recharge, assimilation and fractional crystallization. For a case study of the 21–19 Ma basaltic series, the …


Actively Forming Kuroko-Type Volcanic-Hosted Massive Sulfide (Vhms) Mineralization At Iheya North, Okinawa Trough, Japan, Christopher J. Yeats, Steven P. Hollis, Angela Halfpenny, Juan-Carlos Corona, Crystal Laflamme, Gordon Southam, Marco Fiorentini, Richard J. Herrington, John Spratt Apr 2017

Actively Forming Kuroko-Type Volcanic-Hosted Massive Sulfide (Vhms) Mineralization At Iheya North, Okinawa Trough, Japan, Christopher J. Yeats, Steven P. Hollis, Angela Halfpenny, Juan-Carlos Corona, Crystal Laflamme, Gordon Southam, Marco Fiorentini, Richard J. Herrington, John Spratt

All Faculty Scholarship for the College of the Sciences

Modern seafloor hydrothermal systems provide important insights into the formation and discovery of ancient volcanic-hosted massive sulfide (VHMS) deposits. In 2010, Integrated Ocean Drilling Program (IODP) Expedition 331 drilled five sites in the Iheya North hydrothermal field in the middle Okinawa Trough back-arc basin, Japan. Hydrothermal alteration and sulfide mineralization is hosted in a geologically complex, mixed sequence of coarse pumiceous volcaniclastic and fine hemipelagic sediments, overlying a dacitic to rhyolitic volcanic substrate. At site C0016, located adjacent to the foot of the actively venting North Big Chimney massive sulfide mound, massive sphalerite-(pyrite-chalcopyrite ± galena)-rich sulfides were intersected (to 30.2% …


Timing Of Mid-Crustal Ductile Extension In The Northern Snake Range Metamorphic Core Complex, Nevada: Evidence From U/Pb Zircon Ages, Jeffrey Lee, Terrence Blackburn, Scott Johnston Mar 2017

Timing Of Mid-Crustal Ductile Extension In The Northern Snake Range Metamorphic Core Complex, Nevada: Evidence From U/Pb Zircon Ages, Jeffrey Lee, Terrence Blackburn, Scott Johnston

All Faculty Scholarship for the College of the Sciences

Metamorphic core complexes within the western U.S. record a history of Cenozoic ductile and brittle extensional deformation, metamorphism, magmatism, and exhumation within the footwalls of high-angle Basin and Range normal faults. In models proposed for the formation of metamorphic core complexes there is a close temporal and spatial link between upper crustal normal faulting, lower crustal ductile extension and flow, and detachment faulting. To provide constraints on the timing of ductile extension in the northern Snake Range metamorphic core complex (Nevada) and thereby test these models, we present new 238U-206Pb dates on zircons from both deformed and undeformed rhyolite dikes …


Unusual Geologic Evidence Of Coeval Seismic Shaking And Tsunamis Shows Variability In Earthquake Size And Recurrence In The Area Of The Giant 1960 Chile Earthquake, M. Cisternas, E. Garrett, R. Wesson, T. Dura, Lisa L. Ely Mar 2017

Unusual Geologic Evidence Of Coeval Seismic Shaking And Tsunamis Shows Variability In Earthquake Size And Recurrence In The Area Of The Giant 1960 Chile Earthquake, M. Cisternas, E. Garrett, R. Wesson, T. Dura, Lisa L. Ely

All Faculty Scholarship for the College of the Sciences

An uncommon coastal sedimentary record combines evidence for seismic shaking and coincident tsunami inundation since AD 1000 in the region of the largest earthquake recorded instrumentally: the giant 1960 southern Chile earthquake (Mw 9.5). The record reveals significant variability in the size and recurrence of megathrust earthquakes and ensuing tsunamis along this part of the Nazca-South American plate boundary. A 500-m long coastal outcrop on Isla Chiloé, midway along the 1960 rupture, provides continuous exposure of soil horizons buried locally by debris-flow diamicts and extensively by tsunami sand sheets. The diamicts flattened plants that yield geologically precise ages to correlate …


Contributions Of Wood Smoke And Vehicle Emissions To Ambient Concentrations Of Volatile Organic Compounds And Particulate Matter During The Yakima Wintertime Nitrate Study, Graham Vanderschelden, Benjamin De Foy, Courtney Herring, Susan D. Kaspari, Tim Vanreken, Bertram Jobson Feb 2017

Contributions Of Wood Smoke And Vehicle Emissions To Ambient Concentrations Of Volatile Organic Compounds And Particulate Matter During The Yakima Wintertime Nitrate Study, Graham Vanderschelden, Benjamin De Foy, Courtney Herring, Susan D. Kaspari, Tim Vanreken, Bertram Jobson

All Faculty Scholarship for the College of the Sciences

A multiple linear regression (MLR) chemical mass balance model was applied to data collected during an air quality field experiment in Yakima, WA, during January 2013 to determine the relative contribution of residential wood combustion (RWC) and vehicle emissions to ambient pollutant levels. Acetonitrile was used as a chemical tracer for wood burning and nitrogen oxides (NOx) as a chemical tracer for mobile sources. RWC was found to be a substantial source of gas phase air toxics in wintertime. The MLR model found RWC primarily responsible for emissions of formaldehyde (73%), acetaldehyde (69%), and black carbon (55%) and mobile sources …


Implications Of Sea Ice On Southern Ocean Microseisms Detected By A Seismic Array In West Antarctica, Martin J. Pratt, Douglas A. Wiens, J. Paul Winberry, Sridhar Anandakrishnan, Garrett G. Euler Jan 2017

Implications Of Sea Ice On Southern Ocean Microseisms Detected By A Seismic Array In West Antarctica, Martin J. Pratt, Douglas A. Wiens, J. Paul Winberry, Sridhar Anandakrishnan, Garrett G. Euler

All Faculty Scholarship for the College of the Sciences

The proximity of Southern Ocean storms coupled with seasonal variation in sea ice make Antarctica ideal for the study of microseism sources. We explore frequency-dependent beamforming results using a short-duration, 60 km aperture, broad-band seismic array located on the Whillans Ice Stream, West Antarctica. Locations of single-frequency microseism (13–16 s period) generation are in regions where the continental shelf is ice-free, consistent with previous studies, and show Rayleigh wave sources remaining at consistent backazimuths throughout the duration of the array. Beamforming analysis of daily noise correlations shows that long-period double-frequency microseisms (9–11 s) consist predominantly of Rayleigh waves excited by …


Surface Offset And Slip Rates For The Winter Rim Fault System In The Summer Lake Basin, Oregon, Jennifer Hall Jan 2017

Surface Offset And Slip Rates For The Winter Rim Fault System In The Summer Lake Basin, Oregon, Jennifer Hall

All Master's Theses

The 66-km-long Winter Rim Fault (WRF) system, located in the northwestern Basin and Range Province, encompasses several Holocene fault scarps within the Summer Lake basin that include the WRF system, a normal fault divided into three segments: Slide Mountain (SMF), Winter Ridge, and Ana River (ARF), and the newly-mapped Thousand Springs fault (TSF). The current least-compressive stress field is oriented ~264° (Crider, 2001). The USGS estimates a slip rate of 0.43 mm/yr, earthquake magnitudes of 6.5-7.19, and recurrence interval of 3.1 ka (Crone et al., 2009). However, these estimates are only based upon ARF and the unfavorably slip-oriented SMF. With …


Estimating The Thickness Of An Ultrahigh-Pressure (Uhp) Terrane: Insights From Phase Equilibria Modelling And Zr-In-Rutile Thermometry, Dulan Area, North Qaidam Terrane, China, David Hernández Uribe Jan 2017

Estimating The Thickness Of An Ultrahigh-Pressure (Uhp) Terrane: Insights From Phase Equilibria Modelling And Zr-In-Rutile Thermometry, Dulan Area, North Qaidam Terrane, China, David Hernández Uribe

All Master's Theses

The North Qaidam UHP terrane, in western China, exposes minor UHP eclogites hosted by ortho- and paragneisses. In the southeastern part of the terrane, the Dulan area exposes eclogite with the mineral assemblage Grt + Omp ± Ky ± Ph ± Zo ± Qz/Coe. LASS U-Pb analyses of zircons yield weighted mean ages of 463-425 Ma, and REE patterns indicate that these ages record the eclogite-facies metamorphism. Inherited zircon cores yield ages of 928-905 Ma, and REE patterns indicate that the eclogite´s protolith had a magmatic origin. Zr-in-rutile thermometry reveals that Dulan eclogites record peak temperatures of 647-711°C. Spatially distributed …


Catastrophic Landscape Modification From Massive Landslide Tsunamis: An Example From Taan Fiord, Alaska, Colin Bloom Jan 2017

Catastrophic Landscape Modification From Massive Landslide Tsunamis: An Example From Taan Fiord, Alaska, Colin Bloom

All Master's Theses

The October 17th 2015 Taan landslide and tsunami generated a high runup of 192 m, nearly an order of magnitude greater than most previously surveyed tsunamis. Extensive modifications observed and documented on several low gradient fan deltas within the fiord make Taan Fiord an excellent laboratory for characterizing geomorphic signatures of a high runup tsunami event. Although interest in this topic is high, most prior post-tsunami surveys are from earthquake-generated tsunamis with relatively low runup, thus the geomorphic signatures of high runup tsunamis or their potential for preservation are uncharacterized. Additionally, clear modifications described during post-tsunami surveys are typically …


150 Years Of Light Absorbing Impurity Deposition On South Cascade Glacier, Washington State Usa, Dan Pittenger Jan 2017

150 Years Of Light Absorbing Impurity Deposition On South Cascade Glacier, Washington State Usa, Dan Pittenger

All Master's Theses

Glaciers and seasonal snowpack in Washington State have undergone significant decline over the past 50 years. While warming global temperatures are widely recognized as the cause of glacial decline, the deposition of black carbon (BC) can also contribute to increased melt. BC, commonly referred to as soot, is produced by the incomplete combustion of fossil and biofuels. These particles are subject to atmospheric transport and are deposited on snow by wind and precipitation events. When BC is deposited, it lowers the albedo of the glacial surface resulting in increased energy absorption and melt. We used a 158 m long ice …


Post-Wildfire Black Carbon Deposition On The Snowpack In The Cascade Range, Washington State: Temporal And Spatial Variability With Implications For Accelerated Melt, Ted Uecker Jan 2017

Post-Wildfire Black Carbon Deposition On The Snowpack In The Cascade Range, Washington State: Temporal And Spatial Variability With Implications For Accelerated Melt, Ted Uecker

All Master's Theses

Wildfires in the seasonal snow zone affect both snow accumulation and ablation patterns by decreasing forest canopy and depositing light absorbing impurities (LAI) on the snowpack. LAI such as black carbon (BC), burned woody debris, and dust reduce snow albedo (reflectance), accelerate melt, and affect the timing and availability of water resources. Charred trees in post-wildfire forests provide a significant source of BC that is deposited on the snowpack for years following a wildfire, and this effect varies with burn conditions and forest structure. Snow samples were gathered from five sites of varying burn age (0.7, 2.7, 3.8, and 9.8 …


Isotope Investigation Of Nitrate In Soils And Agricultural Drain Waters Of The Lower Yakima Valley, Washington, Dallin Jensen Jan 2017

Isotope Investigation Of Nitrate In Soils And Agricultural Drain Waters Of The Lower Yakima Valley, Washington, Dallin Jensen

All Master's Theses

Nitrate in the groundwater of the Lower Yakima Valley, Washington has long been known to frequently exceed the EPA maximum contaminant level standard for potable water (10 mg/L), adversely impacting communities with disadvantaged socio-economic status. In this research, nitrogen and oxygen isotopic signatures were determined for nitrate soil leachates and irrigation return flow collected in the Lower Yakima Valley, Washington and compared to previous isotopic studies of nitrate in Central Washington. δ15N, δ18O and Δ17O values are used to constrain sources of to groundwater. Isotope signatures for nitrate from soil leachate largely overlapped with …


Using Strontium Isotopes In Conjunction With Major, And Trace Elements To Identify Water/Rock Interaction In The Upper Kittitas County, Washington, James Patterson, Carey Gazis Jan 2017

Using Strontium Isotopes In Conjunction With Major, And Trace Elements To Identify Water/Rock Interaction In The Upper Kittitas County, Washington, James Patterson, Carey Gazis

All Master's Theses

The complex bedrock lithologies in the Upper Kittitas County provide an ideal setting for developing isotopic methodology to identify groundwater sources and track flow paths through water-rock interaction. A wide range of 87Sr/86Sr (0.7040 to 0.7068) in surface waters, springs, and groundwater from wells was found, allowing for identification of the individual signatures of lithologic units. Rock leachates from different lithology were compared to water samples to determine a general 87Sr/86Sr signature of the water-rock interaction for that lithology. The signatures identified were systematically lower than their associated waters, but similar enough to identify the expected 87Sr/86Sr of water-rock interaction …


Stratigraphy And Site Formation At The Sanders Site (45 Kt 315), Kittitas County, Washinton, James Mclean Jan 2017

Stratigraphy And Site Formation At The Sanders Site (45 Kt 315), Kittitas County, Washinton, James Mclean

All Master's Theses

The Sanders site (45KT315) was excavated in 1971 and 1972 by Central Washington State College under the direction of Dr. William Smith, then Associate Professor of Anthropology at CWSC. A total of 88 1 x 1 meter units were excavated up to 270 cm below surface. During the initial excavations and in subsequent student work, there was investigation of what would now be called site geoarchaeology, but this work was not reported in detail. In this thesis, I synthesize existing records on site stratigraphy and completed new field characterization and laboratory analyses to build a geoarchaeological summary for the site. …


Data Potential Of Archaeological Deposits At The Chelan Station Site, Matthew J. Breidenthal Jan 2017

Data Potential Of Archaeological Deposits At The Chelan Station Site, Matthew J. Breidenthal

All Master's Theses

The Chelan Station Site (45CH782/783), located along the Rocky Reach of the Columbia River, includes lithic and faunal artifacts buried beneath volcanic tephra from Mt. Mazama (6,830 BP). Artifacts were inadvertently discovered in buried soils within a secondary alluvial terrace during construction of a pipeline to supply water to the Beebe Springs Fish Hatchery. This thesis stems from participation in original field work and includes the author’s own models of early land forms and site formation. The study reviews the construction monitoring and archaeological testing of both sites, and documents the archaeological data potential early occupations of the vicinity. The …


Why Now?: A Case Study Of Split Estate And Fracking Activity In Garfield County Colorado, Janessa Zucchetto Jan 2017

Why Now?: A Case Study Of Split Estate And Fracking Activity In Garfield County Colorado, Janessa Zucchetto

All Master's Theses

This research examines the socio-environmental impacts associated with hydraulic fracturing activities and issues of split estate in Battlement Mesa Planned Unit Development in Garfield County, CO. Data for this research was collected during 2 months in the summer of 2015 using a series of ethnographic research methods. In doing so, this research adopts political ecology and political economy of nature as theoretical frameworks to understand the interconnections that exist between local impacts of fracking activities and a national strategy to secure gas markets internationally. I argue that the socio-environmental impacts associated with hydraulic fracturing in Garfield County, CO are not …


Tidal And Structural Controls On Seismic Events Near The Grounding Line At Beardmore Glacier, Antarctica, Jade Cooley Jan 2017

Tidal And Structural Controls On Seismic Events Near The Grounding Line At Beardmore Glacier, Antarctica, Jade Cooley

All Master's Theses

Here I report seismic events occurring over a three-week period during the 2013-2014 austral summer near the grounding line of Beardmore Glacier, Antarctica. The ~24000 events over this time frame had a noticeable temporal pattern that correlates well with the principally diurnal tides of Antarctica. Falling and rising tide each accounted for nearly equal occurrence of events, and most (~42%) events occurred in the last third of any tidal cycle. Event epicenters were located using beamforming, and display a spatial pattern of two distinct clusters. Appearance of event location clusters differ on rising and falling tide. I theorize that, due …