Earth Sciences Commons^™

Changes In Arctic Climate And Central U.S. Weather Patterns Is There A Link?, Donald A. Wilhite, Kimberly C. Morrow, Martha Shulski

National Drought Mitigation Center: Faculty Publications

Earlier snowmelt, decreasing soil moisture, decreased corn yields, increasing extreme precipitation events—these are some of the weather effects currently observed in the central United States that might well have their origin in the rapidly warming Arctic. These and other implications of Arctic warming were among the topics discussed at a fall 2015 workshop, Implications of a Changing Arctic on Water Resources and Agriculture in the Central U.S (Wilhite and Morrow 2016).

The United States assumed chairmanship of the Arctic Council in April 2015, making the workshop topic timely. Given the importance of the Midwest and Great Plains region as a …

Evaluation Of Satellite-Based Rainfall Estimates And Application To Monitor Meteorological Drought For The Upper Blue Nile Basin, Ethiopia, Yared Bayissa, Tsegaye Tadesse, Getachew B. Demisse, Andualem Shiferaw

National Drought Mitigation Center: Faculty Publications

Drought is a recurring phenomenon in Ethiopia that significantly impacts the socioeconomic sector and various components of the environment. The overarching goal of this study is to assess the spatial and temporal patterns of meteorological drought using a satellite-derived rainfall product for the Upper Blue Nile Basin (UBN). The satellite rainfall product used in this study was selected through evaluation of five high-resolution products (Climate Hazards Group InfraRed Precipitation with Stations (CHIRPS) v2.0, Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN), African Rainfall Climatology and Time-series (TARCAT) v2.0, Tropical Rainfall Measuring Mission (TRMM) and Africa Rainfall Estimate …

Geologic Map Of The Lima Peaks 7.5' Quadrangle, Beaverhead County, Montana, Betty Skipp, William J. Perry Jr., Susanne U. Jänecke

Geosciences Faculty Publications

The Lima Peaks quadrangle is located in southwestern Beaverhead County in southwestern-most Montana, near the southern terminus of the Beaverhead Mountains (fig. 1). Rocks and deposits of Mississippian through Quaternary age are present along the eastern margin of the Cretaceous to early Tertiary Sevier fold-and-thrust belt. This area is structurally complex because rocks of older, Laramide Blacktail-Snowcrest uplift (Perry and others, 1988; Skipp, 1988; Lonn and others, 2006).

Revised Structure And Correlation Of The Great Salt Lake, North Promontory, Rozel And Hansel Valley Fault Zones Revealed By The 2015-2016 Low Stand Of Great Salt Lake, Susanne U. Jänecke, James P. Evans

Geosciences Faculty Publications

Years of drought conspired to produce the present historic low stand in Gunnison Bay of Great Salt Lake. The lake has receded enough to expose the Great Salt Lake fault zone, and reveal its geometry through the shallow and clear lake water. We mapped the newly visible escarpments along the fault zone, upgraded the Utah fault map, and revised the regional correlation of the Great Salt Lake, Rozel, and North Promontory fault zones. We explored the origin of wave-cut platforms in the footwall of the faults, and identify geometrically unique types of microbial communities along faults and fault-related springs and …

Preservation Of Sea Anemone Burrows In Silurian (~432 Million Years Old) Carbonate Rocks Of Southeastern Indiana, Usa, Marissa Tomin

Williams Honors College, Honors Research Projects

Preservation of trace fossils (ichnofossils) in siliciclastic environments is often quite different from preservation in carbonate environments, representing an important source of variation that must be well understood in order to enhance interpretations of paleoenvironments and paleoecology. This study focuses on Conostichus, a relatively common burrow constructed by solitary sea anemones. These trace fossils are generally well-preserved (i.e., they display detailed external features) in siliciclastic rocks but are typically little more than conical masses in carbonate rocks. However, certain specimens recovered from the middle Silurian Massie Formation at the Napoleon quarry of southeastern Indiana are composed entirely out of …

Dam Removal In The Usa: Effects On River Water Quality, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Dam removal decisions should ideally be made after a thorough cost-benefit analysis. If dam obsolescence, structural safety, harm to fisheries, maintenance costs, and reservoir eutrophication are among the primary concerns, decommissioning would likely be favored. On the other hand, dams provide considerable benefits including water storage for agricultural and urban consumption, renewable electricity generation, support of navigational canal systems, flood control, and lakes for recreation. Because of these competing factors and interests, dam removal decision-making in the United States is often a slow process fraught with controversy, as in the case of the Klamath River.

Dams provided mechanical water power …

Experimental Biomechanics Of Trinucleid Fringe Pits (Trilobita), Kirk Pearson

Honors Papers

The morphometric uniqueness of the trinucleid family of fossil arthropods, known as the trilobites, has led to a considerable amount of attention in paleontology literature. In particular, the distinctive hourglass-shaped pits that dot their anterior have been the subject of debate for over a century. Though anatomically well understood, their function remains unknown. Many proposals have been suggested, including its use as a sieve for filter-feeding, a strong shield for defense, and a sensory mechanism to compensate for their blindness. Despite the wide range of speculations, no study has attempted to model these hypotheses experimentally. Flume experiments and mechanical strength …

Lithologic Stratigraphic Position, Sequence And Diagenetic History, Lower Mississippian Tripolitic Chert, Northern Arkansas And Southern Missouri, S. Mckim, J. Cains, J. Chick, F. Mcfarlin, A. Potra

Journal of the Arkansas Academy of Science

Tripolitic chert development in the southern Ozark region is associated with a third-order, transgressive-regressive cycle comprising St. Joe transgressive packstones, succeeded by lower Boone calcisiltites, with black, penecontemporaneous, nodular chert deposited during maximum flooding, overlain by basal upper Boone calcisiltites deposited during highstand. The onset of regression produced upper Boone packstones and grainstones with white-gray, later diagenetic chert reflecting groundwater replacement along bedding planes. Tripolitic chert is a product of the highstand calcisiltites at the base of the upper Boone Formation of Arkansas, and its equivalent, the Elsey Formation of southern Missouri. This tripolitic chert appears to reflect a hydrothermal …

Hydrothermally Emplaced, Lower Mississippian, Tripolitic Chert And Its Possible Relationship To The Tri-State Lead-Zinc Mining District, J. Chick, J. Cains, F. Mcfarlin, S. Mckim, A. Potra

Journal of the Arkansas Academy of Science

Across the southern Ozark Region, northern Arkansas, southwestern Missouri, and northeastern Oklahoma, exposures of the Lower Mississippian Boone Formation and its equivalents exhibit well-developed tripolitic chert that has been mined, more or less continuously, for at least 80 years. The tripolitic chert is a replacement of an interval within the basal portion of the upper Boone Formation in Arkansas and Oklahoma, and equivalent to the Elsey Formation in Missouri. The movement of silica-rich, hydrothermal fluids appears to have been much like that of a confined aquifer. It followed the basal upper Boone Formation (Arkansas) = Elsey Formation (Missouri) and was …

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

All Master's Theses

The October 17^th 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 …

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 …

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

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 …

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 …

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 …

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 …

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. …

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 …

Relationships Between Sequence Stratigraphy And Diagenesis Of Corals And Foraminifers In The Middle Eocene, Northern Egypt, Mohamed Tawfik, Abdelbaset S. El-Sorogy, Mahmoud Moussa

Turkish Journal of Earth Sciences

Outcrops of the Middle Eocene in northern Egypt represent a Tethyan reef-rimmed carbonate platform with bedded inner-platform facies. The diagenesis of these outcrops was studied in detail. The facies are characterized by a reef core, back reef and outer lagoon, shoal, inner lagoon, and tidal flat carbonate sequences. The diagenetic sequences on the scleractinian corals and foraminifers were thoroughly examined. These sequences show various diagenetic features during episodes of fluctuating sea levels and appear to be related to the primary composition of the studied components and the transgressive-regressive cycles. The carbonate diagenetic history of the examined samples successively includes marine-phreatic, …

Comparing Field And Laboratory Measurements Of Hydraulic Conductivity In The Mississippi Delta, Taylor Moore

Honors Theses

This research is part of a wider effort to investigate the decreasing water levels of the Mississippi River Valley Alluvial Aquifer (MRVAA), which is partially located in the Mississippi Delta in northwestern Mississippi. The extent of this research compares laboratory and field based measurements of saturated hydraulic conductivity, known as Ksat, in the vadose zone of the Delta. The soil samples used for the laboratory Ksat tests and textural analysis were collected at various depths from two boreholes near Sky Lake in Belzoni, Mississippi. Each sample was classified by Unified Soil Classification System (USCS) standards after being sieved and tested …

Glacial Deposits, Vol. 42, 2017, Department Of Geography, Geology, And The Environment

Glacial Deposits

Newsletter of the Department of Geography, Geology, and the Environment

A Comparison Of Benthic Macroinvertebrate Assemblages Between Perennial And Intermittent Headwater Streams Of The Mattole River In Northern California, Usa, Mason S. London

Cal Poly Humboldt theses and projects

Intermittent streams are common throughout the world and comprise 60% or more of total river lengths in the conterminous United States. Despite their prevalence, intermittent streams are understudied, particularly first-order headwater streams, which are vital for maintaining the function, health and biotic diversity of river networks. In June 2016, I sampled five intermittent and five perennial headwater streams in the Mattole River watershed in northwestern coastal California, USA, to compare benthic macroinvertebrate (BMI) assemblages between intermittent and perennial streams. BMI samples were collected using a 500µm mesh D-net at eight randomly located riffles along a 150-m reach, and then composited, …

Paleoecology Of Foraminifera From The Late Miocene - Early Pliocene Pullen And Saint George Formations, Northwestern California, Trenton J. Ryan

Cal Poly Humboldt theses and projects

The Pullen and Saint George formations are coeval late Miocene-early Pliocene sedimentary formations in northwestern California. The type localities of both formations were studied from a micropaleontologic perspective that focused primarily on Foraminifera, but with additional observations of other fossil groups to reconstruct their past depositional environments. The results obtained in this study provided a photomicrographic inventory of the microfossils from both formations, aided in investigating changes in paleobathymetry of the formations during the late Miocene and early Pliocene based on Foraminifera, and allowed for interpretation of paleoecological signals from the foraminiferan associations. Foraminifera have not been previously described in …

Spatial Variability Of The Depth To The Magma Reservoir Beneath The Yellowstone Caldera Inferred From Observations Of Seiche Loading Induced Strain, Kevin James Gryger

LSU Master's Theses

Seiche waves in Yellowstone Lake at ~78, ~51, and ~25 minute periods and heights <10 cm can cause measurable strain (< 40 ns) as observed on borehole strainmeters both near (<300 m) and far (~20 km) from the lake. Observations of the correlation between the seiche waves and the associated strain response can be used to constrain the rigidity of the upper crust, the depth to magma bodies in the subsurface, and the viscosity (related to melt percentage) of the magma bodies in place. Lake level was directly measured with campaign absolute pressure gauges deployed in the West Thumb basin, Breeze Channel, and central basin of Yellowstone Lake, and 13 large seiche events (¡Ý7 cm) were identified from these observations. Periodic strain transients were measured on borehole strainmeters in the caldera during the 13 large seiche events. The peak-to-trough amplitude and phase of the seiche wave and strain response were estimated by fitting a multi-frequency sinusoid to the time series over a 4-hour window during each seiche event. It was found that the relationship between an applied seiche load and the associated strain response is self-consistent and linearly proportional at each borehole strainmeter in the caldera. Over multiple seiche events the observed strain response is consistent with a modeled strain-field produced by a seiche load on a two-layered viscoelastic model defined by free parameters Young¡¯s modulus (E1), plate thickness (H), and shear modulus ratio (¦Ì2/¦Ì1). The two-layered viscoelastic model represents a solid upper crust overlying a partially molten body which may be small pockets of melt (<1 km thickness) or a larger magma reservoir. Results suggest crystallizing melt beneath Yellowstone caldera at depths (H) of ~4¨C8 km in the south-southeast and ~3-5 km in the north-northwest sections of the caldera. Temporal observations between strain meters, coupled with constraints of Young¡¯s and shear moduli suggest that melt in the shallow crust has a viscosity ¡Ü1013 Pa s.

Microseismic Event Characteristics Associated With The Spatial And Temporal Stages Of Hydraulic Fracture Growth In Laboratory Experiments, Abigail Arielle Maxwell

LSU Master's Theses

There are uncertainties in the exact mechanisms that occur during hydraulic fracture growth and the interactions of hydraulic fractures with pre-existing fractures. In some cases fracture growth is seen to be purely tensile and in others a combination of tensile and shear mechanisms. In order to develop a seismic model to explain fracture propagation, there is a need for a complete classification of the microseismic events occurring during fracturing using waveform characteristics such as frequency, duration and magnitude. This classification would allow for more accurate prediction of the behavior of the hydraulic fracture from its initiation to when it intersects …

Palynostratigraphy And Environmental Implication Of Organic-Walled Microfossils Recovered From Iodp Site U1435, Mitchell Clifford Gregory

LSU Master's Theses

Extensive studies have examined the syn- and post-rift sediments in the South China Sea and surrounding margins, but pre-rift, Eocene deposits are rare. Here we examine organic-walled microfossils from the South China Sea, recovered at Site U1435 of IODP Expedition 349 to provide palynostratigraphic control and characterize the environmental setting before, and in response to, the initiation of seafloor spreading in the basin ~33 Ma. The well preserved palynological assemblage recovered allow dating of sediments sampled at Site U1435. Units II and III are now subdivided in 4 subzones; Zone 1 is essentially barren, Zones 2 and 3A are assigned …

Shallow Shear-Wave Seismic Analysis Of Point Bar Deposits Of False River, Louisiana, Martial James Morrison

LSU Master's Theses

Current point-bar complex models do not include subsurface unit bars as a normal feature. This study provides evidence for a potential buried unit bar amongst point-bar sediments of the large-scale, modern-day False River point-bar complex of the Mississippi River. We collect, process and interpret a two-dimensional, 150-m-long CMP seismic reflection profile that cuts perpendicularly across a major discontinuity surface in the False River point bar complex. The seismic source consists of a ground recoil device that fires a shotgun shell horizontally, producing shear waves. Multiple field experiments demonstrated which type of source and receiver provided the least amount of noise, …

Sediment Infilling Of Louisiana Continental-Shelf Dredge Pits: A Record Of Sedimentary Processes In The Northern Gulf Of Mexico, Meg Cathlin O'Connor

LSU Master's Theses

Sediment cores were collected at continental-shelf sites of the Northern Gulf of Mexico off the coast of Louisiana to develop a better understanding of post-dredging evolution of mud-capped dredge pits. The two pits studied were Sandy Point (SP) and Raccoon Island (RI) (both with water depths of ~10m and dredged to ~ 15-20 m below water surface), which were dredged in 2012 and 2013 respectively. Vibracores and multicores were collected in 2015. Preliminary radiochemistry analyses identified Beryllium-7 distribution in multicore samples from both sites. SP1, the northwestern site in the Sandy Point dredge pit, showed 26 cm of 7Be penetration. …

The Relationship Between The Timing Of Hydrocarbon Generation Between The Bristol Bay Depositional Basin And The Port Moller Area And Southern Portion Of The Bristol Bay Basin Of The Alaska Peninsula, Claire Rochelle Jones

LSU Master's Theses

The Alaska Peninsula has been the target of oil and gas exploration throughout much of the 20th century. Although most exploration efforts have focused on the Cook Inlet area, the geological setting of the Alaskan Peninsula suggests that economically viable resources may be located further south on the northern side bordering Bristol Bay (Port Moller area). This study investigates the relation of petroleum system elements between the northern and southern section of the Alaskan Peninsula with a particular focus on the potential for petroleum accumulation on the southern section close to Herendeen Bay. The analysis included the integration of a …