Geology Commons^™

Geomorphic Response To Catastrophic Flooding In A Karst Mountain Stream System, Brighton-Blue Hole Watershed, Southwest Jamaica, Sarah M. Letarte

Graduate Theses/Dissertations

The geomorphic effects of flooding are poorly understood in the karst, mountain watersheds along the southwest coast of Jamaica. This study describes the flow path and geomorphic response of an extreme flood event in the Brighton-Blue Hole watershed (BBHW) (6.8 km²) near Belmont, Westmoreland, Jamaica. A tropical depression classified as a >100-year rainfall event produced 32 inches of rain in a 24 hour period in Westmoreland on June 12, 1979. For this study, geomorphic indicators of flood disturbance in BBHW were assessed in 2017-18, finding that channel system responded to the flood with channel incision, debris flows, and …

Detecting Ocean Microplastics With Remote Sensing In The Near-Infrared: A Feasibility Study, Jandlyn Bentley

Honors Program Theses and Projects

Since plastic began entering the oceans in the 1950s, trends have shown that this pollution has been and will continue to increase in the future. The only method to estimate the abundance and distribution of ocean plastic pollution is by computer-generated models using data from in-situ plankton net tows, which are costly, time consuming, and cover a relatively small scale. This project investigates the potential of detecting ocean microplastics with satellite remote sensing based on theoretically elevated near-infrared (NIR) reflectance. Emphasis was placed on the Great Pacific Garbage Patch in the North Pacific Ocean, notorious for its extremely high concentration …

Floodwater Impact On Galveston Bay Phytoplankton Taxonomy, Pigment Composition And Photo-Physiological State Following Hurricane Harvey From Field And Ocean Color (Sentinel-3a Olci) Observations, Eurico D'Sa

Faculty Publications

Phytoplankton taxonomy, pigment composition and photo-physiological state were studied in Galveston Bay (GB), Texas (USA), following the extreme flooding associated with Hurricane Harvey (25-29 August 2017) using field and satellite ocean color observations. The percentage of chlorophyll a (Chl a) in different phytoplankton groups was determined from a semi-analytical IOP (inherent optical property) inversion algorithm. The IOP inversion algorithm revealed the dominance of freshwater species (diatom, cyanobacteria and green algae) in the bay following the hurricane passage (29 September 2017) under low salinity conditions associated with the discharge of floodwaters into GB. Two months after the hurricane (29-30 October 2017), …

Glacial Meltwater Modeling To Simulate Streamflow And Lake Levels In Taylor Valley, Antarctica, Julian M. Cross, Andrew G. Fountain

Student Research Symposium

The McMurdo Dry Valleys (MDV) are the largest ice-free region (4,500 km²) in Antarctica. The MDV are a polar desert with an average annual temperature of -18˚C and minimal precipitation, < 50 mm w.e. a^-1. In Taylor Valley (77°35’ S, 163°00’ E), a closed-basin, perennially ice-covered lakes occupy the valley floor. Ephemeral streams transfer glacier meltwater for ~10 weeks each summer. Glacial meltwater accounts for nearly the total inflow to these streams and lakes, groundwater is essentially non-existent. A microbially-dominated ecosystem in Taylor Valley depends on glacier runoff and thus is highly sensitive to changes to the hydroclimatic regime. A model …

Cluster Chondrite Accretion Temperatures Determined With Electron Backscatter Diffraction, Secana Goudy, Alexander Ruzicka

Student Research Symposium

We studied ordinary chondrites with cluster chondrite lithologies using electron backscatter diffraction to measure the temperatures of their olivine grains during deformation. Samples analyzed with the technique are shock classified as S1 and are type 3, so the deformation analyzed is inferred to represent the temperatures of the chondrules during accretional deformation. It was found that the studied samples are of a mixture of chondrules at mostly hot temperatures (>850°C) and some at cold.

Multi-Proxy Characterization Of Acex Subunit 1/5 (The “Zebra” Interval) To Better Understand Sediment Deposition At This Critical Age Boundary And Paleoceanographic Transition, Victoria Hojnacki

Senior Honors Projects, 2010-2019

Sediment cores recovered from the Lomonosov Ridge on IODP Expedition 302, the Arctic Coring Expedition (ACEX), provided the first major insights into long-term Cenozoic history of climate and ocean conditions in the central Arctic. However, the ACEX record is hampered by a major hiatus or severely condensed interval (depending on age-model interpretations) at 198.7 mcd separating the middle Eocene and Miocene records. Lithologic subunit 1/5 lies above this depth horizon, and is informally called the “zebra interval” because of distinctive stripes - black and gray tilted and cross-banded silty-clay layers, up to 3 cm thick that characterize the lower ~2.5 …

Soil Capability Assessment For Expanding Irrigated Agriculture In The Irwin Focus Area And Surrounding Lands, Edward (Ted) Arnold Griffin, Angela Stuart-Street, Peter Tille

Resource management technical reports

The Midlands groundwater and land assessment is a $4.7 million Water for Food project using Royalties for Regions funding. It is seeking to confirm groundwater availability in focus areas that may form precincts of 2000–3000ha suitable for intensive irrigated horticulture. Irwin is one of these.

The Department of Water identified the Irwin focus area for investigation for irrigated agriculture potential. It covers almost 7000ha to the east of Dongara in the Mid West region of Western Australia.

This report provides the land assessment for the Irwin area. We expanded the investigation to include land outside of the focus area because …

Assessing Paleoenvironmental And Geomorphic Variability In Relationship To Paleoindian Site Burial; Centennial Valley, Montana, Hillary A. Jones

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wave action along the shores of Lima Reservoir in Centennial Valley, Montana is actively eroding the southern margins of three neighboring Paleoindian sites. Despite ostensible similarity among the sites, major site formation differences are apparent in exposed sediments. Shoreline cutbank exposures one-to-five meters high connect the sites and reveal a complicated geomorphic history. Although each site contains artifact evidence of terminal Pleistocene-early Holocene occupations, Paleoindian components at these three localities occur in very different contexts: one is buried, while the other two are apparent surface scatters. This raise the question of why sites of the same age are in both …

Micro- To Macro-Scale Structural And Lithological Architecture Of Basal Nonconformities: Implications For Fluid Flow And Injection Induced Seismicity, Garth Hesseltine

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rising incidents of earthquakes caused by human activity in the United States, known as induced earthquakes, is a growing concern. Induced earthquakes may occur when fluid and/or wastewater is injected several kilometers beneath the Earth’s surface into sedimentary rocks. Fluids and pressures can migrate from the sedimentary rocks, which are typically friendlier to fluid flow, into underlying less friendlier crystalline rocks along fluid pathways weakening and possibly reactivating preexisting faults. Understanding potential fluid pathways and/or barriers from the sedimentary rocks to crystalline rocks is crucial. I investigate the structure, composition, and heterogeneity of rocks near the contact between the sedimentary …

Facies And Diagenesis Analyses Of The Fort Terrett Formation Of The Lower Cretaceous Edwards Group, Near Junction, Texas, Richard Alden Urwin Jr.

Electronic Theses and Dissertations

The Fort Terrett Formation was deposited on the western edge of the Comanche Shelf in central Texas. The predominate lithology of the Fort Terrett Formation is limestone which caps the hills that surround Junction, Texas. Deposition of the Fort Terrett Formation occurred within shallow, quiet waters during the Lower Cretaceous. Rose (1974) developed a general stratigraphic correlation and lithostratigraphic framework for the Cretaceous Shelf and established a regional correlation. Four stratigraphic divisions have been recognized in the Fort Terrett Formation. These are: a basal nodular unit, a burrowed unit, a dolomitic unit, and the Kirschberg evaporites. Wilkerson (2018) provided the …

Petrogenesis Of Off-Axis Lavas Erupted Along The 8˚20’ N Seamount Chain, East Pacific Rise, Molly Kassandra Anderson

Boise State University Theses and Dissertations

Lavas erupted at off-axis seamounts provide a window into mantle heterogeneity and melting systematics that are not easily observed on-axis at fast spreading mid-ocean ridges (MORs). This is because axial melts are efficiently mixed and homogenized within shallow axial magma chambers prior to eruption. To understand the deeper magmatic processes contributing to oceanic crustal formation, we examine the compositions of lavas erupted along a chain of off-axis seamounts, adjacent to the East Pacific Rise (EPR). Essential questions include: (1) What is the range of compositional variability erupted off-axis and how does that compare to lavas erupted on-axis? (2) Is there …

A Bayesian Framework For Estimating Seismic Wave Arrival Time, Hua Zhong

Graduate Theses and Dissertations

Because earthquakes have a large impact on human society, statistical methods for better studying earthquakes are required. One characteristic of earthquakes is the arrival time of seismic waves at a seismic signal sensor. Once we can estimate the earthquake arrival time accurately, the earthquake location can be triangulated, and assistance can be sent to that area correctly. This study presents a Bayesian framework to predict the arrival time of seismic waves with associated uncertainty. We use a change point framework to model the different conditions before and after the seismic wave arrives. To evaluate the performance of the model, we …

Petrogenesis Of Unusual Occurrence Of Amphibole Asbestos In Mohave County, Arizona And Clark County, Nevada, Tomoyo Austin

UNLV Theses, Dissertations, Professional Papers, and Capstones

The term “asbestos” applies to six types of fibrous amphiboles or chrysotile with specific morphologies that are commercially mined and processed. Inhaling asbestos fibers is known to cause many negative health effects, including mesothelioma, several different cancers, various respiratory diseases and non-respiratory diseases, and fatalities. The recent years, several cases of non-occupational exposure to asbestos fibers raised an awareness of environmental exposure to naturally occurring asbestos (NOA) which refers to asbestiform minerals that fall out of the regulatory definition of asbestos.

There are two sources of NOA in the area, Wilson Ridge pluton, AZ, and Boulder City pluton, NV which …

Early Contractional History Of The Funeral Mountains And Its Influence On The Formation Of The Funeral Mountains Metamorphic Core Complex, Death Valley, Ca, Taylor Douglas Craig

UNLV Theses, Dissertations, Professional Papers, and Capstones

Zones of localized crustal thickening in orogenic belts commonly host low-angle normal faults, which have been controversial since their recognition. The metamorphic core complexes of the Sevier hinterland are localized within a belt that is attributed with the highest degrees of crustal thickening during Sevier orogenesis. This association of deep-rooted detachment faulting and early contractional deformation indicates an important link between the two processes, however repeated tectonic episodes often overprint and obscure the earlier fabrics, making this link difficult to study. The Funeral Mountains metamorphic core complex, located in Death Valley, CA, has a complex history of protracted SE-contraction and …

Mountain-Block Recharge To The Cache Valley Principal Aquifer And Geochemical Controls On Groundwater Movement In Alpine Karst, Skyler J. Sorsby

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Groundwater is documented to flow through solution-widened fractures and bedding planes in limestone and dolostone units in low-relief topography. This enhancement, or karstification, is much harder to study in alpine environments like the Bear River Range of northern Utah. This is problematic, due to the fact that the Bear River Range karst aquifer system supplies the City of Logan with a large quantity of water at Dewitt Spring. Furthermore, the karst aquifer sustains the Logan River for much of the year, and may allow groundwater to flow directly in the subsurface to the Cache Valley principal aquifer system.

Flow measurements …

Geochemical Analysis Of Mississippian Cherts And Devonian-Mississippian Novaculites, Southern Midcontinent Region, Julie Mary Cains

Graduate Theses and Dissertations

This study uses trace elements and radiogenic isotopes (Pb, Sr, and Nd) to investigate the origin and mode of formation for the siliceous deposits in the Lower Mississippian Boone Formation and the Devonian-Mississippian Arkansas Novaculite in the southern midcontinent. Mississippi Valley-type Pb-Zn ore deposits in the Tri-State District and the Northern Arkansas District were deposited by hydrothermal fluids, and highly radiogenic Pb isotope ratios suggest a genetic relationship between the Boone Formation chert (206Pb/204Pb ~ 21.59, 207Pb/204Pb ~ 15.87, 208Pb/204Pb ~ 40.10) and the MVT ores. Due to the very low concentration of Pb in the Boone chert (~2 ppm) …

Petrogenesis Of The El Rechuelos Rhyolite, Jemez Mountains Volcanic Field, New Mexico, Usa, Kelsy Jo Konkright

UNLV Theses, Dissertations, Professional Papers, and Capstones

The El Rechuelos Rhyolite represents volcanic activity preceding the multiple caldera collapse events of the Jemez Mountains volcanic field (JMVF) in northern New Mexico. This study focuses on seven rhyolitic units clustered north of the Valles caldera. These units have been studied in order to interpret their relationships to one another and the eruptive history of the JMVF. Additionally, this study adds to the research on the relationships between effusive and explosive rhyolitic volcanism, and understanding how caldera-forming eruptions develop from silicic systems.

Limited previous research includes K/Ar dates and a few inconsistent 40Ar/39Ar dates, in addition to whole rock …

Analysis Of Small Faults In A Sandstone Reservoir Analog, San Rafael Desert: Implications For Fluid Flow At The Reservoir-Scale, Leslie Noël Clayton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We examined small-displacement faults in the Jurassic Entrada Sandstone adjacent to the Iron Wash Fault, central Utah east of the San Rafael Swell, in order to describe the nature and timing of past fluid movement and deformation in the Entrada Sandstone. Using field studies, microscopy, and X-ray diffraction analysis, we identified mineralized fractures and cementation features in association with deformation bands and fractures at the interface of the Earthy and Slick Rock Members of the Entrada Sandstone.

Where the faults cross the Earthy-Slick Rock Member interface, deformation band faults in the Slick Rock Member become opening-mode fractures in the Earthy …

Ediacaran Depositional Age And Subsequent Fluid-Rock Interactions In The Mutual And Browns Hole Formations Of Northern Utah, Ashley W. Provow

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Constraining the depositional age of Neoproterozoic stratigraphy in western North America has implications for correlating global glaciation and tectonic events. The depositional ages of the Neoproterozoic Mutual and Browns Hole formations of northern Utah are controlled by two conflicting datapoints. However, new U-Pb geochronological data from 95 detrital apatite grains refines the maximum depositional age of the volcanic member of the Browns Hole Formation to 613 ± 12 Ma (2σ). This places new restrictions on the time available for the deposition of underlying units. Due to debate regarding the age models for underlying stratigraphy, two scenarios for sediment accumulation rates …

Structural Control Of Thermal Fluid Circulation And Geochemistry In A Flat-Slab Subduction Zone, Peru, Brandt E. Scott

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hot spring geochemistry from the Peruvian Andes provide insight on how faults, or fractures in the Earth's crust, are capable of influencing fluid circulation. Faults can either promote or inhibit fluid flow and the goal of this study is test the role of a major fault, such as the Cordillera Blanca detachment, as a channel for transporting deep fluids to the surface. Hot springs are abundant in the Cordillera Blanca and Huayhuash ranges in Peru, and several springs issue along the Cordillera Blanca detachment, making this region an ideal setting for our study. To test the role of the Cordillera …