Geophysics and Seismology Commons^™

New U–Pb Geochronology For The Central Atlantic Magmatic Province, Critical Reevaluation Of High-Precision Ages And Their Impact On The End-Triassic Extinction Event, Alisson L. Oliveira, Mark D. Schmitz, Corey J. Wall, James L. Crowley, Antomat A. Macêdo Filho, Maria Helena B. M. Hollanda

Geosciences Faculty Publications and Presentations

The end-Triassic extinction (ETE) event represents one of the ‘big five’ episodes of mass extinction. The leading hypothesis for the cause of the ETE is the intrusion of voluminous magmas of the Central Atlantic Magmatic Province (CAMP) into carbon-rich sediments of two South American sedimentary basins, around 201.5 Ma. The timing of dikes and sills emplacement, however, must be considered in light of age models from CAMP rocks occurring in North America. In this work, we present new high-precision ages for critical samples in NE Brazil (201.579 ± 0.057 Ma) and Canada (201.464 ± 0.017 Ma), in order to evaluate …

Geophysical Characterization Of Underground Storage In Salt Domes During The Clean Energy Transition, Joses B. Omojola

LSU Master's Theses

Safely transforming geological formations into cost-effective underground storage is critical for the US energy security and global energy transition. Seasonal energy demand requires relatively cheap, impermeable, non-reactive materials for storing vast amounts of natural gas and hydrogen. Due to their low risk of fracturing and leakage, salt formations are ideal for these purposes however, pressure variations during drawdown, differential salt creep, and reactivation of pre-existing fractures along boundary shear zone(s) (BSZ) can be detrimental to salt cavern safety and long-term cavern operations. Several environmental disasters at storage facilities in the US and Europe, have created a need to understand how …

Critical Workforce Skills For Bachelor-Level Geoscientists: An Analysis Of Geoscience Job Advertisements, G. W. Shafer, K. Viskupic, A. E. Egger

Geosciences Faculty Publications and Presentations

Understanding the skills bachelor-level geoscientists need to enter the workforce is critical to their success. The goal of this study was to identify the workforce skills that are most requested from a broad range of geoscience employers. We collected 3668 job advertisements for bachelor-level geoscientists and used a case-insensitive, code-matching function in Matlab to determine the skills geoscience employers seek. Written communication (67%), field skills (63%), planning (53%), and driving (51%) were most frequently requested. Field skills and data collection were frequently found together in the ads. Written communication skills were common regardless of occupation. Quantitative skills were requested less …

Tectonomagmatic Evolution Of Southwestern Laurentia: Insights From Zircon U-Pb Geochronology And Hafnium Isotopic Composition Of The Red Bluff Granite Suite, West Texas, Usa, Munazzam Ali Mahar, Philip C. Goodell, Jason W. Ricketts, Eric J. Kappus, James L. Crowley, Anthony M. Alvarez

Geosciences Faculty Publications and Presentations

We provide laser ablation–multicollector–inductively coupled plasma–mass spectrometry (LA-MC-ICP-MS) and high-precision chemical abrasion–isotope dilution–thermal ionization mass spectrometry (CA-ID-TIMS) U-Pb ages and Hf isotopic compositions of zircons from the Red Bluff Granite Suite and mafic dikes in the Franklin Mountains of El Paso, Texas, USA. Granitoids exposed in the Franklin Mountains were previously divided into five magmatic stages based on cross-cutting relationships. Major and trace element compositions showed that these granitoids are ferroan, alkaline, and A2 type. Homogeneity in the whole-rock geochemistry suggests that the granite stages are genetically related and share similar petrogenetic histories. Weighted mean zircon ²⁰⁶Pb/²³⁸U …

Advances In Our Understanding Of Pyroclastic Current Behavior From The 1980 Eruption Sequence Of Mount St. Helens Volcano (Washington), Usa, Brittany D. Brand, Aaron A. Marshall

Geosciences Faculty Publications and Presentations

This review summarizes what the volcanology community has learned thus far from studying the deposits of pyroclastic currents (PCs) from the 1980 eruption sequence at Mount St. Helens. The review includes mass flow events during the May 18 eruption, including the lateral blast, the afternoon column collapse and boil-over PC activity, and some aspects of the debris avalanche. We also include a summary of PCs generated in the smaller eruptions following the climactic May 18 event. Our objective is to summarize the state of our understanding of PC transport and emplacement mechanisms from the combination of field and laboratory observations, …

New Insights Into The Age And Origin Of Two Small Cretaceous Seamount Chains Proximal To The Northwestern Hawaiian Ridge, Arturo Sotomayor, Andrea Balbas, Kevin Konrad, Anthony A. P. Koppers, Jasper G. Konter, V. Dorsey Wanless, Thomas F. Hourigan, Christopher Kelley, Nicole Raineault

Geosciences Faculty Publications and Presentations

The Northwestern Hawaiian Ridge is an age-progressive volcanic chain sourced from the Hawaiian mantle plume. Proximal to the Northwestern Hawaiian Ridge are several clusters of smaller seamounts and ridges with limited age constraints and unknown geodynamic origins. This study presents new bathymetric data and ⁴⁰Ar/³⁹Ar age determinations from lava flow samples recovered by remotely operated vehicle (ROV) from two east–west-trending chains of seamounts that lie north of the Pūhāhonu and Mokumanamana volcanoes. The previously unexplored Naifeh Chain (28°48′N,167°48′W) and Plumeria Chain (25°36′N, 164°35′W) contain five volcanic structures each, including three guyots in the Naifeh Chain. New ^{40 …}

Quantifying Oil And Gas Industry Related Geohazard Using Radar Interferometry And Hydro-Geomechanical Modeling, Weiyu Zheng

Earth Sciences Theses and Dissertations

The Permian Basin, containing a large amount of oil and gas, has been intensively developed for hydrocarbon production. However, the hazards related to the oil and gas industry including surface deformation and the underlying mechanisms in this region have not been well known. My PhD study aims to monitor the geohazards in the Permian Basin and better comprehend the subsurface mechanisms with the aid of high-resolution and high-accuracy Interferometric Synthetic Aperture Radar (InSAR) images. Generally, as the pore pressure is influenced by wastewater injection/hydrocarbon production, the pressure changes can propagate to other surrounding underground and overlying rock/soil layers, resulting in …

Benthic Habitat Mapping Of Mountain Top Bank Within The Northern Gulf Of Mexico Through Integrated Geophysical And Visual Data Analysis, Bethany Pertain

Master's Theses

Mesophotic coral ecosystems (MCEs) are among the seafloor ecosystems that have been poorly studied throughout the world’s oceans, but they are a vital and diverse ecosystem that should be prioritized for future mapping and ecological studies. Priority should be given to them because they possess natural, social, and economic values, and face a variety of threats, all of which, if not better understood will result in the loss of this unique ecosystem. Insights into these ecosystems, among other deep-sea environments, are lacking due to difficulty accessing them, inherent lag between data collection by an autonomous system and observation by a …

Dynamic Mass Loss From Greenland's Marine-Terminating Peripheral Glaciers (1985–2018), Katherine E. Bollen, Ellyn M. Enderlin, Rebecca Muhlheim

Geosciences Faculty Publications and Presentations

Global glacier mass balance decreased rapidly over the last two decades, exceeding mass loss from the Greenland and Antarctic Ice Sheets. In Greenland, peripheral glaciers and ice caps (GICs) cover only ~5% of Greenland's area but contributed ~20% of the island's ice mass loss between 2000 and 2018. Although Greenland GIC mass loss due to surface meltwater runoff has been estimated using atmospheric models, mass lost to changes in ice discharge into oceans (i.e., dynamic mass loss) remains unquantified. We use the flux gate method to estimate discharge from Greenland's 585 marine-terminating peripheral glaciers between 1985 and 2018, and compute …

Lidar And Deep Learning Reveal Forest Structural Controls On Snowpack, Ahmad Hojatimalekshah, Joel Gongora, Josh Enterkine, Nancy F. Glenn, T. Trevor Caughlin, Hans-Peter Marshall, Christopher A. Hiemstra

Geosciences Faculty Publications and Presentations

Forest structure has a strong relationship with abiotic components of the environment. For example, canopy morphology controls snow depth through interception and modifies incoming thermal radiation. In turn, snow water availability affects forest growth, carbon sequestration, and nutrient cycling. We investigated how structural diversity and topography affect snow depth patterns across scales. The study site, Grand Mesa, Colorado, is representative of many areas worldwide where declining snowpack and its consequences for forest ecosystems are increasingly an environmental concern. On the basis of a convolution neural network model (R² of 0.64; root mean squared error of 0.13 m), we …

Sediment Transport And Geomorphological Evolution In The Northern Gulf Of Mexico, Kelli Moran

LSU Doctoral Dissertations

This dissertation explores the mechanisms driving sediment transport and deposition on the continental shelf and within the bays of the northern Gulf of Mexico via a suite of geophysical methods and sediment cores on a variety of timescales. This dissertation is comprised of three main chapters, each focusing on a different location, environment, and process but tied together using geophysical survey, a thematic focus on geomorphic change and sediment transport within the deltaic cycle and deltaic plain environments, and the implications this change poses for both past and future sediment transport and environmental change in response to sea level change. …

The Kanarra Fold-Thrust Structure - The Leading Edge Of The Sevier Fold-Thrust Belt, Southwestern Utah: Geology Of The Intermountain West, William J. Chandonia, John P. Hogan

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The multiple origins proposed for the Kanarra anticline in southwestern Utah as a drag-fold along the Hurricane fault, a Laramide monocline, a Sevier fault-propagation fold, or a combination of these process­es, serve to muddy its tectonic significance. This in part reflects the structural complexity of the exposed eastern half of the fold. The fold evolved from open and up-right to overturned and tight, is cross-cut by multiple faults, and was subsequently dismembered by the Hurricane fault. The western half of the fold is obscured because of burial, along with the hanging wall of the Hurricane fault, beneath Neogene and younger …

Operational Water Forecast Ability Of The Hrrr-Isnobal Combination: An Evaluation To Adapt Into Production Environments, Joachim Meyer, John Horel, Patrick Kormos, Andrew Hedrick, Ernesto Trujillo, S. Mckenzie Skiles

Geosciences Faculty Publications and Presentations

Operational water-resource forecasters, such as the Colorado Basin River Forecast Center (CBRFC) in the Western United States, currently rely on historical records to calibrate the temperature-index models used for snowmelt runoff predictions. This data dependence is increasingly challenged, with global and regional climatological factors changing the seasonal snowpack dynamics in mountain watersheds. To evaluate and improve the CBRFC modeling options, this work ran the physically based snow energy balance iSnobal model, forced with outputs from the High-Resolution Rapid Refresh (HRRR) numerical weather prediction model across 4 years in a Colorado River Basin forecast region. Compared to in situ, remotely sensed, …

The Geology Of El Paso, William Cornell, Diane Doser, Richard Langford, Joshua Villalobos, Jason Ricketts

Books & Monographs

The Geology of El Paso describes the history of El Paso, Texas and its surrounding region from the Precambrian formation of the continent to the modern use of geologic resources. This book is written in an easy to digest format, with definitions or links for specific geologic terms and references for further reading. It reviews the formation and evolution of local landmark features such as the Franklin Mountains, Cerro Cristo Rey, and the Sierra de Juarez. Fossils and stratigraphic units of the El Paso area are described as well as important geologic features. The book puts the events that shaped …

Magnetic Anomaly Data Products Of The Central And Eastern United States, Dhananjay Ravat

Earth and Environmental Sciences Research Data

This data set contains Central and Eastern U.S. Magnetic Anomaly, DRTP, Tilt Derivative, and Analytic Signal Amplitude Products ultimately derived from Ravat, D., Finn, C., Hill, P., Kucks, R., Phillips, J., Blakely, R., Bouligand, C., Sabaka, T., Elshayat, A., Aref, A., and Elawadi, E., 2009, A preliminary, full spectrum, magnetic anomaly grid of the United States with improved long wavelengths for studying continental dynamics--A website for distribution of data: U.S. Geological Survey Open- File Report 2009–1258, 2 p.

Precise Zircon U-Pb Dating Of The Mesoproterozoic Gawler Large Igneous Province, South Australia, Elizabeth A. Jagodzinski, Anthony J. Reid, James L. Crowley, Claire E. Wade, Stacey Curtis

Geosciences Faculty Publications and Presentations

The Mesoproterozoic Gawler Range Volcanics and Benagerie Volcanic Suite of the Gawler Craton and Curnamona Province, South Australia, together with associated intrusive magmatism, define an intracontinental, subaerial large igneous province (LIP) preserving an estimated 110 000 km³ of volcanic rock, which hosts one of the world's largest orebodies, the Fe oxide-Cu-Au-U deposit at Olympic Dam, and numerous other related Cu-Au deposits. New high-precision Chemical Abrasion Isotope Dilution Thermal Ionization Mass Spectrometry (CA-TIMS) U-Pb dates on volcanic zircons allow for regional correlations between stratigraphic units of the GRV and BVS, and an understanding of how magmatic styles, temperatures, composition and …

Drivers Of Spatiotemporal Patterns Of Surface Water Inputs In A Catchment At The Rain-Snow Transition Zone Of The Water-Limited Western United States, E. Trujillo, J. Mcnamara

Geosciences Faculty Publications and Presentations

Spatial and temporal dynamics of rainfall and snowmelt (i.e., surface water inputs, SWI) control soil moisture, groundwater recharge, and streamflow at annual, seasonal, and event scales. In the rain-snow transition zone, comprising a large portion of the mountainous western United States, there is limited understanding of the sensitivity of spatiotemporal SWI dynamics across hydrologically variable water years (WYs). We modeled rainfall and snowpack dynamics in a small headwater catchment (1.8 km²) spanning the rain-snow transition in southwestern Idaho, USA, for two hydrologically distinct WYs (2011 and 2014). In wet WY 2011 and dry WY 2014, total precipitation drove …

Elastic Thermobarometry, Matthew J. Kohn, Mattia L. Mazzucchelli, Matteo Alvaro

Geosciences Faculty Publications and Presentations

Upon exhumation and cooling, contrasting compressibilities and thermal expansivities induce differential strains (volume mismatches) between a host crystal and its inclusions. These strains can be quantified in situ using Raman spectroscopy or X-ray diffraction. Knowing equations of state and elastic properties of minerals, elastic thermobarometry inverts measured strains to calculate the pressure-temperature conditions under which the stress state was uniform in the host and inclusion. These are commonly interpreted to represent the conditions of inclusion entrapment. Modeling and experiments quantify corrections for inclusion shape, proximity to surfaces, and (most importantly) crystal-axis anisotropy, and they permit accurate application of the more …

Pacific Northwest Streamflow Data Landscape: A Report From The 2022 Streamflow Data Roundtables, Kendra E. Kaiser

Geosciences Faculty Publications and Presentations

This project was funded by the U.S. Geological Survey Northwest Climate Adaptation Science Center to catalog the location, temporal extent and purpose of non-USGS streamflow datasets. As part of this project, roundtable meetings convened local, state and federal agencies, and nonprofits to explore the complexity of gathering and integrating the identified datasets and identify issues surrounding data-sharing across organizations.

This report synthesizes discussions from each of the state roundtable discussions convened in the spring of 2022, and highlights common challenges and needs across the region. Additional information from organizations not able to be present at the meetings were added after …

New Age Constraints On The Break-Up Of Rodinia And Amalgamation Of Southwestern Gondwana From The Choquequirao Formation In Southwestern Peru, Eben Blake Hodgin, Victor Carlotto, Francis A. Macdonald, Mark D. Schmitz, James L. Crowley

Geosciences Faculty Publications and Presentations

The Choquequirao Formation is a >3 km-thick amphibolite-grade succession that outcrops in the Central Andes of southern Peru. To constrain its age and tectonostratigraphic setting, detrital zircon and metamorphic zircon, titanite, and rutile U–Pb isotopic analyses were conducted. Mantle-derived c. 640 Ma detrital zircons constrain the maximum age of the lower part of the succession and 550–490 Ma metamorphic zircon domains constrain its minimum age. The absence of early Paleozoic detrital zircons suggests that deposition predated early Paleozoic orogenesis in southwestern Gondwana. The close similarity of detrital zircon age spectra to those from sediments deposited on the Arequipa basement suggests …