Volcanology Commons^™

Trace Element And Isotopic Fingerprinting Of Olivine Phenocrysts As Recorders Of Magmatic Processes In The Golden Trout Volcanic Field, Kern Plateau, Ca, Mark E. Szymanski

Cal Poly Humboldt theses and projects

Quaternary mafic volcanism in the western Basin and Range and in the southeastern Sierra Nevada is largely controlled by extensional stresses that promote magma generation through decompression melting of the lithospheric and asthenospheric mantle. Where volcanism occurs in the Sierra Nevada, like at the Golden Trout Volcanic Field GTVF), the eruption rate, number of vents, and eruption volume is an order of magnitude less than at neighboring Basin and Range volcanic fields such as the Big Pine Volcanic Field (BPVF). To determine the factors that cause these differences in adjacent and contemporaneous volcanic fields, I sampled rocks from both fields …

Giant Plagioclase In The Steens Basalt, Se Oregon: Cumulate Entrainment Revealed By Textural And In Situ Chemical Analysis, Conner H. Toth

All Master's Theses

Many of the lava flows comprising the Steens Basalt in SE Oregon, the oldest and most mafic formation of the Columbia River Basalt Group (CRBG), contain exceptionally large (up to 5 cm) and abundant (up to 40 modal %) plagioclase crystals. This thesis presents a model for giant plagioclase formation in a complex system that integrates petrographic and in situ plagioclase compositional analyses with whole-rock data and computational modeling to explain systematic textural and chemical differences between plagioclase of the lower and upper Steens Basalt sub-sections. Lower Steens plagioclase are typically more chemically homogenous than upper Steens plagioclase and exhibit …

A New Approach To Probabilistic Lava Flow Hazard Assessments, Applied To The Idaho National Laboratory, Eastern Snake River Plain, Idaho, Usa, Elisabeth Gallant, Jacob Richardson, Charles Connor, Paul Wetmore, Laura Connor

School of Geosciences Faculty and Staff Publications

We present a new probabilistic lava flow hazard assessment for the U.S. Department of Energy’s Idaho National Laboratory (INL) nuclear facility that (1) explores the way eruptions are defined and modeled, (2) stochastically samples lava flow parameters from observed values for use in MOLASSES, a lava flow simulator, (3) calculates the likelihood of a new vent opening within the boundaries of INL, (4) determines probabilities of lava flow inundation for INL through Monte Carlo simulation, and (5) couples inundation probabilities with recurrence rates to determine the annual likelihood of lava flow inundation for INL. Results show a 30% probability of …

Differentiation In Impact Melt Sheets As A Mechanism To Produce Evolved Magmas On Mars, Ari Koeppel

Dissertations and Theses

Asteroid bombardment contributed to extensive melting and resurfacing of ancient (> 3 Ga) Mars, thereby influencing the early evolution of the Martian crust. However, information about how impact melting has altered Mars’ crustal petrology is limited. Evidence from some of the largest impact structures on Earth, such as Sudbury and Manicouagan, suggests that some impact melt sheets experience chemical differentiation. If these processes occur on Mars, we expect to observe differentiated igneous materials in some exhumed rock samples. Some rocks observed in Gale crater are enriched in alkalis (up to 14 wt% Na₂O + K₂O) and …

Quantifying Crustal Assimilation In Historical To Recent (1329-2005) Lavas At Mt. Etna, Italy: Insights From Thermodynamic Modeling, Marie Takach

All Master's Theses

The nearly continuous volcanic eruption record at Mt. Etna dating back approximately 700 years provides an excellent opportunity to investigate the geochemical evolution of a highly active volcano. Of particular interest is elucidating the cause of a selective enrichment in alkali elements (K, Rb, Cs) and ⁸⁷Sr/⁸⁶Sr. This alkali enrichment trend, which began in the 17^th century and accelerated after 1971, was accompanied by an increase in the volume, frequency, and explosivity of eruptions. To explain this enrichment, two major arguments are invoked: (1) crustal contributions (e.g., assimilation of the sedimentary basement), and (2) changes in …

Ground Deformation Studies And Evacuation Behavior During Eruptions At Guatemalan Volcanoes, Hans Lechner

Dissertations, Master's Theses and Master's Reports

Volcanic eruptions can be an especially problematic hazard when considering the uncertainty in eruption timing and magnitude coupled with challenges associated with delivering warnings to remote areas and facilitating effective evacuations. The hazards presented by Guatemala’s active volcanoes demand enhanced monitoring capabilities and instrumentation infrastructure. Strengthening the link between the physical and social sciences should lead to more accurate, reliable, and timely hazard information to the people living in proximity to the volcano and facilitate rational decisions and actions that reduce their level of risk. While there is no one single technique that can provide unambiguous diagnostics about the timing, …

Tuhualite In A Peralkaline Rhyolitic Ignimbrite From Pantelleria, Italy, Boguslaw Baginski, Ray Macdonald, John C. White, Lidia Jezak

EKU Faculty and Staff Scholarship

An occurrence of the rare mineral tuhualite (NaFe3+Fe2+Si6O15) is reported in a peralkaline rhyolitic ignimbrite from the 11 island of Pantelleria, Italy. The mineral formed during devitrification of glassy fiamme and varies in form from anhedral plates to 12 perfect euhedral in open vesicles. There is significant replacement of Fe2+ by Mn (FMQ in the presence of a 14 hydrous fluid.

Structural Analysis Of The Northwest Wind Mountain Quadrangle, New Mexico: Proterozoic Shearing To Cenozoic Brittle Faulting In The Burro Mountains, Jensen Kohl Angelloz

Electronic Theses and Dissertations

Preliminary investigation of the Bullard Peak metamorphic series (BPMS) in the northwestern Wind Mountain quadrangle within the Burro Mountains of southwestern New Mexico suggests a possible previously unidentified shear zone, prompting detailed (1:12,000) geologic mapping and collection of structural data. The study area has a complex tectonic history, including 1) ~1.65 Ga metamorphism during accretion of the Mazatzal terrane to Laurentia’s southern margin; 2) ~1.4 Ga intrusion of Granite and Rhyolite Province granitoids; 3) significant uplift during the formation of the Ancestral Rockies (~300 Ma) and the Rocky Mountains (~70-50 Ma); and 4) inversion tectonics with reactivation of compressional faults …

40ar/39ar Ages And Zircon Petrochronology For The Rear Arc Of The Izu-Bonin-Marianas Intra-Oceanic Subduction Zone, Graham Dm Andrews

Faculty & Staff Scholarship

Long-lived intra-oceanic arcs of Izu-Bonin-Marianas (IBM)-type are built on thick, granodioritic crust formed in the absence of pre-existing continental crust. International Ocean Discovery Program Expedition 350, Site U1437, explored the IBM rear arc to better understand continental crust formation in arcs. Detailed petrochronological (U–Pb geochronology combined with trace elements, oxygen and hafnium isotopes) characterizations of zircon from Site U1437 were carried out, taking care to exclude potential contaminants by (1) comparison of zircon ages with ship-board palaeomagnetic and biostratigraphic ages and 40Ar/39Ar geochronology, (2) analysing zircon from drill muds for comparison, (3) selectively carrying out in situ analysis in petrographic …

Conduction Plus Convection Heat Flow Modeling For The Linga Complex, Peruvian Coastal Batholith, Luciano Uriel González Olivares

Loma Linda University Electronic Theses, Dissertations & Projects

Factors affecting the thermal evolution of the Linga magmatic intrusion in the Ica-Pisco area of the Peruvian Coastal Batholith were studied using field work, petrography, geochemistry data, and computer modeling. Field work and petrography involved collecting samples for geochemical analysis and documenting widespread propylitic and potassic hydrothermal alteration. Major element geochemistry was used to estimate rock density, viscosity, liquidus temperature, and water content. The δ18O values of seven fresh samples showed a slightly increasing west-east and old-young trend of approximately 7-8‰, indicating an increasing crustal component. The δ18O and δD values for eleven altered samples indicated that alteration came mostly …

The Dynamic Relationship Between The Bear River, Quaternary Basaltic Center, Normal Faults, And The Resulting Rearrangement Of Rivers In The Northeast Edge Of The Great Basin, Southeast Idaho, Brady Utley

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The objective of this research project in Gem Valley graben, southeast Idaho is to identify the location, age and history of the Quaternary diversion of the Bear River into paleo-Lake Thatcher, and then into the Lake Bonneville basin from the Columbia River basin. Mapping, geochemical analysis, cross-cutting relationships, and five new age determinations, together with prior published research, shed new light on the complex history of interaction between the volcanic rocks, rivers, lakes, and faults in Gem Valley. Research goals were to test the hypothesis that local faulting and volcanism drove the diversion of the Bear River and controlled the …

Magmatic Hydrothermal Alteration And Secondary Post-Shock Features In Martian Olivine-Phyric Basalt Northwest Africa 10416; Petrology And Geochemistry Of Primitive Achondrite Northwest Africa 11042, Zoltan Vaci

Earth and Planetary Sciences ETDs

The Martian olivine-phyric basalt Northwest Africa (NWA) 10416 contains large olivine xenocrysts whose cores have been stained brown by hydrothermal alteration and whose rims are composed of pristine olivine overgrowths. Microanalysis of these olivine cores reveals various degrees of amorphization, some of which have been overprinted by terrestrial weathering, evident as part of a weathering rind along the exposed surface of the meteorite. Studies of a completely unweathered terrestrial analogue basalt from southern Colorado reveal similar features and indicate that both basalts were altered in a supersolidus magma chamber setting. The alteration features in NWA 10416 thus imply the presence …

Classifying Microseismicty At Mount St. Helens Using A Large-N Array, Margaret E. Glasgow

Earth and Planetary Sciences ETDs

A dense array of ~1,000 continuously recording, short-period geophones was deployed in the summer of 2014 within ~15 km of Mount St. Helens. Two earthquake catalogs created using reverse time imaging and template detection techniques, increase the detection rate and completeness of the earthquake catalog when compared to the permanent network, Pacific Northwest Seismic Network, catalog. An investigation into event type for ~200 of the earthquake detections leads to the discrimination of two major classification groups, volcano-tectonic and long period. Previous to this study, long period earthquakes had not been identified in the upper crust during a volcanically inactive period …

The Oligocene West Elk Breccia: Evidence For Massive Volcanic Debris Avalanches In The Eastern Gunnison River Valley, West-Central Colorado, U.S.A., Patrick J. Whalen

Theses and Dissertations--Earth and Environmental Sciences

The West Elk Breccia has been studied since the late 1800’s with many interpretations regarding its origin. One unrecognized possibility is that parts of it are debris-avalanche deposits. This study has recognized evidence for this interpretation at three scales: volcano scale, outcrop scale, and intra-outcrop scale. At the volcano scale, a scarp in the old volcano reveals underlying Mesozoic bedrock, suggesting sector collapse. At the outcrop scale, megablocks of the original edifice, up to hundreds of meters in length, have atypical orientations and are surrounded by a gravel matrix. At the intra-outcrop scale, jigsaw-fit fracturing and rip-up clasts are common …

Change Detection Of Mount Nyiragongo Post Eruption, Molly E. Karnes

Scholars Week

Because of the dangerous nature of volcanic eruptions, it makes them very difficult to study, however this makes them even more important for us to study because of how much destruction they can cause in such a short amount of time. We need to study all parts of an eruption to gain more insight into the specifics of how a volcano works. Having a better understanding of how large of an area is effected by an eruption will allow governments to decide on evacuation procedures. The goal of my project is to answer a very simple question, “How can we …

Birth And Evolution Of The Rio Grande Fluvial System In The Last 8 Ma:Progressive Downward Integration And Interplay Between Tectonics, Volcanism, Climate, And River Evolution, Marisa N. Repasch

Earth and Planetary Sciences ETDs

The Rio Grande-Rio Chama (RG-RC) fluvial system has evolved dramatically over the last 8 Ma, undergoing channel migrations, drainage capture and integration events, volcanic damming, and carving and refilling of paleocanyons. Volcanism concurrent with the development of the river system provides a unique opportunity to apply multiple geochronometers to the study of its incision and drainage evolution. This paper reports 19 new ⁴⁰Ar/³⁹Ar basalt ages and 19 detrital mineral samples (zircon and sanidine) collected from RG-RC alluvium overlain by dated basalt flows in the context of a compilation of published ⁴⁰Ar/³⁹Ar basalt ages. The …

Silicic Volcanism At The Northern And Western Extent Of The Columbia River Basalt Rhyolite Flare-Up: Rhyolites Of Buchanan Volcanic Complex And Dooley Mountain Volcanic Complex, Oregon, Adam M. Large

Dissertations and Theses

Two mid-Miocene (16.5-15 Ma) rhyolite volcanic centers in eastern Oregon, the Buchanan rhyolite complex and Dooley Mountain rhyolite complex, were investigated to characterize eruptive units through field and laboratory analysis. Results of petrographic and geochemical analysis add to field observations to differentiate and discriminate the eruptive units. Additionally, new geochemical data are used to correlate stratigraphically younger and older basalt and ash-flow tuff units with regional eruptive units to constrain the eruptive periods with modern Ar-Ar age dates.

Previous work at the Buchanan rhyolite complex was limited to regional mapping (Piper et al., 1939; Greene et al., 1972) and brief …

Tube Coalescence In The Jingfudong Lava Tube And Implications For Lava Flow Hazard Of Tengchong Volcanism, Zhengquan Chen, Yongshun Liu, Haiquan Wei, Jiandong Xu, Wenfeng Guo

International Journal of Speleology

Tube-fed structure occurs as a general phenomenon in Tengchong basic lavas, such as lava tubes, lava plugs and tube-related collapse depressions. We deduced the development of Laoguipo lava flows, which is the longest lava tube (Jingfudong lava tube) evolved in Tengchong volcanic area. Following the detailed documentation of the tube morphology of the Jingfudong lava tube, we propose that the Jingfudong lava tube was formed through vertical coalescence of at least three tubes. The coalescence and bifurcation process are re-constructed by interpretation of tube floor continuity, the distribution of remnant tubes and the scales of lava tube branches (shapes of …

Field Geology And Petrologic Investigation Of The Strawberry Volcanics, Northeast Oregon, Arron Richard Steiner

Dissertations and Theses

The Strawberry Volcanics of Northeast Oregon are a group of geochemically related lavas with a diverse chemical range (basalt to rhyolite) that erupted between 16.2 and 12.5 Ma and co-erupted with the large, (~200,000 km3) Middle Miocene tholeiitic lavas of the Columbia River Basalt Group (CRBG), which erupted near and geographically surround the Strawberry Volcanics. The rhyolitic lavas of the Strawberry Volcanics produced the oldest 40Ar/39Ar ages measured in this study with ages ranging from 16.2 Ma to 14.6 Ma, and have an estimated total erupted volume of 100 km3. The mafic and intermediate lavas of the Strawberry Volcanics include …

Documenting Mantle And Crustal Contributions To Flood Basalt Magmatism Via Computational Modeling Of The Steens Basalt, Southeast Oregon, Sylvana J. Bendaña

All Master's Theses

Flood basalts are enormous volcanic events with volumes of volcanic cover and intrusive equivalents that are affected by and significantly affect the crust. Steens Basalt represents 31,800 km³ of flood basalt lavas that erupted in eastern Oregon ~16.8 Ma in less than 300,000 years. Analytical data of flows from a 1 km vertical exposure at Steens Mtn. documents time-transgressive changes in composition of two geochemically distinct units: (1) lower Steens, MgO-rich lavas with lower incompatible trace element concentrations and ⁸⁷Sr/⁸⁶Sr, and (2) upper Steens, MgO-poor, with higher incompatible trace element concentrations and ⁸⁷Sr/⁸⁶Sr. …

Evolution Of A Flood Basalt Crustal Magmatic System: In Situ Mineral Data And Computational Modeling Of The Steens Basalt, Megan Graubard

All Master's Theses

Flood basalts are gigantic basaltic eruptions that modify the mass of the crust via intrusion of mantle-derived magma, and change its composition through interaction between magma and crust. The Steens Basalt, located in southeast Oregon, erupted approximately 16.8 million years ago, and is the oldest member of the Columbia River Basalt Group, the youngest and best-exposed flood basalt province on Earth. The Steens Basalt has an eruption volume of approximately 31,800 km³ and the duration of eruption is estimated to be between ~50,000 and 300,000 years. Major- and trace element whole rock data from 111 stratigraphically controlled samples from …

Geochemical And Petrological Characterization Of The Back Forty Volcanogenic Massive Sulfide Deposit, Anthony Robert Boxleiter

Masters Theses

The Back Forty Zn-Au deposit is the eastern-most Volcanogenic Massive Sulfide (VMS) deposit in the Penokean Volcanic Belt (PVB). It is the only VMS deposit found in Michigan, and is located along the east side of the Menominee River in Menominee County (45°26'57.5"N, 87°49'43.2"W). The Back Forty is the most zinc-enriched, copper depleted deposit among the major VMS deposits within the PVB that include Flambeau, Crandon, Bend, and Lynne. This work constitutes the first sulfur isotope study on the Back Forty VMS deposit.

The Back Forty is characterized by massive, semi-massive, disseminated and stringer sulfide mineralization hosted within felsic-dominated volcanic …

Interpretation Of Late Cretaceous Volcanic Mounds And Surrounding Gulfian Series Formations Using 3d Seismic Data In Zavala County, Texas, Laura Claire Bennett

Graduate Theses and Dissertations

The Late Cretaceous Gulfian series is a prominent and important series across the State of Texas that has been extensively studied since the nineteenth century. It is composed of series of southeast-dipping shelf carbonates and clastics deposited on the northwest margin of the Gulf of Mexico Basin. In south Texas, the Gulfian series was deposited in the Rio Grande Embayment and Maverick Basin and is comprised of the Eagle Ford Group, Austin Group, Anacacho Limestone, San Miguel Formation, Olmos Formation, and Escondido Formation that crop out and continue basinward in the subsurface. Late Cretaceous volcanism formed volcanic mounds composed of …

Peralkaline Felsic Magmatism At The Nemrut Volcano, Turkey: Impact Of Volcanism On The Evolution Of Lake Van (Anatolia), Ray Macdonald, Mari Sumita, Hans-Ulrich Schmincke, Boguslaw Baginski, John C. White, Slawomir S. Ilnicki

EKU Faculty and Staff Scholarship

Nemrut volcano, adjacent to Lake Van (Turkey), is one of the most important peralkaline silicic centres in the world, where magmatism for ~570,000 years has been dominated by peralkaline trachytes and rhyolites. Using onshore and Lake Van drill site tephra samples, we document the phenocryst and glass matrix compositions, confirming a complete spectrum from very rare mafic to dominantly silicic magmas. Magma mixing has been common and, along with the multi-lineage nature of the magmas, indicates that Nemrut has been a very open system where, nevertheless, compositionally zoned caps developed during periods of relative eruptive quiescence. Geothermometry suggests that the …

Bubble Mobility In Mud And Magmatic Volcanoes, Aaron Tran, Maxwell L. Rudolph, Michael Manga

Geology Faculty Publications and Presentations

The rheology of particle-laden fluids with a yield stress, such as mud or crystal-rich magmas, controls the mobility of bubbles, both the size needed to overcome the yield stress and their rise speed. We experimentally measured the velocities of bubbles and rigid spheres in mud sampled from the Davis-Schrimpf mud volcanoes adjacent to the Salton Sea, Southern California. Combined with previous measurements in the polymer gel Carbopol, we obtained an empirical model for the drag coefficient and bounded the conditions under which bubbles overcome the yield stress. Yield stresses typical of mud and basaltic magmas with sub-mm particles can immobilize …

Timing And Source Of Alkali Enrichment At Mt. Etna, Sicily: Constraints From Clinopyroxene Geobarometry And In Situ Sr Isotope Data, Kaitlyn Nelson

All Master's Theses

Since 1971, Mt. Etna, Europe’s largest and most active volcano, has exhibited increased eruption frequency and explosivity. Associated with this increased activity, researchers have documented higher abundances of alkali elements (K, Rb, Cs) as well as elevated ⁸⁷Sr/⁸⁶Sr in Etnean lavas. The source of this alkali-enrichment has been hotly debated, with end-member hypotheses involving mantle vs. crustal contributions. To further characterize the evolution of the subvolcanic magma storage and transport system, as well as the timing and source of alkali-enrichment, clinopyroxene from ten samples erupted between 1329 and 2004 was targeted for in situ textural, major element …

Multi-Instrumental Investigation Of Volcanic Outgassing At Pacaya Volcano, Guatemala., Carlo Prandi

Dissertations, Master's Theses and Master's Reports

Pacaya is one of the most active volcano in the world and it is only ≈30Km South of Guatemala City, the capital of Guatemala, that has a population of about 2 million of people and a surrounding metropolitan area where ≈4.5 million of people live. So mitigate the volcanic hazard improving the knowledge and the understanding of Pacaya is fundamental to decrease the risk factor at which the surrounding population is exposed. This study aims to furnish a new large database, the analysis, the comparison and the interpretations of data that come from different techniques of sampling, about the volcanic …

Subalklaine Volcanism In The Eastern Basin And Range Province: Examples From The Miocene Mccullough Range Volcanic Field And The Pliocene To Holocene Black Rock Desert Volcanic Field, Racheal Leighann Johnsen

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation is composed of three papers that apply geologic mapping, whole rock geochemical and isotopic analysis, and mineral chemistry to describe two large, long-lived (~6 million years), and compositionally heterogeneous volcanic fields and posit sources of the rock types present in each. These fields are the McCullough Range in southern Nevada, which was a locus of volcanic activity from ~19 - 12 Ma and the Black Rock Desert volcanic field in west-central Utah, which began forming at ~6 Ma and is still active today, with the most recent eruption occurring ~720 years ago.

Chapter Two is composed of a …

Geology – Future Continent, Joy Wulke

The Transdisciplinary STEAM+ Journal

Terra Mirabila, a multi-media presentation illustrating the geological story of Stony Creek Granite back through complex sequence of geological events that spanned some 600 million years of early history.

Structural Deformation Across The Southwest Mina Deflection, California-Nevada: Field Studies In The Huntoon Spring Quadrangle, Eliya R. Hogan

All Master's Theses

New geologic data provides insight into Pliocene strain rates across the southwest Mina deflection. ⁴⁰ Ar/³⁹ Ar geochronology of geologic units indicate cooling of Miocene ignimbrite at 11.86 ± 0.01 Ma, Pliocene basalt lavas at 3.7241 ± 0.0051 and 3.5262 ± 0.0172 Ma, and basaltic andesite and andesite lavas at 3.4715 ± 0.0107 Ma and 3.1078 ± 0.0088 Ma. Pliocene cinder cones and Quaternary sediments are also exposed in the Huntoon Spring quadrangle. Volcanic units are cut by a dominant set of NNE-, NE-, and ENE- striking sinistral faults and a lesser set of NNW- and NW- striking normal …