Volcanology Commons^™

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 …

Chile’S Calbuco Volcano Erupts Without Warning. What Can We Expect Next?, Brittany Brand

Geosciences Faculty Publications and Presentations

Around 5:00 pm local time on April 22, scientists at Southern Andean Volcano Observatory in Chile began picking up volcanic earthquakes at the Calbuco volcano. A disturbingly short 60 minutes later, the volcano was in full eruption, producing an impressive column of ash extending to more than 49,000 feet into the sky. Ash primarily drifted north and northeast of the volcano, covering towns below in a layer of fine ash. Observatory scientists quickly called for an evacuation zone of 12.5 miles.

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 …

Mesoamerican Sacred Geography And Archeological Landscapes: A Case Study In The Volcanic Highlands Of Michoacan, Mexico, Jarod Scott Drozdowski

All Master's Theses

US and Mexican teams have investigated the La Alberca Structure Complex with the community of Parangaricutiro. Their forest reserve, located near San Juan Nuevo in Michoacan, Mexico, contains several volcanic cones, including the famous Paricutin cinder cone. Sixteen earthen-rock structures have been mapped using aerial photography, GPS, GIS, and total station surveys. The structures range from 300 to 2,400 cubic meters in volume. The larger mound-like structures are traditionally called yacatas. Early radiocarbon dates for two of the three central structures (ca. 5200-2000 BCE) bracket dates for the Late Archaic burial in the La Alberca caldera. Arrangements of the larger …

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 …

Insights Into The Relationship Between Mixing Duration And Volcanic Explosivity Index (Vei): Pacaya And Fuego Volcanoes, Guatemala, Nicola Mari

Dissertations, Master's Theses and Master's Reports

This study investigates whether the timing of magma mixing phenomena could be related to explosivity and style of volcanic activity. Lava flow and tephra samples, derived from observed, energetically-diverse eruptions, from Pacaya and Fuego volcanoes (Guatemala), were studied, the Volcanic Explosivity Index (VEI) was used as an indicator of eruption intensity. Polarized light microscopy and Scanning Electron Microscopy (SEM) techniques were used for textural and geochemical measurements. Results are interpreted as evolution of mixing through changes in textures of plagioclase and olivine crystals. These suggest that boxy-cellular plagioclase (high frequency in VEI 0 samples) is associated with brief mixing residence …

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 …

Safety Procedures For Volcanic Activity In The United States And Japan, Ashley Eisenmenger

A with Honors Projects

This paper discusses the volcanic eruption evacuation and safety procedures in the United States, a country where few realize the potential risks and compares them with procedures in Japan, which experiences frequent eruptions.

The Geology And Petrology Of Enigmatic Rhyolites At Graveyard And Gordon Buttes, Mount Hood Quadrangle, Oregon, Elizabeth G. Westby

Dissertations and Theses

Rhyolite lava flows are found at two dome complexes at Graveyard Butte and Gordon Butte, Mount Hood Quadrangle, Oregon. At Graveyard Butte, the White River has cut a winding canyon 150 m deep, exposing at its base, a 40-meter-thick outcrop of flow-banded rhyolite (73 wt.% SiO₂, 3.67±0.01 Ma) that laterally extends along the canyon wall for about 1 km. Stratigraphically above the flow-banded rhyolite is locally-erupted iron-rich andesites (lava flows, agglutinate and other pyroclastic rocks as well as clastic debris), a rhyolitic ash-flow tuff (74 wt.% SiO₂), and the 2.77±0.36 Ma tholeiitic basalt lava flows of …

Strontium, Lead, And Oxygen Isotopic Signatures Of Mid-Miocene Silicic Volcanism In Eastern Oregon, Emily Nancy Hess

Dissertations and Theses

Widespread, mid-Miocene rhyolite volcanism of eastern Oregon that are coeval or slightly postdate flood basalts of the Columbia River Basalt Province allows for mapping crustal domains using radiogenic and stable isotopes. Rhyolites are thought to be derived in large part by partial melting of the crust and thus yield direct information on the composition of the crust. Silicic volcanism is expressed in the form of numerous domes and tuffs exposed over a wide area (~300 km in N-S dimension and ~200 km in E-W dimension) west of the presumed craton boundary, which runs parallel but mostly east of the Oregon-Idaho …

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 …

Thermodynamic Model For Energy-Constrained Open-System Evolution Of Crustal Magma Bodies Undergoing Simultaneous Recharge, Assimilation And Crystallization: The Magma Chamber Simulator, Wendy A. Bohrson, Frank J. Spera, Mark S. Ghiorso, Guy Brown, Jeffrey Creamer, Aaron Mayfield

All Faculty Scholarship for the College of the Sciences

The Magma Chamber Simulator quantifies the impact of simultaneous recharge, assimilation and crystallization through mass and enthalpy balance in a multicomponent–multiphase (melt + solids ± fluid) composite system. As a rigorous thermodynamic model, the Magma Chamber Simulator computes phase equilibria and geochemical evolution self-consistently in resident magma, recharge magma and wallrock, all of which are connected by specified thermodynamic boundaries, to model an evolving open-system magma body. In a simulation, magma cools from its liquidus temperature, and crystals ± fluid are incrementally fractionated to a separate cumulate reservoir. Enthalpy from cooling, crystallization, and possible magma recharge heats wallrock from its …

Volcanism-Induced Karst Landforms And Speleogenesis, In The Ankarana Plateau (Madagascar). Hypothesis And Preliminary Research, Eric Gilli

International Journal of Speleology

The Ankarana is a limestone plateau in the northern part of Madagascar, where a cave system, more than 120 km long, has been explored. The plateau is bordered by volcanoes and is cut across by several canyons. An analysis of surface landforms and caves suggests that the karst genesis was probably initiated by volcanism beneath an impervious cover. Volcanic bulging and magma intrusions may have favored a basalt-limestone assimilation process and metamorphism. The ascent of deep volcanic fluids (CO₂ and SO₂) from magma degassing and from limestone metamorphism, may explain the speleogenesis. Once denuded, the karst evolved …

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.

Revisiting Volcanology And Composition Of Rhyolites And Associated Ree Rich Mafic Clasts Of The Three Fingers Caldera, Se Oregon, Phillip Ira Marcy

Dissertations and Theses

Two adjacent caldera systems, the Mahogany Mountain and the Three Fingers caldera constitute voluminous rhyolitic volcanic deposits on the eastern margin of the Oregon-Idaho graben during the middle-Miocene. Both calderas are part of the Lake Owyhee volcanic field that in turn is part of widespread rhyolite deposits associated with the Columbia River Basalt province. We focus on establishing relationships between intracaldera units of Three Fingers caldera and caldera-forming tuff of Spring Creek and surveying the distribution of entrained mafic clasts which often display anomalous concentrations of rare earth elements.

Previous mapping identified two intra-caldera facies and one outflow facies of …

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 …

Relationship Between Static Stress Change And Volcanism. How And If Tectonic Earthquake Could Influence Volcanic Activity. Example Of El Reventador Volcano, Ecuador, Daniele Alami

Dissertations, Master's Theses and Master's Reports - Open

No abstract provided.

The Geology Of The South Antelope Pass Area Of The Southern Peloncillo Mountains, Hidalgo County, New Mexico, John A. Yellich

Masters Theses

Volcanic activity during the middle and late Tertiary has been recorded in the mountain ranges of the southwestern United States and northern Mexico and the two provinces of prominent volcanic activity, the Sierra Madre Occidental and the Mogollon Plateau, dominantly rhyolitic in composition, are connected by the Peloncillo Range. The predominant rock chemistry of the south Antelope Pass area is “rhyolitic”; however, lava rock types dominate over welded tuff rock types of the two provinces. There is a limited pre-Tertiary rock record of limestones and sandstones in the northeastern part of the study area. The rest of the study area …

Cretaceous And Eocene U-Pb Zircon Migmatite Ages From The East Humboldt Range Metamorphic Core Complex, Nevada, Jordan Drew

UNLV Theses, Dissertations, Professional Papers, and Capstones

Zircon separates from migmatite samples from the East Humboldt Range (EHR), northern Nevada were U-Pb dated using secondary ionization mass spectrometry. Cathodoluminescence images of zircons show bright anhedral cores with abundant euhedral overgrowths surrounding them.

The overgrowths give U-Pb dates indicating two periods of zircon growth. Inner rims have a Cretaceous age population at 70.6 ± 2.6 Ma. Outer rims give Eocene ages that either fall in to a single-age population at 45 ± 1.3 Ma or are part of a range from 41-31 Ma. Discordant zircon cores have upper intercepts between 1.8 -1.0 Ga.

Cretaceous and Eocene ages are …

Visualizing And Understanding Tectonism And Volcanism On Earth And Other Terrestrial Bodies, Mladen M. Dordevic

Physics Theses & Dissertations

This dissertation presents new methods of visualizing, teaching, assessing, modeling, and understanding tectonics on Earth and other celestial bodies. Tectonics is the study of planetary lithospheres and includes impact, plate, plume, cryo- and gravitational mechanisms. This dissertation is concerned with plate tectonics and plate/mantle plume interactions. Plate tectonics describes the mainly horizontal motion of lithospheric plates over the asthenosphere. Lithosphere is created at ridges and consumed at subduction zones. In addition to the plate tectonic system, mantle plumes also contribute to mass motions in the subsurface Earth. Both plate tectonics and plume upwelling processes help shape the present form of …

Petrogenesis Of The East Fork Member Rhyolites, Valles Caldera, New Mexico, Usa, Carla Eichler

UNLV Theses, Dissertations, Professional Papers, and Capstones

The most recent volcanism in the Valles caldera is represented by the El Cajete Pyroclastic Beds (ECPB), Battleship Rock Ignimbrite (BRI), and Banco Bonito Flow (BBF) as well as the VC-1 rhyolite, which are collectively known as the East Fork Member (EFM) of the Valles Rhyolite. The EFM was erupted at approximately 55 ka and 40 ka after an approximate 460 ka lull in volcanism. Previous studies suggested a mafic intrusion at depth triggered the eruptions. This thesis represents the first detailed study of the EFM.

Crystal assemblages consist of plagioclase, biotite, clinopyroxene, orthopyroxene, amphibole, sanidine, quartz, and oxides. Electron …

Volcanic Evolution Of The Southern Quinn Canyon Range: Implications For Regional Correlation Of Volcanic Units, Christina Emery

UNLV Theses, Dissertations, Professional Papers, and Capstones

The southern Quinn Canyon Range lies in an area of the Great Basin subjected to large-volume Oligocene-Miocene silicic volcanism and smaller volume basaltic volcanism during the Pliocene. Three major ash-flow tuff units were correlated in the southern Quinn Canyon Range (the Pahranagat Tuff, Clifford Spring Tuff, and the Cow Canyon Tuff) with regional units by utilizing U/Pb and 40 Ar/ 39Ar geochronology, geochemical correlation, and field mapping. Isotopic analysis suggests that basalt in the southern Quinn Canyon Range is part of the Death Valley-Pancake Range Basalt Zone and is similar to Reveille Range Episode 1 and 2 basalts. Further comparison …

Petrogenesis Of The Linked River Mountains Volcanic Section And Wilson Ridge Pluton, Denise Kelly Honn

UNLV Theses, Dissertations, Professional Papers, and Capstones

The River Mountains (RM) volcanic suite and Wilson Ridge pluton (WRP), in the northern Colorado River extensional corridor of southern Nevada and northwestern Arizona, provide an ideal opportunity to investigate one of the most fundamental questions in igneous petrology: Do volcanic rocks erupt from subjacent plutons and do plutons vent to form volcanic fields? The RM volcanic suite (14.47± 0.26 to 12.66 ± 0.54 Ma; uncertainties are 2sigma) consists of a stack of andesite and rhyolite sills beneath a stratovolcano that primarily erupted dacite with lesser volumes of basalt and rhyolite. This volcanic suite is cored by a multiphase quartz …

Introducing Geoscience Students To Numerical Modeling Of Volcanic Hazards: The Example Of Tephra2 On Vhub.Org, Leah M. Courtland, Charles Connor, Laura Connor, Costanza Bonadonna

Numeracy

The Tephra2 numerical model for tephra fallout from explosive volcanic eruptions is specifically designed to enable students to probe ideas in model literacy, including code validation and verification, the role of simplifying assumptions, and the concepts of uncertainty and forecasting. This numerical model is implemented on the VHub.org website, a venture in cyberinfrastructure that brings together volcanological models and educational materials. The VHub.org resource provides students with the ability to explore and execute sophisticated numerical models like Tephra2. We present a strategy for using this model to introduce university students to key concepts in the use and evaluation of Tephra2 …

Bulk Rock Composition And Geochemistry Of Olivine-Hosted Melt Inclusions In The Grey Porri Tuff And Selected Lavas Of The Monte Dei Porri Volcano, Salina, Aeolian Islands, Southern Italy., Angela L. Doherty, Robert J. Bodnar, Benedetto De Vivo, Wendy A. Bohrson, Harvey E. Belkin, Antonia Messina, Robert J. Tracy

All Faculty Scholarship for the College of the Sciences

The Aeolian Islands are an arcuate chain of submarine seamounts and volcanic islands, lying just north of Sicily in southern Italy. The second largest of the islands, Salina, exhibits a wide range of compositional variation in its erupted products, from basaltic lavas to rhyolitic pumice. The Monte dei Porri eruptions occurred between 60 ka and 30 ka, following a period of approximately 60,000 years of repose. The bulk rock composition of the Monte dei Porri products range from basaltic-andesite scoria to andesitic pumice in the Grey Porri Tuff (GPT), with the Monte dei Porri lavas having basaltic-andesite compositions. The typical …

Continued Exploration Of The Santorini Volcanic Field And Cretan Basin, Aegean Sea, Katherine L. C. Bell, Paraskevi Nomikou, Steven N. Carey, Eleni Stathopoulou, Paraskevi Polymenakou, Athanasios Godelitsas, Chris Roman, Michelle Parks

Graduate School of Oceanography Faculty Publications

No abstract provided.

Submarine Volcanism In The Straits Of Sicily, Steven N. Carey, Katherine L. C. Bell, Michael Marani, Mauro Rosi, Edward T. Baker, Chris Roman, Marco Pistolesi, Joshua Kelly

Graduate School of Oceanography Faculty Publications

No abstract provided.

Mapping Lava Flows From Nyamuragira Volcano (1967-2011) With Satellite Data And Automated Classification Methods, Elisabet Head, Ann L. Maclean, Simon A. Carn

Faculty Research and Creative Activity

The volume, location and extent of historical lava flows are important when assessing volcanic hazards, as well as the productivity or longevity of a volcanic system. We use a Landsat/Hyperion/ALI dataset and automated classification methods to map lava flows at Nyamuragira volcano (1967-2011) in the Democratic Republic of the Congo. The humid tropical climate ofNyamuragira is advantageous because its lava flows are emplaced onto heavily forested flanks, resulting in strong contrast between lava and vegetation, which contributes to efficient flow mapping. With increasing age, there is an increase in Landsat band-4 reflectance, suggesting lava flow revegetation with time. This results …

Documenting Magma Evolution Of The Fossa Delle Felci (Salina Island, South Tyrrhenian Sea) By Integrating In Situ Plagioclase Data With Quantitative Modeling, Aaron Mayfield

All Master's Theses

Compositional diversity occurs via processes dominated by recharge, assimilation and fractional crystallization (RAFC), quantification of which can provide insights into eruption catalysts, and therefore assist in hazard mitigation. This study evaluates the relative roles of RAFC processes in Fossa delle Felci (Salina Island, Italy) magmas, which span the basalt to dacite range (52-65 wt% SiO2). Integration of petrographic, whole rock, and in situ plagioclase data with quantitative magma chamber models suggests differentiation dominated by fractional crystallization and magma recharge/mixing in reservoirs located at different crustal levels. At ~12 km depth, magma evolved through crystallization of a pyroxene dominated assemblage; plagioclase …