Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 12 of 12
Full-Text Articles in Entire DC Network
Dynamics And Timescales Of Magmatic Processes At Cerro Uturuncu, Bolivia, Sarah Jane Rasor
Dynamics And Timescales Of Magmatic Processes At Cerro Uturuncu, Bolivia, Sarah Jane Rasor
MSU Graduate Theses
Between 12-25°S latitude there is prolific volcanism fueled by the Altiplano-Puna Magmatic Body (APMB), a mid-crustal magma body above the 30° angle subduction of the Nazca plate and within 60-70 km thick South American crust. Cerro Uturuncu, a stratovolcano constructed above the center of the APMB, can provide insight to the evolution of the APMB over time. Previous research suggests that the APMB is more homogenous near its center as opposed to its edges. However, the processes that led to greater homogenization as well as the structure of the magma body below Cerro Uturuncu remain unknown. This research contributes greater …
Magmatic Evolution Of The Chasca Orkho Lava Series And Its Magmatic Enclaves, Volcán Ollagüe, Central Andes, Nathaniel W. Lenhard
Magmatic Evolution Of The Chasca Orkho Lava Series And Its Magmatic Enclaves, Volcán Ollagüe, Central Andes, Nathaniel W. Lenhard
MSU Graduate Theses
Magma mixing is a common factor in the creation of intermediate composition magmas and a potential instigator of a volcanic eruption. Magmatic enclaves, physical evidence of magma mixing within a volcanic system, are a phenomenon whose mechanisms remain unclear and debated. Common hypotheses explaining the occurrence of magmatic enclaves within a host lava range from the repeated injection of a new magma into a shallow reservoir to the disruption of equilibrium within a stratified magma chamber. Within the Andean Central Volcanic Zone (CVZ), the occurrence of magmatic enclaves yields similar geochemical compositions to their respective host rocks, bringing more difficulty …
Chemical And Thermal Influence On Intermediate Magma Storage Conditions: Volcán Ollagüe, Chile-Bolivia, Central Andes, Drew Allen Laviada-Garmon
Chemical And Thermal Influence On Intermediate Magma Storage Conditions: Volcán Ollagüe, Chile-Bolivia, Central Andes, Drew Allen Laviada-Garmon
MSU Graduate Theses
Continental arc volcanoes are the single best portrayal of the evolution of recycled earth material stemming from subduction, one of the most important and foundational phenomena in global tectonics. Understanding the genesis of intermediate-composition magmas produced at arc volcanoes is a difficult process making them a focal point for investigation. Geochemical investigation of zircon and plagioclase mineral phases erupted from continental arcs can provide insight into magma process, generation, storage conditions, timescales and differentiation of sub-volcanic plumbing systems prior to eruption events. The Central Volcanic Zone is a prime example of continental arc volcanism through subduction, and is host to …
Geochemical Investigation Of Monogenetic Volcanoes From The Pribilof Islands, Bering Sea, Alaska, Clayton L. Reinier
Geochemical Investigation Of Monogenetic Volcanoes From The Pribilof Islands, Bering Sea, Alaska, Clayton L. Reinier
MSU Graduate Theses
Small-volume basaltic magmas found at continental intraplate environments have not been as extensively studied compared to their polygenetic counterparts. Specifically, regions such as the Bering Sea basalt province, described as a diffuse igneous province, have commonly been overlooked. Assumptions that these systems are invoked by simple, single batches of magma has subsequently left a gap in understanding the processes responsible for primary magma generation away from plate boundaries with little tectonic influence. The following studies that constitute this thesis focus on an in-depth geochemical investigation at the crystal and sub-crystal scale to evaluate lithospheric mantle heterogeneities, processes that govern primary …
A Geochemical And Statistical Investigation Of The Big Four Springs Region In Southern Missouri, Jordan Jasso Vega
A Geochemical And Statistical Investigation Of The Big Four Springs Region In Southern Missouri, Jordan Jasso Vega
MSU Graduate Theses
The Big Four Springs region hosts four major first-order magnitude springs in southern Missouri and northern Arkansas. These springs are Big Spring (Carter County, MO), Greer Spring (Oregon County, MO), Mammoth Spring (Fulton County, AR), and Hodgson Mill Spring (Ozark County, MO). Based on historic dye traces and hydrogeological investigations, these springs drain an area of approximately 1500 square miles and collectively discharge an average of 780 million gallons of water per day. The rocks from youngest to oldest that are found in Big Four Springs region are the Cotter and Jefferson City Dolomite (Ordovician), Roubidoux Formation (Ordovician), Gasconade Dolomite …
Geochemistry Of The Lazufre Volcanic Complex: Determining The Geometries And Processes Of The Magmatic Sources In The Central Andean Volcanic Zone, Brooke Erin Benz
Geochemistry Of The Lazufre Volcanic Complex: Determining The Geometries And Processes Of The Magmatic Sources In The Central Andean Volcanic Zone, Brooke Erin Benz
MSU Graduate Theses
The Central Andes in South America contain many active volcanoes and volcano complexes due to constant subduction producing extrusive rocks varying in composition. The Lazufre Complex, Chile-Argentina border, consists of two Pleistocene volcanic centers, Lastarria and Cordon del Azufre andesite and dacite lava flows and domes. Whole-rock K-Ar dates of lavas from Cordon del Azufre place the most recent eruptions at 0.6-0.3 Ma ±0.3 Ma. Major-element data of plagioclase and pyroxene show homogeneous compositions between the centers, which is consistent with whole rock major- and trace-element compositions. The primary composition of the pyroxenes are augite and diopsides for cpx and …
Pumice Compositions And Mineral Chemistry From Lascar Volcano, Chile, Madelaine M. Stearn
Pumice Compositions And Mineral Chemistry From Lascar Volcano, Chile, Madelaine M. Stearn
MSU Graduate Theses
Lascar volcano is one the most active volcano in the Central Volcanic Zone of the Andean Cordillera, with 36 Holocene eruptions including a VEI 4 eruption in April 1993. Activity has not been consistent throughout time, and therefore, the processes behind it are poorly understood. Lascar volcano has cyclic behavior and has had four stages of activity, each of which had a unique eruptive style and product composition. Stage I (<43 >ka) had primarily mafic andesite lavas erupted effusively from a stratocone. Stage II initiated with dome building events ESE of the original vent and culminated in the 26.45 ka …
Chemical And Statistical Analysis Of Karst Groundwater Basin Signatures - Springfield, Mo, Benjamin E. Lockwood
Chemical And Statistical Analysis Of Karst Groundwater Basin Signatures - Springfield, Mo, Benjamin E. Lockwood
MSU Graduate Theses
Springfield, MO is located on the Springfield Plateau physiographic province. The Springfield plateau contains a number of Mississippian aged units and is mainly capped by the Burlington-Keokuk Formation. The Burlington-Keokuk is a highly fossiliferous limestone with nodular and interbedded chert. Beneath the Burlington-Keokuk lies the Elsey, Reeds Spring, and Pierson Formations respectively which comprise the Springfield Plateau aquifer hydrostratigraphic unit. Within the Springfield Plateau aquifer, a well-developed karst system includes springs, sinkholes, and caves. The Springfield Plateau aquifer is the predominant source for springs and seeps in the Springfield area. The purpose of this study was to understand the differences …
Provenance Analysis Of The Grover Gravel Using Detrital Zircon Geochronology, Petrology And Heavy Mineral Analysis, Grant Spoering
Provenance Analysis Of The Grover Gravel Using Detrital Zircon Geochronology, Petrology And Heavy Mineral Analysis, Grant Spoering
MSU Graduate Theses
The Grover Gravel in the St. Louis, Missouri area contains a mix of chert, quartzite, jasper, and ironstone in clast sizes ranging up to 60 cm. The gravel varies in thickness from a veneer to over 30 feet and rests on upland surfaces at elevations sometimes exceeding 300 feet above the floors of major valleys. A pre-Pleistocene age generally has been proposed or assumed for the gravel, which classically has been interpreted to be a meandering-stream deposit atop an extensive flat upland surface, which was subsequently eroded and dissected by rejuvenated streams. However, large quartzite boulders in the gravel also …
Geology And Geochemistry Of The Uvas Volcanic Field And Rubio Peak Formation Of South-Central New Mexico, Usa, Max Logan Hoffman
Geology And Geochemistry Of The Uvas Volcanic Field And Rubio Peak Formation Of South-Central New Mexico, Usa, Max Logan Hoffman
MSU Graduate Theses
South-central New Mexico is characterized by many Cenozoic volcanic and tectonic events that produced a complex system of magma sources. These mechanisms are responsible for the diverse volcanic activity and magmatic evolution in New Mexico. To understand the growth and development of the mantle sources associated with these events, geochemical, petrographic, structural and spatial distribution data were collected from the Uvas volcanic field (UVF) and the Rubio Peak Formation of the Mogollon-Datil volcanic field (MDVF). Volcanic rocks from these volcanic fields were chosen based on their importance to relative timing of magmatic and tectonic transitioning events. The structural and spatial …
Urban Detention Basin Contamination With Polycyclic Aromatic Hydrocarbons (Pahs) And Metals, Holly Marie Duff
Urban Detention Basin Contamination With Polycyclic Aromatic Hydrocarbons (Pahs) And Metals, Holly Marie Duff
MSU Graduate Theses
Polycyclic aromatic hydrocarbons (PAHs) are organic compounds that can be toxic to wildlife and humans when released to the environment. Coal-tar sealants, which are applied to parking lots or driveways, contribute up to 1,000 times more PAHs than alternative sealants. Over time, these sealants abrade and are transported into drainage networks. Coal-tar sealants are currently used in Springfield, Missouri, however the extent of PAH contamination throughout urban drainage systems is unclear. This study focused on PAH contamination within an urban detention basin on the Missouri State University campus which receives runoff from several coal-tar sealed parking lots. Sediment samples collected …
A Trace Metal Content Database Of Cave Sediments Of Midcontinent U.S.A., Matthew Dale Smith
A Trace Metal Content Database Of Cave Sediments Of Midcontinent U.S.A., Matthew Dale Smith
MSU Graduate Theses
The midcontinent of the United States has thousands of documented caves. These caves contain cave sediments, which are the accumulation of biological, geological, and anthropological debris. At this time there is no known database for trace metals of cave sediments of the midcontinent United States. Considering that caves host a wide variety of life, it is important to create a database to examine potential effects of trace metals on cave systems. In order to develop this baseline, 14 caves were sampled from across the midcontinent. Caves were selected based on geologic and hydrologic attributes. The sediments were analyzed for the …