Geochemistry Commons^™

Natural Fracture Evolution: Investigations Into The Middle Devonian Marcellus Shale, Appalachian Basin, Usa, Natalie Abigail Mitchell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Optimizing recovery from unconventional shale reservoirs has generated considerable research into optimal recovery methods through hydraulic fracturing design and shale reservoir characterization in the development of long-term hydrocarbon producers. Permeability at multiple scales from nanometer-scale pore sizes and nano-darcy permeability to completion-induced fractures defining a 100’s of meter stimulated reservoir volume plays a significant role in hydrocarbon flow during production in shale reservoirs. Preexisting cemented fractures in unconventional shale reservoirs are abundant and preferentially reactivate during induced hydraulic fracturing treatment to create necessary large-scale permeability. While previous investigations have significantly improved our knowledge of shale reservoirs, it has also highlighted …

Use Of Carbonation For Treatment Of Coal Mine Drainage To Increase Limestone Dissolution And Generate Alkalinity, Dietrich Henry Kuhlmann Iv

Graduate Theses, Dissertations, and Problem Reports (ETD)

Abstract

Use of Carbonation for Treatment of Coal Mine Drainage to Increase Limestone Dissolution and Generate Alkalinity

Dietrich Kuhlmann IV

Anoxic limestone drains (ALDs) are a common component used within passive treatment systems for coal mine drainage (CMD). Contact between limestone aggregate and CMD results in limestone dissolution, producing carbonate alkalinity. Though ALDs are one of the least expensive CMD treatment technologies, alkalinity generation is limited by limestone solubility. This necessitates a long retention time (>12 hours) and sometimes results in net acidic effluent which requires additional alkalinity generation steps downstream. One way to increase calcite dissolution and alkalinity …

Synthetic Aperture Radar Observations At Salar De Pajonales, Chile, Michael A. A. Mcinenly

Graduate Student Theses, Dissertations, & Professional Papers

Remotely sensed microwave radars provide the spatial and temporal coverage needed to improve our understanding of the relationship between moisture content and salt pan mineralogy and, ultimately, climate variability. Moisture content in the surface and near-surface crusts found in salt pan environments, such as salt pan, has a significant impact on the backscatter values recorded by synthetic aperture radar (SAR) systems. This is because moisture affects the dielectric constant and surface roughness of the saline surface, which in turn influences the amount of electromagnetic energy reflected back to the SAR sensor. Changes in backscatter values are attributed to seasonal and …

Age And Chemistry Of Bell Creek Batholith, Elana G. Barth

Dissertations, Master's Theses and Master's Reports

The Southern Complex, located near Marquette, Michigan is in the southernmost portion of the Superior Province. This complex consists of granitoids and granitic gneiss that vary in composition. In twentieth century research, Hoffman (1987) and Tinkham (1997) concluded that the Southern Complex contained two units in which the granitoid was emplaced in the granitic gneiss. Recent research conducted by Petryk (2019) determined that the Southern Complex has a U-Pb zircon age of 2600 Ma. Dalle Fratte (2020) concluded that the granitic gneiss migmatite texture was the result of a felsic magma mixing with several generations of mafic intrusions that were …

Analysis Of Chemical Elements In Basalts Using Mislabeled Data, A Machine Learning Approach, Jenifer Vivar

Dissertations and Theses

Scientists use basalt chemistry to discriminate among different tectonic settings. There are well-known chemical elements used to classify tectonic settings. An exploration of new features is done using Logistic Regression and Random Forest to discover any new elements of interest. The models were used with other tools, such as recursive feature elimination and permutations, to increase reliability. Among the scarcely explored chemical elements are Terbium (Tb), Holmium (Ho), Samarium (Sm), and Erbium (Er). The data used for the exploration contained many outliers. Therefore, an ensemble model was created to explore the location and composition of such outliers. The ensemble was …

Shallow Water Coral Distribution And Its Response To Climate Change, Amaury De Jesus

Dissertations and Theses

Shallow water corals are one of the main reef-building organisms that secrete carbonates as their skeletons, and therefore, are one of the major sinks of CO2 in the ocean. These reef builders are also very crucial to marine environments and human society. As the global energy demand continues rising, fossil fuel burning increases at a faster pace despite the increase in energy supply using clean and renewable energy. The increase of CO2 in the atmosphere has been shown to exacerbate global warming and may cause ocean acidification, threatening the habitat of shallow-water corals. Many recent observations show alarming signs of …

Physicochemical Constraints To Melts From Láscar Volcano Recorded By Syn-Eruptive Apatite, Cesar Andres Bucheli Olaya

Graduate Theses/Dissertations

Geochemical microanalysis of apatite crystals was conducted to model the composition and thermodynamic conditions of melts involved in explosive eruptions at Láscar volcano (NE Chile). Apatite crystals were extracted from representative samples of Láscar’s eruptive stages II (Soncor ignimbrite), III (Tumbres scoria deposit), and IV (1993 CE pumice). I used electron microprobe analysis, laser ablation - inductively coupled plasma mass spectrometry, and secondary ionization mass spectrometry to generate quantitative compositional maps and gather data of major, trace, and volatile element contents in crystals. Major and trace-element behavior in Láscar apatites reflects general whole-rock compositional trends of Láscar and other Andean …

Magmatic Evolution Of The Chasca Orkho Lava Series And Its Magmatic Enclaves, Volcán Ollagüe, Central Andes, Nathaniel W. Lenhard

Graduate Theses/Dissertations

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 …

Relationships Between Geochemistry, Carbon Content, And Grain Size In Clastic Cave Sediments, Rebekah Rose Nicholas

Graduate Theses, Dissertations, and Problem Reports (ETD)

Understanding geochemical and physical properties of cave sediment gives insight to sediment characterization and carbon storage in the cave system. Previous work on clastic sediments largely encompasses physical properties, neglecting the importance of geochemical parameters on sediment deposition.

This study reports physical and chemical properties of sediment cores from three caves: two caves in Puerto Rico and one cave in Virginia. A total of 25 cores were used in this study; 6 of these cores were new and collected in 2022 from Butler Cave (BTC) in Virginia to focus on the effects of water level. Core samples were analyzed for …

Late Holocene Terrestrial Hydroclimate Reconstructions From Central And South American Sites, Brittany N. Price

Graduate Research Theses & Dissertations

Terrestrial records of hydroclimate variability from Central and South America were developed to better constrain previously unknown regional responses to a range of hydroclimate drivers in the recent past. Developing these late Holocene terrestrial hydroclimate records improves our understanding of past hydroclimate variability by increasing temporal resolution and allows us to further understand complexities in spatial dynamics of the climate system. From South-Central Chile, a geomorphic analysis of landforms emplaced in a glacial valley indicated a positive glacial mass balance in the recent past. A high-precision chlorine-36 chronology was developed from basaltic boulders, with additional minimum constraining ages from Araucaria …

Petrological And Geochemical Evaluation Of Rare-Earth Element Potential In The Sparta Granite Complex, Max J. Eshbaugh

Honors College Theses

Rare earth elements (REEs) are important resources with applications in the electronics, renewable energy, and automotive industries. REEs may be concentrated in the residual weathered portion of igneous parent rocks, typically granites. These residual deposits are mined in southeast Asia, but analogous climatic and geologic conditions suggest the existence of economically viable REE residual deposits in the southeastern United States (U.S.). The Sparta Granite Complex in east-central Georgia is a granitoid complex emplaced at the end of the Alleghanian orogeny, forming a suture between the Savannah River and Milledgeville terranes. Petrologic and geochemical assessments of the Sparta Granite and overlying …

Phosphorus Release And Recovery From Simulated Ferric Wastewater Sludge, Aseel Alnimer

Theses and Dissertations (Comprehensive)

Phosphorus (P) is a fundamental element necessary for all life forms and a key component in the fertilizer industry. Meanwhile, the excessive load of P to water bodies due to human activities has the potential to promote eutrophication. Wastewater treatment plants remove P either biologically or chemically and produce P rich sludge which could be a potential renewable source for P. At present, commercial technologies exist for P recovery from biological wastewater sludge. However, P recovery from chemical sludge particularly iron(III)-phosphate (Fe-P) sludge generated in chemical P removal plants that use iron(III) salts remains a challenge.

This study explored, in …