Geochemistry Commons^™

Anatomy Of The Magmatic Plumbing System Of Los Humeros Caldera (Mexico): Implications For Geothermal Systems., Federico Lucci, Gerardo Carrasco-Nuñez, Federico Rossetti, Thomas Theye, John C. White, Stefano Urbani, Hossein Azzizi, Yosihiro Asahara, Guido Giordano

EKU Faculty and Staff Scholarship

Understanding the anatomy of magma plumbing systems of active volcanoes is essential not only for unraveling magma dynamics and eruptive behaviors but also to define the geometry, depth, and temperature of the heat sources for geothermal exploration. The Pleistocene–Holocene Los Humeros volcanic complex is part of the eastern Trans- Mexican Volcanic Belt (central Mexico), and it constitutes one of the most important exploited geothermal fields in Mexico with ca. 90MWof produced electricity. With the aim to decipher the anatomy (geometry and structure) of the magmatic plumbing system feeding the geothermal field at Los Humeros, we carried out a field-based petrological …

Groundwater Investigations To Support Irrigated Agriculture At La Grange, Western Australia: 2013–18 Results, Robert J. Paul, Gregory Paul Raper, Richard J. George Dr, Nicholas J. Wright, Adam M. Lillicrap, Peter S. Gardiner

Resource management technical reports

The Broome Sandstone aquifer is the main aquifer and groundwater resource in the La Grange area, near Broome in the West Kimberley, Western Australia. Land use is dominated by cattle grazing on pastoral stations, dispersed mining and tourism. Irrigated agriculture has developed at a small scale, with about 470 hectares under cultivation in 2014. Groundwater abstraction is licensed under the La Grange groundwater allocation plan (Department of Water 2010) and managed by the Department of Water and Environmental Regulation. The La Grange groundwater allocation area is split into the La Grange North subarea and La Grange South subarea, with groundwater …

A Granger Causality Analysis Of Groundwater Patterns Over A Half-Century, Nitin K. Singh, David M. Borrok

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Groundwater depletion in many areas of the world has been broadly attributed to irrigation. However, more formal, data-driven, causal mechanisms of long-term groundwater patterns have not been assessed. Here, we conducted the first Granger causality analysis to identify the "causes" of groundwater patterns using the rice-producing parishes of Louisiana, USA, as an example. Trend analysis showed a decline of up to 6 m in groundwater level over 51 years. We found that no single cause explained groundwater patterns for all parishes. Causal linkages were noted between groundwater and area harvested, number of irrigation wells, summer precipitation totals, and drought. Bi-directional …

Temporal And Spatial Scales Of Correlation In Marine Phytoplankton Communities, A. M. Kuhn, S. Dutkiewicz, O. Jahn, Sophie Clayton, T. A. Rynearson, M. R. Mazloff, A. D. Barton

OES Faculty Publications

Ocean circulation shapes marine phytoplankton communities by setting environmental conditions and dispersing organisms. In addition, processes acting on the water column (e.g., heat fluxes and mixing) affect the community structure by modulating environmental variables that determine in situ growth and loss rates. Understanding the scales over which phytoplankton communities vary in time and space is key to elucidate the relative contributions of local processes and ocean circulation on phytoplankton distributions. Using a global ocean ecosystem model, we quantify temporal and spatial correlation scales for phytoplankton phenotypes with diverse functional traits and cell sizes. Through this analysis, we address these questions: …

Characterizing Hydrothermal System Groundwater Dynamics Using Conservative And Non-Conservative Tracers: Insights And Implications Drawn From Study At The Taupo Volcanic Zone (New Zealand) And Valles Caldera (Usa), Joshua Michael Blackstock

Graduate Theses and Dissertations

Hydrothermal systems constitute an important component of heat and mass transport within Earth’s crust having direct and indirect impacts to society. Investigating contemporary hydrochemical differences and change are critical to evaluating and deconvolving factors that influence geothermal systems through time. In this dissertation, groundwater mixing approaches were used to study hydrochemical differences in two globally significant hydrothermal areas, which included fabrication of a low-cost dissolved CO2 monitoring for dissolved inorganic carbon (DIC). In the Taupo Volcanic Zone (New Zealand), empirical spatial relations were used to derive low-temperature groundwater end-members of Cl and Cl/Br for end-member mixing analysis (EMMA). Using EMMA, …

Evidence Of Variable Climate And Resources During The Late Pleistocene And Holocene At Gona, Ethiopia, Marie White

Steeplechase: An ORCA Student Journal

The African Humid Period (AHP) spanned a period of approximately 15 to 5 thousand years ago (ka) and resulted in Northern and Eastern Africa being wetter than today. This climate change event impacted flora, fauna, and humans to an unknown extent. Much of the work on the AHP across Eastern Africa utilizes lacustrine and marine proxies rather than river-based (fluvial). Gona, located in the Afar region of Ethiopia, is known for its extensive archaeological and fossil records in fluvial deposits. However, the paleoenvironment of the AHP at Gona has not been investigated. This study uses stratigraphy, geochronology, and paleopedology to …

Chemostratigraphic Correlations Across The First Major Trilobite Extinction And Faunal Turnovers Between Laurentia And South China, Jih-Pai Lin, Frederick A. Sunberg, Ganqing Jiang, Isabel P. Montanez, Thomas Wotte

Geoscience Faculty Research

During Cambrian Stage 4 (~514 Ma) the oceans were widely populated with endemic trilobites and three major faunas can be distinguished: olenellids, redlichiids, and paradoxidids. The lower–middle Cambrian boundary in Laurentia was based on the first major trilobite extinction event that is known as the Olenellid Biomere boundary. However, international correlation across this boundary (the Cambrian Series 2–Series 3 boundary) has been a challenge since the formal proposal of a four-series subdivision of the Cambrian System in 2005. Recently, the base of the international Cambrian Series 3 and of Stage 5 has been named as the base of the Miaolingian …

The Potential Of Radium-224 As A Tracer Of Timescales Of Gulf Of Mexico Crude Oil Exposure To The Marine Environment, Matthew T. Kurpiel

Electronic Theses and Dissertations

Petroleum pollution in the marine environment can be deleterious to coastal and marine ecosystems and can have sustained effects for years. While oil slicks on the surface of the ocean are tracked with relative ease using satellite-based technology, deep sea, neutrally-buoyant hydrocarbon plumes remain exceedingly difficult to track. We provide evidence for the utility of Ra-224 as a potential hydrocarbon tracer to determine the marine exposure time of crude oil. We employed time course incubations to constrain a time dependent Ra-224 release signature and tested a variety of timescales, temporal resolutions, oil sources, seawater, and experimental treatments to determine potential …

Reinterpreting The Tectonic Model Of The Southern Part Of The Taconic Orogeny Through A Provenance Study Of Late Ordovician Sandstones, Juan Carlos Guerrero

LSU Master's Theses

A provenance study of quartz arenites that stratigraphically are closely associated with major Ordovician K-bentonites has been conducted in order to further our understanding of the tectonic setting of eastern Laurentia during the Late Ordovician. Using laser ablation ICP-MS, detrital zircons separated from Ordovician sandstone samples in the southeastern Appalachian Mountains (Virginia to Alabama) were dated using U-Pb geochronology. Analytical results show three dominate age ranges for the zircons from these sandstones: ~440-490 Ma, ~900-1300 Ma, and ~1300-1500 Ma. In addition, some zircon ages grouped into older ranges of ~1600-1800 Ma, ~1800-1900 Ma, and ~2600-2800 Ma. Zircon ages from ~900-2800 …

Boron Variation And The Subducted Sediment Component In The Volcanics From The Bifurcated Portion Of The Lesser Antilles Island Arc (Laia), Ami Margret Ngo Ward

USF Tampa Graduate Theses and Dissertations

North of Martinique island the Lesser Antilles volcanic arc bifurcates, creating a double arc. Here volcanic activity has migrated up to 50 km westward with time, resulting in two volcanic lines that are distinct in age. The eastern line, commonly referred to as the old arc, was active from Early Eocene to Mid-Miocene (Nagle, 1971; Nagle et al., 1976; Westercamp and Tazieff, 1980; Andreieff et al., 1988). The western line, commonly referred to as the recent arc, has been active since the late Pliocene, ~6 Ma ago (Nagle, 1971; Nagle et al., 1976; Westercamp and Tazieff, 1980; Andreieff et al., …

Exploring Planetary Surfaces With Remote Sensing, Donald R. Hood

LSU Doctoral Dissertations

Aside from Earth, Mars is the most well-explored planetary body in our solar system. Much has been learned about its geologic past including a history of volcanism, ice ages, and potentially long-lasting liquid water. Much of this knowledge of Mars comes from remote observations of the surface and atmosphere from Mars-orbiting satellites. Such remote observations remain the only way to examine the entirety of Mars’ surface as rovers and landers can only examine small areas. The chapters of this work cover three projects that explore the surface of Mars through a variety of remote sensing methods.

In chapter 1, Gamma-ray …

Neogene Chemical Weathering And Provenance Records Of The Western Himalaya Preserved In The Arabian Sea, Peng Zhou

LSU Doctoral Dissertations

Some tectonic models for the Himalaya emphasize the importance of surface processes in controlling the structural evolution. To investigate this tectonic–climatic interactions, and the weathering and erosion of the western Himalaya, International Ocean Discovery Program (IODP) Expedition 355 drilled two sites (site U1456 and U1457) in Laxmi Basin, which located in the Eastern Arabian Sea. In my research project, I plan to use a series of geochemical and geochronological methods on the sediment samples from the cores of these two sites, and sediments from an industrial borehole Indus Marine A-1, which near the Indus river mouth, to reconstruct a climatic …

A Terrestrial Reconstruction Of Gona, Ethiopia Before And During The African Humid Period, Marie N. White, Gary E. Stinchcomb

Posters-at-the-Capitol

The African Humid Period (AHP) resulted in more humid conditions across Northern and Eastern Africa from 15 to 5 thousand years ago (ka). This wetter climate affected flora, fauna and the Homo sapiens living in East Africa. The lack of terrestrial paleoenvironmental reconstructions is a problem in East Africa, especially during the AHP, where most are done utilizing lacustrine or marine proxies. In the case of Gona, Ethiopia, terrestrial proxies are desired due to the rich archaeological and fossil concentrations that occur in the area. Paleosols provide more direct, localized reconstructions that provide context for these finds. This study utilizes …

On The Ablation Of Meteors And The Implications On Organic Delivery To Earth, Christopher Alan Mehta

USF Tampa Graduate Theses and Dissertations

The synthesis of prebiotic organic compounds is a key step in the origin of life. Sources of these materials are divided into endogenous and exogenous sources. Endogenous synthesis—occurring potentially on the surface of the Earth—includes such historic experiments as the Miller spark discharge and formose chemistry. However, one avenue for exogenous synthesis to occur is when meteors enters an atmosphere. Using principles of orbital mechanics, geology, physics, and chemistry, we study meteor ablation and the transport of organic matter to the surface of Earth. To do so, I create numerical models that simulates meteors traveling through the atmosphere of Earth …

Ch. 20 - Deep Carbon Through Deep Time, Robert M. Hazen, Yana Bromberg, Robert T. Downs, Ahmed Eleish, Paul G. Falkowksi, Peter Fox, Eli K. Moore

School of Earth & Environment Departmental Research

This chapter highlights the use of data-driven discovery to address remaining gaps in our understanding of deep carbon.

Influence Of Spring Flow Reversals On Cave Dissolution In A Telogenetic Karst Aquifer, Mammoth Cave, Ky, Chelsey Kipper

Masters Theses & Specialist Projects

An often overlooked connection between karst groundwater systems and surface water is spring flow reversal, the flow of river water into karst springs caused by changes in hydraulic gradient. Karst aquifers are subject to the intrusion of river water when the hydraulic head of a base level river is higher than the hydraulic head of a base level spring. When this occurs, the flow out of the spring reverses, allowing river water to enter base level conduits. River water thus becomes a source of recharge into karst basins, transporting both valuable nutrients and harmful contaminants into karst aquifers. The rapid …

Improving Thorium-230 Determination In Marine Sediment, Katherine Mateos

Independent Study Project (ISP) Collection

Our oceans are intimately related to the climate of our planet. Paleoceanographic approaches aim to study oceans through geologic time to improve models of future climate. Radioisotopes provide us with chemical tracers that help us understand change through time. The uraniumseries decay chain contains thorium-230, a decay product of uranium-234. This isotope is useful to paleoceanographers in its disequilibrium to its parent isotope and in determining the flux of sediment falling to the ocean floor. In order to use 230Th to study oceans, we must be able to accurately measure the amount of thorium in sediment samples. Thorium is found …

Genesis Of Iron And Manganese Sediments In Zoloushka Cave (Ukraine/Moldova) As Revealed By Δ13C Organic Carbon, Piotr Kotula, Viacheslav Andreychouk, Jacek Pawlyta, Leszek Marynowski, Izabela Jendrzejewska

International Journal of Speleology

Zoloushka Cave is one of the largest maze gypsum caves in the world. Mining of the gypsum bedrock and lowering of the water level due to the pumping of groundwater led to exposure of the cave passages to vadose conditions and changed the hydrochemistry of the karst water. As a result, large quantities of Fe and Mn hydroxides were deposited in the passages. It was found that at least two groups of various organisms were involved in depositing ferrous and manganese sediments. In order to establish the mechanism of deposition, we conducted chemical analyses of the sediments and isotopic analyses …

Identification Of Mined Areas That May Contribute To Water Quality Degradation At Hobet Coal Mine, West Virginia, Brian P. Murphy

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

No abstract provided.

Oldowan Tool Behaviors Through Time On The Homa Peninsula, Kenya, Emma M. Finestone

Dissertations, Theses, and Capstone Projects

The adaptive significance of tool use to genus Homo is a central theme in human origins. However, what we know from the early Oldowan sites suggests that persistent technology may have begun as an opportunistic behavior with minimal investment, rather than a habitual and widespread adaptive revolution. This dissertation seeks to investigate investment in Oldowan tool production on the Homa Peninsula, Kenya, considering raw material selection, transport, and lithic production at two newly discovered Oldowan localities: Nyayanga (ca. 2.6 Ma) and Sare River (ca. 1.7 Ma).

The first section of this dissertation outlines a method that enables the comparison of …