Geochemistry Of Crusts In Palaeontological Deposits, Taphonomic Settings In An Upper Pleistocene Cave Site (San Teodoro, Sicily),
2026
University of Palermo, Italy
Geochemistry Of Crusts In Palaeontological Deposits, Taphonomic Settings In An Upper Pleistocene Cave Site (San Teodoro, Sicily), Gerlando Vita, Luca Sineo, Francesco Armetta, Maria Luisa Saladino
International Journal of Speleology
The mineralogical and geochemical composition of cave sediments provides crucial insights into past climatic and biological dynamics. This study investigates the authigenic crusts of San Teodoro Cave (Sicily), a key Upper Pleistocene palaeontological site, through a multi-analytical approach.The cave hosts two superimposed phosphatic crusts, separated by sterile sediment, reflecting shifts in depositional and post-depositional conditions. Our analyses reveal a complex mineral assemblage consisting of calcite, aragonite, and various phosphate phases. Calcite is the dominant phase in the older crust, whereas the presence of aragonite in the younger brown crust likely indicates periods of increased aridity, potentially corresponding to conditions during …
Exceptional Variety Of Baryte-Celestine-Series Speleothems In Lechuguilla Cave (New Mexico, Usa),
2026
Senckenberg am Meer, Marine Research Department, Südstrand 40, 26382 Wilhelmshaven, Germany
Exceptional Variety Of Baryte-Celestine-Series Speleothems In Lechuguilla Cave (New Mexico, Usa), Max Wisshak, Johannes Birkenstock, Andrea Schröder-Ritzrau, Norbert Frank, Hazel A. Barton, Harvey R. Duchene
International Journal of Speleology
An inventory of speleothems primarily composed of the closely related sulfate minerals baryte (BaSO4) and celestine (SrSO4) in Lechuguilla Cave (New Mexico, USA) has revealed an extraordinary variety. This includes subaerial stalactites, stalagmites, flowstone, coralloids, wall crusts, floor crystals, snow, frostwork, and subaqueous pool crystals. Large baryte and celestine crystals have also been documented in hydrothermal veins in the host rock, predating the cave and truncated when intersected by it. The respective carbonate mineral phases witherite (BaCO3) and strontianite (SrCO3), in contrast, were found to be rare in the studied speleothem samples, …
Assessing The Impact Of Visitors On Airborne Particle Deposition In The Giant Gypsum Geode Of Pulpí (Se Spain),
2026
University of Almería, Spain
Assessing The Impact Of Visitors On Airborne Particle Deposition In The Giant Gypsum Geode Of Pulpí (Se Spain), Ana Camila Mendoza, Ángel Fernández-Cortés, Fernando Gázquez, Jesús Morilla, Milagros Carretero, Jose Maria Calaforra, David Benavente
International Journal of Speleology
The Giant Geode of Pulpí is a unique mineralogical phenomenon worldwide, remarkable for its large selenite gypsum crystals. Its recent development as a tourist site and inclusion on UNESCO’s Tentative World Heritage List, highlight the need to assess the impact of visits on its conservation. This study investigates airborne particle dynamics inside the Geode, focusing on tourist activity and natural ventilation. We measured deposition rates and composition of airborne particles using passive traps and a continuous laser-optical particle counter. Microenvironmental variables linked to ventilation, such as temperature and radon gas concentration (²²²Rn), were simultaneously monitored. Results show a predominance of …
Exploring Mesoproterozoic Marine Redox States In A Young Banded Iron Formation From The Needle Mountains,
2026
Dartmouth College
Exploring Mesoproterozoic Marine Redox States In A Young Banded Iron Formation From The Needle Mountains, Jaya Sharma, Brenhin Keller
Wetterhahn Science Symposium Posters
Banded iron formations (BIF), as redox-dependent chemical sedimentary rocks, have served as proxies for marine and atmospheric oxygen and iron conditions throughout Earth history. While abundant in the Archean and early Proterozoic, the widespread deposition of BIFs declined following the Great Oxidation Event, as oxygenated surface waters prevented the accumulation of ferrous iron. However, the Needle Mountains, located in southwestern Colorado, houses an anomalously young BIFs deposited between 1.786±10 - 1.801±6 Ga given existing geochronology. Here, we use rare earth element (REE) systematics, bulk chemistry, and petrographic analysis to determine the depositional conditions under which this BIF was formed. We …
Carbon Storage In Headwaters Can Respond Rapidly To Climate Change,
2026
Dartmouth College
Carbon Storage In Headwaters Can Respond Rapidly To Climate Change, Maddie Benello, Carl Renshaw, Joshua Landis
Wetterhahn Science Symposium Posters
Headwater streams play a critical role in the global carbon cycle, serving as significant sites of carbon storage. While there have been recent efforts to quantify carbon storage in headwater streams in the western United States, there remains limited understanding of both the volume and timescale of carbon storage in northeastern forests which often have extensive logging and agricultural histories. Here, we quantify the carbon stock, residence time, and flux of a zero-to-first order headwater stream in Charles Downer State Forest (DF), VT using novel fallout radionuclide (FRN) chronometry. We find DF headwaters have a carbon stock of 66.2 Mg …
Timing, Orbital Pacing, And Provenance Of Late Paleogene Loess In The Western United States,
2026
University of Texas at Arlington
Timing, Orbital Pacing, And Provenance Of Late Paleogene Loess In The Western United States, Xiangwei Guo
Earth & Environmental Sciences Dissertations - Archive
This project examines the timing of loess emergence, the nature of the fluvial–eolian transition, orbital forcing on dust accumulation, and sediment recycling in the late Paleogene White River Formation (Group) of Wyoming and Nebraska, western United States. By integrating traditional sedimentology with machine learning–enhanced grain-size analysis, this research shows that loess accumulation at Flagstaff Rim in central Wyoming began during active fluvial deposition at approximately 35.8 Ma, indicating a gradual transition from fluvial to eolian conditions. Machine learning complements field sedimentology and granulometric interpretation while enabling the development of new, testable hypotheses. Extending this framework eastward to Toadstool Geologic Park …
A Stable Isotope Comparison Of The Biogenic Carbonate Of Mammalian Tooth Enamel From The Modern Ohio River Valley And Fort Ancient Buffalo Sites,
2026
Marshall University
A Stable Isotope Comparison Of The Biogenic Carbonate Of Mammalian Tooth Enamel From The Modern Ohio River Valley And Fort Ancient Buffalo Sites, Sara Elizabeth Slack
Theses, Dissertations and Capstones
δ18O and δ13C values change in response to anthropogenic factors (Ghosh & Brand, 2003). Little is known about the effects of anthropogenic climate and land use change on the ecology of the Ohio River Valley. The goal of this research was to quantify the effects of European colonization on the native ecology of the region. The specific questions of this research were: (1) How have mammalian tooth enamel δ18O and δ13C compositions shifted over time within the Ohio River Valley in response to anthropogenic climate change and vegetation? (2) Are there differences …
Comparative Assessments Of Methane Flux Measurement Techniques In Serpentinite-Influenced Groundwater Wells,
2026
University of Rhode Island
Comparative Assessments Of Methane Flux Measurement Techniques In Serpentinite-Influenced Groundwater Wells, Madison J. Stetson
Open Access Master's Theses
Methane (CH4) emissions from continental serpentinizing systems represent a significant component of Earth’s carbon cycling. Despite increasing recognition of serpentinite-hosted water-rock interactions as a source of trace gases, standardized field methodologies for quantifying trace gas flux from groundwater wells and similar subsurface conduits remain limited. This study addresses that gap by evaluating the reliability and replicability of three chamber-based sampling methods for measuring gas flux in serpentinite-hosted groundwater systems accessed by groundwater monitoring wells. Field measurements were conducted at the Coast Range Ophiolite Microbial Observatory (CROMO) within the McLaughlin Natural Reserve in Lower Lake, California, a site …
Supplemental Bibliographic Details. From 2001 Mars Odyssey To Earth’S Climate Crisis: Integrating Gamma Spectroscopy, Martian Soil Simulants, And Plant Genomes For Agroecology, Anchored In Sri Lanka’S Mars-Context Serpentinites,
2026
Louisiana State University at Baton Rouge
Supplemental Bibliographic Details. From 2001 Mars Odyssey To Earth’S Climate Crisis: Integrating Gamma Spectroscopy, Martian Soil Simulants, And Plant Genomes For Agroecology, Anchored In Sri Lanka’S Mars-Context Serpentinites, Suniti Karunatillake, Maheshi Dassanayake, Carlos Gary Bicas
Planetary Science Lab
Bibliographic details follow to supplement hyperlinked citations in the multinational GANGOTRI-supporting project conceived by Karunatillake, Dassanayake, and Gary-Bicas
Investigation Of Reey Concentrations In Argillaceous Rocks Associated With Coal Beds In Southwestern West Virginia,
2026
Marshall University
Investigation Of Reey Concentrations In Argillaceous Rocks Associated With Coal Beds In Southwestern West Virginia, Alyssa Cameron Long
Theses, Dissertations and Capstones
Rare earth elements (REEs) and Yttrium are classified as “critical minerals” that are used in many industries and are typically extracted from carbonatites and related alkaline plutonic rocks. The limited availability of REE+Y requires finding alternate sources such as coal fly ash, tonstein, fireclays, and shales. This study investigates the potential enrichment of shales, fireclays, and siltstones interbedded with coal from southwestern WV in REEY, and the mechanisms of such enrichment. Using ICP-AES analysis of various rock types shows that shales, silty shales, and siderite nodules interbedded with Fire Clay and Chilton Coal beds in the Kanawha Formation record the …
Constraining The Tectono-Climatic Evolution Of The Northern Rocky Mountains: Insights From Volcanic Glass, Leaf Water, And Leaf Wax Hydrogen Isotopes,
2026
University of Texas at Arlington
Constraining The Tectono-Climatic Evolution Of The Northern Rocky Mountains: Insights From Volcanic Glass, Leaf Water, And Leaf Wax Hydrogen Isotopes, Rijumon Nandy
Earth & Environmental Sciences Dissertations
The Eocene-Oligocene period in the North American Cordillera represents a period of great intrigue with complex interactions among tectonics, climate, and surface processes. Although this period is generally associated with synorogenic extension associated with gravitational collapse of the Cordillera, the paleotopographic history remains debated. Existing studies offer conflicting interpretations, suggesting either sustained elevations or modest uplift during this time. Notably, recent reconstructions based on volcanic glass δD values have proposed renewed uplift during the early Oligocene, which needs to be tested with a more extensive and robust dataset. Concurrently, global cooling and aridification during this interval may have been amplified …
Understanding The Drivers Of Marine Sediment Diagenesis In Carbonate-Bearing Sediments,
2026
University of Kentucky
Understanding The Drivers Of Marine Sediment Diagenesis In Carbonate-Bearing Sediments, Alex Reis
Theses and Dissertations--Earth and Environmental Sciences
Marine sediments serve as an important geochemical record used to study how the Earth’s climate and oceans have changed throughout geologic time. As such, it is critical to understand how these sediments can be altered following deposition on the seafloor. This dissertation targeted two key geochemical archives, carbonate and pyrite, to link changing burial conditions with the resulting marine sediment chemistry. In particular, primary carbonate minerals record several indicators of past ocean chemistry, while pyrite preserves information related to the redox state of the sediment during deposition and burial. Additionally, secondary processes associated with changes in pore fluid chemistry and …
Use Of Stable Isotope Geochemistry To Determine The Paleoenvironment Of The Pond Creek Coal Bed, Pike County, Eastern Kentucky,
2026
University of Kentucky
Use Of Stable Isotope Geochemistry To Determine The Paleoenvironment Of The Pond Creek Coal Bed, Pike County, Eastern Kentucky, Vivian A. Edwards
Theses and Dissertations--Earth and Environmental Sciences
Wetlands are both critical habitats and bellwethers of the health of the environment. Coal, being the remains of wetlands, offers the possibility of understanding the evolution of wetlands over large climatic shifts. The paleoenvironment of coals can be determined from palynology, petrology, and geochemistry. Stable isotope ratios within coal, including carbon (δ13C), nitrogen (δ15N), and sulfur (δ34S), are established tools for paleoenvironmental reconstructions. These ratios can be correlated to flora, geochemistry, macerals, and bacterial activity. However, carbon, nitrogen, and sulfur have given conflicting results in some studies and their correlation to known variables is …
Supplementary Material For Experimental Constraints On Rock And Mineral Alteration By Magmatic Gas: Implications For Mars (Safari Et Al., In Review),
2026
Stony Brook University
Supplementary Material For Experimental Constraints On Rock And Mineral Alteration By Magmatic Gas: Implications For Mars (Safari Et Al., In Review), Natalie Zimmermann
Geosciences Research Data
This file contains supplemental data for the JGR manuscript Experimental Constraints on Rock and Mineral Alteration by Magmatic Gas: Implications for Mars (Safari et al., in review). It includes SEM images and associated EDS spectra of altered targets and phase coatings produced in gas-rock alteration experiments.
Hydrogeochemical And Redox Controls On Nitrate And Arsenic Co-Occurrence In The Western Kansas High Plains Aquifer (Usa): A Composite Health Risk Assessment And The Case For Risk-Informed Private Well Governance,
2026
Fort Hays State University
Hydrogeochemical And Redox Controls On Nitrate And Arsenic Co-Occurrence In The Western Kansas High Plains Aquifer (Usa): A Composite Health Risk Assessment And The Case For Risk-Informed Private Well Governance, Jonathan Kuffour Owusu
Master's Theses or Doctor of Nursing Practice
Fifty-one private domestic wells across western Kansas were sampled to quantify nitrate and arsenic occurrence, identify geochemical controls, and evaluate carcinogenic and non-carcinogenic health risks for adult and child receptors in a region where groundwater serves as the primary drinking water source with no routine regulatory oversight. Samples were analyzed for major ions, nutrients, and trace elements by ICP-MS, ion chromatography, and UV-Vis spectrophotometry. Shapiro-Wilk testing confirmed non-normal distributions for both contaminants; inter-county comparisons were therefore conducted using Kruskal-Wallis tests with Dunn's post-hoc correction. Health risk was quantified via chronic daily intake (CDI), hazard quotient (HQ), HQ-based Water Quality Index …
Pre-Eruptive Timescales Via Olivine Diffusion Chronometry For Lava And Tephra Of The Schreibers Meadow Cinder Cone Eruption, Mount Baker (Kulshan), Wa,
2026
Central Washington University
Pre-Eruptive Timescales Via Olivine Diffusion Chronometry For Lava And Tephra Of The Schreibers Meadow Cinder Cone Eruption, Mount Baker (Kulshan), Wa, Sabrina Ansari
All Master's Theses
Mount Baker is a very-high threat Cascade volcano and is located near densely populated areas in northern Washington, putting many at risk if an eruption were to occur. Schreibers Meadow cinder cone is located on the southern flank of Mount Baker and produced the Sulphur Creek (SC) tephra and lava 9.8 ka. Previous work on the SC eruption used petrology and geochemistry to reconstruct the pre-eruptive magmatic architecture beneath Mount Baker Volcanic Field, including olivine-hosted melt inclusions to determine crystallization pressures, as well as plagioclase- and clinopyroxene-derived diffusion timescales to determine magma storage timescales of several months and recharge-to-eruption timescales …
Paleoflood Chronology For The West Branch Of The Susquehanna River Using Abandoned Chute Channel Sediments, Pennsylvania, Usa,
2026
Bucknell University
Paleoflood Chronology For The West Branch Of The Susquehanna River Using Abandoned Chute Channel Sediments, Pennsylvania, Usa, Juliette A. Vanluven
Honors Theses
Anthropogenic climate change is altering the hydrologic cycle, increasing flood frequency and severity, with associated increased risks in population exposure. This is associated with increasing risks to the population of the Susquehanna River Valley, which supports over 600,000 people today. However, our understanding of the frequencies of large floods is limited by relatively short instrumental records. By studying sediments from an abandoned chute channel in the Robert Allen Natural Area near Williamsport, PA, we can extend the existing flood records using paleoflood slackwater sediments along the West Branch of the Susquehanna River. Sylvan Dell is an abandoned chute channel that …
Deep Crustal Boundaries As Fluid Conduits: A Geochemical Investigation Of Mvt Mineralization In Kentucky And Beyond,
2026
University of Kentucky
Deep Crustal Boundaries As Fluid Conduits: A Geochemical Investigation Of Mvt Mineralization In Kentucky And Beyond, Dairian Boddy M. Boddy
Theses and Dissertations--Earth and Environmental Sciences
Critical minerals are vital to the United States economy and national security, yet their supply chains are at risk. Common minerals in Mississippi Valley-type (MVT) deposits, such as sphalerite, galena, fluorite, and barite, host critical metals such as barium, gallium, germanium, and zinc, which are essential for energy technologies. An investigation of three MVT mineral districts in Kentucky elucidated previously unrecognized systematics, genetic relationships, and sources of ore components using stable and radiogenic isotope geochemistry, particularly from galena, sphalerite, barite, and gangue minerals (e.g., carbonates). The localization and dominant type of mineralization in each district are potentially influenced by deep …
Origin Of The World-Class Eagle, Eagle East, And Tamarack Ni-Cu-Pge Deposits And Comparative Analysis With Other Midcontinent Rift- And Siberian Trap-Related Intrusions,
2026
Michigan Technological University
Origin Of The World-Class Eagle, Eagle East, And Tamarack Ni-Cu-Pge Deposits And Comparative Analysis With Other Midcontinent Rift- And Siberian Trap-Related Intrusions, Robert M. Nowak
Dissertations, Master's Theses and Master's Reports
The 1.1 Ga Mesoproterozoic Midcontinent rift hosts the Eagle, Eagle East, and Tamarack Ni-Cu-PGE deposits and Embayment Prospect. These deposits are hosted by ultramafic igneous rocks and have some of the highest Ni-Cu grades on Earth. We use new bulk-rock data and published datasets (bulk-rock, mineral chemistry, and isotopic analyses) to examine major, minor, and trace element trends of both Midcontinent rift-related alkaline and tholeiitic intrusions. In addition, we compare the geochemical data to local kimberlite-hosted lower-crustal xenoliths and local igneous (Archean) and sedimentary (Paleoproterozoic) country rocks. We found the peridotite magma compositions dominantly consist of primitive mantle compositions with …
Volatiles In Mantle Sources At Mid-Ocean Ridge And Intraplate Settings,
2026
University of Rhode Island
Volatiles In Mantle Sources At Mid-Ocean Ridge And Intraplate Settings, Rebecca Lippitt
Open Access Dissertations
Volatiles play an integral role in upper mantle processes and the eruptive styles of volcanoes. Although we know the importance of volatiles to volcanic systems, processes like melting, crystallization, and degassing alter the volatile abundances of mantle melts, making it difficult to quantify mantle source compositions and the extent to which volatiles influence melting processes. Additionally, volatile content may be a key factor in setting the oxidation conditions of mantle source rocks and subsequently changing those conditions in a body of magma as it ascends through the crust and is erupted at the Earth’s surface. Recent work, however, has identified …
