Geochemistry Commons^™

Cave Dripwater Isotopic Signals Related To The Altitudinal Gradient Of Mount-Lebanon: Implication For Speleothem Studies, Carole Nehme, Sophie Verheyden, Fadi H. Nader, Jocelyne Adjizian-Gerard, Dominique Genty, Kevin De Bont, Benedicte Minster, Ghada Salem, David Verstraten, Philippe Clayes

International Journal of Speleology

An important step in paleoclimate reconstructions based on vadose cave carbonate deposits or speleothems is to evaluate the sensitivity of the cave environment and speleothems to regional climate. Accordingly, we studied four caves, located at different altitudes along the western flank of Mount-Lebanon (Eastern Mediterranean). The objectives of this study are to identify the present-day variability in temperature, pCO₂, and water isotopic composition and to assess the possible influence of the altitudinal gradient on cave drip waters and cave streams. We present here an overview of the spatial variability of rainwater based on local and regional data, and …

Multivariate Analysis Of Hydrochemical Data For Jewel Cave, Wind Cave, And Surrounding Areas, Andrew J. Long, James B. Paces, William G. Eldridge

United States National Park Service: Publications

Abstract

Jewel Cave National Monument and Wind Cave National Park in South Dakota contain two of the six longest caves worldwide. These caves contain subterranean lakes that are important points of intersection between the water table of the Madison aquifer and the caves. During 2015 to 2017, several subterranean lakes were discovered in Jewel Cave, which previously was thought to be above the regional water table. The objectives of this study were to better understand the hydrology of the recently discovered subterranean lakes in Jewel Cave and to evaluate their relation or possible connection to similar lakes in Wind Cave. …

Isolution 1.0: An Isotope Evolution Model Describing The Stable Oxygen (Δ18O) And Carbon (Δ13C) Isotope Values Of Speleothems, Michael Deininger, Denis Scholz

International Journal of Speleology

Stable oxygen and carbon isotope ratios (δ¹³C and δ¹⁸O) are the most applied climate and environmental proxies in speleothems allowing to infer past changes in cave drip water δ¹³C and δ¹⁸O related to climate and environmental variations from above the cave. However, disequilibrium isotope fractionation processes can modify δ¹³C and δ¹⁸O values in speleothems, which is in most cases difficult to estimate due to inter-dependencies on various cave specific parameter. To better understand the effect of these disequilibrium isotope fractionation processes proxy system models were developed in recent …

A Multi-Proxy Approach To Refining Paleotempestology Records On The Northern Gulf Of Mexico Coast, Marianne Elizabeth Dietz

LSU Doctoral Dissertations

Reconstructing pre-historic hurricane activity is typically accomplished through the analysis of sandy overwash deposits identified in coastal lake settings. This method has been used successfully in many parts of the world and can extend the hurricane record thousands of years into the past. However, this approach also has its limitations. This dissertation addresses some of the limitations associated with geologic proxies used to reconstruct hurricane landfalls in the absence of historic data and tests new proxies for the identification of hurricane-derived overwash deposits. Modern storm deposits from two sites on the northern Gulf of Mexico coast are analyzed in detail …

Stable Isotopes Of Clay Minerals From Autoclave Tests Of Oil Sands: Implications For Clay Formation During Steaming Of Alberta Clearwater Oil Sands, Shaoneng He, Fred J. Longstaffe, Zhihong Zhou

Earth Sciences Publications

In an effort to evaluate mineral-water isotopic exchange during cyclic steam stimulation (CSS), solutions and<2 μm berthierine-dominated solids from the Clearwater Formation oil sands of Alberta, Canada were analyzed for stable isotope compositions before and after reaction in autoclaves for 1008 h at 250 °C. There was no significant change in solution δ¹⁸O and δ²H, which is consistent with the high water/mineral ratio used in the experiments. The solids showed a marked decrease in both δ¹⁸O and δ²H following the experiments. Pre-run solids have δ¹⁸O of +9.5 to +12.9‰and …

Reframing The Mammoth Steppe: Insights From Analysis Of Isotopic Niches, Rachel Schwartz-Narbonne, Fred J. Longstaffe, Kevin J. Karydynal, Patrick Druckenmiller, Keith A. Hobson, Christopher N. Jass, Jessica Z. Metcalfe, Grant Zazula

Earth Sciences Publications

Woolly mammoth (Mammuthus primigenius), horse (Equus spp.) and bison (Bisonspp.) coexisted with a variety of mammalian megafauna across the Pleistocene mammoth steppe e a megacontinental ecosystem that spanned northern Eurasia and northwestern North America. Previous research has suggested that highly conserved niches with minimal niche overlap allowed high levels of species diversity on the mammoth steppe. Here we evaluate previously published and some new collagen carbon and nitrogen isotope data (delta¹³C, delta¹⁵N) for mammoth steppe megaherbivores using Stable Isotope Bayesian Ellipses in R (SIBER) and linear regression models to determine isotopic …

Fluid-Present Anatexis Of Neoarchean Tonalite And Amphibolite In The Western Shandong Province, Chris Yakymchuk, Wenran Zhao, Yusheng Wan, Shoufa Lin, Fred Longstaffe

Earth Sciences Publications

Metatonalite and amphibolite from the Taishan region of the Western Shandong Province in the North China Craton record c. 2.60 Ga fluid-present partial melting via the breakdown of biotite, plagioclase and quartz to produce peritectic hornblende and anatectic melt. Eight paired leucosome–melanosome samples from metatonalite and three paired samples from amphibolite were investigated to evaluate the composition of the melt. Hornblende, biotite and plagioclase in the leucosomes and hornblende and plagioclase in melanosomes from both rock types have similar compositions. Two leucosome samples from the metatonalite were influenced by the removal of heavy rare earth element-rich hornblende and the accumulation …

Stable Isotopic Characterization Of A Coastal Floodplain Forest Community: A Case Study For Isotopic Reconstruction Of Mesozoic Vertebrate Assemblages, Thomas M. Cullen, Fred Longstaffe, Ulrich G. Wortmann, Mark B. Goodwin, Li Huang, David C. Evans

Earth Sciences Publications

Stable isotopes are powerful tools for elucidating ecological trends in extant vertebrate communities, though their application to Mesozoic ecosystems is complicated by a lack of extant isotope data from comparable environments/ecosystems (e.g. coastal floodplain forest environments, lacking significant C₄ plant components). We sampled 20 taxa across a broad phylogenetic, body size, and physiological scope from the Atchafalaya River Basin of Louisiana as an environmental analogue to the Late Cretaceous coastal floodplains of North America. Samples were analysed for stable carbon, oxygen and nitrogen isotope compositions from bioapatite and keratin tissues to test the degree of ecological resolution that can …

Flood-Inundation Maps For The North Platte River At Scottsbluff And Gering, Nebraska, 2018, Kellan R. Strauch

United States Geological Survey: Publications

Digital flood-inundation maps for an 8.8-mile reach of the North Platte River, from 1.5 miles upstream from the Highway 92 bridge to 3 miles downstream from the Highway 71 bridge in Scottsbluff County, were created by the U.S. Geological Survey (USGS) in cooperation with the Cities of Scottsbluff and Gering, Nebraska. The flood-inundation maps, which can be accessed through the Flood Inundation Mapping (FIM) Program website at https://www.usgs.gov/mission-areas/water-resources/science/flood-inundation-mapping-fim-program?qt-science_center_objects=0#qt-science_center_objects, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage on the North Platte River at Scottsbluff, Nebr. (station number 06680500). Near-real-time …

Evaluating The Iron Geochemistry Of Terrestrial Aerosol Sources To The Subarctic Pacific Ocean, Meg Yoder

Honors Theses

Wind-blown dust and volcanic ash deposited in high nutrient, low chlorophyll (HNLC) regions can fertilize phytoplankton by providing iron and other trace nutrients, in turn impacting ecosystems as well as the global carbon and nitrogen cycles. The second largest HNLC region in the world is the northeastern subarctic Pacific. Aeolian transport to this region deposits lithogenic material including desert-derived dust from Asia, glacier-derived dust from Alaska and northwestern Canada, and volcanic ash from Eurasia and North America.

This research aims to assess the geochemistry of aerosol sources to the northeastern subarctic Pacific in relation to the biological availability of iron. …

Biodiversity And Distribution Of Benthic Foraminifera In Harrington Sound, Bermuda: The Effects Of Physical And Geochemical Factors On Dominant Taxa, Nam Le

Honors Theses

Harrington Sound, Bermuda, is a nearly enclosed lagoon acting as a subtropical/tropical, carbonate-rich basin in which carbonate sediments, reef patches, and carbonate-producing organisms accumulate. Here, one of the most important calcareous groups is the Foraminifera. Analyses of common benthic orders, including miliolids (Quinqueloculina and Triloculina spp.) and rotaliids (Homotrema rubrum, Elphidium spp., and Ammonia beccarii), are essential in understanding past and present environmental conditions affecting the island's coastal environment. These taxa have been studied previously; however, factors explaining their individual patterns of abundance in the Sound are not well detailed. The goal of this study is …

Formation Of Water-Soluble Organic Matter Through Fungal Degradation Of Lignin, Seyyedhadi Khatami, Ying Deng, Ming Tien, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

Lignin is a major component of decaying terrestrial vegetation in soils and has been reported to contribute substantially to the formation of soil carbon humus and associated water extracts of soil. To better understand this process of humification, lignin from brown-rot degraded wood is subjected to a white-rot fungus (Phanerochaete chrysosporium)whose enzymes are particularly effective in lignin degradation. This enzymatic attack was monitored by ultrahigh resolution mass spectrometry of water soluble extracts of the fungal cultures. The ensuing molecular level characterizations showed that the P. chrysosporium fungi induced aromatic ring oxidations followed by ring opening as expected. However, …

The Petrogenesis Of The No Agua High-Silica Rhyolite In The Taos Plateau Volcanic Field, Northern New Mexico, Kevin M. Voelz

Graduate Research Theses & Dissertations

The Taos Plateau volcanic field (TPVF) is located in Northern New Mexico between the eastern flanks of the Tusas Mountains and west of the Sangre de Cristo range. The TPVF is dominantly composed of basaltic lava flows, olivine andesites, and two-pyroxene dacites which erupted from 5.88 to 1.03 Ma. The variety of compositions within the field owes its origin to processes such as magma mixing, fractional crystallization, and crustal assimilation based on chemical modeling. Curiously placed within this spectrum of mafic to intermediate lavas exists the singular high-silica rhyolite of the No Agua Peaks. XRF and ICP-MS analyses from this …

Carbon In The Deep Biosphere: Forms, Fates, And Biogeochemical Cycling, Susan Q. Lang, Magdalena R. Osburn, Andrew D. Steen

Faculty Publications

Building on the synthesis of carbon reservoirs in Earth's subsurface, this chapter focuses on the forms, cycling, and fate of the carbon supporting microbial life in the terrestrial and marine subsurface. As the subsurface is estimated to host a vast reservoir of life on Earth, identifying the carbon compounds that life uses for energy and growth is key to understanding ecosystem functioning in the past and at present, and also for extrapolating these findings to the search for life in the universe. This chapter highlights advances in quantifying small carbon compounds, measuring rates of carbon turnover, and the fate of …

The Origin Of An Archean Batholith In Michigan’S Upper Peninsula, Brandi Petryk

Dissertations, Master's Theses and Master's Reports

The Southern Complex is part of the Archean Superior Province in the Upper Peninsula of Michigan and includes a batholithic sized body of Archean high-K megacrystic granitoid rocks informally called the Bell Creek granite. U-Pb zircon ages of the granitoid from previous studies suggest an emplacement age of ~2.6 Ga (Tinkham, 1997). Based on those ages the Bell Creek granite formed around the Archean-Proterozoic transition. This transition is a crucial time period in Earth’s history for crustal growth because of the onset of subduction and increased sedimentary environments at the end of the Archean (Taylor and McLennan, 1995). In this …

Response Of Vegetation In Open And Partially Wooded Fens To Prescribed Burning At Seney National Wildlife Refuge, Jane E. Austin, Wesley E. Newton

United States Geological Survey: Publications

The health and function of northern peatlands, particularly for fens, are strongly affected by fire and hydrology. Fens are important to several avian species of conservation interest, notably the yellow rail (Coturnicops noveboracensis). Fire suppression and altered hydrology often result in woody encroachment, altering the plant community and structure. Woody encroachment and its effects on biodiversity have become an increasing concern in the conservation and management of plant communities. This study evaluated the effects of spring and summer prescribed burns on the plant community, cover, and structure in open and partially wooded fens at Seney National Wildlife Refuge, Michigan, using …

The Medicine Hat Block And The Assembly Of Laurentia: New Interpretations From Single-Grain Zircon Analyses, Blake Oswell Ladouceur

Electronic Theses and Dissertations

The Medicine Hat Block (MHB) is one of the core cratonic elements that amalgamated in the Paleoproterozoic to form Laurentia. However the role of the MHB in the formation of Laurentia is poorly constrained due to virtually all of the MHB being concealed by Proterozoic and younger supracrustal sequences limiting availability of data. The primary sources of samples from the MHB are 1) xenoliths of variable metamorphic grade including gneisses amphibolites and meta-plutonic rocks collected from Eocene volcanic rock; and 2) similar lithologies recovered from boreholes that penetrate to the MHB basement. Previous work on samples from the MHB yielded …

Variability In Groundwater Flow And Chemistry In The Houzhai Karst Basin, Guizhou Province, China, Joshua M. Barna

Theses and Dissertations--Earth and Environmental Sciences

Understanding how karst aquifers store and transmit water and contaminants is an ongoing problem in hydrogeology. Flowpath and recharge heterogeneity contribute to the complexity of these systems. This thesis explores karst-conduit connectivity and water chemistry variability in the Houzhai catchment in Guizhou province, China. Artificial tracer tests were conducted during both the monsoon and dry seasons to understand temporal variability in connectivity and water velocity between karst features. Multiple flowpaths through the catchment are activated during the monsoon season and partially abandoned during the dry season. Additionally, gradient reversals during monsoonal high-flow events and as a result of pumping can …

A Joint Xrf-Δ13CCarb Chemostratigraphic Approach For Characterizing Paleo-Environmental Processes In The Mudstone-Dominated Wolfcamp Formation Of West Texas, Frank Tamakloe

Theses and Dissertations--Earth and Environmental Sciences

The Late Paleozoic Ice Age represents a dynamic period in Earth system history recording a shift from icehouse to greenhouse conditions. Concomitant with this change was a series high-frequency, high-amplitude sea level fluctuations leading to the deposition of “Kansas type” cyclothems in the Mid-Continent, and a similar rhythmic expression of interbedded shales and carbonates in the Midland Basin. Stable isotope geochemistry is a particularly powerful tool when examining these mud-rich successions because changes in organic matter partitioning may be recorded first in δ¹³C_DIC of sea-water and consequently in δ¹³C_carb of marine rocks. The δ …

Temporal And Spatial Variability In Groundwater Flow And Chemistry Along The Cumberland River, Artemus, Kentucky, Amanda Rachelle Sherman

Theses and Dissertations--Earth and Environmental Sciences

Groundwater in the Kentucky Appalachian region is constrained by physiography and lithology. Lithostratigraphy, groundwater flow, and chemistry were delineated in the alluvial aquifer along the Cumberland River at H.L. Disney Training Center. To assess groundwater-river interactions and water quality, 11 monitoring wells were installed and sampled quarterly, plus the river and an existing bedrock well. Analytical results were evaluated for temporal and spatial trends. Collected soil cores were analyzed for bulk chemistry and grain size. Solute speciation and saturation indices were calculated and hydraulic conductivity estimated from grain-size analyses. Pumping and slug tests were performed to estimate hydraulic conductivity and …