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Processes Controlling Carbon Cycling In Antarctic Glacier Surface Ecosystems, Elizabeth A. Bagshaw, Martyn Tranter, Jemma L. Wadham, Andrew G. Fountain, A. Dubnick, S. Fitzsimons 2016 Cardiff University

Processes Controlling Carbon Cycling In Antarctic Glacier Surface Ecosystems, Elizabeth A. Bagshaw, Martyn Tranter, Jemma L. Wadham, Andrew G. Fountain, A. Dubnick, S. Fitzsimons

Andrew G. Fountain

Glacier surface ecosystems, including cryoconite holes and cryolakes, are significant contributors to regional carbon cycles. Incubation experiments to determine the net production (NEP) of organic matter in cryoconite typically have durations of 6-24 hours, and produce a wide range of results, many of which indicate that the system is net heterotrophic. We employ longer term incubations to examine the temporal variation of NEP in cryoconite from the McMurdo Dry Valleys, Antarctica to examine the effect of sediment disturbance on system production, and to understand processes controlling production over the lifetimes of glacier surface ecosystems. The shorter-term incubations have durations of ...


Cone In Cone Concretions Of The Stanley Group In Southeastern Oklahoma, Kyle B. Ayres 2016 Stephen F Austin State University

Cone In Cone Concretions Of The Stanley Group In Southeastern Oklahoma, Kyle B. Ayres

Electronic Theses and Dissertations

Cone in cone concretions found in the Stanley Group of Southeastern Oklahoma have a variety of external and internal attributes which allow diagenetic and theoretical models of formation to be hypothesized. Stanley Group carbonate cone in cone concretions are initially formed in sulfur reducing horizons at shallow burial depths in a poorly circulated possibly deep trough containing siliceous sediments and organic matter. Collected concretions near the town of Smithville, Oklahoma displayed four different external morphologies and four variations of mineral constituents. All concretions contained microscopic cones which initiated diffusion and/or fluid patterns and is an early cementation process that ...


An Investigation Of Hydrogeologic, Stratigraphic, And, Melinda S. Faulkner 2016 Stephen F Austin State University

An Investigation Of Hydrogeologic, Stratigraphic, And, Melinda S. Faulkner

Electronic Theses and Dissertations

The Owl Mountain Province is located within the Fort Hood Military Installation, an approximately 880 km2 installation established in the 1940s in Bell and Coryell counties, Texas, which has undergone extensive land use changes associated with military training, maintaining much of the vegetation in early succession. This study investigates thelithologic, stratigraphic, and structural controls on the hydrologic, hydrogeologic, and geomorphologic evolution of the Owl Mountain Province as expressed by mesic vegetation communities, including Pleistocene relicts Acer grandidentatum, within karst terrains. These systems exhibit complexly overprinted speleogenetic evolutions within a dynamic groundwater regime resulting from regional climate shifts throughout the Neogene ...


The Stratigraphic Position Of Fossil Vertebrates From The Pojoaque Member Of The Tesuque Formation (Middle Miocene, Late Barstovian) Near Española, New Mexico, Garrett R. Williamson 2016 Stephen F. Austin State University

The Stratigraphic Position Of Fossil Vertebrates From The Pojoaque Member Of The Tesuque Formation (Middle Miocene, Late Barstovian) Near Española, New Mexico, Garrett R. Williamson

Electronic Theses and Dissertations

The stratigraphy of the Pojoaque Member of the Tesuque Formation near Española, NM is not well understood. This region, during the Middle Miocene, represented a dynamic alluvial fan-fluvial-lacustrine environment within the Española Basin while the Rio Grande Rift was active. Cavazza (1986) identified two paleodrainage systems (lithosome A, basin-margin facies and B, basin-floor facies) by means of sandstone and conglomerate petrology, paleocurrent, and sedimentary facies analyses. After x-ray diffraction analyses of claystones within lithosome B, mordenite was discovered, which is a zeolite mineral commonly found within volcanic rocks. This is significant because the presence of mordenite confirms Cavazza’s (1986 ...


Evaluation Of Groundwater Quality In Paleozoic Aquifers Using Gis Techniques, Central Texas, Garrett R. Harris 2016 Stephen F Austin State University

Evaluation Of Groundwater Quality In Paleozoic Aquifers Using Gis Techniques, Central Texas, Garrett R. Harris

Electronic Theses and Dissertations

Lab analyses of groundwater chemistry from monitoring wells completed in the Paleozoic Aquifers surrounding the Llano Uplift of Central Texas has been recorded and made available to the public through the Texas Water Development Board (TWDB). This study evaluated the results of these data dating back to the 1940s to determine changes over time, the dynamics of the hydrologic system, and the locations where hydraulic connectivity is most probable. The initial results established two distinct hydrologic systems that required the separation of the northern from the southern region. The northern sub-region (NSR) contains the largest expanse of continuity of both ...


The Petrology And Geochemistry Of The Independence Dike Swarm, Owen’S Valley, California, Sean B. O'Donnell 2016 Cedarville University

The Petrology And Geochemistry Of The Independence Dike Swarm, Owen’S Valley, California, Sean B. O'Donnell

The Research and Scholarship Symposium

Petrologic studies are important because they provide insights into the conditions under which rocks form. The Late Jurassic Independence Dike Swarm is a series of vertical igneous dikes that crop out in eastern and southern California, and range from mafic to felsic in composition. In order to examine their petrology and geochemistry, surface samples were collected from four different dike outcrops within Owen’s Valley, CA. The samples were examined through thin-section analysis under a petrographic microscope, X-ray diffraction analysis, and X-ray fluorescence analysis. Mineral composition, mineral size, major, trace, and rare earth element concentrations were collected from these analyses ...


Evidence For Shallow Saltwater Intrusion: Wormsloe State Historic Site, Chatham County, Georgia, Chelsea E. Bush, Lori A. Farley, Tim J. Herold 2016 Georgia State University

Evidence For Shallow Saltwater Intrusion: Wormsloe State Historic Site, Chatham County, Georgia, Chelsea E. Bush, Lori A. Farley, Tim J. Herold

Georgia State Undergraduate Research Conference

No abstract provided.


Reconstructing Paleoenvironmental Conditions From Hydrothermally Altered Lacustrine Sediments From Hspdp West Turkana-Kaitio Core Material Via Coupled Mineralogical And Geochemical Analysis, Mamta Sanam Chaudhary 2016 Georgia State University

Reconstructing Paleoenvironmental Conditions From Hydrothermally Altered Lacustrine Sediments From Hspdp West Turkana-Kaitio Core Material Via Coupled Mineralogical And Geochemical Analysis, Mamta Sanam Chaudhary

Georgia State Undergraduate Research Conference

No abstract provided.


A Mineralogical And Geochemical Analysis Of Bed I In Olduvai Gorge, Tanzania, David Michael Davis, Sanam M. Chaudhary, Alex M. Simpson, Daniel M. Deocampo, Nathan M. Rabideaux, Gail Ashley, Kevin Garrett 2016 Georgia State University

A Mineralogical And Geochemical Analysis Of Bed I In Olduvai Gorge, Tanzania, David Michael Davis, Sanam M. Chaudhary, Alex M. Simpson, Daniel M. Deocampo, Nathan M. Rabideaux, Gail Ashley, Kevin Garrett

Georgia State Undergraduate Research Conference

No abstract provided.


Preliminary Investigations Of Seasonal Changes In The Geochemical Evolution Of The Logdson River, Mammoth Cave, Kentucky, Chris Groves, Darlene Anthony, Joe Meiman 2016 Western Kentucky University

Preliminary Investigations Of Seasonal Changes In The Geochemical Evolution Of The Logdson River, Mammoth Cave, Kentucky, Chris Groves, Darlene Anthony, Joe Meiman

Chris Groves

Many geochemical studies have been made of karst waters worldwide. Most data that provide the framework for our current understanding of the evolution of karst waters have come from sampling at discrete times and locations, such as springs or wells. Relatively few studies have been made of the geochemical evolution of groundwater as it moves through an open flow system. This paper addresses the seasonal changes in the geochemistry of the Logsdon River conduit as it passes through nearly 10km of the carbonate aquifer of south-central Kentucky . The most important control on the ability of groundwaters to dissolve limestone is ...


U-Pb Dating Of Speleogenetic Dolomite: A New Sulfuric Acid Speleogenesis Chronometer, Victor J. Polyak, Paula P. Provencio, Yemane Asmerom 2016 University of New Mexico

U-Pb Dating Of Speleogenetic Dolomite: A New Sulfuric Acid Speleogenesis Chronometer, Victor J. Polyak, Paula P. Provencio, Yemane Asmerom

International Journal of Speleology

The 1100-meter Big Room elevation level of Carlsbad Cavern, New Mexico USA, formed 4 Ma by hypogenic sulfuric acid speleogenesis (SAS). The age of the Big Room level of 4.0 ± 0.2 Ma was previously determined by dating alunite, a byproduct of speleogenesis, using the 40Ar/39Ar method. Duplication of these results is possible by radiometric dating of other byproducts interpreted to be speleogenetic (a byproduct of speleogenesis) such as calcite and dolomite in certain settings. XRD and TEM analyses of sample 94044, a piece of crust collected within the Big Room level of SAS just below ...


Agriculture Causes Nitrate Fertilization Of Remote Alpine Lakes, Elizabeth J. Hundey, Sam S.D. Russell, Fred Longstaffe, Katrina A. Moser 2016 Western University

Agriculture Causes Nitrate Fertilization Of Remote Alpine Lakes, Elizabeth J. Hundey, Sam S.D. Russell, Fred Longstaffe, Katrina A. Moser

Earth Sciences Publications

Humans have altered Earth’s nitrogen cycle so dramatically that reactive nitrogen (Nr) has doubled. This has increased Nr in aquatic ecosystems, which can lead to reduced water quality and ecosystem health. Apportioning sources of Nr to specific ecosystems, however, continues to be challenging, despite this knowledge being critical for mitigation and protection of water resources. Here we use D17O, d18O and d15N from Uinta Mountain (Utah, USA) snow, inflow and lake nitrate in combination with a Bayesian-based stable isotope mixing model, to show that at least 70% of nitrates in aquatic systems are ...


Processes Controlling Carbon Cycling In Antarctic Glacier Surface Ecosystems, Elizabeth A. Bagshaw, Martyn Tranter, Jemma L. Wadham, Andrew G. Fountain, A. Dubnick, S. Fitzsimons 2016 Cardiff University

Processes Controlling Carbon Cycling In Antarctic Glacier Surface Ecosystems, Elizabeth A. Bagshaw, Martyn Tranter, Jemma L. Wadham, Andrew G. Fountain, A. Dubnick, S. Fitzsimons

Geology Faculty Publications and Presentations

Glacier surface ecosystems, including cryoconite holes and cryolakes, are significant contributors to regional carbon cycles. Incubation experiments to determine the net production (NEP) of organic matter in cryoconite typically have durations of 6-24 hours, and produce a wide range of results, many of which indicate that the system is net heterotrophic. We employ longer term incubations to examine the temporal variation of NEP in cryoconite from the McMurdo Dry Valleys, Antarctica to examine the effect of sediment disturbance on system production, and to understand processes controlling production over the lifetimes of glacier surface ecosystems. The shorter-term incubations have durations of ...


Seasonal Evolution Of Active Layer Formation In Subarctic Peat Plateaux And Implications For Dissolved Organic Matter Composition And Transfer, Jennifer L. Hickman 2016 Wilfrid Laurier University

Seasonal Evolution Of Active Layer Formation In Subarctic Peat Plateaux And Implications For Dissolved Organic Matter Composition And Transfer, Jennifer L. Hickman

Theses and Dissertations (Comprehensive)

Peat-accumulating wetlands are ecosystems whose rate of photosynthetic production of organic matter is greater than that of its decomposition, resulting in a build up of soil organic matter that may take centuries to fully decompose. Carbon (C) stocks within these ecosystems are a function of inputs from photosynthesis, and losses from heterotrophic decomposition. Due to the short growing season and overall cold climate of boreal and tundra regions, C has been accumulating within these landscapes, mostly in soil organic matter, since the last glaciation. Climate change, predicted to result in rising temperatures and increased precipitation, has begun to degrade the ...


Taxonomy, Location Of Origin, And Health Status Of Proboscideans From Western Canada Investigated Using Stable Isotope Analysis, Jessica Z. Metcalfe, Fred Longstaffe, Christopher N. Jass, Grant D. Zazula, Grant Keddie 2016 The University of Western Ontario

Taxonomy, Location Of Origin, And Health Status Of Proboscideans From Western Canada Investigated Using Stable Isotope Analysis, Jessica Z. Metcalfe, Fred Longstaffe, Christopher N. Jass, Grant D. Zazula, Grant Keddie

Earth Sciences Publications

We investigated the application of stable isotope analysis of proboscidean remains (collagen in bone/dentin/cementum and structural carbonate in enamel bioapatite) for genus-level identification of isolated specimens, assessment of geographic origins, and testing for nutritional stress. Mammoths (Mammuthus sp.) tended to have higher δ15Ncol and lower δ13Ccol than mastodons (Mammut americanum), but differences were not significant in every location. Determining the genus of isolated specimens may be possible for locations and time periods with good isotopic baselines, but environmental changes can confound interpretations. For example, an Alberta proboscidean with a δ15N ...


Petrological Conditions Associated With Gold Deposition At Browns Creek Skarn, Australia, Stephanie Junior 2016 University of Colorado, Boulder

Petrological Conditions Associated With Gold Deposition At Browns Creek Skarn, Australia, Stephanie Junior

Undergraduate Honors Theses

Browns Creek is a skarn that hosts an Au-Cu ore deposit in the Blayney region of New South Wales, Australia. Skarn rock at this location is wollastonite marble, highly mineralized by sulfides and gold deposited as native Au, electrum, telluride minerals and within arsenopyrite crystals. Related alteration includes metasomatized hornfels of the Ordovician Blayney Volcanics and marbleized interbedded limestone lenses of the Cowriga Limestone Member. Magmatic fluids responsible for this alteration were derived from a Silurian felsic-intermediate multi-phase intrusive system, the Browns Creek Intrusive Complex. Main constituents of this intrusive system include the Carcaor Granodiorite, the first and largest phase ...


Surface Water Geochemistry And Strontium Characteristics Of Colorado Creeks, Natalie P. Cristo 2016 geology

Surface Water Geochemistry And Strontium Characteristics Of Colorado Creeks, Natalie P. Cristo

Undergraduate Honors Theses

Strontium isotopic composition and major and minor trace element compositional data allows us to classify waters and identify sources of dissolved solutes to deduce history of surface waters. In this study, such data were used to investigate the compositions and sources of solute found in selected surface waters from the Colorado Front Range and vicinity. The major ion compositions of surface waters draining from the eastern slope of the central Front Range are similar. Bulk water composition of upper Boulder Creek, Left Hand Creek and Coal Creek are all classified as Ca-Mg-Cl type. Most of the solutes in these waters ...


Investigating Radiation Damage In The Zircon (U-Th)/He Thermochronometer With Raman Spectroscopy, Ryan Kevin Stoner 2016 University of Colorado, Boulder

Investigating Radiation Damage In The Zircon (U-Th)/He Thermochronometer With Raman Spectroscopy, Ryan Kevin Stoner

Undergraduate Honors Theses

Radiation damage has a strong influence on He diffusion kinetics and the temperature sensitivity of (U-Th)/He thermochronometers. Understanding these effects is critical for the accurate interpretation of (U-Th)/He datasets and can lead to more detailed thermal history reconstructions. This information is particularly important for settings with protracted thermal histories, such as the Kaapvaal Craton, where U and Th-rich minerals have accumulated significant radiation damage. Models for how radiation damage influences He diffusion kinetics have been published for apatite (Flowers et al., 2009) and zircon (Guenthner et al., 2013). However, the kinetic model for zircon is less calibrated at ...


Mineralogy And Geochemistry Of Late Archean And Paleoproterozoic Granites And Pegmatites In The Northern Penokean Terrane Of Marquette And Dickinson Counties, Michigan, Christopher M. Johnson, Christopher M. Van Daalen 2015 University of New Orleans

Mineralogy And Geochemistry Of Late Archean And Paleoproterozoic Granites And Pegmatites In The Northern Penokean Terrane Of Marquette And Dickinson Counties, Michigan, Christopher M. Johnson, Christopher M. Van Daalen

University of New Orleans Theses and Dissertations

This thesis focuses on mineralogy, geochemistry, and origin of eight pegmatites and two spatially associated granites of Late Archean and Paleoproterozoic ages located in Marquette and Dickinson Counties, Michigan. Biotite geochemistry reveals that both granites and all pegmatites are peraluminous and have an orogenic signature. However, bulk composition reveals the Humboldt granite is a peraluminous A-type granite and the Bell Creek granite is a peraluminous mix between I-, S-, and A-type granites. The Republic Mine pegmatite appears to be geochemically similar to the Bell Creek granite and Grizzly pegmatite. The Crockley pegmatite is genetically related to the Humboldt granite. The ...


An Investigation Of The Effects Of Chemical And Physical Weathering On Submerged Karst Surfaces, Bryan Charles Booth 2015 University of South Florida

An Investigation Of The Effects Of Chemical And Physical Weathering On Submerged Karst Surfaces, Bryan Charles Booth

Graduate Theses and Dissertations

Reports an investigation of the effects of chemical and physical weathering on submerged karst surfaces that pairs laboratory studies with computer modeling studies. The first study attempts to quantify the production of carbonate fines; soluble sediments produced by the incomplete dissolution of karst minerals during chemical weathering. Results show carbonate fine production in relation to dissolutional action; Chalk: 42.8%; Coquina: 2.6%; Dolomite: 3.1%; Gray Limestone: 4.8%; Ocala Limestone: 3.1%; Shell Limestone: 6.1%; Travertine: 8.6%. Due to the use of hydrochloric acid as opposed to carbonic acid these results may not be fully valid ...


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