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Petrography And Geochemistry Of The Jajarm Bauxite Ore Deposit, Northeast Iran: Implications For Source Rock Material And Ore Genesis, Dariush Esmaeily, Hosein Rahimpour-Bonab, Amir Esna-Ashari, Ali Kananian

Turkish Journal of Earth Sciences

The Jajarm bauxite deposit, northeast Iran, is the largest such deposit in Iran. The deposit is sandwiched between the Triassic Elika formation and the Jurassic Shemshak formation, housed within karstic features developed within the former unit. The deposit generally shows an internal layering defined by the following four distinct horizons (from bottom to top): (a) a lower argillaceous horizon, approximately 50-80 cm thick, is mainly composed of clay minerals that directly overlies the carbonate footwall (Elika formation); (b) a bauxitic clay layer approximately 2-3 m thick that consists mainly of hematite, kaolinite, anatase, and diaspore; (c) a red bauxite layer …

Debrunia Occitanica Nov. Sp. (Monopleuridae) From The Early Aptian Of Se France, Mükerrem Fenerci̇-Masse, Jean-Pierre Masse

Turkish Journal of Earth Sciences

Debrunia occitanica nov. sp., described from the early Aptian platform limestones of SE France, is characterized by: a moderately convex left valve, inconspicuous radial bands and a ligament groove in a depression flanked by two longitudinal rounded edges. Debrunia occitanica nov. sp. is considered as a chronospecies belonging to a single lineage rooted in the Barremian, and including Debrunia bruni and Debrunia mutabilis. Evolutionary trends in the three species include flattening of the left valve, development of the corresponding myophores, and reduction of the radial bands. This new species has the potential to be a stratigraphic marker for the early …

Blending Rudists With Technology; Non-Destructive Examination Of The Internal And External Structures Of Rudists Using High Quality Scanning And Digital Imagery, Ann Molineux, Robert W. Scott, Jessie Maisano, Richard Ketcham, Louis Zachos

Turkish Journal of Earth Sciences

Certain formations within the Cretaceous of Texas include zones of silicified rudists. Such diagenetic alteration, combined with the timing of alteration, has preserved many structural features of the rudist suitable for computed tomography (CT scanning). The excellent density differences between those skeletal structures (silica) and the internal sediment (calcitic mud) or later crystallization (calcite), fulfill a fundamental requirement for such analysis. The Jackson School of Geosciences at The University of Texas provides access to a high resolution computed tomography scanning system. This equipment, not identical to medical scanners, provides higher resolution and sophisticated software to analyze the imagery. Several rudist …

Dimethylmercury Production In Freshwater Sediments, David C. Kelly

Browse all Theses and Dissertations

Dimethylmercury (DMHg) has been examined almost exclusively in marine environments to date, plays an uncertain role in the global cycling of Hg, and is produced by a currently unknown mechanism in natural systems. We examined DMHg production in microcosms containing 100 cm3 of freshwater sediment sampled from 3 wetlands and a lake near Dayton, Ohio. DMHg was produced from all sediments analyzed, and found that production is increased significantly by the addition of inorganic Hg from ~0.1pM to ~10pM, its production is unaffected by autoclaving the sediment, and organic carbon additions had no discernible effect on production. Its total concentrations …

Functional Identification Of Microorganisms That Transform Mercury In Marine Sediments, Lisa Romas

Browse all Theses and Dissertations

Monomethylmercury (MMHg) is the toxic form of mercury (Hg) that biomagnifies in food webs, and human exposure to MMHg occurs predominantly via consumption of fish. The primary source of MMHg to the marine environment is thought to be in situ sedimentary production by benthic microorganisms, namely sulfate-reducing bacteria (SRB). I collected sediments from the continental shelf (stations 2 and 6) and slope (station 9) of the NW Atlantic Ocean, and amended them with various inhibitor and promoter solutions to target specific functional groups capable of Hg transformations. I also added stable enriched Hg isotopes to quantify gross Hg methylation and …

Mercury Speciation In Temperate Tree Foliage, Melissa Danielle Tabatchnick

Browse all Theses and Dissertations

Cycling of mercury (Hg) and monomethylmercury (MMHg) in forest ecosystems can affect exposures of terrestrial and aquatic wildlife within the watershed. Litterfall has been posited to be a major source of MMHg and total Hg to the forest floor; however, the origin of MMHg associated with tree foliage is largely unknown. I tested the hypothesis that leaf MMHg would be controlled by root uptake and thereby proportional to levels in soil. Fresh leaves and associated soil samples were sampled from nine tree species (deciduous and coniferous) at 30 locations spanning a 1145 km2 area in southwest Ohio, a region presumed …

Trace Metal Fluxes In Southwest Ohio Watersheds, Avani Naik

Browse all Theses and Dissertations

Land-use and watershed characteristics affect the cycling and transport of trace metals in rivers. I investigated the influence of different land uses and water physicochemistry on loadings, partitioning, and speciation of Hg, Zn, Cr, Ni, V, Cd, Cu, and Pb in three contrasting watersheds near the Dayton, Ohio metropolitan area over a 13-month period; Wolf Creek (urban/residential), Holes Creek (urban/residential), and Little Miami River (agricultural). Metal concentrations were related positively to discharge in each stream. Dissolved organic ligands appear to influence trace-metal partitioning between filtered and particle phases, however, particle-associated metals were dominant in each site. Total Hg concentrations and …

Melting Alpine Glaciers Enrich High-Elevation Lakes With Reactive Nitrogen, Jasmine E. Saros, Kevin C. Rose, David W. Clow, Verlin C. Stevens, Andrea B. Nurse, Heather A. Arnett, Jeffery R. Stone, Craig E. Williamson, Alexander P. Wolfe

Department of Earth and Atmospheric Sciences: Faculty Publications

Alpine glaciers have receded substantially over the last century in many regions of the world. Resulting changes in glacial runoff not only affect the hydrological cycle, but can also alter the physical (i.e., turbidity from glacial flour) and biogeochemical properties of downstream ecosystems. Here we compare nutrient concentrations, transparency gradients, algal biomass, and fossil diatom species richness in two sets of high-elevation lakes: those fed by snowpack melt alone (SF lakes) and those fed by both glacial and snowpack meltwaters (GSF lakes). We found that nitrate (NO₃^-) concentrations in the GSF lakes were 1-2 orders of magnitude …

Millennial-Scale Climate Variability During The Last Glacial Period In The Tropical Andes, Sherilyn C. Fritz, P. A. Baker, E. Ekdahl, G. O. Seltzer, L. R. Stevens

Department of Earth and Atmospheric Sciences: Faculty Publications

Millennial-scale climate variation during the Last Glacial period is evident in many locations worldwide, but it is unclear if such variation occurred in the interior of tropical South America, and, if so, how the low-latitude variation was related to its high-latitude counterpart. A high-resolution record, derived from the deep drilling of sediments on the floor of Lake Titicaca in the southern tropical Andes, is presented that shows clear evidence of millennial-scale climate variation between ~60 and 20 ka BP. This variation is manifested by alternations of two interbedded sedimentary units. The two units have distinctive sedimentary, geochemical, and paleobiotic properties …

Inferring Lake Depth Using Diatom Assemblages In The Shallow, Seasonally Variable Lakes Of The Nebraska Sand Hills (Usa): Calibration, Validation, And Application Of A 69-Lake Training Set, Avery L. C. Shinneman, Danuta M. Bennett, Sherilyn C. Fritz, Jens Schmieder, Daniel R. Engstrom, Aris Efting, John Holz

Department of Earth and Atmospheric Sciences: Faculty Publications

The Nebraska Sand Hills are a distinctive eco-region in the semi-arid Great Plains of the western United States. The water table underlying the Sand Hills is part of the High Plains/ Ogallala aquifer, an important water resource for the central Great Plains. Lake levels are affected directly by fluctuations in the water table, which is recharged primarily by local precipitation and responds quickly to climatically induced changes in regional water balance. Instrumental records are available for only 50–100 years, and paleolimnological data provide important insights into the extremes and variability in moisture balance over longer time scales. A set of …

Effect Of Low And High- Kinetic Energy Wetting On Quality Of Sediment Produced By Interrill Erosion, Eduardo Abel Rienzi

University of Kentucky Doctoral Dissertations

Raindrop kinetic energy and sheet flow can disintegrate aggregates during interrill erosion, a process responsible for non point source pollution. Also, the dissolution process during aggregate wetting can affect interrill erosion. These factors can be responsible for changes in particle size distribution in the sediment, especially when different tillage systems are compared. The effect of soil tillage and management on soil properties is not uniform, which determine a wide range of runoff and sediment delivery rate. Variety in these rates can be associated with pore functions and their interactions with aggregate stability. One of the objectives of this study was …

Tetrapod Fauna Of The Lowermost Usili Formation (Songea Group, Ruhuhu Basin) Of Southern Tanzania, With A New Burnetiid Record, Christian A. Sidor, Kenneth D. Angielczyk, D. Marie Weide, Roger M. H. Smith, Sterling J. Nesbitt, Linda A. Tsuji

Department of Earth and Atmospheric Sciences: Faculty Publications

Vertebrate fossils from the Ruhuhu Basin of southern Tanzania have been known for over 75 years, but the details of their stratigraphic distribution remain imperfectly understood. Recent fieldwork in the Upper Permian Usili Formation (Songea Group) has led to the discovery of a tetrapod assemblage in a conglomeratic unit at its base. The fossils are concentrated in matrix-supported intraformational clay pebble conglomerates interpreted as mass flow deposits in wide, shallow channels in the distal reaches of an alluvial fan. Included in this new collection are fossils representing the first record of a burnetiid therapsid from Tanzania. The anatomy of the …

Collapse Of The Maya: Could Deforestation Have Contributed?, Robert Oglesby, Thomas L. Sever, William Saturno, David J. Erickson Iii, Jayanthi Srikishen

Department of Earth and Atmospheric Sciences: Faculty Publications

The collapse of the Maya civilization during the ninth century A.D. is a major conundrum in the history of mankind. This civilization reached a spectacular peak but then almost completely collapsed in the space of a few decades. While numerous explanations have been put forth to explain this collapse, in recent years, drought has gained favor. This is because water resources were a key for the Maya, especially to ensure their survival during the lengthy dry season that occurs where they lived. Natural drought is a known, recurring feature of this region, as evidenced by observational data, reconstructions of past …

Abandoned Mine Drainage In The Swatara Creek Basin, Southern Anthracite Coalfield, Pennsylvania, Usa: 1. Stream Water Quality Trends Coinciding With The Return Of Fish, Charles A. Cravotta Iii, Robin A. Brightbill, Michael J. Langland

United States Geological Survey: Staff Publications

Acidic mine drainage (AMD) from legacy anthracite mines has contaminated Swatara Creek in eastern Pennsylvania. Intermittently collected base-flow data for 1959–1986 indicate that fish were absent immediately downstream from the mined area where pH ranged from 3.5 to 7.2 and concentrations of sulfate, dissolved iron, and dissolved aluminum were as high as 250, 2.0, and 4.7 mg/L, respectively. However, in the 1990s, fish returned to upper Swatara Creek, coinciding with the implementation of AMD treatment (limestone drains, limestone diversion wells, limestone sand, constructed wetlands) in the watershed. During 1996–2006, as many as 25 species of fish were identified in the …

The Influence Of Topology On Hydraulic Conductivity In A Sand-And-Gravel Aquifer, Roger H. Morin, Denis R. Leblanc, Brent M. Troutman

United States Geological Survey: Staff Publications

A field experiment consisting of geophysical logging and tracer testing was conducted in a single well that penetrated a sand-and-gravel aquifer at the U.S. Geological Survey Toxic Substances Hydrology research site on Cape Cod, Massachusetts. Geophysical logs and flowmeter/pumping measurements were obtained to estimate vertical profiles of porosity ϕ, hydraulic conductivity K, temperature, and bulk electrical conductivity under background, freshwater conditions. Saline-tracer fluid was then injected into the well for 2 h and its radial migration into the surrounding deposits was monitored by recording an electromagnetic-induction log every 10 min. The field data are analyzed and interpreted primarily …

Microbial Production Of Isotopically Light Iron(Ii) In A Modern Chemically Precipitated Sediment And Implications For Isotopic Variations In Ancient Rocks, G. E. Tangalos, B. L. Beard, C. M. Johnson, Charles N. Alpers, E. S. Shelobolina, H. Xu, H. Konishi, E. E. Roden

United States Geological Survey: Staff Publications

The inventories and Fe isotope composition of aqueous Fe(II) and solid-phase Fe compounds were quantified in neutral-pH, chemically precipitated sediments downstream of the Iron Mountain acid mine drainage site in northern California, USA. The sediments contain high concentrations of amorphous Fe(III) oxyhydroxides [Fe(III)_am] that allow dissimilatory iron reduction (DIR) to predominate over Fe–S interactions in Fe redox transformation, as indicated by the very low abundance of Cr(II)-extractable reduced inorganic sulfur compared with dilute HCl-extractable Fe. δ⁵⁶Fe values for bulk HCl- and HF-extractable Fe were ≈ 0. These near-zero bulk δ⁵⁶Fe values, together with the …

Evidence For Recent Population Bottlenecks In Northern Spotted Owls (Strix Occidentalis Caurina), W. Chris Funk, Eric D. Forsman, Matthew Johnson, Thomas D. Mullins, Susan M. Haig

United States Geological Survey: Staff Publications

The northern spotted owl (Strix occidentalis caurina) is one of the most controversial threatened subspecies ever listed under the US Endangered Species Act. Despite protection of its remaining forest habitat, recent field studies show continued declines of northern spotted owls. One potential threat to northern spotted owls which has not yet been shown is loss of genetic variation from population bottlenecks. Bottlenecks can increase the probability of mating among related individuals, potentially causing inbreeding depression, and can decrease adaptive potential. Here we report evidence for recent bottlenecks in northern spotted owls using a large genetic dataset (352 individuals …

Subspecies Status And Population Genetic Structure In Piping Plover (Charadrius Melodus), Mark P. Miller, Susan M. Haig, Cheri L. Gratto-Trevor, Thomas D. Mullins

United States Geological Survey: Staff Publications

Piping Plover (Charadrius melodus) is a migratory shorebird that is listed as endangered in Canada and the U.S. Great Lakes and as threatened throughout the rest of its breeding and winter range. We undertook a comprehensive molecular-genetic investigation to (1) address subspecific taxonomy, (2) characterize population genetic structure, and (3) infer past bottlenecks and demographic processes in this species. Analyses included individuals from 23 U.S. states and Canadian provinces and were based on mitochondrial DNA sequences (580 base pairs, n = 245) and 8 nuclear microsatellite loci (n = 229). Our findings provide support for separate Atlantic and …

Barcoding Bushmeat: Molecular Identification Of Central African And South American Harvested Vertebrates, Mitchell J. Eaton, Greta J. Meyers, Sergios-Orestis Kolokotronis, Matthew S. Leslie, Andrew P. Martin, George Amato

United States Geological Survey: Staff Publications

The creation and use of a globally available database of DNA sequences from a standardized gene region has been proposed as a tool for species identification, assessing genetic diversity and monitoring the legal and illegal trade in wildlife species. Here, we contribute to the Barcode of Life Data System and test whether a short region of the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene would reliably distinguish among a suite of commonly hunted African and South American mammal and reptile species. We used universal primers to generate reference barcode sequences of 645 bp for 23 species from five vertebrate …

Barcoding Bushmeat: Molecular Identification Of Central African And South American Harvested Vertebrates, Mitchell J. Eaton, Greta L. Meyers, Sergios-Orestis Kolokotronis, Matthew S. Leslie, Andrew P. Martin, George Amato

United States Geological Survey: Staff Publications

The creation and use of a globally available database of DNA sequences from a standardized gene region has been proposed as a tool for species identification, assessing genetic diversity and monitoring the legal and illegal trade in wildlife species. Here, we contribute to the Barcode of Life Data System and test whether a short region of the mitochondrial cytochrome c oxidase subunit 1 (COX1) gene would reliably distinguish among a suite of commonly hunted African and South American mammal and reptile species. We used universal primers to generate reference barcode sequences of 645 bp for 23 species from five vertebrate …

La Yeguada Volcanic Complex, Western Panama : An Assessment Of The Geologic Hazards Using New 40Ar/39Ar Ages, Karinne L. Knutsen

Dissertations, Master's Theses and Master's Reports - Open

La Yeguada volcanic complex is one of three Quaternary volcanic centers in Panama, and is located on the southern slope of the Cordillera Central mountain range in western Panama, province of Veraguas. To assess potential geologic hazards, this study focused on the main dome complex near the village of La Laguna and also examined a cinder cone 10 km to the northwest next to the village of Media Luna. Based on newly obtained ⁴⁰Ar/³⁹Ar ages, the most recent eruption occurred approximately 32 000 years ago at the Media Luna cinder cone, while the youngest dated eruption at …

Gadolinium Concentration Analysis In Brain Phantom By X-Ray Fluorescence, Musaed Almalki, Samir Abdul Majid, Philip H. Butler, Lou Reinisch

Research, Publications & Creative Work

We have measured the X-ray fluorescence from gadolinium as a function of concentration and position in tumors of different sizes and shapes in a head phantom. The gadolinium fluorescence was excited with a 36 GBq Am-241 source. The fluorescence signal was detected with a CdTe detector and a multi-channel analyzer. The fluorescence peak was clearly separated from the scattered X-rays. Concentrations of 5.62–78.63 mg/ml of Gd ion were used in 1, 2, and 3 cm diameter spherical tumors and a 2 9 4 cm oblate spheroid tumor. The data show trends approaching saturation for the highest concentrations, probably due to …

Trace Metal Biogeochemistry In The Western North Pacific, Peter Lynn Morton

OES Theses and Dissertations

Dissolved and suspended particulate samples collected during the Intergovernmental Oceanographic Commission 2002 Contaminant Baseline Survey were analyzed to determine the surface and vertical distributions of Cd, Co, Cu, Mn, Ni Zn and Pb across the western and central North Pacific.

Dissolved trace metal concentrations were measured using a novel isotope dilution-ICP-MS method after extraction over an 8-hydroxyquinoline resin column and validated through the use of the SAFe consensus reference materials. Filtered suspended particulate matter was digested using an HCl/HNO3/HF mixture and analyzed by HR-ICP-MS to obtain total particulate concentrations for the trace metals and other tracer elements such as Al, …

Concentrations, Distributions And Chemical Speciation Of Zinc And Cadmium In The Equatorial And South Atlantic Ocean, Gonzalo G. Carrasco

OES Theses and Dissertations

Certain trace metals are important cofactors in enzymatic systems and are thus, essential for life in the world's oceans. Two of these metals, Zn and Cd, are required by phytoplankton for enzymes that facilitate carbon uptake (Morel and Price, 2003). In seawater the total dissolved concentration of a metal (MTD) is distributed among different chemical species and this chemical speciation dictates a metal's bioavailability. Strong organic metal-binding ligands greatly affect the metal's chemical speciation in the ocean, potentially limiting phytoplankton growth by reducing the concentrations of Zn²⁺ and Cd²⁺, the bioavailable forms of these two metals to …

A Real Time Optical Biosensor Assay For Amoxicillin And Other Β-Lactams In Water Samples, Israel M. Scott, Lewis J. Kraft, Jonathan D. Parker, Kathryn Daniel, Sarah Kustick, Diana Kennen, Jonathan L. Mcmurry

Faculty Articles

Antibiotic contamination of drinking water and sewage is a matter of environmental and public health concern. Traditionally, ELISA or HPLC methods have been used to detect and measure antibiotic contamination. By applying an optical biosensing method, biolayer inteferometry (BLI), we have developed a kinetic competition binding assay capable of quantitating less than lppm (~33 μM) amoxicillin. Similar to surface plasmon resonance, BLI senses changes that occur upon binding of one molecule to another near a surface to measure association and dissociation. Immobilized amoxicillin was used to screen for binding against an analyte solution of anti-amoxicillin equilibrated with amoxicillin-containing water samples, …

Teaching Resources In Speleology And Karst: A Valuable Educational Tool, Jo De Waele

International Journal of Speleology

There is a growing need in the speleological community of tools that make teaching of speleology and karst much easier. Despite the existence of a wide range of major academic textbooks, often the caver community has a difficult access to such material. Therefore, to fill this gap, the Italian Speleological Society, under the umbrella of the Union International de Spéléologie, has prepared a set of lectures, in a presentation format, on several topics including geology, physics, chemistry, hydrogeology, mineralogy, palaeontology, biology, microbiology, history, archaeology, artificial caves, documentation, etc. These lectures constitute the “Teaching Resources in Speleology and Karst”, available online. …

Modern C, O, And H Isotope Composition Of Speleothem And Dripwater From Modrič Cave, Eastern Adriatic Coast (Croatia), Maša Surić, Zvjezdana Roller-Lutz, Magda Mandić, Ines Krajcar Bronić, Mladen Juračić

International Journal of Speleology

Modrič Cave is a shallow horizontal cave situated in the middle of the eastern Adriatic coast (Croatia). The cave entrance is located 120 m from the coast at an altitude of 32 m above sea level, and due to its position on the SW slope of the Dinaridic mountain range, a Mediterranean climatic influence is dominant. Due to the stable environmental conditions [(15.6 ± 0.1) °C] Modrič Cave was recognized as a potential site for detailed palaeoclimatic studies. Isotope analyses of modern carbonate speleothems, rain and dripwater were conducted in order to evaluate the isotopic equilibrium conditions. The δ18O composition …

Karst Geology And Cave Fauna Of Austria: A Concise Review, Erhard Christian, Christoph Spötl

International Journal of Speleology

The state of cave research in Austria is outlined from the geological and zoological perspective. Geologic sections include the setting of karst regions, tectonic and palaeoclimatic control on karst, modern cave environments, and karst hydrology. A chapter on the development of Austrian biospeleology in the 20th century is followed by a survey of terrestrial underground habitats, biogeographic remarks, and an annotated selection of subterranean invertebrates.

Do Karst Rivers “Deserve” Their Own Biotic Index? A Ten Years Study On Macrozoobenthos In Croatia, Biljana Rađa, Sanja Puljas

International Journal of Speleology

In this study we present the results of a ten year survey of the aquatic macroinvertebrate fauna along four karst rivers: Jadro, Žrnovnica, Grab and Ruda, all of them situated in the Middle Dalmatia region of Croatia, in an attempt to construct the Iliric Biotic Index, which will be more applicable for the water quality analysis than the most frequently applied biotic index in Croatia, the Italian Modification of Extended Biotic Index. The rivers geologically belong to the Dinaric karst, unique geological phenomena in Europe. Benthic macroinvertebrates were collected along each river at 15 sites by standard methods of sampling …

Age Frequency Distribution And Revised Stable Isotope Curves For New Zealand Speleothems: Palaeoclimatic Implications, Paul W. Williams, Helen L. Neil, Jian-Xin Zhao

International Journal of Speleology

The occurrence of speleothems in New Zealand with reversed magnetism indicates that secondary calcite deposition in caves has occurred for more than 780 thousand years (ka). 394 uranium-series dates on 148 speleothems show that such deposition has taken place somewhere in the country with little interruption for more than 500 ka. A relative probability distribution of speleothem ages indicates that most growth occurred in mild, moist interglacial and interstadial intervals, a conclusion reinforced by comparing peaks and troughs in the distribution with time series curves of speleothem δ¹⁸O and δ¹³C values. The stable isotope time series …