Physical Sciences and Mathematics Commons^™

Iron Behavior In A Northern Estuary: Large Pools Of Non-Sulfidized Fe(Ii) Associated With Organic Matter, Changxun Yu, Joonas J. Virtasalo, Torbjörn Karlsson, Pasi Peltola, Peter Österholm, Edward D. Burton, Laura Arppe, Johan K. Hogmalm, Antti E K Ojala, Mats E. Aström

Associate Professor Edward D Burton

The estuaries of the Northern Baltic Sea (Gulf of Bothnia) receive an abundance of diagenetically reactive catchment-derived Fe, which is to a large degree complexed with organic matter or present as Fe (hydr-)oxides. However, our understanding of sedimentary Fe diagenesis in these estuaries is limited. To address this limitation, the present study examines Fe geochemistry in a 3.5-m-thick estuarine benthic mud layer and three samples of suspended particulate matter of a catchment on the eastern Gulf of Bothnia. The age–depth model of the mud, constructed on the basis of sedimentary features as well as ¹³⁷Cs and aquatic plant ^{14 …}

Enhanced Aox Accumulation And Aquatic Toxicity During 2,4,6-Trichlorophenol Degradation In A Co(Ii)/Peroxymonosulfate/Cl− System, Changling Fang, Dongxue Xiao, Wenqian Liu, Xiaoyi Lou, Jun Zhou, Zhaohui Wang, Jianshe Liu

Dr Zhaohui Wang

Chloride ion is known to affect on degradation kinetics in different ways during HO• and SO4 •−-based advanced oxidation processes (AOPs). However, its effect on absorbable organic halogen (AOX) evolution and acute toxicity of treated water remains unknown, despite the importance of the two parameters in evaluating the applicability of AOPs. In the present study, Co/peroxymonosulfate (Co/PMS) and UV/hydrogen peroxide (UV/H2O2) treatment of 2,4,6-trichlorophenol was compared in terms of AOX formation, chlorinated byproducts and acute toxicity. Both Co/PMS and UV/H2O2 systems were more reactive under acidic conditions, resulting in elevated AOX levels when compared with those at neutral pH. The …

Transition From Contraction To Extension In The Northeastern Basin And Range: New Evidence From The Copper Mountains, Nevada, Jeffrey M. Rahl, Allen J. Mcgrew, Kenneth A. Foland

Allen J. McGrew

New mapping, structural analysis, and 40Ar/39Ar dating reveal an unusually well‐constrained history of Late Eocene extension in the Copper Mountains of the northern Basin and Range province. In this area, the northeast‐trending Copper Creek normal fault juxtaposes a distinctive sequence of metacarbonate and granitoid rocks against a footwall of Upper Precambrian to Lower Cambrian quartzite and phyllite. Correlation of the hanging wall with footwall rocks to the northwest provides an approximate piercing point that requires 8–12 km displacement in an ESE direction. This displaced fault slice is itself bounded above by another normal fault (the Meadow Fork Fault), which brings …

Correspondence Of Historic Salinity Fluctuations In Florida Bay, Usa, To Atmospheric Variability And Anthropogenic Changes, Anna Wachnicka, Evelyn Gaiser, Laurel Collins

Evelyn E. Gaiser

Florida Bay is a highly dynamic estuary that exhibits wide natural fluctuations in salinity due to changes in the balance of precipitation, evaporation and freshwater runoff from the mainland. Rapid and large-scale modification of freshwater flow and construction of transportation conduits throughout the Florida Keys during the late nineteenth and twentieth centuries reshaped water circulation and salinity patterns across the ecosystem. In order to determine long-term patterns in salinity variation across the Florida Bay estuary, we used a diatom-based salinity transfer function to infer salinity within 3.27 ppt root mean square error of prediction from diatom assemblages from four ~130 …

Paleogeographic, Paleoceanographic, And Tectonic Controls On Early Late Ordovician Graptolite Diversity Patterns, Daniel Goldman, Shuang-Ye Wu

Daniel Goldman

The Katian Age (early Late Ordovician) was a time of significant decline in marine biodiversity, but whether this decline was a real phenomenon or an artifact of the relatively few studies devoted to this interval requires further research. We examined the pattern of graptolite faunal changes across the boundary between the Climacograptus bicornis and Diplacanthograptus caudatus graptolite zones in North America and on several other continents.

A sharp decline in species diversity occurs in the Appalachian Basin. Scores for normalized diversity dropped from 20 in the C. bicornis Zone to 7 in the D. caudatus Zone. Only 11% of the …

Multispectral Image Analysis Of Glaciers And Glacier Lakes In The Chugach Mountains, Alaska, Jeffrey Kargel, Matthew Beedle, Andrew Bush, Francisco Carreño, Elena Castellanos, Umesh Haritashya, Gregory Leonard, Javier Lillo, Ivan Lopez, Mark Pleasants, Edward Pollock, David Wolfe

Umesh Haritashya

The Chugach Mountains contain the largest nonpolar alpine glaciers in the world and include a wide variety of glacier types: some are land terminating; some calve variously into tidewater, lakes, and rivers; some are heavily debris covered; some are surge-type, whereas others are neither debris covered nor surge type. Nearly all are retreating, thinning, or both, though some rare ones are advancing, and some are thickening at high elevations. To assist the further documentation of changes, we establish an inventory of glaciers in the eastern Chugach Mountains. Several case studies of diverse glacier types showcase remotesensing applications and are used …

New Body Mass Estimates For Canis Dirus, The Extinct Pleistocene Dire Wolf, William Anyonge, Christopher Roman

Christopher Roman

Quantitative study of the body mass of Canis dirus. Results indicate a mean body mass comparable to the extant gray wolf, suggesting larger individual animals probably exceed the body mass range of extant gray wolves.

Iceland: Extreme Learning In The Land Of Fire And Ice, Jason Polk, Leslie North

Leslie North

WKU Libraries kicked off the spring season of "Far Away Places" with Dr. Jason Polk and Dr. Leslie North, Asstant Professors from the Department of Geography and Geology at WKU, who talked about leading a study abroad group to Iceland in the summer of 2015. WKU Libraries kicks off the spring season of Far Away Places with Jason Polk and Leslie North, Asst. Professors from the Department of Geography and Geology at WKU, who will be talking about leading a study abroad group to Iceland in the summer of 2015. Dr. Polk and Dr. North co-taught this course with faculty …

What's The Dirt On The Dirt? Sunnyslope's Soils Exposed, Alan Busacca, David Wilkins

David E. Wilkins

Logistic Curves, Extraction Costs And Peak Oil, Robert Brecha

Robert J. Brecha

Debates about the possibility of a near-term maximum in world oil production have become increasingly prominent over the past decade, with the focus often being on the quantification of geologically available and technologically recoverable amounts of oil in the ground. Economically, the important parameter is not a physical limit to resources in the ground, but whether market price signals and costs of extraction will indicate the efficiency of extracting conventional or nonconventional resources as opposed to making substitutions over time for other fuels and technologies. We present a hybrid approach to the peak-oil question with two models in which the …

Arsenic Solid-Phase Speciation In An Alluvial Aquifer System Adjacent To The Himalayan Forehills, Nepal, Scott Johnston, Jasmine Diwakar, Edward Burton

Associate Professor Edward D Burton

Alluvial aquifers contaminated by geogenic arsenic often lack direct solid-phase speciation data, hindering efforts to understand landscape-scale spatial heterogeneity and controls on As mobility. Here, we examine solid-phase As and Fe speciation of alluvial aquifer, river and hyporheic-seep sediments along a topographic gradient at the Himalayan foothills/upper-Ganges floodplain margin. We employ a combination of X-ray absorption spectroscopy, selective extracts, electron microscopy and X-ray fluorescence. Source-river sediments were found to contain a mixture of solid-phase As(V) and As(III) species, while vertically heterogeneous bore-hole sediments also contained a solid-phase As-sulfide species. In general, the abundance of reduced As species [As(III) + As-sulfide] …

Alkalinity Conversion Of Bauxite Refinery Residues By Neutralization, M Johnston, M Clark, P Mcmahon, N Ward

Dr Nicholas J Ward

Red mud remains the largest environmental issue for the alumina industry due to its high pH (>13), fine-grained nature (>90% is <10 >μm), elevated sodium concentration (>50 g/kg), and soluble alkalinity (≈30 g/kg as equivalent CaCO3), which reduce the transport and reuse options of red mud. The neutralization of red mud provides potential reuse options because neutralization lowers pH, increases grain-size (e.g., coagulation), and precipitates or converts alkalinity. This paper investigates the geochemistry of 3 treatments of a red mud to affect neutralization and potentially convert materials from a waste material to a resource. This study investigates two …

Readily Available Acidity In Schwertmannite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Chamindra Vithana

Schwertmannite and jarosite are considered as less soluble ironhydroxy sulfate minerals which are present in highly acidic environments (pH < 3). These minerals release acidity in the long run as they weather by hydrolysis [1]. However, 1M KCl extraction of soil samples (Clarence and Quartz) spiked with those two minerals showed that schwertmannite has some acidity that may be readily available.

Effect Of Fulvic Acid On Liberation Of Acidity And Arsenic Form Arsenic Substituted Schwertmannite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Chamindra Vithana

INTRODUCTION

Schwertmannite is one of the main secondary iron hydroxy sulfate minerals contributing to acidity in acid sulfate soils (ASS). While it is an important source of acidity in ASS, schwertmannite is also known to be a potential sink for trace metals such as arsenic (As) and chromium (Cr) (Fukushi et al. 2003; Regenspurg and Peiffer. 2005).Trace metal adsorption/substitution is known to stabilize schwertmannite which in turn retards its transformation to goethite which is one of the main processes of acidity generation in ASS. Fulvic Acid (FA) is a subclass of natural organic materials that are ubiquitous in aquatic environments …

A Critical Evaluation Of Retained Acidity (Ar) Estimating Methods In Acid Base Account (Aba) Approach For Acid Sulfate Soils (Ass), Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Chamindra Vithana

No abstract provided.

Underestimation Of Retained Acidity Measured Using Chromium Suite In Acid Sulfate Soils Containing Schwermannite And Jarosite, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Chamindra Vithana

No abstract provided.

Understanding The Behaviour Of Schwertmannite And Jarosite In Acid Sulfate Soils, Chamindra Vithana, Leigh Sullivan, Richard Bush, Edward Burton

Chamindra Vithana

No abstract provided.

Sulfur, Iron And Carbon Cycling Following Hydrological Restoration Of Acidic Freshwater Wetlands, Scott Johnston, Edward Burton, Thor Aaso, Gerard Tuckerman

Associate Professor Edward D Burton

Freshwater re-flooding is a relatively novel approach to remediate drained acid sulfate soil (ASS) wetlands. This study documents the geochemical consequences of restoring freshwater re-flooding for contemporary reduced inorganic sulfur (RIS) and iron species in two coastal floodplain ASS wetlands. Re-flooding has established predominantly reducing/suboxic conditions and encouraged organic carbon accumulation in surface sediments (~ 20–30%). The pH of former sulfuric horizons has increased by ~ 2–3 units, partly in response to alkalinity generation from anaerobic metabolism of organic carbon coupled with Fe(III) and SO42 − reduction. Despite considerable sulfidisation, reactive Fe (FeR; sum of 1 M HCl and citrate–dithionite …

The Unusual 3d Interplay Of Basement Fault Reactivation And Fault-Propagation-Fold Development: A Case Study Of The Laramide-Age Stillwell Anticline, West Texas (Usa), Benjamin Surpless, Nicola Hill, Cara Beasley

Benjamin E Surpless

Subsurface fault geometries have a systematic influence on folds formed above those faults. We use the extraordinarily well-exposed fold geometries of the Laramide-age Stillwell anticline in west Texas (USA) to develop a strain-predictive model of fault-propagation fold formation. The anticline is a 10-km long, NW-trending, NE-vergent, asymmetric fold system with an axis that displays a map-view left-stepping, en echelon pattern. We integrated field observations, geologic and structural data, cross-sections, and 2D kinematic modeling to establish an unusual 3D two-stage model of contractional fold formation, including: 1) reverse reactivation of a pre-existing, NW-striking, SW-dipping, left-stepping, en echelon normal fault system in …

Holocene Earthquakes And Late Pleistocene Slip-Rate Estimates On The Wassuk Range Fault Zone, Nevada, Jayne Bormann, Benjamin Surpless, Marc Caffee, Steven Wesnousky

Benjamin E Surpless

The Wassuk Range fault zone is an 80‐km‐long, east‐dipping, high‐angle normal fault that flanks the eastern margin of the Wassuk Range in central Nevada. Observations from two alluvial fan systems truncated by the fault yield information on the vertical slip rate and Holocene earthquake history along the range front. At the apex of the Rose Creek alluvial fan, radiocarbon dating of offset stratigraphy exposed in two fault trenches shows that multiple earthquakes resulted in 7.0 m of vertical offset along the fault since ∼9400 cal B.P. These data yield a Holocene vertical slip rate of 0.7±0.1  mm/yr. The south trench …

Jurassic Eolian Oolite On A Paleohigh In The Sundance Sea, Bighorn Basin, Wyoming, Zoran Kilibarda, David Loope

David B. Loope

Aeolian limestones are widespread in the Quaternary record and have been identified in outcrops and cores of late Palaeozoic strata. These rocks have been interpreted as a low latitude signal of glacio-eustatic sea level fluctuations and have not been previously reported from the Mesozoic or from other episodes of earth history generally believed to have been non-glacial. Numerous lenticular bodies of cross-stratified oolite lie near the contact between the lower and upper members of the mudstone-dominated lower Sundance Formation (Middle and Upper Jurassic) in the Bighorn Basin of north-central Wyoming, USA. The lenses, up to 12 m thick, contain sedimentary …

The Unusual Temporal And Spatial Slip History Of The Wassuk Range Normal Fault, Western Nevada (Usa): Implications For Seismic Hazard And Walker Lane Deformation, Benjamin Surpless, Glenn Kroeger

Benjamin E Surpless

We document temporal and spatial variations in vertical displacement rate across 6 temporal orders of magnitude to better under stand how the 100-km-long, east-dipping Wassuk Range normal fault system has accommodated strain in the context of the Walker Lane, a tectonically active, NNWtrending zone of dextral and extensional deformation that affects significant portions of western Nevada and eastern California. We combine 10Be and 26Al cosmonuclide exposure ages with shallow seismic and gravity data from the buried hanging wall of the Wassuk fault to derive a post-113 ka (105 yr time scale) vertical displacement rate of 0.82 ± 0.16 mm/yr. We …

Neotectonics Of Major Faults Based On Strain Analysis And U-Th Dating Of Syntectonic Calcite, R. Weinberger, P. Nuriel, John Craddock

John Craddock

No abstract provided.

Lake Core Record Of Grinnell Glacier Dynamics During The Late Pleistocene And Younger Dryas, Glacier National Park, Montana, Usa, N. Schachtmann, K. Macgregor, A. Myrbo, N. Hencir, C. Riihimaki, J. Thole, Louisa Bradtmiller

Louisa I. Bradtmiller

No abstract provided.

Holocene Earthquakes And Late Pleistocene Slip Rate Estimates On The Wassuk Range Fault Zone, Nevada, Usa, Jayne Bormann, Benjamin Surpless, Marc Caffee, Steven Wesnousky

Benjamin E Surpless

The Wassuk Range fault zone is an 80‐km‐long, east‐dipping, high‐angle normal fault that flanks the eastern margin of the Wassuk Range in central Nevada. Observations from two alluvial fan systems truncated by the fault yield information on the vertical slip rate and Holocene earthquake history along the range front. At the apex of the Rose Creek alluvial fan, radiocarbon dating of offset stratigraphy exposed in two fault trenches shows that multiple earthquakes resulted in 7.0 m of vertical offset along the fault since ∼9400 cal B.P. These data yield a Holocene vertical slip rate of 0.7±0.1  mm/yr. The south trench …

A Detailed Record Of Shallow Hydrothermal Fluid Flow In The Sierra Nevada Magmatic Arc From Low-Δ18o Skarn Garnets, Megan D'Errico, Jade Lackey, Benjamin Surpless, Staci Loewy, Joseph Wooden, Jaime Barnes, Ariel Strickland, John Valley

Benjamin E Surpless

Garnet from skarns exposed at Empire Mountain, Sierra Nevada (California, United States) batholith, have variable δ18O values including the lowest known δ18O values of skarn garnet (–4.0‰) in North America. Such values indicate that surface-derived meteoric water was a significant component of the fluid budget of the skarn-forming hydrothermal system, which developed in response to shallow emplacement (∼3.3 km) of the 109 Ma quartz diorite of Empire Mountain. Values of δ18O, measured in situ across single garnet crystals by secondary ion mass spectrometry, vary considerably (up to 7‰) and sometimes abruptly, indicating variable mixing of meteoric, magmatic, and metamorphic water. …

Oxidation Dynamics Of Monosulfidic Toxic Sediment From A Eutrophic Estuary, Girish Choppala, Richard Bush, N Carroll, Leigh Sullivan, K Grice, S Appleyard, P Greenwood, S Wong, Nicholas Ward

Dr Girish Choppala

No abstract provided.

Investigations Into The Factors Affecting The Rates Of Recovery Of Acid Sulfate Soils In The Lower Lakes, Nicholas Ward, Richard Bush, Zhaohui Wang, Leigh Sullivan, Diane Fyfe, Girish Choppala, L Williams, N Toppler, Michelle Bush

Dr Girish Choppala

No abstract provided.

Assessing And Managing Sulfidic Dredge Spoil, Richard Bush, N Carroll, Leigh Sullivan, K Grice, S Appleyard, S Wong, N Ward, Peter Kraal, Girish Choppala

Dr Girish Choppala

No abstract provided.

The Influence Of Biochar And Black Carbon On Reduction And Bioavailability Of Chromate In Soils, Girish Choppala, Nanthi Bolan, M Megharaj, Z Chen, Ravi Naidu

Dr Girish Choppala

The widespread use of chromium (Cr) has a deleterious impact on the environment. A number of pathways, both biotic and abiotic in character, determine the fate and speciation of Cr in soils. Chromium exists in two predominant species in the environment: trivalent [(Cr(III)] and hexavalent [Cr(VI)]. Of these two forms, Cr(III) is nontoxic and is strongly bound to soil particles, whereas Cr(VI) is more toxic and soluble and readily leaches into groundwater. The toxicity of Cr(VI) can be mitigated by reducing it to Cr(III) species. The objective of this study was to examine the effect of organic carbon sources on …