Earth Sciences Commons^™

Guanophilic Fungi In Three Caves Of Southwestern Puerto Rico, Ángel M. Nieves-Rivera, Carlos J. Santos-Flores, Frank M. Dugan, Thomas E. Miller

International Journal of Speleology

Fifty species of guanophilic (bat guano-loving) fungi were isolated from field-collected samples within three caves in southwestern Puerto Rico; most were mitosporic fungi (23 species). The caves studied were Cueva La Tuna (Cabo Rojo), Cueva de Malano (Sistema de Los Chorros, San Germán), and Cueva Viento (El Convento Cave-Spring System, Guayanilla-Peñuelas). The most conspicuous fungus by far was the zygomycete Circinella umbellata (Mucorales). Circinella umbellata dominated the bat guano incubation chambers (Petri dishes lined with sterile filter paper moistened with sterile water) at ambient laboratory conditions. Nineteen species of basidiomycetes (e.g., Ganoderma cf. resinaceum, Geastrum cf. minimum, Lepiota …

A Terminological Matter: Paragenesis, Antigravitative Erosion Or Antigravitational Erosion?, Giancarlo Pasini

International Journal of Speleology

In the speleological literature three terms are utilized to designate the “ascending erosion”: paragenesis (= paragénésis, coined in 1968), antigravitative erosion (= erosione antigravitativa, coined in 1966) and antigravitational erosion (wrong English translation of the Italian term erosione antigravitativa, utilized later on). The term paragenesis should be abandoned because of the priority of the term erosione antigravitativa - on the ground of the “law of priority” – and because of its ambiguous etimology. On the other hand, the term antigravitational erosion should be forsaken in favour of the term antigravitative erosion, given the meaning that the terms gravitation and gravity …

Detrital-Zircon Geochronology Of The Metasedimentary Rocks Of North-Western Graham Land, David L. Barbeau Jr, Justin T. Davis, Kendra E. Murray, Victor Valencia, George E. Gehrels, Khandaker M. Zahid, David J. Gombosi

Faculty Publications

Metasedimentary rocks constitute an important but comparatively poorly understood part of the Antarctic Peninsula. Herein we report single-grain U-Pb detrital-zircon ages from samples of the Trinity Peninsula and Botany Bay Groups of north-western Graham Land. All studied samples are dominated by a large and narrowly defined population of late Palaeozoic zircons. Significant early–middle Palaeozoic and minor Neoproterozoic and Mesoproterozoic sub-populations constitute the majority of pre-Carboniferous grains. These detrital-zircon age populations are consistent with sediment derivation entirely from western Gondwana sources. Despite the clear Gondwana signatures, our data suggest that the Trinity Peninsula Group province was either a parautochthonous peri-Gondwanan terrane …

Pilot Study: The Nature And Thickness Of The Unsaturated Zone And Delineation Of Confined Aquifers, Sue Olafsen Lackey, Les Howard

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Holocene Carbon Burial By Lakes In Sw Greenland, N. J. Anderson, W. D'Andrea, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

The role of the Arctic in future global change processes is predicted to be important because of the large carbon (C) stocks contained in frozen soils and peatlands. Lakes are an important component of arctic landscapes although their role in storing C is not well prescribed. The area around Kangerlussuaq, SW Greenland (66–68°N, 49–54°W) has ex¬tremely high lake density, with ~20 000 lakes that cover about 14% of the land area. C accumulation rates and standing stock (kg C m⁻²), representing late- to mid-Holocene C burial, were calculated from AMS ¹⁴C-dated sediment cores from 11 lakes. Lake …

Towards The Standardization Of Sequence Stratigraphy, Octavian Catuneanu, V. Abreu, J. P. Bhattacharya, M. D. Blum, R. W. Dalrymple, P. G. Eriksson, Christopher R. Fielding, W. L. Fisher, W. E. Galloway, M. R. Gibling, K. A. Giles, J. M. Holbrook, R. Jordan, C. G. St.C. Kendall, B. Macurda, O. J. Martinsen, A. D. Miall, J. E. Neal, D. Nummedal, L. Pomar, H. W. Posamentier, B. R. Pratt, J. F. Sarg, K. W. Shanley, R. J. Steel, A. Strasser, M. E. Tucker, C. Winker

Department of Earth and Atmospheric Sciences: Faculty Publications

Sequence stratigraphy emphasizes facies relationships and stratal architecture within a chronological framework. Despite its wide use, sequence stratigraphy has yet to be included in any stratigraphic code or guide. This lack of standardization reflects the existence of competing approaches (or models) and confusing or even conflicting terminology. Standardization of sequence stratigraphy requires the definition of the fundamental model-independent concepts, units, bounding surfaces and workflow that outline the foundation of the method. A standardized scheme needs to be sufficiently broad to encompass all possible choices of approach, rather than being limited to a single approach or model.

A sequence stratigraphic framework …

Long-Legged Pursuit Carnivorans (Amphicyonidae, Daphoeninae) From The Earlymiocene Of North America, Robert M. Hunt Jr.

Department of Earth and Atmospheric Sciences: Faculty Publications

In the early Miocene, endemic North American amphicyonids of the subfamily Daphoeninae evolved a lineage of large beardogs adapted for prey pursuit over open terrain. Three species comprise this lineage, here placed in the genus Daphoenodon, subgenus Borocyon Peterson, 1910, the sister subgenus to the daphoenine beardog Daphoenodon (Daphoenodon). These species (Borocyon robustum, B. niobrarensis, B. neomexicanus, n. sp.) are distinguished by limbs modified for fore–aft motion and parasagittal alignment contributing to a lengthened stride. These adaptive features are most evident in the terminal species, B. robustum, where the forelimb is conspicuously …

Nebraska Statewide Groundwater-Level Monitoring Report 2009, Jesse T. Korus Dr., Mark E. Burbach

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Forecasting The Combined Effects Of Urbanization And Climate Change On Stream Ecosystems: From Impacts To Management Options, Kären C. Nelson, Margaret A. Palmer, James E. Pizzuto, Glenn A. Moglen, Paul L. Angermeier, Robert H. Hilderbrand, Michael Dettinger, Katharine Hayhoe

United States Geological Survey: Staff Publications

Streams collect runoff, heat, and sediment from their watersheds, making them highly vulnerable to anthropogenic disturbances such as urbanization and climate change. Forecasting the effects of these disturbances using process-based models is critical to identifying the form and magnitude of likely impacts. Here, we integrate a new biotic model with four previously developed physical models (downscaled climate projections, stream hydrology, geomorphology, and water temperature) to predict how stream fish growth and reproduction will most probably respond to shifts in climate and urbanization over the next several decades.

Taxonomy Of Quaternary Deep-Sea Ostracods From The Western North Atlantic Ocean, Moriaki Yasuhara, Hisayo Okahashi, Thomas M. Cronin

United States Geological Survey: Staff Publications

Late Quaternary sediments from Ocean Drilling Program (ODP) Hole 1055B, Carolina Slope, western North Atlantic (32°47.041’ N, 76°17.179’ W; 1798 m water depth) were examined for deep-sea ostracod taxonomy. A total of 13 933 specimens were picked from 207 samples and c. 120 species were identified. Among them, 87 species were included and illustrated in this paper. Twenty-eight new species are described. The new species are: Ambocythere sturgio, Argilloecia abba, Argilloecia caju, Argilloecia keigwini, Argilloecia robinwhatleyi, Aversovalva carolinensis, Bythoceratina willemvandenboldi, Bythocythere eugeneschornikovi, Chejudocythere tenuis, Cytheropteron aielloi, Cytheropteron demenocali, Cytheropteron didieae, Cytheropteron richarddinglei, Cytheropteron fugu, Cytheropteron guerneti, Cytheropteron richardbensoni, Eucytherura hazeli, …

Climate Trends Of The North American Prairie Pothole Region 1906–2000, Bruce Millett, W. Carter Johnson, Glenn Guntenspergen

United States Geological Survey: Staff Publications

The Prairie Pothole Region (PPR) is unique to North America. Its millions of wetlands and abundant ecosystem goods and services are highly sensitive to wide variations of temperature and precipitation in time and space characteristic of a strongly continental climate. Precipitation and temperature gradients across the PPR are orthogonal to each other. Precipitation nearly triples from west to east from approximately 300 mm/year to 900 mm/year, while mean annual temperature ranges from approximately 1°C in the north to nearly 10°C in the south. Twentieth-century weather records for 18 PPR weather stations representing 6 ecoregions revealed several trends. The climate generally …

Climate Trends Of The North American Prairie Pothole Region 1906–2000, Bruce Millett, W. Carter Johnson, Glenn R. Guntenspergen

United States Geological Survey: Staff Publications

The Prairie Pothole Region (PPR) is unique to North America. Its millions of wetlands and abundant ecosystem goods and services are highly sensitive to wide variations of temperature and precipitation in time and space characteristic of a strongly continental climate. Precipitation and temperature gradients across the PPR are orthogonal to each other. Precipitation nearly triples from west to east from approximately 300 mm/year to 900 mm/year, while mean annual temperature ranges from approximately 1◦C in the north to nearly 10◦C in the south. Twentieth-century weather records for 18 PPR weather stations representing 6 ecoregions revealed several trends. The climate generally …

The Influence Of Fallback Foods On Great Ape Tooth Enamel, Paul J. Constantino, Peter W. Lucas, James J.-W. Lee, Brian R. Lawn

Biological Sciences Faculty Research

Lucas and colleagues recently proposed a model based on fracture and deformation concepts to describe how mammalian tooth enamel may be adapted to the mechanical demands of diet (Lucas et al.: Bioessays 30[2008] 374-385). Here we review the applicability of that model by examining existing data on the food mechanical properties and enamel morphology of great apes (Pan, Pongo, and Gorilla). Particular attention is paid to whether the consumption of fallback foods is likely to play a key role in influencing great ape enamel morphology. Our results suggest that this is indeed the case. We also consider the implications of …

Arkosic Rocks From The San Andreas Fault Observatory At Depth (Safod) Borehole, Central California: Implications For The Structure And Tectonics Of The San Andreas Fault Zone, S. D. Springer, James P. Evans, J. I. Garver, D. Kirschner, Susanne U. Janecke

Geosciences Faculty Publications

The San Andreas Fault Observatory at Depth (SAFOD) drill hole encountered indurated, high-seismic-velocity arkosic sedimentary rocks west of the active trace of the San Andreas fault in central California. The arkosic rocks are juxtaposed against granitic rocks of the Salinian block to the southwest and against fine-grained Great Valley Group and Jurassic Franciscan rocks to the northeast. We identify three distinct lithologic units using cuttings, core petrography, electrical resistivity image logs, zircon fission-track analyses, and borehole-based geophysical logs. The upper arkose occurs from 1920 to 2530 m measured depth (mmd) in the borehole and is composed of five structural blocks …

Magnitude Of Right-Lateral Offset On The Southern Death Valley Fault Zone From Miocene Volcanic Assemblages, Sabrina Michelle Canalda

Open Access Theses & Dissertations

In this study correlation of Miocene volcanic and sedimentary rocks in southern Death Valley is used to constrain the total amount of slip on the southern Death Valley fault. The tertiary volcanic section near Ibex Pass is correlated to rocks ~35 km to the northwest, in the Wingate Wash region (Luckow et al., 2005). Geochronology by Luckow et al. (2005) in Wingate Wash and the Owlshead Mountains has the region divided into two basic periods: an early interval (~14-13.4Ma), and a later phase (~13-12.5Ma). One date from the volcanic sequence in Ibex Pass has been reported (Calzia, 2000) suggesting that …

The Pluvial Lake Palomas - Samalayuca Dunes System, Miguel Dominguez Acosta

Open Access Theses & Dissertations

A lacustro-aeolian system formed by the Pluvial Lake Palomas (PLP), the Samalayuca Dunes (SMD) and a connecting aeolian corridor is found in the central Chihuahuan Desert of North America approximately 50 km upwind (SW) of the binational Paso del Norte metroplex. The system is described by its three individual components. They comprise one of the largest paleo-lacustrine (Pleistocene) environments in the Chihuahuan Desert (PLP), one of the largest and least-studied sand seas of North America (SMD), and a newly described and geomorphically heterogeneous aeolian corridor connecting the two.

The Chihuahuan Desert has been a major and underappreciated dust production region …

Insight Into The Physics Of Rupture: Dynamic Triggering Seismicity, Hector Gonzalez-Huizar

Open Access Theses & Dissertations

Seismic waves can trigger earthquakes and tremor at large distances from the causable event. Dynamic triggering occurs when the surface waves from large earthquakes change the stresses conditions on previously overstressed faults, promoting failure. To understand the causative stresses and environments behind dynamic triggering, we model the change in the stress field that the passing of Rayleigh and Love waves cause on a fault plane of arbitrary orientation relative to the direction of propagation of the waves, and apply a Coulomb failure criterion to calculate the potential of these stress changes to trigger seismicity. We apply our model to three …

Resistivity And Conductivity Studies Of The Rattlesnake Springs, New Mexico Watershed, Claudia Santiago

Open Access Theses & Dissertations

Rattlesnake Springs are a high-discharge artesian springs situated in the upper Black River Valley in southwestern Eddy Country, New Mexico. The aquifer that supplies the Rat- tlesnake Springs has been the main water source for domestic use by visitors of Carlsbad Caverns National Park and residents of neighboring ranches since the 1930s. Several ge- ological studies relying on surface geology and limited water wells had previously been conducted in the area to examine the trend of ground water flow. In this study I used con- ductivity and resistivity geophysical techniques to identify possible locations of fractures in the subsurface of …

Analysis Of Shallow Seismicity And Stress Fields In Southeastern Alaska, Hugo Rodriguez

Open Access Theses & Dissertations

Southeastern Alaska is dominated by strike-slip motion along the Queen Charlotte-southern Fairweather fault system (QCFS) in the south and transitions to oblique convergent motion partitioned between strike-slip motion along the Denali and northern Fairweather fault systems and thrusting along faults of the St. Elias region. Geologic complications are further increased by the subduction of the Yakutat microplate beneath North America and glacial processes. By studying regional background seismicity we intend to better determine the current state of stress of southeastern Alaska from the Dixon Entrance to Yakutat Bay. Phase data was gathered for over 4000 earthquakes of depths <20 km and magnitude <5 that occurred from 1973-2005 from Alaskan and Canadian databases. We relocated these earthquakes using the Double-Difference joint hypocenter method. Two areas of interest were identified with high concentrations of seismicity after relocation calculations for the entire southeast Alaska region; Glacier Bay through Yakutat (GBY) and the area surrounding Mt. Ogden (MOG). Earthquake locations in GBY are diffuse with some isolated clusters. The MOG subregion is dominated by a large northeast to southwest trending cluster that trends along the Speel River. We used these relocations and first motion data to estimate the stress fields for earthquake clusters that formed. Only a few of the calculated stress tensors were successful in representing the region's overall tectonic signature. We combined the calculated stress information with GPS, magnetic and gravity data in order determine how plate motion is partitioned in this region and to identify other potentially active faults.

Estimating Variation In Stiffness And Volume Change Of Clays From Geochemical And Index Properties, Cynthia Roxanna Zuniga

Open Access Theses & Dissertations

Clayey soils from six different locations in Texas were analyzed and evaluated with respect to their expansion and shrinkage and change in stiffness associated with moisture content variation. These soils consist of five high plasticity-index (PI) clays (PI greater than 25) and one low-PI clay (PI = 17). The behavior of the clays changes dramatically with moisture content fluctuation, thus causing stiffness and volume changes throughout the year. Total or differential volume movements caused by swell or shrinkage strains of expansive soils and reduction in modulus can exert enough pressure to damage the pavements and cause maintenance problems.

The intent …

Two-Dimensional Gravity Modeling Of The Rattlesnake Springs Watershed, Carlsbad Caverns National Park, New Mexico, Nikolay D. Boykov

Open Access Theses & Dissertations

A series of non-invasive geophysical investigations at the Rattlesnake Springs part of Carlsbad Caverns National Park, New Mexico, were performed in an effort to better delineate the watershed of the springs. The goal of this project is to determine possible locations of fractures and faults that may control the distribution of groundwater that feeds Rattlesnake Springs. Once the water flow paths are identified, the park will be able to better protect Rattlesnake Springs from environmental hazards, such as oil and gas drilling, as well as from upstream water development. As part of this effort I conducted a precision gravity survey …

Suswa Volcano, Kenya Rift: Evidence Of Magma Mixing, Na-F Complexing And Eruptions Triggered By Recharge, Vanessa Veronica Espejel Garcia

Open Access Theses & Dissertations

The Cenozoic East African rift system (EARS) is a sequence of grabens, intraplate transforms, accommodation zones, and abundant magmatism. The Central Kenya Peralkaline Province (CKPP) includes a variety of volcanic rocks -trachyte, pantellerite, comendite, phonolite, trachy-basalt, basaltic trachy-andesite, and basalt- which erupted from volcanoes including: Mount Kenya; Eburru and the Greater Olkaria volcanic complexes; Longonot, Menengai, and Suswa volcanoes; and Ndabibi, Elmenteita, and Tandamara mafic volcanic fields. Only two of the volcanoes, Mount Kenya (on the flank of the central graben) and Suswa (the southernmost of the CKPP volcanoes), have phonolites as part of their assemblage.

The evolution of Suswa …

Temporal And Geochemical Insights Related To Volcanic And Plutonic Activity Within Big Bend National Park, Texas, Daniel Paul Miggins

Open Access Theses & Dissertations

Big Bend National Park located in the southeastern part of the Trans-Pecos Magmatic Province in west Texas contains a diverse suite of volcanic and intrusive rocks. Ongoing geologic mapping, geochronology, and geochemical studies have focused on the timing and geological relationships associated with these volcanic and intrusive rocks. Igneous activity within Big Bend National Park occurred from 46.5 to 22.0 Ma. Precise 40Ar/39Ar and U-Pb zircon geochronology has resolved the timing of this activity into five discrete episodes: 1) eruption and emplacement of both intrusive and volcanic mafic rocks at 46.5 Ma followed by ~42.0 Ma mafic volcanic pulse; 2) …

Pdi, Reactive Oxygen Species Stress And Polyphenolic Phytochemicals: Implications For Neurodegenerative Diseases, Rituraj Pal

Open Access Theses & Dissertations

PDI, protein disulfide isomerase, is one of the most versatile proteins and highly expressed in mammalian cells because there is a vast number of proteins that must undergo processing before secretion to their final destinations. PDI has several functions: oxidation of nascent proteins and isomerization of existing disulfide bonds. It also possesses chaperone activity and participates in protein degradation. Because of its structure, PDI can exist in a reduced or oxidized form. In mammalian cells it is mostly reduced due to the high demand of disulfide bond shuffling of secreted proteins within the ER, PDI a, a', and b' posses …

Characterizing The Deformation Of Reservoirs Using Interferometry, Gravity, And Seismic Analyses, Cara Schiek

Open Access Theses & Dissertations

In this Dissertation, I characterize how reservoirs deform using surface and subsurface techniques. The surface technique I employ is radar interferometry, also known as InSAR (Interferometric Synthetic Aperture Radar). The subsurface analyses I explore include gravity modeling and seismic techniques consisting of determining earthquake locations from a small-temporary seismic network of six seismometers. These techniques were used in two different projects to determine how reservoirs deform in the subsurface and how this deformation relates to its remotely sensed surface deformation.

The first project uses InSAR to determine land subsidence in the Mimbres basin near Deming, NM. The land subsidence measurements …

Zinc And Copper Isotopes As Tracers Of Anthropogenic Contamination In A Sediment Core From An Urban Lake, Anita Thapalia

Open Access Theses & Dissertations

Concentration data alone are often insufficient to resolve metal sources. This study applies stable Zn and Cu isotopes to fingerprint and track the sources of these metals in a sediment core from Lake Ballinger near Seattle, Washington, USA. The base of the Lake Ballinger core pre-dates settlement in the region, while the upper sections record the impact of atmospheric emissions from the nearby Tacoma smelter, as well as Cu and Zn inputs from urban sources. δ⁶⁶Zn and δ⁶⁵Cu varied by 0.42 / and 0.29 /, respectively, over the >300 year core record. Isotopic changes were correlated …

Using Chromium Stable Isotopes To Monitor Chromium Reactive Transport: Oxidation Experiments And Field Studies, Alejandro Villalobos Aragon

Open Access Theses & Dissertations

Chromium (Cr) is a common contaminant found at a number of sites globally. Cr sources can be either anthropogenic or natural. Cr occurs in nature in two valences, with Cr(VI) being carcinogenic, more toxic and mobile than Cr(III). Reduction of Cr(VI) to Cr(III) is a common remediation strategy, but monitoring Cr reduction using only concentration and speciation analyses is a difficult endeavor because concentrations can be affected by dilution and advection in addition to reduction. Cr isotopes are fractionated during reduction processes, so monitoring isotopic changes in Cr may be a faster and more effective way to monitor reduction. This …

Analytical Method Development For Determination Of Volatile Organic Compounds In Calcareous Desert Soil, Mary F. Turner

UNLV Theses, Dissertations, Professional Papers, and Capstones

Soil sample preservation for volatile organic compound analysis generally requires short sample holding times or preservation of the sample's chemical constituents with sodium bisulfate (NaHSO 4 ). Calcareous soils cannot be preserved using NaHSO4 because effervescence will promote the loss of analytes, and short holding times before analysis are not practical for remote sampling locations. An experimental approach was developed for determination of volatile organic compounds (VOCs) in soil that utilizes solid sorbents for sample preservation and solid-phase microextraction (SPME) sample preparation technique coupled with gas chromatography/mass spectrometry (GC/MS) for analysis. Solid sorbents are used to sequester readily extractable (vapor …

Pleistocene Reorganization Of The Southern San Andreas Fault System, A. N. Steely, Susanne U. Janecke, G. J. Axen, R. J. Dorsey

Geosciences Faculty Publications

Structural and stratigraphic analyses along the western margin of the Salton Trough show that the San Andreas fault system was reorganized in early Pleistocene time from a system dominated by two fault zones (the San Andreas fault and the West Salton detachment fault) to a network of dextral faults that include the San Andreas and at least four dextral faults to the southwest. The San Felipe fault zone, one of these dextral faults, has ~5.8 ± 2.8 km of right separation and consists of three principal faults in the Peninsular Ranges. These are the San Felipe fault in the WNW, …

Annual And Transient Signatures Of Gas Exchange And Transport In The Castañar De Ibor Cave (Spain), Angel Fernandez-Cortes, Sergio Sanchez-Moral, Soledad Cuezva, Juan Carlos Cañaveras, Rafael Abella

International Journal of Speleology

The large microclimatic stability is a basic characteristic of the subterranean karst systems and causes a high sensitivity to changes in environmental conditions. High-accuracy monitoring of Castañar de Ibor cave (Spain) determined the temporal evolution of the aerodynamic processes and ventilation rate by tracking CO₂ and ²²²Rn levels over a twelve-month period. This cave is characterized by a very stable microclimate, with high and relatively constant radon content (the mean value is 32200 Bq/m³, roughly, and the standard deviation is 7600 Bq/m³) and a moderate and quite stable CO2 concentration (the mean value is …