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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 ...


The Differing Biogeochemical And Microbial Signatures Of Glaciers And Rock Glaciers, Timothy S. Fegel, Jill S. Baron, Andrew G. Fountain, Gunnar F. Johnson, Ed K. Hall 2016 Colorado State University

The Differing Biogeochemical And Microbial Signatures Of Glaciers And Rock Glaciers, Timothy S. Fegel, Jill S. Baron, Andrew G. Fountain, Gunnar F. Johnson, Ed K. Hall

Andrew G. Fountain

Glaciers and rock glaciers supply water and bioavailable nutrients to headwater mountain lakes and streams across all regions of the American West. Here we present a comparative study of the metal, nutrient, and microbial characteristics of glacial and rock glacial influence on headwater ecosystems in three mountain ranges of the contiguous U.S.: the Cascade Mountains, Rocky Mountains, and Sierra Nevada. Several meltwater characteristics (water temperature, conductivity, pH, metals, nutrients, complexity of dissolved organic matter (DOM), and bacterial richness and diversity) differed significantly between glacier and rock glacier meltwaters, while other characteristics (Ca2+, Fe3+, SiO2 concentrations, reactive ...


Thermal Behaviour Of Organic Radicals And Paramagnetic Centres In Chert: A Case Study Of Bergeracois Brown Chert, Dordogne, France, Renaud Joannes-Boyau, Anja Scheffers, Rémy Chapoulie, Christelle Lahaye, Jeffrey F. Parr, Marie Orange, Ian Moffat, Pierre Guibert 2016 Southern Cross University

Thermal Behaviour Of Organic Radicals And Paramagnetic Centres In Chert: A Case Study Of Bergeracois Brown Chert, Dordogne, France, Renaud Joannes-Boyau, Anja Scheffers, Rémy Chapoulie, Christelle Lahaye, Jeffrey F. Parr, Marie Orange, Ian Moffat, Pierre Guibert

Dr Renaud Joannes-Boyau

In order to successfully understand the complex evolution of prehistoric societies, archaeologists require absolute dating tools, which are not only accurate but also widely applicable. Thermoluminescence (TL) dating is one such approach that has been successfully used to establish a general chronological framework for prehistoric sites and is particularly suited for use on heated lithic artefacts. Experiments conducted in this study have clearly shown the applicability of Electron Spin Resonance (ESR) isothermal modelling in combination with TL dating to constrain firing temperature. This expands the potential application for TL dating to include artefacts treated at low firing temperatures. The present ...


Fire And Fuels: Vegetation Change Over Time In The Zuni Mountains, New Mexico, Luke Wylie 2016 University of Southern Mississippi

Fire And Fuels: Vegetation Change Over Time In The Zuni Mountains, New Mexico, Luke Wylie

Master's Theses

The Zuni Mountains are a region that has been dramatically changed by human interference. Anthropogenically, fire suppression practices have allowed a buildup of fuels and caused a change in the fire-adapted ponderosa pine ecosystem such that the new ecosystem now incorporates many fire-intolerant species. As a result, the low-severity fires that the ecosystem once depended on to regenerate the forest are much reduced, and these low-severity fires are now replaced by crown-level infernos that threaten the forest and nearby towns. In order to combat these effects, land managers are implementing fuel reduction practices and are striving to better understand the ...


Natural And Anthropogenic Processes Contributing To Metal Enrichment In Surface Soils Of Central Pennsylvania, A. M.L. Kraepiel, Ashlee L.D. Dere, E. M. Herndon, Susan L. Brantley 2016 Princeton University

Natural And Anthropogenic Processes Contributing To Metal Enrichment In Surface Soils Of Central Pennsylvania, A. M.L. Kraepiel, Ashlee L.D. Dere, E. M. Herndon, Susan L. Brantley

Ashlee Dere

Metals in soils may positively or negatively affect plants as well as soil micro-organisms and mesofauna, depending on their abundance and bioavailability. Atmospheric deposition and biological uplift commonly result in metal enrichment in surface soils, but the relative importance of these processes is not always resolved. Here, we used an integrated approach to study the cycling of phosphorus and a suite of metals from the soil to the canopy (and back) in a temperate watershed. The behavior of elements in these surface soils fell into three categories. First, Al, Fe, V, Co, and Cr showed little to no enrichment in ...


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 ...


Characterization Of Lower Permian Carbonate Subaqueous Gravity Flows In Crockett County, Texas, Wesley L. Turner 2016 Stephen F Austin State University

Characterization Of Lower Permian Carbonate Subaqueous Gravity Flows In Crockett County, Texas, Wesley L. Turner

Electronic Theses and Dissertations

Transitional sediments on carbonate ramp slopes act as a link to relatively well-studied platform and basin depositional environments. In the southern Midland Basin, the key to understanding the relationship between these environments lies in the allochthonous gravity flow sediments found on the slope. Here, a succession of various gravity flow deposits is used to interpret how base level fluctuations affect the type of deposits found on the slope and their effect on the deep basinal environment. This study utilizes core samples from the Wolfcamp Formation adjacent to the Central Basin Platform in five wells in Northwest Crockett County, Texas. The ...


Search For An Artificially Buried Karst Cave Entrance Using Ground Penetrating Radar: A Successful Case Of Locating The S-19 Cave In The Mt. Kanin Massif (Nw Slovenia), Andrej Gosar, Teja Čeru 2016 University of Ljubljana

Search For An Artificially Buried Karst Cave Entrance Using Ground Penetrating Radar: A Successful Case Of Locating The S-19 Cave In The Mt. Kanin Massif (Nw Slovenia), Andrej Gosar, Teja Čeru

International Journal of Speleology

The S-19 Cave was with its explored depth of 177 m one of the most important caves of the Mt. Kanin massif, but after its discovery in 1974, a huge snow avalanche protection dyke was constructed across the cave entrance. To excavate the buried cave, the accurate location of the cave had to be determined first. Since the entrance coordinates were incorrect and no markers were available, application of geophysical techniques was necessary to do this. A Ground Penetrating Radar (GPR) with special 50 MHz rough terrain antennas was selected as the single suitable geophysical method for the given conditions ...


Reducing Nutrient Loss: Science Shows What Works, C. A. J. Thompson, Matthew J. Helmers, Thomas M. Isenhart, John D. Lawrence 2016 Iowa State University

Reducing Nutrient Loss: Science Shows What Works, C. A. J. Thompson, Matthew J. Helmers, Thomas M. Isenhart, John D. Lawrence

John Lawrence

Iowa has been working for decades to protect and improve water quality. However, progress measured toward reduction targets at the watershed scale has been challenging, and many complex nutrient-related impacts in Iowa’s lakes, reservoirs, and streams remain to be addressed. The Iowa Nutrient Reduction Strategy is a science and technology-based framework to assess and reduce nutrients to Iowa waters and the Gulf of Mexico. It directs efforts to reduce nutrients in surface water from both point and nonpoint sources in a scientific, reasonable, and cost-effective manner.


Paleotsunami Research - Current Debate And Controversies, Anja Scheffers 2016 Southern Cross University

Paleotsunami Research - Current Debate And Controversies, Anja Scheffers

Associate Professor Anja Scheffers

During 1989–2014, our knowledge and research focus on modern and paleotsunami events have increased exponentially. Before the catastrophic Indian Ocean Tsunami of 2004 AD, nearly 1000 scientific papers had discussed the topic, but since then, over another 1000 research articles have been published. The strong tsunami events of Chile, 2010, and particularly the Tohoku megatsunami in Japan of March 2011 will certainly advance tsunami research further. Hitherto, a large percentage of tsunami-related articles have highlighted the origin of tsunamis, their geophysics, tsunami wave progradation, tsunami risk evaluation, and mitigation. This contribution focuses on fields of debate that still exist ...


Age Re-Assessment Of The Cave Bear Assemblage From Urşilor Cave, North-Western Romania, Marius V. Robu 2016 "Emil Racoviţă" Institute of Speleology

Age Re-Assessment Of The Cave Bear Assemblage From Urşilor Cave, North-Western Romania, Marius V. Robu

International Journal of Speleology

The most common methods used for assessing the relative age of a cave bear bone assemblage are the P4/4 index (morphodynamic index of the cave bear fourth premolar), the K-index and the Index of Plumpness (both used for cave bear’s 2nd metatarsal). Preliminary work on this (Robu et al., 2011), for Urşilor Cave (NW Romania), has indicated one of the youngest European cave bear populations. As the number of extracted fossil bones from the palaeontological excavation increased recently, a re-assessment of the of the age of the cave bear assemblage is necessary. 206 cave bear fourth ...


Speleogenesis Of Critchfield Bat Caves And Associated Hydrogeology Of The Northern Edwards Aquifer, Williamson County, Texas, Ashley N. Landers 2016 Stephen F Austin State University

Speleogenesis Of Critchfield Bat Caves And Associated Hydrogeology Of The Northern Edwards Aquifer, Williamson County, Texas, Ashley N. Landers

Electronic Theses and Dissertations

Karst development in the Edwards Aquifer has been significantly studied in the San Antonio and Barton Spring Segments; however, karst development remains poorly studied in the Northern Segment. Detailed characterization of the Northern Segment is vital for future water conservation because of increasing urban sprawl along the Interstate 35 corridor. The Northern Segment of the Edwards Aquifer consists of Lower Cretaceous strata of the Comanche Peak, Edwards, and Georgetown formations. The stratigraphy is dominated by Edwards Limestone as it is the only formation that crops out in the study area.

Karst, stratigraphic, GIS, and geochemical studies were conducted to evaluate ...


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 ...


The End-Permian Mass Extinction And The Siberian Traps Eruptions, Rebecca Teed 2016 Wright State University

The End-Permian Mass Extinction And The Siberian Traps Eruptions, Rebecca Teed

Rebecca Teed

This handout focuses on the evidence for the theory that a series of flood-basalt eruptions in Siberia caused the mass extinction at the end of the Permian Period.  This is the worst mass extinction known to geologists, and 90% or more of all species on Earth were wiped out.

It is part of a set of four articles on possible causes of the Permian and Cretaceous mass extinctions can be used to organize classroom debates or to have students compare and contrast the events and their causes.


The End-Permian Mass Extinction And A Possible Massive Impact, Rebecca Teed 2016 Wright State University

The End-Permian Mass Extinction And A Possible Massive Impact, Rebecca Teed

Rebecca Teed

This handout examines the evidence for the theory that a massive meteor impact caused the mass extinction at the end of the Permian Period.  This is the worst mass extinction known to geologists, and 90% or more of all species on Earth were wiped out.

It is part of a set of four articles on possible causes of the Permian and Cretaceous mass extinctions can be used to organize classroom debates or to have students compare and contrast the events and their causes.


The End-Cretaceous Mass Extinction And The Chicxulub Impact, Rebecca Teed 2016 Wright State University

The End-Cretaceous Mass Extinction And The Chicxulub Impact, Rebecca Teed

Rebecca Teed

This handout focuses on the evidence for the theory that massive meteor impact off the coast of Mexico caused the mass extinction at the end of the Cretaceous Period.  The dinosaurs and about 75% of all marine invertebrate species and many other organisms died abruptly at this time.

It is part of a set of four articles on possible causes of the Permian and Cretaceous mass extinctions can be used to organize classroom debates or to have students compare and contrast the events and their causes.


The End-Cretaceous Mass Extinction And The Deccan Traps Eruptions, Rebecca Teed 2016 Wright State University

The End-Cretaceous Mass Extinction And The Deccan Traps Eruptions, Rebecca Teed

Rebecca Teed

This handout focuses on the evidence for the theory that a series of flood-basalt eruptions in northern India caused the mass extinction at the end of the Cretaceous Period. The dinosaurs and about 75% of all marine invertebrate species and many other organisms died abruptly at this time.

This is one of a set of four articles on possible causes of the Permian and Cretaceous mass extinctions can be used to organize classroom debates or to have students compare and contrast the events and their causes.


Reply To The Comment On “Chronostratigraphy And Paleoclimatology Of The Lodève Basin, France: Evidence For A Pan-Tropical Aridification Event Across The Carboniferous–Permian Boundary” By Michel Et Al., (2015). Palaeogeography, Palaeoclimatology, Palaeoecology 430, 118–131, Lauren A. Michel, Mark D. Schmitz, Neil J. Tabor, Isabel P. Montañez, Vladimir I. Davydov 2016 Southern Methodist University

Reply To The Comment On “Chronostratigraphy And Paleoclimatology Of The Lodève Basin, France: Evidence For A Pan-Tropical Aridification Event Across The Carboniferous–Permian Boundary” By Michel Et Al., (2015). Palaeogeography, Palaeoclimatology, Palaeoecology 430, 118–131, Lauren A. Michel, Mark D. Schmitz, Neil J. Tabor, Isabel P. Montañez, Vladimir I. Davydov

Mark D. Schmitz

Michel et al. (2015) present new radioisotopic age estimates coupled with paleosol data from the Lodève basin, France that indicate a Pennsylvanian–Permian trend toward aridity that is similar to trends seen in other western equatorial basins across tropical Pangaea. In their comment, Pochat and Van Den Driessche (2015) call into question these newly published U-Pb zircon chemical-abrasion isotope dilution thermal ionization mass spectrometry (CAIDTIMS) age estimates from volcanic ash layers preserved within the Lodève Basin. Furthermore, Pochat and Van Den Driessche (2015) reject our assertion that the rates of sediment accumulation for the Carboniferous–Permian strata in the Lodève ...


Dendrochronology And Middle Miocene Petrified Oak: Modern Counterparts And Interpretation, William E. Wright, Martin J. Streck, Christopher Baisan, W. Walton Wright, Paul Szejner 2016 University of Arizona

Dendrochronology And Middle Miocene Petrified Oak: Modern Counterparts And Interpretation, William E. Wright, Martin J. Streck, Christopher Baisan, W. Walton Wright, Paul Szejner

Martin J. Streck

This study reports the first successful statistical crossdating among many ring width time series from petrified wood, thus providing a replicable continuous annual resolution window into tree growth and environmental influences during the middle Miocene. The petrified samples, of the genus Quercus, originated at the Stinking Water (SW) locality in Oregon, a Miocene-aged exposure associated with the Columbia River Basalts. 40AR/39AR dating on pillow basalt from the locality yielded a weighted Plateau Age of 13.79 ±0.09 Ma placing the death of the trees at the end of the Langhian Stage of the Middle Miocene (15 ...


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