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Full-Text Articles in Other Earth Sciences

Hot Rocks: Constraining The Thermal Conditions Of The Mistastin Lake Impact Melt Deposits Using Zircon Grain Microstructures, Gavin Douglas Tolometti, Timmons M. Erickson, Gordon R. Osinski, Cyril Cayron, Catherine Neish Apr 2022

Hot Rocks: Constraining The Thermal Conditions Of The Mistastin Lake Impact Melt Deposits Using Zircon Grain Microstructures, Gavin Douglas Tolometti, Timmons M. Erickson, Gordon R. Osinski, Cyril Cayron, Catherine Neish

Earth Sciences Publications

The production of superheated melt during hypervelocity impact events has been proposed to be a common occurrence on terrestrial planetary bodies. Recent direct evidence of superheated impact melt temperatures exceeding >2370°C from the Kamestastin (Mistastin Lake) impact structure, Canada, was based on a single impact glass sample. Such high superheated melt temperatures have strong implications for the evolution of crustal material, the thermal history of impact cratering events, and the rheology of impact melt. However, although widely predicted in previous studies, with the exception of the Mistastin Lake impact glass, there is little direct evidence for superheated temperatures in multiple …


Ignoring Species Availability Biases Occupancy Estimates In Single-Scale Occupancy Models, Graziella V. Direnzo, David A. W. Miller, Evan H. C. Grant Apr 2022

Ignoring Species Availability Biases Occupancy Estimates In Single-Scale Occupancy Models, Graziella V. Direnzo, David A. W. Miller, Evan H. C. Grant

United States Geological Survey: Staff Publications

  1. Most applications of single-scale occupancy models do not differentiate between availability and detectability, even though species availability is rarely equal to one. Species availability can be estimated using multi-scale occupancy models; however, for the practical application of multi-scale occupancy models, it can be unclear what a robust sampling design looks like and what the statistical properties of the multi-scale and single-scale occupancy models are when availability is less than one.
  2. Using simulations, we explore the following common questions asked by ecologists during the design phase of a field study: (Q1) what is a robust sampling design for the multi-scale occupancy …


The Mineralogy And Geochemistry Of Illinois Basin Paleosols: Recognizing Detrital, Pedogenic, And Diagenetic Minerals, Julia A. Mcintosh Apr 2022

The Mineralogy And Geochemistry Of Illinois Basin Paleosols: Recognizing Detrital, Pedogenic, And Diagenetic Minerals, Julia A. Mcintosh

Earth Sciences Theses and Dissertations

The geochemical compositions of minerals in paleosols are assumed to be homogenous and attained through chemical weathering processes during episodes of pedogenesis in the geologic past. As such, the geochemical composition of minerals from paleosols may be used to reconstruct ancient climates and environments. One problem with this assumption is that paleosols were initially clastic sedimentary rocks or substrate prior to pedogenesis, thus it is likely that some portion of the paleosol is still composed of detrital minerals. Secondly, conditions may change in a sedimentary basin as the basin is buried and later uplifted, potentially triggering new mineralization or transformation …


Informing Management Of Henrys Lake, Idaho, Using An Integrated Catch-At-Age Model, Joshua L. Mccormick, Jennifer Vincent, Brett High, Darcy K. Mccarrick, Michael C. Quist Mar 2022

Informing Management Of Henrys Lake, Idaho, Using An Integrated Catch-At-Age Model, Joshua L. Mccormick, Jennifer Vincent, Brett High, Darcy K. Mccarrick, Michael C. Quist

United States Geological Survey: Staff Publications

Henrys Lake, Idaho, supports a popular fishery for Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri and Yellowstone Cutthroat Trout × Rainbow Trout O. mykiss hybrids. A majority of the adult population of fish in Henrys Lake are of hatchery origin that were stocked as fingerlings. The fishery is closed to angling during the late winter and spring months, but fisheries managers are considering opening the fishery year-round with catch-and-release- only regulations or with a two-fish bag limit during the extended season. However, there is concern that the proposed management actions may negatively affect the current fishery. Therefore, we developed an integrated …


Accuracy Assessment, Comparative Performance, And Enhancement Of Public Domain Digital Elevation Models (Aster 30 M, Srtm 30 M, Cartosat 30 M, Srtm 90 M, Merit 90 M, And Tandem-X 90 M) Using Dgps, Kumari Preety, Anup K. Prasad, Atul K. Varma, Hesham El-Askary Mar 2022

Accuracy Assessment, Comparative Performance, And Enhancement Of Public Domain Digital Elevation Models (Aster 30 M, Srtm 30 M, Cartosat 30 M, Srtm 90 M, Merit 90 M, And Tandem-X 90 M) Using Dgps, Kumari Preety, Anup K. Prasad, Atul K. Varma, Hesham El-Askary

Mathematics, Physics, and Computer Science Faculty Articles and Research

Publicly available Digital Elevation Models (DEM) derived from various space-based platforms (Satellite/Space Shuttle Endeavour) have had a tremendous impact on the quantification of landscape characteristics, and the related processes and products. The accuracy of elevation data from six major public domain satellite-derived Digital Elevation Models (a 30 m grid size—ASTER GDEM version 3 (Ast30), SRTM version 3 (Srt30), CartoDEM version V3R1 (Crt30)—and 90 m grid size—SRTM version 4.1 (Srt90), MERIT (MRT90), and TanDEM-X (TDX90)), as well as the improvement in accuracy achieved by applying a correction (linear fit) using Differential Global Positioning System (DGPS) estimates at Ground Control Points (GCPs) …


Paradigm Versus Paradox On The Prairie: Testing Competing Stream Fish Movement Frameworks Using An Imperiled Great Plains Minnow, Zachary D. Steffensmeier, Maeghen Wedgeworth, Lauren Yancy, Noah Santee, Shannon K. Brewer, Joshuah S. Perkin Feb 2022

Paradigm Versus Paradox On The Prairie: Testing Competing Stream Fish Movement Frameworks Using An Imperiled Great Plains Minnow, Zachary D. Steffensmeier, Maeghen Wedgeworth, Lauren Yancy, Noah Santee, Shannon K. Brewer, Joshuah S. Perkin

United States Geological Survey: Staff Publications

Background: Movement information can improve conservation of imperiled species, yet movement is not quantified for many organisms in need of conservation. Prairie chub (Macrhybopsis australis) is a regionally endemic freshwater fish with unquantified movement ecology and currently considered for listing under the Endangered Species Act. The purpose of this study was to test competing ecological theories for prairie chub movement, including the colonization cycle hypothesis (CCH) that posits adults must make upstream movements to compensate for downstream drift at early life stages, and the restricted movement paradigm (RMP) that describes populations as heterogeneous mixes of mostly stationary …


Fluids And Melts At The Magmatic-Hydrothermal Transition, Recorded By Unidirectional Solidification Textures At Saginaw Hill, Arizona, Usa, Wyatt M. Bain, Pilar Lecumberri-Sanchez, Erin E. Marsh, Matthew Steele-Macinnis Feb 2022

Fluids And Melts At The Magmatic-Hydrothermal Transition, Recorded By Unidirectional Solidification Textures At Saginaw Hill, Arizona, Usa, Wyatt M. Bain, Pilar Lecumberri-Sanchez, Erin E. Marsh, Matthew Steele-Macinnis

United States Geological Survey: Staff Publications

Fluid exsolution and melt evolution at the magmatic-hydrothermal transition are critical processes driving the metal enrichment of porphyry systems. Coeval fluid and melt inclusion assemblages in unidirectional solidification textures (USTs) at Saginaw Hill—a small, porphyry Cu system in southwestern Arizona—record a dynamic and repetitious process of fluid accumulation and release. The cores of quartz crystals throughout the UST bands host coeval silicate melt and brine inclusions but lack vapor-rich inclusions. This could indicate preferential expulsion of vapor and trapping of high-density brine during episodes of fracturing or the direct exsolution of single-phase high-salinity brine from the silicate melt. In contrast, …


Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev Jan 2022

Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev

United States Geological Survey: Staff Publications

Predictive modeling of submerged archaeological sites requires accurate sea-level predictions in order to reconstruct coastal paleogeography and associated geographic features that may have influenced the locations of occupation sites such as rivers and embayments. Earlier reconstructions of the paleogeography of parts of the western U.S. coast used an assumption of eustatic sea level, but this neglects the large spatial variations in relative sea level (RSL) associated with glacial isostatic adjustment (GIA) and tectonics. Subsequent work using a one-dimensional (1-D) solid Earth model showed that reconstructions that accounted for GIA result in significant differences from those based on eustatic sea level. …


Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev Jan 2022

Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev

United States Geological Survey: Staff Publications

Predictive modeling of submerged archaeological sites requires accurate sea-level predictions in order to reconstruct coastal paleogeography and associated geographic features that may have influenced the locations of occupation sites such as rivers and embayments. Earlier reconstructions of the paleogeography of parts of the western U.S. coast used an assumption of eustatic sea level, but this neglects the large spatial variations in relative sea level (RSL) associated with glacial isostatic adjustment (GIA) and tectonics. Subsequent work using a one-dimensional (1-D) solid Earth model showed that reconstructions that accounted for GIA result in significant differences from those based on eustatic sea level. …


Mis 5e Sea-Level History Along The Pacific Coast Of North America, Daniel R. Muhs Jan 2022

Mis 5e Sea-Level History Along The Pacific Coast Of North America, Daniel R. Muhs

United States Geological Survey: Staff Publications

The primary last interglacial, marine isotope substage (MIS) 5e records on the Pacific coast of North America, from Washington (USA) to Baja California Sur (Mexico), are found in the deposits of erosional marine terraces. Warmer coasts along the southern Golfo de California host both erosional marine terraces and constructional coral reef terraces. Because the northern part of the region is tectonically active, MIS 5e terrace elevations vary considerably, from a few meters above sea level to as much as 70m above sea level. The primary paleo-sea-level indicator is the shoreline angle, the junction of the wave-cut platform with the former …


Chemical Characterization Of Clastic Cave Sediments And Insights Into Particle Transport And Storage In Karst Aquifers, Jill L. Riddell Jan 2022

Chemical Characterization Of Clastic Cave Sediments And Insights Into Particle Transport And Storage In Karst Aquifers, Jill L. Riddell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Abstract

Chemical characterization of clastic cave sediments and insights into particle transport and storage in karst aquifers

Jill L. Riddell

Cave sediments can be divided into two groups: precipitates and clastics. Precipitates are speleothems, or lithologic or mineral features that are chemically precipitated in the cave environment. Clastic cave sediments are frequently described by depositional facies, sorting, and particle size (Bosch and White, 2004). Robust analytical chemical analyses of these sediments to quantify their physical and chemical components is rarely performed although some chemical characterization of mineralogy and paleomagnetism has become prevalent in recent years (Chess et al., 2010; Sasowsky …


Interspecific And Local Variation In Tern Chick Diets Across Nesting Colonies In The Gulf Of Maine, Keenan Yakola, Adrian Jordaan, Stephen Kress, Paula Shannon, Michelle D. Staudinger Nov 2021

Interspecific And Local Variation In Tern Chick Diets Across Nesting Colonies In The Gulf Of Maine, Keenan Yakola, Adrian Jordaan, Stephen Kress, Paula Shannon, Michelle D. Staudinger

United States Geological Survey: Staff Publications

The Gulf of Maine, USA is home to four colonial co-nesting tern species: Least Tern (Sternula antillarum), Common Tern (Sterna hirundo), Arctic Tern (Sterna paradisaea), and the federally endangered Roseate Tern (Sterna dougallii). Over three decades of visual observations of chick provisioning were compiled for a comparative dietary study in the region, including the first detailed descriptions of Least and Roseate Tern chick diets. Three prey groups comprised the majority of chick diets among tern species between 1986–2017: hake (Urophycis spp. or Enchelyopus cimbrius) 28–37% frequency of occurrence (FO), sand lance …


Exposure Of Predatory And Scavenging Birds To Anticoagulant Rodenticides In France: Exploration Of Data From French Surveillance Programs, Meg-Anne Moriceau, Sébastien Lefebvre, Isabelle Fourel, Etienne Benoit, Florence Buronfosse-Roque, Pascal Orabi, Barnett A. Rattner, Virginie Lattard Nov 2021

Exposure Of Predatory And Scavenging Birds To Anticoagulant Rodenticides In France: Exploration Of Data From French Surveillance Programs, Meg-Anne Moriceau, Sébastien Lefebvre, Isabelle Fourel, Etienne Benoit, Florence Buronfosse-Roque, Pascal Orabi, Barnett A. Rattner, Virginie Lattard

United States Geological Survey: Staff Publications

Wild raptors are widely used to assess exposure to different environmental contaminants, including anticoagulant rodenticides (ARs). ARs are used on a global scale for rodent control, and act by disruption of the vitamin K cycle that results in haemorrhage usually accompanied by death within days. Some ARs are highly persistent and bioaccumulative, which can cause significant exposure of non-target species.We characterized AR exposure in a heterogeneous sample of dead raptors collected over 12 years (2008–2019) in south-eastern France. Residue analysis of 156 liver samples through LC-MS/MS revealed that 50% (78/156) were positive for ARs, with 13.5% (21/156) having summed second-generation …


Timescales Of Magma Transport In The Columbia River Flood Basalts, Determined By Paleomagnetic Data, Joseph Biasi, Leif Karlstrom Oct 2021

Timescales Of Magma Transport In The Columbia River Flood Basalts, Determined By Paleomagnetic Data, Joseph Biasi, Leif Karlstrom

Other Staff Materials

Flood basalts represent major events in Earth History, in part because they are linked to large climate perturbations and mass extinctions. However, the durations of individual flood basalt eruptions, which directly impact potential environmental crises, are poorly constrained. Here we use a combination of paleomagnetic data and thermal modeling to create a magnetic geothermometer (MGT) that can constrain the active transport lifetime of magmatic conduits and intrusions. We apply the MGT technique to eight feeder dike segments of the Columbia River basalts (CRB), demonstrating that some dike segments were actively heating host rocks for less than one month, while other …


The Morphology And Evolution Of Transverse Aeolian Ridges On Mars, Timothy Paul Nagle-Mcnaughton Oct 2021

The Morphology And Evolution Of Transverse Aeolian Ridges On Mars, Timothy Paul Nagle-Mcnaughton

Earth and Planetary Sciences ETDs

Transverse aeolian ridges (TARs) are enigmatic and largely relict bedforms on the surface of Mars. TARs are sparsely distributed but common on Mars, but their history, preservation, and past role in the sediment cycle is not well understood. First described in 2003, and detailed extensively in 2008, our study of TARs has been narrowly focused in the last decade, with more and more research noting their presence, but little investigation of the features themselves. Recent work has mostly focused on identifying Terran analogues for TARs, but TARs remain largely a unique Martian feature. In this manuscript, I clarify and refine …


Analysis And Risk Estimation Of High Priority Unstable Rock Slopes In Great Smoky Mountains National Park, Tennessee And North Carolina, Samantha Farmer Aug 2021

Analysis And Risk Estimation Of High Priority Unstable Rock Slopes In Great Smoky Mountains National Park, Tennessee And North Carolina, Samantha Farmer

Electronic Theses and Dissertations

Great Smoky Mountains National Park (GRSM) received 12.5 million visitors in 2020. With a high traffic volume, it is imperative roadways remain open and free from obstruction. Annual unanticipated rockfall events in GRSM often obstruct traffic flow. Using the Unstable Slope Management Program for Federal Land Management Agencies (USMP for FLMA) protocols, this study analyzes high priority unstable rock slopes through 1) creation of an unstable slope geodatabase and 2) generation of a final rockfall risk model using Co-Kriging from a preliminary risk model and susceptibility model. A secondary goal of this study is to provide risk estimation for the …


Field And Remote Sensing Analysis Of The 2015 Pyroclastic Density Currents At Colima (Mexico) And Calbuco (Chile) Volcanoes: Implications For Hazard Assessment And Crisis Management, Elodie Macorps Jun 2021

Field And Remote Sensing Analysis Of The 2015 Pyroclastic Density Currents At Colima (Mexico) And Calbuco (Chile) Volcanoes: Implications For Hazard Assessment And Crisis Management, Elodie Macorps

USF Tampa Graduate Theses and Dissertations

Although one of the most spectacular phenomena of active volcanoes, Pyroclastic density currents, or PDCs, are considered the most dangerous volcanic hazards. PDCs are avalanches of hot volcanic gases, ash, and larger volcanic fragments that travel at incredible speed down the flank of a volcano. High dynamic pressures, high temperatures, and high velocities are the primary dangers associated with PDCs and lead to near-complete destruction and death.

I use a multi-disciplinary approach to study the deposits left behind by PDCs, in order to understand their dynamics, their interactions with the receiving landscape, and their final distribution, starting on the ground …


Geologic Study Of The Palisades Park, Spokane, Washington, Ethan Jeffrey Ducken, Alex Michael Navarra Jun 2021

Geologic Study Of The Palisades Park, Spokane, Washington, Ethan Jeffrey Ducken, Alex Michael Navarra

Geosciences Student Work

The Palisades Park is a large City owned tract of land located on the western bluffs above Spokane. The purpose of this project was to create a geologic map and assess the features within the park for the benefit of a public conservation group, Friends of the Palisades. There are 3 main units identified by previous research in the vicinity. Volcanic rock units are part of the Columbia River Basalt Group (CRBG), which erupted primarily between 16.5 to 15.6 MA (Hammond 2013). Large sedimentary interbeds identified as Latah formation present between CRB flows (Swanson et al 1979a, 1979b). Latah formation …


Characterization Of Landslide Processes From Radar Remote Sensing And Hydromechanical Modeling, Yuankun Xu May 2021

Characterization Of Landslide Processes From Radar Remote Sensing And Hydromechanical Modeling, Yuankun Xu

Earth Sciences Theses and Dissertations

Landsides are a natural geomorphic process yet a dangerous hazard which annually causes thousands of casualties and billions of property loss in a global scale. Understanding landslide motion kinematics from early initiation to final deposition is critical for monitoring, assessing, and forecasting landslide movement in order to mitigate their hazards. Landslides occur under diverse environmental settings and appear in variable types; however, all types of landslides can be mechanically attributed to shearing failure at the basal surface due to stress regime shift contributed by internal and/or external forcing. Typical internal factors include soil/rock weathering, whereas typical external triggering forces encompass …


Late Amazonian Wind Regimes And Landscape Evolution In Northern Meridiani Planum, Mars, Thomas Stritch May 2021

Late Amazonian Wind Regimes And Landscape Evolution In Northern Meridiani Planum, Mars, Thomas Stritch

Geology: Student Scholarship & Creative Works

Aeolian process have dominated the lower latitudes of Mars for billions of years. Aeolian landforms can act as records of current and past climates and landscape evolution processes. The etched deposits of Meridiani Planum, a vast suite of layered bedrock extending from southwest Arabia Terra to Schiaparelli crater, have long been noted to have been eroded by aeolian processes. However, little detailed work on the aeolian landforms of Meridiani Planum beyond the Opportunity rover landing site has been done. In this study, I examine wind streaks, aeolian bedforms (including dunes and large ripples), and yardangs in a valley about 370 …


Joint Spacing In The Caples Lake Granodiorite Of The Sierra Nevada Batholith In Eldorado National Forest, California: A Comparative Analysis Of Joint Sets And Data Resolution, Jimmy Wood May 2021

Joint Spacing In The Caples Lake Granodiorite Of The Sierra Nevada Batholith In Eldorado National Forest, California: A Comparative Analysis Of Joint Sets And Data Resolution, Jimmy Wood

Theses/Capstones/Creative Projects

Joints are the most common deformation structure in the Earth’s upper crust and exert a significant influence on structural stability, landscape morphology, and fluid flow . Therefore, a greater understanding of fracture parameters (e.g., length, aperture, etc.) allows us to more accurately predict their presence, persistence, and prevalence, in the subsurface . We study the fracture spacing of two sub-orthogonal joint sets—66 NE-246 SW and 330 NW-150 SE—in the Caples Lake granodiorite of the Sierra Nevada Batholith, California. Specifically, we investigate 1) their spacing distributions with a keen interest in power-law (fractal) spacing, 2) distribution comparisons between master and cross …


Distribution And Trends Of Endemic Hawaiian Waterbirds, Eben H. Paxton, Kevin Brinck, Adonia Henry, Afsheen Siddiqi, Rachel Rounds, Jennifer Chutz Mar 2021

Distribution And Trends Of Endemic Hawaiian Waterbirds, Eben H. Paxton, Kevin Brinck, Adonia Henry, Afsheen Siddiqi, Rachel Rounds, Jennifer Chutz

United States Geological Survey: Staff Publications

Four endemic species of wetland-dependent waterbirds occur on the main Hawaiian Islands, all of which have experienced sharp population declines and are listed as endangered species. Twice per year, state-wide surveys are conducted to count waterbirds, but these surveys are evaluated only infrequently. We used a state-space approach to evaluate long-term (1986–2016) and short-term (2006–2016) trends and current distribution and abundance of endemic Hawaiian waterbirds. The most numerous species was the Ae‘o, or Hawaiian Stilt (Himantopus mexicanus knudseni), with a 5-year estimated average abundance of 1,932 individuals, followed by ‘Alae Ke‘oke‘o, or Hawaiian Coot (Fulica alai), …


A Reimagining Of The Chacoan World, Larry Benson, Richard W. Loose Feb 2021

A Reimagining Of The Chacoan World, Larry Benson, Richard W. Loose

United States Geological Survey: Staff Publications

A new paradigm of the Chacoan world is presented, wherein Chaco Canyon is considered to be a mostly unoccupied architectural complex that functioned primarily as a pilgrimage destination. Chaco was the political, religious, and social focal point of people living in outlying regions. The resident population of the Canyon consisted of a small number of caretakers, charged with maintaining great house structures, food supplies, and their ceremonial contents. Chacoan chiefdoms were mostly located in large, well-watered, agriculturally-based communities situated at the base of mountains that ring the San Juan Basin, e.g., the Chuskas. Chiefly elites lived year-round in those areas, …


Exploiting Common Senses: Sensory Ecology Meets Wildlife Conservation And Management, Laura K. Elmer, Christine L. Madliger, Daniel T. Blumstein, Chris K. Elvidge, Esteban Ernández-Juricic, Andrij Z. Horodysky, Nicholas S. Johnson, Liam P. Mcguire, Ronald R. Swaisgood, Steven J. Cooke Jan 2021

Exploiting Common Senses: Sensory Ecology Meets Wildlife Conservation And Management, Laura K. Elmer, Christine L. Madliger, Daniel T. Blumstein, Chris K. Elvidge, Esteban Ernández-Juricic, Andrij Z. Horodysky, Nicholas S. Johnson, Liam P. Mcguire, Ronald R. Swaisgood, Steven J. Cooke

United States Geological Survey: Staff Publications

Multidisciplinary approaches to conservation and wildlife management are often effective in addressing complex, multi-factor problems. Emerging fields such as conservation physiology and conservation behaviour can provide innovative solutions and management strategies for target species and systems. Sensory ecology combines the study of ‘how animals acquire’ and process sensory stimuli from their environments, and the ecological and evolutionary significance of ‘how animals respond’ to this information. We review the benefits that sensory ecology can bring to wildlife conservation and management by discussing case studies across major taxa and sensory modalities. Conservation practices informed by a sensory ecology approach include the amelioration …


The “World's Greatest Mineral Locality:” HaiǁOm, Ndonga, Herero, And The Early Colonial Histories Of Tsumeb, Namibia, Selby Hearth Jan 2021

The “World's Greatest Mineral Locality:” HaiǁOm, Ndonga, Herero, And The Early Colonial Histories Of Tsumeb, Namibia, Selby Hearth

Geology Faculty Research and Scholarship

The Tsumeb copper mine in the Otavi Mountains of Namibia is famous both for its spectacular mineral specimens and for its unparalleled diversity of mineral species. The site was mined for nearly 100 years, first by Anglo-German and then by multinational companies; however, prior to that, the site was central to the economies of the Ndonga, Haiǁom, and Herero, who mined, smelted, crafted, and traded the copper. This paper attempts to fill a major gap in the early history of Tsumeb: how did control of Tsumeb’s copper transfer from local communities to Germany? By synthesizing a wide variety of sources, …


Atmosphere/Landscape Co2 Interactions In Mammoth Cave National Park: Hydrochemistry Of Cascade River, Great Onyx Cave, Jessica Williams Jan 2021

Atmosphere/Landscape Co2 Interactions In Mammoth Cave National Park: Hydrochemistry Of Cascade River, Great Onyx Cave, Jessica Williams

Mahurin Honors College Capstone Experience/Thesis Projects

High-resolution analysis of water/CO2/carbonate rock geochemistry was conducted at the Great Onyx Groundwater Basin in Mammoth Cave National Park. The purpose of this work has been to undertake hydrochemical characterization of the karst groundwater in Cascade River, the largest cave stream in the upper level of Great Onyx Cave, which is below a relatively pristine karst landscape.

Hydrochemical monitoring of Cascade River at Biz Falls using field, laboratory, and high-resolution electronic data-sonde measurements has provided a detailed picture of the stream’s behavior with respect to the transport and influence of carbon dioxide in the surface and groundwater system …


Characterizing The Geomagnetic Field At High Southern Latitudes: Evidence From The Antarctic Peninsula, Joseph Biasi, Joseph Kirschvink, Roger Fu Jan 2021

Characterizing The Geomagnetic Field At High Southern Latitudes: Evidence From The Antarctic Peninsula, Joseph Biasi, Joseph Kirschvink, Roger Fu

Other Staff Materials

Due to a dearth of data from high-latitude paleomagnetic sites, it is not currently clear if the geocentric axial dipole (GAD) hypothesis accurately describes the long-term behavior of the geomagnetic field at high latitudes. Here we present new paleomagnetic and paleointensity data from the James Ross Island (JRI) volcanic group, located on the Antarctic Peninsula. This data set addresses a notable lack of data from the 60°–70°S latitude bin and includes 251 samples from 31 sites, spanning 0.99–6.8 Ma in age. We also include positive fold, conglomerate, and baked contact tests. Paleointensity data from three methods (Thellier- Thellier, pseudo-Thellier, and …


Managing For Radical Ecosystem Change: Applying The Resist-Accept- Direct (Rad) Framework, Abigail J. Lynch, Laura M. Thompson, Erik A. Beever, David N. Cole, Augustin C. Engman, Cat Hawkins Hoffman, Stephen T. Jackson, Trevor J. Krabbenhoft, David J. Lawrence, Douglas Limpinsel, Robert T. Magill, Tracy A. Melvin, John M. Morton, Robert A. Newman, Jay O. Peterson, Mark T. Porath, Frank J. Rahel, Gregor W. Schuurman, Suresh A. Sethi, Jennifer L. Wilkening Jan 2021

Managing For Radical Ecosystem Change: Applying The Resist-Accept- Direct (Rad) Framework, Abigail J. Lynch, Laura M. Thompson, Erik A. Beever, David N. Cole, Augustin C. Engman, Cat Hawkins Hoffman, Stephen T. Jackson, Trevor J. Krabbenhoft, David J. Lawrence, Douglas Limpinsel, Robert T. Magill, Tracy A. Melvin, John M. Morton, Robert A. Newman, Jay O. Peterson, Mark T. Porath, Frank J. Rahel, Gregor W. Schuurman, Suresh A. Sethi, Jennifer L. Wilkening

United States Geological Survey: Staff Publications

Ecosystem transformation involves the emergence of persistent ecological or social–ecological systems that diverge, dramatically and irreversibly, from prior ecosystem structure and function. Such transformations are occurring at increasing rates across the planet in response to changes in climate, land use, and other factors. Consequently, a dynamic view of ecosystem processes that accommodates rapid, irreversible change will be critical for effectively conserving fish, wildlife, and other natural resources, and maintaining ecosystem services. However, managing ecosystems toward states with novel structure and function is an inherently unpredictable and difficult task. Managers navigating ecosystem transformation can benefit from considering broader objectives, beyond a …


Long-Term African Dust Delivery To The Eastern Atlantic Ocean From The Sahara And Sahel Regions: Evidence From Quaternary Paleosols On The Canary Islands, Spain, Daniel R. Muhs, Joaquín Meco, James R. Budahn, Gary L. Skipp, Kathleen R. Simmons, Matthew C. Baddock, Juan F. Betancourt, Alejandro Lomoschitz Jan 2021

Long-Term African Dust Delivery To The Eastern Atlantic Ocean From The Sahara And Sahel Regions: Evidence From Quaternary Paleosols On The Canary Islands, Spain, Daniel R. Muhs, Joaquín Meco, James R. Budahn, Gary L. Skipp, Kathleen R. Simmons, Matthew C. Baddock, Juan F. Betancourt, Alejandro Lomoschitz

United States Geological Survey: Staff Publications

Africa is the most important source of dust in the world today and dust storms from that continent frequently deposit sediment on the nearby Canary Islands. Many investigators have inferred African dust inputs to Canary Islands paleosols based only on the presence of quartz. However, some local rocks do contain this mineral, so quartz alone is insufficient proof of dust deposition. Further, it is not known whether the Sahara Desert or the Sahel region is more important as a dust source. We address these issues by study of sequences of Pleistocene aeolian sands on the islands of Lanzarote and Fuerteventura. …


Eolian Sediments, Daniel R. Muhs Jan 2021

Eolian Sediments, Daniel R. Muhs

United States Geological Survey: Staff Publications

Eolian (windblown) sediments form some of the world’s most dramatic landscapes and comprise important parts of the geologic record. This article reviews the characteristics, origins, and significance of eolian deposits, including windblown sand, silt, and dust.

Landforms composed of eolian sand, either as dunes or sand sheets, occupy substantial areas over the surface of the Earth (perhaps as much as 6% globally, but over ~20% of the world’s arid zones, according to Pye and Tsoar, 2009). Low-latitude arid or semiarid regions, usually under the influence of subtropical high-pressure cells, are some of the largest areas of eolian sand accumulation (Lancaster, …