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2013

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Articles 181 - 210 of 355

Full-Text Articles in Geology

Maps (Monitoring Avian Productivity And Survivorship), Brice Leech Feb 2013

Maps (Monitoring Avian Productivity And Survivorship), Brice Leech

Mammoth Cave Research Symposia

The Monitoring Avian Productivity and Survivorship (MAPS) Program comprises a continent-wide network of hundreds of constant-effort mist netting stations. Analyses of the resulting banding data provide critical information relating to the ecology, conservation, and management of North American landbird populations, and the factors responsible for changes in their populations. MAPS is coordinated by the Institute for Bird Populations which also conducts winter monitoring programs MoSI (Monitoreo de Sobrevivencia Invernal) in the Neotropics & MAWS (Monitoring Avian Winter Survival) program in temperate North America.


Seasonal Occurrence And Habitat Affi Liations Of Trichoptera At Mammoth Cave National Park, Luke E. Dodd, Michael A. Floyd, David A. Etnier Feb 2013

Seasonal Occurrence And Habitat Affi Liations Of Trichoptera At Mammoth Cave National Park, Luke E. Dodd, Michael A. Floyd, David A. Etnier

Mammoth Cave Research Symposia

The order Trichoptera is an ecologically-important, diverse group of insects. We investigated the relative abundance and occurrence of these insects at Mammoth Cave National Park (MCNP). We focused our efforts on adults captured at blacklight traps placed across four forest habitats in MCNP on 14 nights during 2010-2011. Large-bodied Trichoptera (≥ 10 mm in length) were identified and enumerated, yielding 2,153 specimens of ≥ 45 species and 11 families. Unique captures were recorded at mixed deciduous-dominated, mixed coniferdominated, and upland deciduous sites (13, 4, and 3 species, respectively). While composition of the assemblage varied across collection sites, as well as …


The Cave Beetle Neaphaenops Tellkampfi Erichson: Relationships Within And Among Related Genera Using Molecular Data, T. Keith Philips, Elise Valkanas, Kurt Helf Feb 2013

The Cave Beetle Neaphaenops Tellkampfi Erichson: Relationships Within And Among Related Genera Using Molecular Data, T. Keith Philips, Elise Valkanas, Kurt Helf

Mammoth Cave Research Symposia

Studies of North American cave beetle systematics have been based primarily on morphology. This project analyzes the relationships and validity of the four subspecies of the monotypic Neaphaenops based on monophyly, as well as relationships with the remaining four eastern N.A. cave beetle genera (Pseudanophthalmus, Nelsonites, Darlingtonea, and Ameroduvalius) using molecular methods. This study utilized 39 beetle samples collected from 27 Kentucky caves and one outgroup accessed from GenBank. Evidence for phylogenetic hypotheses is based on sequences of one nuclear protein-coding gene (arginine kinase) and one mitochondrial gene (CO1). Analyses support Neaphaenops as sister to all other taxa. One subspecies …


Long-Term Monitoring Of Aquatic Biota Using Occupancy Modeling, Kurt Helf Feb 2013

Long-Term Monitoring Of Aquatic Biota Using Occupancy Modeling, Kurt Helf

Mammoth Cave Research Symposia

Monitoring populations of organisms over time is difficult even under the best circumstances; this is especially true of cave organisms. Cave organisms may not be detected during a monitoring survey even though they may be present. Indeed, detectability, i.e., the probability of detecting target taxa during a survey given they’re present at the site, undoubtedly varies among cave habitats (e.g., terrestrial versus aquatic) and cave organisms (e.g., cave beetles versus cave fish). However, to make reliable inferences regarding the relationship between the probability a sampling site is occupied by a cave organism (i.e., occupancy) and abiotic/ biotic factors that affect …


Inventory Of Terrestrial Wild Mammals At Mammoth Cave National Park: 2005-2010, Steven Thomas Feb 2013

Inventory Of Terrestrial Wild Mammals At Mammoth Cave National Park: 2005-2010, Steven Thomas

Mammoth Cave Research Symposia

An inventory aimed at documenting the occurrence of at least 90% of the terrestrial wild mammal species potentially present on Mammoth Cave National Park took place from 2005 to 2010. Documentation of mammal occurrence was accomplished via visual encounters and trapping. Visual encounters included methods like sighting individuals, conducting spotlight surveys by boat, locating mammal sign, hearing mammal calls, and finding dead individuals. A variety of trapping methods were used, including remote “trail” cameras, live traps, pitfall traps, drift fence-pitfall arrays, and several other opportunistic capture methods. 663 mammal records were documented by visual encounter or some trapping method representing …


Monitoring Cave Bats At Mammoth Cave National Park, Steven Thomas Feb 2013

Monitoring Cave Bats At Mammoth Cave National Park, Steven Thomas

Mammoth Cave Research Symposia

Cave-roosting bats are important to the nutrient-poor cave ecosystem because they import organic material which supports a specialized cave invertebrate community. Nine of thirteen bat species found at Mammoth Cave National Park are generally associated with caves at some time of the year. Two of the species that inhabit park caves are on the Federal Endangered Species List: gray bat (Myotis grisescens) and Indiana bat (M. sodalis). Regular population monitoring of hibernating endangered bats has occurred in a few park caves since the early 1980s. Since the early 2000s, cave bat monitoring on the park has expanded to include additional …


White-Nose Syndrome At Mammoth Cave National Park: Actions Before And After Its Detection, Rick Toomey, Steven Thomas, Joel Gillespie, Vickie Carson, Shannon R. Trimboli Feb 2013

White-Nose Syndrome At Mammoth Cave National Park: Actions Before And After Its Detection, Rick Toomey, Steven Thomas, Joel Gillespie, Vickie Carson, Shannon R. Trimboli

Mammoth Cave Research Symposia

Since it was identified in the United States in 2006, white-nose syndrome (WNS) in bats has become an important issue in the management of caves and bats at Mammoth Cave National Park (MACA). The threat of its arrival has led to more intense monitoring of bat populations, increased studies, and interventions with both the visiting public and researchers. The timeline of MACA’s WNS response is shown in Table 1.


Mercury Analysis In Rafi Nesque Big Eared Bat Populations, Lara Van Der Heiden, Cathleen J. Webb Feb 2013

Mercury Analysis In Rafi Nesque Big Eared Bat Populations, Lara Van Der Heiden, Cathleen J. Webb

Mammoth Cave Research Symposia

Mercury (Hg) from atmospheric deposition from coal-burning power plants and other anthropogenic sources was analyzed in Rafinesque’s big-eared bats from Mammoth Cave National Park. The mercury from water progressively moves up the food chain through insects, and eventually into bats. In 2011, 58 bats were collected and hair samples were taken for an analysis. The AMA254 Mercury Analyzer was used to determine the mercury concentration from the bat hair in parts per million. A considerable amount of mercury was discovered in the bats analyzed. The mercury concentration of juvenile Rafinesque’s bigeared bats averaged between 0.5-1.0 ppm. Mercury levels in adult …


Influences Of A Cladophora Bloom On The Diets Of Amblema Plicata And Elliptio Dilatata In The Upper Green River, Kentucky, Jennifer Yates, Scott Grubbs, Albert Meier, Michael Collyer Feb 2013

Influences Of A Cladophora Bloom On The Diets Of Amblema Plicata And Elliptio Dilatata In The Upper Green River, Kentucky, Jennifer Yates, Scott Grubbs, Albert Meier, Michael Collyer

Mammoth Cave Research Symposia

Freshwater mussels are the most imperiled group of freshwater invertebrates globally. Recent research suggests a better understanding of mussel feeding ecology may facilitate and improve conservation efforts. The use of stable isotopes is becoming an increasingly common method to study aquatic food webs. Carbon (C) and nitrogen (N) are two of the most frequently employed elements in food web studies. Differences in natural abundance of 13C/12C can indicate which food sources are the basal sources of carbon incorporated into a consumer’s tissue, while the ratio of 15N /14N provides a method of assessing trophic position within a food web. Attached …


Contribution Of Freshwater Bivalves To Muskrat Diets In The Green River, Mammoth Cave National Park, Kentucky, Kimberly Asmus Hersey, Joseph D. Clark, James B. Layzer Feb 2013

Contribution Of Freshwater Bivalves To Muskrat Diets In The Green River, Mammoth Cave National Park, Kentucky, Kimberly Asmus Hersey, Joseph D. Clark, James B. Layzer

Mammoth Cave Research Symposia

Muskrats (Ondatra zibethicus) are known to prey on freshwater bivalves (mussels and clams) and can negatively impact imperiled mussel species. However, factors that infl uence muskrat predation on bivalves are poorly understood. We evaluated the feeding ecology of muskrats at Mammoth Cave National Park, Kentucky by using stable isotope analysis of muskrat hair samples and by monitoring bivalve shell deposition at muskrat middens. Bayesian mixing-model analysis of stable isotope δ15N and δ13C ratios revealed that the median muskrat biomass derived from bivalves was 51.4% (5th and 95th percentiles were 39.1 to 63.4%, respectively), a much higher dietary proportion than previously …


Fire Regimes, Buff Alo And The Presettlement Landscape Of Mammoth Cave National Park, Cecil C. Frost, Jesse A. Burton, Lillian Scoggins Feb 2013

Fire Regimes, Buff Alo And The Presettlement Landscape Of Mammoth Cave National Park, Cecil C. Frost, Jesse A. Burton, Lillian Scoggins

Mammoth Cave Research Symposia

The glory of the caves has long overshadowed other features of the park but the neglected upland landscape has its own extraordinary tale to tell. The park occupies a naturally fire sheltered setting in a historically vast fire landscape of barrens and woodlands once populated by Native Americans, bison and elk. The events above ground, spanning several thousand years before the arrival of Europeans and the subsequent explosive transformation of the land add rich layers of natural and human history, sadly neglected in development and interpretation of the park. This is the tale of the Barrens region itself.

We constructed …


Using Lidar To Link Forest Canopy Structure With Bat Activity And Insect Occurrence: Preliminary Findings, Luke E. Dodd, Nicholas S. Skowronski, Matthew B. Dickinson, Michael J. Lacki, Lynne K. Rieske Feb 2013

Using Lidar To Link Forest Canopy Structure With Bat Activity And Insect Occurrence: Preliminary Findings, Luke E. Dodd, Nicholas S. Skowronski, Matthew B. Dickinson, Michael J. Lacki, Lynne K. Rieske

Mammoth Cave Research Symposia

Bats are an imperiled, yet ecologically-important group of vertebrate predators. Our ongoing research focuses on testing hypotheses about the relationships between the effects of fire on canopy structure and insect prey availability, and how these factors relate to use of foraging space by bats during the pre- and post-hibernation periods at Mammoth Cave National Park (MCNP). LiDAR-derived data (October 2010) were intersected with spatially explicit sampling of bat and insect populations (2010-2011) in order to characterize relationships between canopy structure, insect abundance, and bat activity. A canonical correspondence analysis for bat data suggested that forest canopy structure has a strong …


Assessing The Impact Of Mercury Bioaccumulation In Mammoth Cave National Park, Cahtleen Webb Feb 2013

Assessing The Impact Of Mercury Bioaccumulation In Mammoth Cave National Park, Cahtleen Webb

Mammoth Cave Research Symposia

This project will examine the fate and transport of mercury in Mammoth Cave National Park, which has an extensive karst ecosystem. Contaminant transport in karst systems (limestone based surface geology) is rapid and extensive. Mercury’s mobility in surface and ground water is of great concern due to its toxicity and ability to bio-magnify within food chains. However, mercury interacts with limestone, thus impairing its mobility. A number of federally listed species are declining in the parks. Further, Kentucky has issued a statewide mercury fish consumption advisory. With eight new coal-fired power plant applications under consideration in Kentucky, the potential exists …


Establishment Of Long-Term Forest Vegetation Monitoring Plots Within Mammoth Cave National Park, Bill Moore, Teresa Leibfreid, Rickie White Feb 2013

Establishment Of Long-Term Forest Vegetation Monitoring Plots Within Mammoth Cave National Park, Bill Moore, Teresa Leibfreid, Rickie White

Mammoth Cave Research Symposia

Beginning in 2011, the Cumberland Piedmont Network (CUPN) of the National Park Service (NPS) in cooperation with NatureServe, began monitoring forested vegetation communities within all 14 network parks, including Mammoth Cave National Park (MACA). The primary objectives of this effort are to: detect meaningful changes in species composition and vegetation structure within each park’s forested habitat and determine whether these changes are correlated with trends in “key stressors.” Thus far, 16 permanent long-term monitoring plots have been established within MACA. An additional 16 plots will be established in 2013- 2014. Within the permanent plots, data are collected on forest structure; …


A Functional Visual System In The Cave Beetle Ptomaphagus Hirtus, Markus Friedrich, Rui Chen, Elke K. Buschbeck, Stewart Peck Feb 2013

A Functional Visual System In The Cave Beetle Ptomaphagus Hirtus, Markus Friedrich, Rui Chen, Elke K. Buschbeck, Stewart Peck

Mammoth Cave Research Symposia

Cave species exhibit a suite of dramatic differences in comparison to their surface living relatives, commonly referred to as troglomorphy (Christiansen 2005). One hallmark feature of troglomorphy is the severe reduction or complete loss of eyes and functional vision. The two most abundant cave beetle species in Mammoth cave, the 2-3 mm small carrion beetle Ptomaphagus hirtus (Packard 1888; Peck 1973; Peck 1975; Tellkampf 1844) and the 6-8 mm long predatory ground beetle Neaphaenops tellkampfii are good examples of this (Barr 1979). P. hirtus tends to hide in crevices and usually goes unnoted to the regular visitor of Mammoth cave. …


Disjunct Eastern Hemlock Populations Of The Central Hardwood Forests: Ancient Relicts Or Recent Long Distance Dispersal Events?, F. Collin Hobbs, Keith Clay Feb 2013

Disjunct Eastern Hemlock Populations Of The Central Hardwood Forests: Ancient Relicts Or Recent Long Distance Dispersal Events?, F. Collin Hobbs, Keith Clay

Mammoth Cave Research Symposia

Eastern hemlock (Tsuga canadensis) is an evergreen conifer with a contiguous distribution extending from the southern Appalachian Mountains north to Nova Scotia and west across the Great Lakes region. Eastern hemlock is threatened with extirpation from much of this range by an introduced pest, the hemlock woolly adelgid (Orwig et al. 2002). In addition to the contiguous distribution, many small, isolated populations are located within the central hardwood forest region of Kentucky, Indiana, and Ohio (Braun 1928, Potzger and Friesner 1937, Van Stockum 1979). These disjunct populations form clearly delineated, often monospecific stands associated with unique natural features such as …


Breeding Bird Survey Summary From Mammoth Cave National Park, 1995 - 2012, Steve Kistler Feb 2013

Breeding Bird Survey Summary From Mammoth Cave National Park, 1995 - 2012, Steve Kistler

Mammoth Cave Research Symposia

Breeding bird surveys are used by ornithologists to study the variations in bird populations across the United States and Canada. Initiated in 1966, the surveys were originally created by Chandler Robbins and colleagues to study the effects of pesticide use on bird populations.

Today, these data are used to monitor changes in avian populations due to habitat loss, habitat fragmentation, land-use changes, and chemical contamination. The administration of these surveys is jointly run by the US Geological Survey and the Canadian Wildlife Service. Almost fifty years of continuous surveying also provides excellent baseline data which can be used to determine …


Landscape Genetics Of The Marbled Salamander, Ambystoma Opacum, In A Nationally Protected Park, Kevin Tewell, Jarrett Johnson Feb 2013

Landscape Genetics Of The Marbled Salamander, Ambystoma Opacum, In A Nationally Protected Park, Kevin Tewell, Jarrett Johnson

Mammoth Cave Research Symposia

Landscape features may influence the patterns of migration and dispersal of amphibian species and create genetic structure. A primary goal of landscape genetics is to analyze these influences in order to make more informed management decisions. We sampled larvae from 50 breeding ponds within the boundaries of Mammoth Cave National Park and genotyped 12 individuals per pond at 10 microsatellite loci to estimate gene fl ow between ponds. We used GIS layers of habitat types to conduct a least-cost path analysis and determine the relative cost of movement through each habitat type. We were interested in answering two questions: does …


Evaluating Interactions Between River Otters And Muskrats At Bridge Crossings In Kentucky, Ryan Williamson, Joseph Clark Feb 2013

Evaluating Interactions Between River Otters And Muskrats At Bridge Crossings In Kentucky, Ryan Williamson, Joseph Clark

Mammoth Cave Research Symposia

Muskrats (Ondatra zibethicus) prey on freshwater mussels in the Green River within Mammoth Cave National Park (MACA), many species of which are threatened or endangered. Reportedly, muskrat populations have been reduced in some streams where North American river otters (Lontra canadensis) were reintroduced and it has been suggested that river otter reintroduction at MACA might help conserve endangered mussels. To test that idea, we used occupancy estimation methods to evaluate the ecological relationship between muskrats and otters by collecting presence/absence data based on field sign found at bridge crossings in eastern and central Kentucky. Mean detection (p) and occupancy probabilities …


Mammoth Cave In Poetry: Davis Mccombs’ Ultima Thule, Judith Hatchett Feb 2013

Mammoth Cave In Poetry: Davis Mccombs’ Ultima Thule, Judith Hatchett

Mammoth Cave Research Symposia

Davis McCombs, former Mammoth Cave park ranger, received the Yale Younger Poets Award for Ultima Thule, his collection of poems based on his experiences in and with Mammoth Cave, not only of his actual experiences as ranger and cave explorer, but also of the history of the cave, including poems in the voice of Stephen Bishop, cave explorer, cave guide, and also a slave. The detail of McCombs’ examination produces what poet W.S. Merwin called “a grave, attentive holding of a light.” In a sense, his poetry illuminates the cave the way ancient torches and modern lighting have done. This …


First Underground Photograph Taken In America, Wm. Gross Magee Feb 2013

First Underground Photograph Taken In America, Wm. Gross Magee

Mammoth Cave Research Symposia

The presentation covers the work of Charles Waldack in Mammoth Cave. Waldack took the first underground photographs in America. He was the pioneer of using magnesium as a light source for cave photography. It explores the who, why, when, where and how of his images in the cave. It covers the recreation of his stereo views in the cave showing the same views taken nearly 150 years apart.


Archaeological Investigations For Proposed Trail Rehabilitation Within Mammoth Cave, Steven R. Ahler, George M. Crothers Feb 2013

Archaeological Investigations For Proposed Trail Rehabilitation Within Mammoth Cave, Steven R. Ahler, George M. Crothers

Mammoth Cave Research Symposia

In 2008, staff from the University of Kentucky Program for Archaeological Research (UK-PAR) and the Illinois State Museum Society (ISMS) conducted archaeological and paleontological investigations at Mammoth Cave National Park in advance of proposed rehabilitation of 40,499 linear feet of selected trail segments within Mammoth Cave. This presentation focuses on the results of archaeological investigations conducted within Mammoth Cave and is confined to discussion of the prehistoric materials. These materials were confined to the upper and lower passages of the Historic Tour, the Lantern Tour, and Gothic Avenue trails


The History And Conservation Of Saltpeter Works In Mammoth Cave, Kentucky, George M. Crothers, Christina A. Pappas, Christian D. Mittendorf Feb 2013

The History And Conservation Of Saltpeter Works In Mammoth Cave, Kentucky, George M. Crothers, Christina A. Pappas, Christian D. Mittendorf

Mammoth Cave Research Symposia

Remains of the saltpeter mining operation in Mammoth Cave are a significant feature of several cave tours and figure prominently in the history of cave use. We undertook a comprehensive review of existing historical descriptions and recent archaeological investigations to construct the most reasonable account of how the saltpeter operation worked and assess its current conditions. At least three types of saltpeter vats were constructed in the cave reflecting an increase in the size of the operation and efficiency of processing sediments over time. Remains of three pump towers are also found in the cave in various states of preservation. …


The Mammoth Cave Mushroom Company: A Brief History Of A Short-Lived Venture, Katie Algeo Feb 2013

The Mammoth Cave Mushroom Company: A Brief History Of A Short-Lived Venture, Katie Algeo

Mammoth Cave Research Symposia

The Mammoth Cave Mushroom Company was formed in August 1881 during a particularly contentious period of family struggle for control of the cave, its resources, and tourism operations. This paper documents the history of the company from original company records and family letters. It places the Mammoth Cave operation within the larger historical context of mushroom production in caves as possibly the first such operation in the United States. It traces developments at the cave during the fall of 1881 as Anthony Muzarelli oversaw preparation of mushroom beds and supporting infrastructure and identifies sources of tension between the new mushroom …


Mammoth Cave National Park's 10th Research Symposium: Celebrating Diversity Of Research In The Mammoth Cave Region, Shannon Trimboli ,Editor Feb 2013

Mammoth Cave National Park's 10th Research Symposium: Celebrating Diversity Of Research In The Mammoth Cave Region, Shannon Trimboli ,Editor

Mammoth Cave Research Symposia

No abstract provided.


Understanding Greenland Ice Sheet Hydrology Using An Integrated Multi-Scale Approach, A. K. Rennermalm, S. E. Moustafa, J. Mioduszewski, V. W. Chu, R. R. Forster, B. Hagedorn, Joel T. Harper, T. L. Mote, D. A. Robinson, C. A. Shuman, L. C. Smith, M. Tedesco Feb 2013

Understanding Greenland Ice Sheet Hydrology Using An Integrated Multi-Scale Approach, A. K. Rennermalm, S. E. Moustafa, J. Mioduszewski, V. W. Chu, R. R. Forster, B. Hagedorn, Joel T. Harper, T. L. Mote, D. A. Robinson, C. A. Shuman, L. C. Smith, M. Tedesco

Geosciences Faculty Publications

Improved understanding of Greenland ice sheet hydrology is critically important for assessing its impact on current and future ice sheet dynamics and global sea level rise. This has motivated the collection and integration of in situ observations, model development, and remote sensing efforts to quantify meltwater production, as well as its phase changes, transport, and export. Particularly urgent is a better understanding of albedo feedbacks leading to enhanced surface melt, potential positive feedbacks between ice sheet hydrology and dynamics, and meltwater retention in firn. These processes are not isolated, but must be understood as part of a continuum of processes …


Water, Climate, And Social Change In A Fragile Landscape, William L. Hargrove, David M. Borrok, Josiah Mc C.C. Heyman, Craig E. Tweedie, Carlos Cabrera Ferregut Feb 2013

Water, Climate, And Social Change In A Fragile Landscape, William L. Hargrove, David M. Borrok, Josiah Mc C.C. Heyman, Craig E. Tweedie, Carlos Cabrera Ferregut

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

We present here and in the companion papers an analysis of sustainability in the Middle Rio Grande region of the U.S.-Mexico border and propose an interdisciplinary research agenda focused on the coupled human and natural dimensions of water resources sustainability in the face of climate and social change in an international border region. Key threats to water sustainability in the Middle Rio Grande River region include: (1) increasing salinization of surface and ground water, (2) increasing water demand from a growing population in the El Paso/Ciudad Juarez area on top of an already high base demand from irrigated agriculture, (3) …


Orbitally Paced Shifts In The Particle Size Of Antarctic Continental Shelf Sediments In Response To Ice Dynamics During The Miocene Climatic Optimum, Sandra Passchier, Candice J. Falk, Fabio Florindo Feb 2013

Orbitally Paced Shifts In The Particle Size Of Antarctic Continental Shelf Sediments In Response To Ice Dynamics During The Miocene Climatic Optimum, Sandra Passchier, Candice J. Falk, Fabio Florindo

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The AND-2A drill hole (ANDRILL [Antarctic Geological Drilling Program] Southern McMurdo Sound Project), ∼10 km from the East Antarctica coastline, records nearly 6 m.y. of sedimentation across the Miocene climatic optimum at a high-latitude site. Sedimentological studies of bedforms and particle size distributions indicate that the paleoenvironment was strongly affected by waves and currents, consistent with deposition in a glacially influenced neritic environment. We document abrupt shifts in mud percent within glacial-interglacial cycles ca. 17.8 Ma and between ca. 16.7 and 15.7 Ma that we attribute to the hydrodynamic effects of wave stirring tied to episodes of ice growth and …


Preservational And Morphological Variability Of Assemblages Of Agglutinated Eukaryotes In Cryogenian Cap Carbonates Of Northern Namibia, Lilly A. Dalton, Tanja Bosak, Francis A. Macdonald, Daniel J.G. Lahr, Sara B. Pruss Feb 2013

Preservational And Morphological Variability Of Assemblages Of Agglutinated Eukaryotes In Cryogenian Cap Carbonates Of Northern Namibia, Lilly A. Dalton, Tanja Bosak, Francis A. Macdonald, Daniel J.G. Lahr, Sara B. Pruss

Geosciences: Faculty Publications

Laminated carbonates of the Rasthof Formation, deposited in the aftermath of the early Cryogenian low-latitude glaciation (Sturtian, 717-662 Ma), preserve abundant round tests of agglutinated microscopic eukaryotes. Previously, fossil tests were reported in two localities (Ongongo and Okaaru) from microbially laminated carbonates in the Rasthof Formation, which revealed a previous unexplored Cryogenian taphonomic window. In order to better understand the lateral variability in these microfossil assemblages, this work systematically examines fossil tests from two additional localities, South Ombepera and Ombepera, and compares their preservation in thinly and thickly laminated microbial laminites. Cap carbonates in South Ombepera and Ombepera contain abundant, …


Neotectonic Evolution Of Grand Canyon : Interaction Between Volcanism, River Incision, Epeirogenic Uplift, And Faulting, Ryan Crow Jan 2013

Neotectonic Evolution Of Grand Canyon : Interaction Between Volcanism, River Incision, Epeirogenic Uplift, And Faulting, Ryan Crow

Earth and Planetary Sciences ETDs

This thesis focuses on the effects of volcanism, river incision, epeirogenic uplift, and faulting on the landscape evolution of the Grand Canyon region. In the first chapter the migration of increasingly asthenospheric basaltic volcanism is used to constrain lithospheric modification of the Colorado Plateau margins. Buoyancy modification of the upper mantle, driven by the upwelling, is a likely driver for recent uplift of the area. In the second chapter, correlation between oversteepened rivers and areas of high-velocity upper mantle is used to show that recent and ongoing mantle-driven uplift is modulating the surface along the western margin of the Colorado …