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A Geomorphic Enthalpy Method: Description And Application To The Evolution Of Fluvial-Deltas Under Sea-Level Cycles, William Anderson, Jorge Lorenzo Trueba, Vaughan Voller 2019 Montclair State University

A Geomorphic Enthalpy Method: Description And Application To The Evolution Of Fluvial-Deltas Under Sea-Level Cycles, William Anderson, Jorge Lorenzo Trueba, Vaughan Voller

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Fluvial deltas are composites of two primary sedimentary environments: a depositional fluvial region and an offshore region. The fluvial region is defined by two geomorphic moving boundaries: an alluvial-bedrock transition (ABT), which separates the sediment prism from the non-erodible bedrock basement, and the shoreline (SH), where the delta meets the ocean. The trajectories of these boundaries in time and space define the evolution of the shape of the sedimentary prism, and are often used as stratigraphic indicators, particularly in seismic studies, of changes in relative sea level and the identification of stratigraphic sequences. In order to better understand the relative ...


Lead And Arsenic Contamination In Urban Soils In New York City, Anna Paltseva 2019 The Graduate Center, City University of New York

Lead And Arsenic Contamination In Urban Soils In New York City, Anna Paltseva

All Dissertations, Theses, and Capstone Projects

This dissertation examined total and bioaccessible soil lead (Pb) and arsenic (As) concentrations and their accumulation in commonly grown garden vegetables in New York City (NYC) metropolitan area. Direct oral ingestion of contaminated soil and consumption of plants that have accumulated Pb or As from underlying soil are known human exposure pathways in urban garden soils that often contain elevated levels of contaminants. The research had four components: (1) assessment of the variability of bioaccessible Pb in NYC urban soils; (2) field experiments to evaluate Pb stabilization and As mobilization by phosphate and alternative amendments; (3) development of a new ...


Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabián G. Fernández, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan 2019 University of Missouri

Statistical And Machine Learning Methods Evaluated For Incorporating Soil And Weather Into Corn Nitrogen Recommendations, Curtis J. Ransom, Newell R. Kitchen, James J. Camberato, Paul R. Carter, Richard B. Ferguson, Fabián G. Fernández, David W. Franzen, Carrie A. M. Laboski, D. Brenton Myers, Emerson D. Nafziger, John E. Sawyer, John F. Shanahan

Agronomy Publications

Nitrogen (N) fertilizer recommendation tools could be improved for estimating corn (Zea mays L.) N needs by incorporating site-specific soil and weather information. However, an evaluation of analytical methods is needed to determine the success of incorporating this information. The objectives of this research were to evaluate statistical and machine learning (ML) algorithms for utilizing soil and weather information for improving corn N recommendation tools. Eight algorithms [stepwise, ridge regression, least absolute shrinkage and selection operator (Lasso), elastic net regression, principal component regression (PCR), partial least squares regression (PLSR), decision tree, and random forest] were evaluated using a dataset containing ...


Environmental Assessment Of Arsenic And Mercury Levels At The Garfield Mill Site, Calico, California, Steven Gregory Thorp 2019 California State University - San Bernardino

Environmental Assessment Of Arsenic And Mercury Levels At The Garfield Mill Site, Calico, California, Steven Gregory Thorp

Electronic Theses, Projects, and Dissertations

Environmental impacts of mining at Calico, California, are poorly understood in comparison to the details of its history of silver production. Human health risks associated with arsenic from the lode rock, as well as mercury from the silver milling process, include central nervous system damage, organ failure, and death. To quantify the potential human health risk and manage remediation of this site, tailings from the Garfield Mill site were digitally mapped and chemically analyzed by portable x-ray fluorescence, which permitted volumetric estimates of total mill tailings and the arsenic and mercury budget, as well as identification of anomalies in the ...


A Geomorphic Enthalpy Method: Description And Application To The Evolution Of Fluvial-Deltas Under Sea-Level Cycles, William Anderson, Jorge Lorenzo Trueba, Vaughan Voller 2019 Montclair State University

A Geomorphic Enthalpy Method: Description And Application To The Evolution Of Fluvial-Deltas Under Sea-Level Cycles, William Anderson, Jorge Lorenzo Trueba, Vaughan Voller

Jorge Lorenzo-Trueba

Fluvial deltas are composites of two primary sedimentary environments: a depositional fluvial region and an offshore region. The fluvial region is defined by two geomorphic moving boundaries: an alluvial-bedrock transition (ABT), which separates the sediment prism from the non-erodible bedrock basement, and the shoreline (SH), where the delta meets the ocean. The trajectories of these boundaries in time and space define the evolution of the shape of the sedimentary prism, and are often used as stratigraphic indicators, particularly in seismic studies, of changes in relative sea level and the identification of stratigraphic sequences. In order to better understand the relative ...


Fractures, Fluids, And Metamorphism: Shear Zone Initiation In The Marcy Anorthosite Massif, Adirondacks, New York, Usa, James Hodge 2019 University of Maine

Fractures, Fluids, And Metamorphism: Shear Zone Initiation In The Marcy Anorthosite Massif, Adirondacks, New York, Usa, James Hodge

Electronic Theses and Dissertations

Localized shear zones are important rheological features that influence deformation behavior throughout the Earth’s middle-to-lower crust. Therefore, the processes through which shear zones initiate and localize remains an important geologic question. The study of strain localization and shear zone initiation is made difficult due to continued deformation overprinting the microstructures which lead to initiation and obfuscating the context in which localization occurred. The Marcy anorthosite in the Adirondack Highlands, New York, is a nominally granulite-facies, plagioclase-rich massif cut by centimeter-to-meter scale shear zones which provides a natural example of shear zone localization within the middle-to-lower crust. My work focuses ...


Searching For Cold-Adapted Microorganisms In The Underground Glacier Of Scarisoara Ice Cave, Romania, Alexandra Maria Hillebrand-Voiculescu, Corina Itcus, Ioan Ardelean, Denisa Pascu, Aurel Persoiu, Andreea Rusu, Traian Brad, Elena Popa, Bogdan P. Onac, Christina Purcarea 2019 Emil Racovita Institute of Speleology

Searching For Cold-Adapted Microorganisms In The Underground Glacier Of Scarisoara Ice Cave, Romania, Alexandra Maria Hillebrand-Voiculescu, Corina Itcus, Ioan Ardelean, Denisa Pascu, Aurel Persoiu, Andreea Rusu, Traian Brad, Elena Popa, Bogdan P. Onac, Christina Purcarea

Bogdan Onac

Scarisoara Ice Cave (Romania) hosts one of world’s largest and oldest underground glacier. While no studies were carried out on the existence of microorganisms in this cave’s ice block, our interest is to investigate the presence of microorganisms and their chronological distribution in the cave’s subterranean ice in relationship with past climatic changes. Samples were collected from ice layers of different age (from present to ~900 cal. yrs. BP), and the diversity of embedded microbial communities was assessed by classical cultivation and molecular techniques. The microorganisms from icesediments were cultivated at 4 °C and 15 °C, in ...


Revisiting Three Minerals From Cioclovina Cave (Romania), Bogdan P. Onac, Herta S. Effenberger, Nathan C. Collins, Joe B. Kearns, Radu C. Breban 2019 University of South Florida

Revisiting Three Minerals From Cioclovina Cave (Romania), Bogdan P. Onac, Herta S. Effenberger, Nathan C. Collins, Joe B. Kearns, Radu C. Breban

Bogdan Onac

Cioclovina Cave in Romania’s Southern Carpathians is a world-renowned cave site for its paleontological, anthropological, and mineralogical (type locality of ardealite) findings. To date, over 25 mineral species have been documented, some unusual for a cave environment. This paper presents details on the occurrence of collinsite [Ca2(Mg,Fe2+)(PO4)2·2H2O], atacamite [Cu22+Cl(OH)3], and kröhnkite [Na2Cu2+(SO4)2·2H2O] based on single-crystal X-ray diffraction, electron microprobe, stable isotope analyses, and scanning electron microscope imaging. This is the first reported occurrence of kröhnkite ...


Linking Mineral Deposits To Speleogenetic Processes In Cova Des Pas De Vallgornera (Mallorca, Spain), Bogdan P. Onac, Joan J. Fornós, Antoni Merino, Joaquín Ginés, Jacqueline Diehl 2019 School of Geosciences, University of South Florida, Tampa, FL, USA

Linking Mineral Deposits To Speleogenetic Processes In Cova Des Pas De Vallgornera (Mallorca, Spain), Bogdan P. Onac, Joan J. Fornós, Antoni Merino, Joaquín Ginés, Jacqueline Diehl

Bogdan Onac

Cova des Pas de Vallgornera (CPV) is the premier cave of the Balearic Archipelago. Over 74 km of passages develop within two carbonate lithofacies (reef front and back reef), which ultimately control the patterns of the cave and to some degree its mineral infilling. The diversity of speleothem-forming minerals is four times greater around or within hypogene-related features (vents, rims, cupolas), compared to any other vadose passages in the cave. The mineralogy of speleothems (crusts, nodules, crystals, earthy masses) associated with hypogene features in the seaward upper maze of Sector F is characterized by the presence of aragonite, ankerite, huntite ...


Kinetic Processes And Stable Isotopes In Cave Dripwaters As Indicators Of Winter Severity, Vasile Ersek, Bogdan P. Onac, Aurel Perșoiu 2019 Northumbria University

Kinetic Processes And Stable Isotopes In Cave Dripwaters As Indicators Of Winter Severity, Vasile Ersek, Bogdan P. Onac, Aurel Perșoiu

Bogdan Onac

We examine how the stable isotope composition of meteoric water is transmitted through soil and epikarst to dripwaters in a cave in western Romania. δ2H and δ18O in precipitation at this site are influenced by temperature and moisture sources (Atlantic and Mediterranean), with lower δ18O in winter and higher in summer. The stable isotope composition of cave dripwaters mimics this seasonal pattern of low and high δ18O, but the onset and end of freezing conditions in the winter season are marked by sharp transitions in the isotopic signature of cave dripwaters of ...


Water Column Variability In A Coastal Tourist Cave In Mallorca, Spain, Liana M. Boop, Bogdan P. Onac, Jonathan G. Wynn, Joan J. Fornós, Marta Rodríguez-Homar 2019 University of South Florida

Water Column Variability In A Coastal Tourist Cave In Mallorca, Spain, Liana M. Boop, Bogdan P. Onac, Jonathan G. Wynn, Joan J. Fornós, Marta Rodríguez-Homar

Bogdan Onac

Coves del Drac is visited by more than 1 million tourists annually and has been a tourist destination in the western Mediterranean for over 100 years. All areas of the cave are developed with historic or current tour route infrastructure, including walkways, handrails, and electric lighting. This study compares one vertical water profile collected along the current tour path with two other profiles from historic tour route locations. Differences in freshwater and organic inputs, as well as direct anthropogenic impacts, are clearly observed in the aquatic parameters and stable isotopes collected in the profiles. Anthropogenically-driven undersaturation in the cave pools ...


Impact Of Climate Change On The Transition Of Neanderthals To Modern Humans In Europe, Michael Staubwasser, Virgil Drăgușin, Bogdan P. Onac, Sergey Assonov, Vasile Ersek, Dirk L. Hoffman, Daniel Veres 2019 University of Cologne

Impact Of Climate Change On The Transition Of Neanderthals To Modern Humans In Europe, Michael Staubwasser, Virgil Drăgușin, Bogdan P. Onac, Sergey Assonov, Vasile Ersek, Dirk L. Hoffman, Daniel Veres

Bogdan Onac

Two speleothem stable isotope records from East-Central Europe demonstrate that Greenland Stadial 12 (GS12) and GS10—at 44.3–43.3 and 40.8–40.2 ka—were prominent intervals of cold and arid conditions. GS12, GS11, and GS10 are coeval with a regional pattern of culturally (near-)sterile layers within Europe’s diachronous archeologic transition from Neanderthals to modern human Aurignacian. Sterile layers coeval with GS12 precede the Aurignacian throughout the middle and upper Danube region. In some records from the northern Iberian Peninsula, such layers are coeval with GS11 and separate the Châtelperronian from the Aurignacian. Sterile layers ...


Holocene Winter Climate Variability In Central And Eastern Europe, Aurel Perşoiu, Bogdan P. Onac, Jonathan G. Wynn, Maarten Blaauw, Monica Ionita, Margareta Hansson 2019 Romanian Academy

Holocene Winter Climate Variability In Central And Eastern Europe, Aurel Perşoiu, Bogdan P. Onac, Jonathan G. Wynn, Maarten Blaauw, Monica Ionita, Margareta Hansson

Bogdan Onac

Among abundant reconstructions of Holocene climate in Europe, only a handful has addressed winter conditions, and most of these are restricted in length and/or resolution. Here we present a record of late autumn through early winter air temperature and moisture source changes in East-Central Europe for the Holocene, based on stable isotopic analysis of an ice core recovered from a cave in the Romanian Carpathian Mountains. During the past 10,000 years, reconstructed temperature changes followed insolation, with a minimum in the early Holocene, followed by gradual and continuous increase towards the mid-to-late-Holocene peak (between 4-2 kcal BP), and ...


Hercules And Diana Hypogene Caves (Herculane Spa, Romania): Dissimilar Chemical Evolutions Documented By Their Present-Day Thermal Water Discharges, Horia Mitrofan, Constantin Marin, Ioan Povară, Bogdan P. Onac 2019 "Sabba Ştefănescu" Institute of Geodynamics of the Romanian Academy

Hercules And Diana Hypogene Caves (Herculane Spa, Romania): Dissimilar Chemical Evolutions Documented By Their Present-Day Thermal Water Discharges, Horia Mitrofan, Constantin Marin, Ioan Povară, Bogdan P. Onac

Bogdan Onac

Hercules Cave and Diana Cave are two small caves situated some 600 m apart, for which a hypogene origin has been previously suggested. Thermal water discharges (up to about 54°C) are hosted by each cave, and were recently made the object of an eight-month chemical monitoring operation. By plotting the concentrations of several chemical species (Na, K, Ca, Sr, Mg, SiO2, Br) against the concentration of the conservative anion Cl, it was found that both caves discharged a binary water mixture, which was derived from the same saline (and hot) parent-fluid and the same fresh (and cold) parent-fluid. This ...


Groundwater Geochemistry Observations In Littoral Caves Of Mallorca (Western Mediterranean): Implications For Deposition Of Phreatic Overgrowths On Speleothems, Liana M. Boop, Bogdan P. Onac, Jonathan G. Wynn, Joan J. Fornós, Marta Rodríguez-Homar, Antoni Merino 2019 University of South Florida School of Geosciences

Groundwater Geochemistry Observations In Littoral Caves Of Mallorca (Western Mediterranean): Implications For Deposition Of Phreatic Overgrowths On Speleothems, Liana M. Boop, Bogdan P. Onac, Jonathan G. Wynn, Joan J. Fornós, Marta Rodríguez-Homar, Antoni Merino

Bogdan Onac

Phreatic overgrowths on speleothems (POS) precipitate at the air-water interface in the littoral caves of Mallorca, Spain. Mainly composed of calcite, aragonite POS are also observed in specific locations. To characterize the geochemical environment of the brackish upper water column, water samples and salinity values were collected from water profiles (0-2.9 m) in April 2012 and March 2013 near aragonite POS in Cova des Pas de Vallgornera and calcite POS in Coves del Drac (hereafter, Vallgornera and Drac). Degassing of CO2 from the water was evidenced by the existence of lower dissolved inorganic carbon (DIC) concentration and enriched ...


Evidence Of Long-Term Nao Influence On East-Central Europe Winter Precipitation From A Guano-Derived Δ15N Record, Daniel M. Cleary, Jonathan G. Wynn, Monica Ionita, Ferenc L. Forray, Bogdan P. Onac 2019 University of South Florida

Evidence Of Long-Term Nao Influence On East-Central Europe Winter Precipitation From A Guano-Derived Δ15N Record, Daniel M. Cleary, Jonathan G. Wynn, Monica Ionita, Ferenc L. Forray, Bogdan P. Onac

Bogdan Onac

Currently there is a scarcity of paleo-records related to the North Atlantic Oscillation (NAO), particularly in East-Central Europe (ECE). Here we report δ15N analysis of guano from a cave in NW Romania with the intent of reconstructing past variation in ECE hydroclimate and examine NAO impacts on winter precipitation. We argue that the δ15N values of guano indicate that the nitrogen cycle is hydrologically controlled and the δ15N values likely reflect winter precipitation related to nitrogen mineralization prior to the growing season. Drier conditions indicated by δ15N values at AD 1848–1852 ...


Evolution Of Guano Under Different Environmental Conditions: A Mineralogical Approach, Alexandra M. Giurgiu, Bogdan P. Onac, Tudor Tămaș, Joan J. Fornos 2019 Babes-Bolyai University

Evolution Of Guano Under Different Environmental Conditions: A Mineralogical Approach, Alexandra M. Giurgiu, Bogdan P. Onac, Tudor Tămaș, Joan J. Fornos

Bogdan Onac

The phosphate minerals from three Romanian caves that host bat guano deposits have been investigated. The XRD and SEM analyses have revealed the presence of seven phosphates (brushite, francoanellite, hydroxylapatite, leucophosphite, taranakite, vashegyite and variscite) along with the more common gypsum, calcite and various allochthonous clay minerals. The occurrence of these phosphate minerals highlights the decomposition and various reactions that take place between the phosphate-rich solutions leaching out from the guano and different cave sediments and/or bedrock. The variation of the environmental conditions in the vicinity and within the guano accumulations is responsible for the type of mineral that ...


Cave Minerals Of San Salvador Island, Bahamas, Bogdan P. Onac, Jonathan Sumrall, John E. Mylroie, Joe B. Kearns 2019 University of South Florida

Cave Minerals Of San Salvador Island, Bahamas, Bogdan P. Onac, Jonathan Sumrall, John E. Mylroie, Joe B. Kearns

Bogdan Onac

This volume describes the results of a 2009 fieldwork season focusing on the cave minerals found in karst environments throughout San Salvador Island in the Bahamian archipelago. The caves visited represent a sampling of pit and flank margin caves. Each cave description includes a map.


Machine Learning Predicts Aperiodic Laboratory Earthquakes, Olha Tanyuk, Daniel Davieau, Charles South, Daniel W. Engels 2019 Southern Methodist University

Machine Learning Predicts Aperiodic Laboratory Earthquakes, Olha Tanyuk, Daniel Davieau, Charles South, Daniel W. Engels

SMU Data Science Review

In this paper we find a pattern of aperiodic seismic signals that precede earthquakes at any time in a laboratory earthquake’s cycle using a small window of time. We use a data set that comes from a classic laboratory experiment having several stick-slip displacements (earthquakes), a type of experiment which has been studied as a simulation of seismologic faults for decades. This data exhibits similar behavior to natural earthquakes, so the same approach may work in predicting the timing of them. Here we show that by applying random forest machine learning technique to the acoustic signal emitted by a ...


Fracture Networks On Mars: Preservation Of Surface And Subsurface Environments At Mawrth Vallis, Phoebe Kinzelman 2019 Purdue University

Fracture Networks On Mars: Preservation Of Surface And Subsurface Environments At Mawrth Vallis, Phoebe Kinzelman

The Journal of Purdue Undergraduate Research

Mawrth Vallis is an outflow channel on Mars that cuts through some of the planet’s most ancient terrains, which contain many different types of fractures. The ExoMars rover mission will search for biosignatures on Mars, and this site was proposed as one of the two final candidate landing sites for the rover. A biosignature is any object that shows evidence of past or present life. Fracture networks are a high priority for the mission because they might contain minerals precipitated by fluid interaction, and these minerals could trap and preserve biosignatures, critical for our understanding of ancient processes. In ...


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