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Articles 961 - 990 of 1193
Full-Text Articles in Earth Sciences
Quantifying The Short-Term Impacts Of Cover Crops And Grazing On Soil Health Under An Integrated Crop-Livestock System In South Dakota, Vishal Seth
Electronic Theses and Dissertations
Cover crops and grazing under Integrated Crop-Livestock System (ICLS) can impact the rhizosphere nutrient cycling and may have potential to increase the long-term sustainability and economic profitability of agricultural production system. In South Dakota, crop production practices and livestock husbandry are both common which provide the opportunity for ICLS to be successful in this region. However, little is known about the impacts of the cover crops and grazing under ICLS on soil properties in this region. The present study was conducted at South Dakota State University Research Farm (44°20'34.8"N, 96°48'14.8"W), Brookings, SD, to quantify the impacts of cover crops and …
Land Use Change Sustainability And Carbon Turnover Rate In The Northern Great Plains Soil, Deepak Raj Joshi
Land Use Change Sustainability And Carbon Turnover Rate In The Northern Great Plains Soil, Deepak Raj Joshi
Electronic Theses and Dissertations
Sustainable land management involves the management of land, water, biodiversity and other resources that meet human requirements while maintaining ecosystem services. In the northern Great Plains (NGP), the combined impacts of landuse and climate variability have placed many soils at the tipping point of sustainability. The objectives of this study were to: 1) calculate land-use changes from 2006 to 2012 and from 2012 to 2014 in South Dakota and Nebraska; 2) assess if land use changes had impacted on soil sustainability; 3) calculate variation in total carbon budget and turnover due to seasonal climate variability, biomass quality and soil properties; …
Re-Evaluation Of The Extent And Tectonic History Of The Helena Banks Fault Zone, Offshore South Carolina, Ahmet Postaagasi
Re-Evaluation Of The Extent And Tectonic History Of The Helena Banks Fault Zone, Offshore South Carolina, Ahmet Postaagasi
Theses and Dissertations
The Helena Banks Fault Zone (HBFZ), first identified in the early 1980’s offshore Charleston, S.C., was originally interpreted to be a major, high-angle, basin-bounding normal fault associated with Mesozoic rifting. Subsequent work suggests that (1) Mesozoic rift basins are not present on the continental shelf of South Carolina, (2) the HBFZ originated as a strike-slip fault within Paleozoic sedimentary rocks of the Suwannee Basin sequence, (3) a mafic intrusion inferred from aeromagnetic data is coincident with a broadly circular zone of highly-complex faulting along the north-eastward continuation of the HBFZ where (4) up to 300 m of local relief can …
The Impact Of Upland Development And Marsh Width On Groundwater Composition In Estuarine Tidal Creeks In The Southeastern Coastal United States, Meghan Shanahan
The Impact Of Upland Development And Marsh Width On Groundwater Composition In Estuarine Tidal Creeks In The Southeastern Coastal United States, Meghan Shanahan
Theses and Dissertations
Coastal upland development has been shown to negatively impact surface water quality in tidal creeks along the southeastern coastal United States, but the impact of development on groundwater quality is not well understood. Increases in impervious cover associated with development has the potential to increase groundwater contamination as well as reduce fresh rainwater infiltration into the subsurface, which may decrease discharge of fresh groundwater to the estuary. We hypothesized that groundwater nutrient concentrations and salinity ranges would be higher in developed watersheds than in undeveloped watersheds.
Groundwater discharging from coastal uplands often travels through salt marshes before discharging to tidal …
Reviews And Syntheses: 210pb-Derived Sediment And Carbon Accumulation Rates In Vegetated Coastal Ecosystems – Setting The Record Straight, Ariane Arias-Ortiz, Pere Masque´, Jordi Garcia-Orellana, Oscar Serrano, Ines Mazarrasa, Nuria Marba, Catherine E. Lovelock, Paul S. Lavery, Carlos M. Duarte
Reviews And Syntheses: 210pb-Derived Sediment And Carbon Accumulation Rates In Vegetated Coastal Ecosystems – Setting The Record Straight, Ariane Arias-Ortiz, Pere Masque´, Jordi Garcia-Orellana, Oscar Serrano, Ines Mazarrasa, Nuria Marba, Catherine E. Lovelock, Paul S. Lavery, Carlos M. Duarte
Research outputs 2014 to 2021
Vegetated coastal ecosystems, including tidal marshes, mangroves and seagrass meadows, are being increasingly assessed in terms of their potential for carbon dioxide sequestration worldwide. However, there is a paucity of studies that have effectively estimated the accumulation rates of sediment organic carbon (Corg), also termed blue carbon, beyond the mere quantification of Corg stocks. Here, we discuss the use of the 210Pb dating technique to determine the rate of Corg accumulation in these habitats. We review the most widely used 210Pb dating models to assess their limitations in these ecosystems, often composed of …
Environmental Monitoring And Peat Assessment Using Multivariate Analysis Of Regional-Scale Geochemical Data, Jennifer M. Mckinley, Eric Grunsky, Ute Mueller
Environmental Monitoring And Peat Assessment Using Multivariate Analysis Of Regional-Scale Geochemical Data, Jennifer M. Mckinley, Eric Grunsky, Ute Mueller
Research outputs 2014 to 2021
A compositional multivariate approach was used to analyse regional-scale soil geochemical data obtained as part of the Tellus Project generated by the Geological Survey of Northern Ireland. The multi-element total concentration data presented comprise X-ray fluorescence (XRF) analyses of 6862 rural soil samples collected at 20-cm depth on a non-aligned grid at one site per 2km2" role="presentation">2km2. Censored data were imputed using published detection limits. Each soil sample site was assigned to the regional geology map, resulting in spatial data for one categorical variable and 35 continuous variables comprised of individual and amalgamated elements. This paper examines the extent …
Preferential Production And Transport Of Grass-Derived Pyrogenic Carbon In Ne-Australian Savanna Ecosystems, Gustavo Saiz, Iain Goodrick, Christopher Wurster, Paul N. Nelson, Jonathan G. Wynn, Michael Bird
Preferential Production And Transport Of Grass-Derived Pyrogenic Carbon In Ne-Australian Savanna Ecosystems, Gustavo Saiz, Iain Goodrick, Christopher Wurster, Paul N. Nelson, Jonathan G. Wynn, Michael Bird
School of Geosciences Faculty and Staff Publications
Understanding the main factors driving fire regimes in grasslands and savannas is critical to better manage their biodiversity and functions. Moreover, improving our knowledge on pyrogenic carbon (PyC) dynamics, including formation, transport and deposition, is fundamental to better understand a significant slow-cycling component of the global carbon cycle, particularly as these ecosystems account for a substantial proportion of the area globally burnt. However, a thorough assessment of past fire regimes in grass-dominated ecosystems is problematic due to challenges in interpreting the charcoal record of sediments. It is therefore critical to adopt appropriate sampling and analytical methods to allow the acquisition …
Land Use, Microclimate, And Surface Runoff Linkages: Space-Time Modeling From Rockel-Seli River Basin, Sierra Leone, C. Wilson, B. Liang, S. Wilson, Fenda A. Akiwumi
Land Use, Microclimate, And Surface Runoff Linkages: Space-Time Modeling From Rockel-Seli River Basin, Sierra Leone, C. Wilson, B. Liang, S. Wilson, Fenda A. Akiwumi
School of Geosciences Faculty and Staff Publications
This study mainly utilized the Soil and Water Assessment Tool (SWAT) together with SWAT-CUP, both free and open source software (FOSS), to construct a distributed hydrologic flow model for the Rokel-Seli River basin, Sierra Leone, in a bid to spatiotemporally evaluate the role of changes in land use/land cover (LULC) and microclimate on streamflow regimes. The model was informed by LULC data derived from three Landsat satellite images collected in 2002, 2010, and 2016. The LULC data was generated with the aid of several python libraries accessed through the FOSS Anaconda Navigator. LULC change analysis demonstrated that between 2002 and …
Volcanic Unrest And Hazard Communication In Long Valley Volcanic Region, California, David P. Hill, Margaret T. Mangan, Stephen R. Mcnutt
Volcanic Unrest And Hazard Communication In Long Valley Volcanic Region, California, David P. Hill, Margaret T. Mangan, Stephen R. Mcnutt
School of Geosciences Faculty and Staff Publications
The onset of volcanic unrest in Long Valley Caldera, California, in 1980 and the subsequent fluctuations in unrest levels through May 2016 illustrate: (1) the evolving relations between scientists monitoring the unrest and studying the underlying tectonic/magmatic processes and their implications for geologic hazards, and (2) the challenges in communicating the significance of the hazards to the public and civil authorities in a mountain resort setting. Circumstances special to this case include (1) the sensitivity of an isolated resort area to media hype of potential high-impact volcanic and earthquake hazards and its impact on potential recreational visitors and the local …
Assessing Effects Of Horizontal And Vertical Urban Vegetation Structures On Land Surface Temperature Using Multisensor Remote Sensing Data, Qiuyan Yu, Shawn M. Landry
Assessing Effects Of Horizontal And Vertical Urban Vegetation Structures On Land Surface Temperature Using Multisensor Remote Sensing Data, Qiuyan Yu, Shawn M. Landry
School of Geosciences Faculty and Staff Publications
No abstract provided.
A New Approach To Probabilistic Lava Flow Hazard Assessments, Applied To The Idaho National Laboratory, Eastern Snake River Plain, Idaho, Usa, Elisabeth Gallant, Jacob Richardson, Charles Connor, Paul Wetmore, Laura Connor
A New Approach To Probabilistic Lava Flow Hazard Assessments, Applied To The Idaho National Laboratory, Eastern Snake River Plain, Idaho, Usa, Elisabeth Gallant, Jacob Richardson, Charles Connor, Paul Wetmore, Laura Connor
School of Geosciences Faculty and Staff Publications
We present a new probabilistic lava flow hazard assessment for the U.S. Department of Energy’s Idaho National Laboratory (INL) nuclear facility that (1) explores the way eruptions are defined and modeled, (2) stochastically samples lava flow parameters from observed values for use in MOLASSES, a lava flow simulator, (3) calculates the likelihood of a new vent opening within the boundaries of INL, (4) determines probabilities of lava flow inundation for INL through Monte Carlo simulation, and (5) couples inundation probabilities with recurrence rates to determine the annual likelihood of lava flow inundation for INL. Results show a 30% probability of …
Grenvillian Tectonomagmatic Evolution Of Southwestern Laurentia; Virtual Tour Of Multidimensional Orders Of Scale; Two Methods To Describe The Vastness Of Time; Math Concepts Utilizing Google Earth; Systematic Approach To Motion Analyses; Mathematics And Earth Science-Based Knowledge And Learning, Anthony M. Alvarez
Open Access Theses & Dissertations
This Dissertation is the product of several individual multi-disciplinary investigations that cover a variety of topics in mathematics, physics, geology, and geoscience education. The first chapter formulates a better understanding of the timings, magma source, and relationships between dikes and associated magmatic bodies of the Red Bluff Granitic Complex to provide a clearer picture of the evolution of post-Grenville magmatism and tectonism of southwestern USA. The second chapter provides an improved method for representing spatial information in the form of a multidimensional virtual tour where the background map is used as a central object. The third chapter describes two methods …
Climate-Change-Driven Accelerated Sea-Level Rise Detected In The Altimeter Era, R. S. Nerem, B. D. Beckley, J. T. Fasullo, B. D. Hamlington, D. Masters, G. T. Mitchum
Climate-Change-Driven Accelerated Sea-Level Rise Detected In The Altimeter Era, R. S. Nerem, B. D. Beckley, J. T. Fasullo, B. D. Hamlington, D. Masters, G. T. Mitchum
CCPO Publications
Using a 25-y time series of precision satellite altimeter data from TOPEX/Poseidon, Jason-1, Jason-2, and Jason-3, we estimate the climate-change-driven acceleration of global mean sea level over the last 25 y to be 0.084 ± 0.025 mm/y2. Coupled with the average climate-change-driven rate of sea level rise over these same 25 y of 2.9 mm/y, simple extrapolation of the quadratic implies global mean sea level could rise 65 ± 12 cm by 2100 compared with 2005, roughly in agreement with the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5) model projections.
Improving In-Stream Nutrient Routines In Water Quality Models Using Stable Isotope Tracers: A Review And Synthesis, Alexandria K. Jensen, William I. Ford, James F. Fox, Admin Husic
Improving In-Stream Nutrient Routines In Water Quality Models Using Stable Isotope Tracers: A Review And Synthesis, Alexandria K. Jensen, William I. Ford, James F. Fox, Admin Husic
Biosystems and Agricultural Engineering Faculty Publications
Water quality models serve as an economically feasible alternative to quantify fluxes of nutrient pollution and to simulate effective mitigation strategies; however, their applicability is often questioned due to broad uncertainties in model structure and parameterization, leading to uncertain outputs. We argue that reduction of uncertainty is partially achieved by integrating stable isotope data streams within the water quality model architecture. This article outlines the use of stable isotopes as a response variable within water quality models to improve the model boundary conditions associated with nutrient source provenance, constrain model parameterization, and elucidate shortcomings in the model structure. To assist …
Exploring The Relationship Between The Nemaha Uplift And The Mid-Continent Rift Using 3d Mapping Visual Analysis, Faris Abanumay
Exploring The Relationship Between The Nemaha Uplift And The Mid-Continent Rift Using 3d Mapping Visual Analysis, Faris Abanumay
Master's Theses or Doctor of Nursing Practice
The present study presents and explains the relationship between Nemaha uplift and Mid-continent rift (MCR), where the understanding of the faulting systems around the study region were extremely important with regard to finding the relationship. The Nemaha is located in Kansas State in the Central United States with a total area of about 719 square miles. It was formed around the pre- Mississippian era. The compression and rifting processes that led to formation of faults, volcanoes, ridges and oceanic plates controls the faulting in the Nemaha region. The MCR system is a major tectonic feature in North America that is …
Interpretation Of A Seismic Reflection Survey And Geophysical Well Logs In Jay County, Indiana: Orientation And Composition Of A Carbonate Layer Below The Mount Simon Sandstone, Md Saiful Alam
Browse all Theses and Dissertations
In August 2017, a dynamite-sourced 2D seismic reflection survey was conducted along a gravel road northwest of Portland, Indiana. The main focus of the survey was to determine the orientation of a lithologic unit previously identified by Welder (2014) on a similar 2D seismic reflection survey in the same area. Drillers logs of two wells within this area identified a limestone layer below the Mt. Simon Sandstone, and a similar limestone layer was identified in a well drilled in Clark County, Ohio. As the focus of this study, this limestone layer will be informally named the `Votaw limestone'. The seismic …
Surface Oxygenation Of Biochar Through Ozonization For Dramatically Enhancing Cation Exchange Capacity, Matthew D. Huff, Sarah Marshall, Haitham A. Saeed, James Weifu Lee
Surface Oxygenation Of Biochar Through Ozonization For Dramatically Enhancing Cation Exchange Capacity, Matthew D. Huff, Sarah Marshall, Haitham A. Saeed, James Weifu Lee
Chemistry & Biochemistry Faculty Publications
Background
Biochar cation exchange capacity (CEC) is a key property that is central to biochar environmental applications including the retention of soil nutrients in soil amendment and removal of certain pollutants in water-filtration applications.
Results
This study reports an innovative biochar-ozonization process that dramatically increases the CEC value of biochars by a factor of 2. The ozonized biochars also show great improvement on adsorption of methylene blue by as much as a factor of about 5. In this study, biochar samples treated with and without ozone were analyzed by means of pH and CEC assays, water field capacity measurement, elemental …
Motivations, Specializations, Identities, And Constraints Associated With Hunting In Nebraska, Alisha Grams
Motivations, Specializations, Identities, And Constraints Associated With Hunting In Nebraska, Alisha Grams
School of Natural Resources: Dissertations, Theses, and Student Research
No abstract provided.
Quantifying The Offset Of Greenhouse Gas Emissions At The University Of North Alabama, Paul Dunn Graham
Quantifying The Offset Of Greenhouse Gas Emissions At The University Of North Alabama, Paul Dunn Graham
Theses
No abstract provided.
Hillslope Coupled Stream Morphology, Flow Conditions, And Their Effects On Detrital Sedimentology In Garnet Canyon, Teton Range, Wyoming, Lisa M. Tranel
Hillslope Coupled Stream Morphology, Flow Conditions, And Their Effects On Detrital Sedimentology In Garnet Canyon, Teton Range, Wyoming, Lisa M. Tranel
Faculty Publications - Geography, Geology, and the Environment
Characterizing stream erosion in any steep mountain landscape is arduous, but the challenge level increases when the stream flows through a glaciated catchment frequently modified by hillslope debris. Glacial landforms and stochastic mass wasting in alpine systems may interfere with sediment delivery to downstream sites where detrital sediments are often collected to represent upstream bedrock sources. To use detrital sediments as indicators of erosion, we need to understand potential sediment accumulation in flat glaciated reaches or behind rockfall barriers. This study investigates the stream channel in Garnet Canyon, a glaciated catchment located in the central Teton Range, to describe hillslope …
Performance Of The Grout Curtain At The Kentucky River Lock And Dam No. 8, Robert C. Hatton
Performance Of The Grout Curtain At The Kentucky River Lock And Dam No. 8, Robert C. Hatton
Theses and Dissertations--Civil Engineering
Karst bedrock conditions and deterioration of the lock and dam structures have resulted in significant leakage through, underneath, and around Lock and Dam No. 8 on the Kentucky River. During severe droughts, the water surface in Pool No. 8 has been observed to drop below the crest of the dam, resulting in water supply shortages and water quality issues for surrounding communities reliant on the pool. Presently, the primary purpose of Lock and Dam No. 8 is water supply. Pool No. 8 is currently where the cities of Nicholasville (Jessamine County, KY) and Lancaster (Garrard County, KY) draw their water. …
Stratigraphy And Organic Geochemistry Reveal Patterns Of Late Quaternary Paleo-Productivity At Mono Lake, California, Bailee Nicole Hodelka
Stratigraphy And Organic Geochemistry Reveal Patterns Of Late Quaternary Paleo-Productivity At Mono Lake, California, Bailee Nicole Hodelka
Theses and Dissertations--Earth and Environmental Sciences
Mono Lake (CA) is a hydrologically closed lacustrine basin well-known for its paleo-shorelines, which record fluctuations in water level for the last deglacial and late Holocene. Mono Lake is a sentinel of California’s water supply, situated in the rain shadow of the Sierra Nevada, a mountain range whose snowpack is a vital source of freshwater for urban and agricultural districts to the west and south. Recent droughts, floods, and wildfires show that California is threatened by climate change, but how these changes impact and get recorded by Mono Lake sediments remains poorly known. Here, we use a new radiocarbon-dated deepwater …
Occurrence And Attributes Of Two Echinoderm-Bearing Faunas From The Upper Mississippian (Chesterian; Lower Serpukhovian) Ramey Creek Member, Slade Formation, Eastern Kentucky, U.S.A., Ann Well Harris
Theses and Dissertations--Earth and Environmental Sciences
Well-preserved echinoderm faunas are rare in the fossil record, and when uncovered, understanding their occurrence can be useful in interpreting other faunas. In this study, two such faunas of the same age from separate localities in the shallow-marine Ramey Creek Member of the Slade Formation in the Upper Mississippian (Chesterian) rocks of eastern Kentucky are examined. Of the more than 5,000 fossil specimens from both localities, only 9–34 percent were echinoderms from 3–5 classes. Nine non-echinoderm (8 invertebrate and one vertebrate) classes occurred at both localities, but of these, bryozoans, brachiopods and sponges dominated. To understand the attributes of both …
Hydrologic Monitoring And 2-D Electrical Resistivity Imaging For Joint Geophysical And Geotechnical Characterization Of Shallow Colluvial Landslides, Matthew M. Crawford
Hydrologic Monitoring And 2-D Electrical Resistivity Imaging For Joint Geophysical And Geotechnical Characterization Of Shallow Colluvial Landslides, Matthew M. Crawford
Theses and Dissertations--Earth and Environmental Sciences
Landslide characterization and hazard assessments require multidisciplinary approaches that connect geologic processes with geotechnical parameters. Field monitoring of hydrologic variables such as water content and water potential, coupled with geoelectrical measurements that can establish relationships used for geotechnical and landslide hazard investigations is deficient.
This study brings together different techniques to develop a methodology that connects geoelectrical measurements and shear strength. A field-based framework was established that includes (1) analysis of long-term soil moisture fluctuations within different landslides (2) establishment of constitutive and new equations that test the use of electrical conductivity to predict soil-water relationships and shear strength (3) …
A Multi-Indicator Approach To Understanding The Diagenesis Of Carbonates In Pennsylvanian Mudrocks Of The Midland Basin, Alex J. Reis
A Multi-Indicator Approach To Understanding The Diagenesis Of Carbonates In Pennsylvanian Mudrocks Of The Midland Basin, Alex J. Reis
Theses and Dissertations--Earth and Environmental Sciences
The Late Pennsylvanian was a time of frequent, rapid glacioeustatic sea-level changes. These changes were recorded in the Wolfcamp D Formation of the Midland Basin as a series of cyclothems similar to those studied in the Midcontinent region (e.g., Algeo and Heckel, 2008). This study focuses on identifying the mechanisms and controls on carbonate deposition and diagenesis through the Upper Pennsylvanian Wolfcamp D Formation and evaluating the potential for these layers to be stratigraphically significant. A stepwise progression of diagenetic processes was identified through the use of δ13Ccarb and δ18Ocarb, bulk geochemical and …
Spectral Properties Of Chloride Salt-Bearing Assemblages: Implications For Detection Limits Of Minor Phases In Chloride-Bearing Deposits On Mars, Cheng Ye, Timothy Glotch
Spectral Properties Of Chloride Salt-Bearing Assemblages: Implications For Detection Limits Of Minor Phases In Chloride-Bearing Deposits On Mars, Cheng Ye, Timothy Glotch
Geosciences Research Data
Chloride salt-bearing deposits have been identified throughout the southern highlands of Mars and have been suggested to be two component mixtures of anhydrous chloride salt and regional basaltic regolith. On Earth, chlorides typically occur as evaporite salts associated with other evaporite minerals such as carbonate and sulfate, and chemical weathering products like clays. In this laboratory study, we document the visible/near-infrared (VNIR) reflectance and mid-infrared (MIR) emissivity spectral characteristics of a series of chloride salt-bearing mineral assemblages. Our data show that the spectral features of various powder mixtures change systematically with variable additional mineral concentrations and particle sizes. Specifically, small …
Differentiation In Impact Melt Sheets As A Mechanism To Produce Evolved Magmas On Mars, Ari Koeppel
Differentiation In Impact Melt Sheets As A Mechanism To Produce Evolved Magmas On Mars, Ari Koeppel
Dissertations and Theses
Asteroid bombardment contributed to extensive melting and resurfacing of ancient (> 3 Ga) Mars, thereby influencing the early evolution of the Martian crust. However, information about how impact melting has altered Mars’ crustal petrology is limited. Evidence from some of the largest impact structures on Earth, such as Sudbury and Manicouagan, suggests that some impact melt sheets experience chemical differentiation. If these processes occur on Mars, we expect to observe differentiated igneous materials in some exhumed rock samples. Some rocks observed in Gale crater are enriched in alkalis (up to 14 wt% Na2O + K2O) and …
Osteohistology And Skeletochronology Of An Ontogenetic Series Of Clidastes (Squamata: Mosasauridae): Growth And Metabolism In Basal Mosasaurids, Cyrus C. Green
Osteohistology And Skeletochronology Of An Ontogenetic Series Of Clidastes (Squamata: Mosasauridae): Growth And Metabolism In Basal Mosasaurids, Cyrus C. Green
Master's Theses or Doctor of Nursing Practice
Clidastes was a large marine reptile from the Late Cretaceous Western Interior Seaway of North America. Though the remains of Clidastes have been found in the Cretaceous chalks and shales for over 150 years, little is known about their growth rates.
Osteohistology is a well-documented technique used to investigate growth in extinct animals. Previous histological studies of Clidastes have hypothesized higher growth rates in basal mosasaurids than varanids due to higher vascularity. These studies focused on adult specimens but did not look at ontogenetic changes in growth rates. Isotopic studies of Clidastes indicate high metabolic temperatures, leading to speculation these …
Influence Of Leachate On The Oligocene-Miocene Clays Of The İstanbul Area, Turkey, Sadik Öztoprak, Davut Laçi̇n
Influence Of Leachate On The Oligocene-Miocene Clays Of The İstanbul Area, Turkey, Sadik Öztoprak, Davut Laçi̇n
Turkish Journal of Earth Sciences
Oligo-Miocene clay outcrops on the European side (west and northwest part) of İstanbul were analysed. Formerly, a landfill and sanitary landfill were built on the clay. Mineral liners of the current and extending parts of the İstanbul landfill consist of these clays, since they include a considerable amount of smectite, illite, and kaolinite. With this feature, these clays are also an important candidate for the buffer material of repositories for nuclear wastes of newly planned nuclear power plants. In this context, one Miocene and two Oligocene clay samples were subjected to leachate under low stress using an odometer device during …
Origin Of The Pleonaste-Bearing Mafic-Ultramafic Rocks From The Armutlu Peninsula, Nw Turkey, Mutlu Özkan, Ömer Faruk Çeli̇k
Origin Of The Pleonaste-Bearing Mafic-Ultramafic Rocks From The Armutlu Peninsula, Nw Turkey, Mutlu Özkan, Ömer Faruk Çeli̇k
Turkish Journal of Earth Sciences
Al-rich spinels were rarely reported compared to Cr-spinels, which were mostly observed in ophiolitic rocks. Pleonaste [(Mg, Fe2+)Al2O4], which is an Al-rich spinel, was observed in the ophiolitic mafic-ultramafic rocks tectonically located in the Early Cretaceous accretionary complex, at the eastern part of the Armutlu peninsula, NW Turkey. The ophiolitic mafic-ultramafic rocks have cumulate character, and most of them are represented by peridotite and pyroxenite. Pleonaste was observed in pyroxenites and gabbros of the ophiolitic rocks. Pyroxenites consist mainly of clinopyroxene + orthopyroxene + amphibole ± olivine + spinel. Gabbros are composed of clinopyroxene + orthopyroxene + amphibole + plagioclase …