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Articles 451 - 480 of 902

Full-Text Articles in Earth Sciences

Bedrock Geological Map Of The Rockhouse Quadrangle, Carroll And Madison Counties, Arkansas, Douglas Eben Jones Dec 2013

Bedrock Geological Map Of The Rockhouse Quadrangle, Carroll And Madison Counties, Arkansas, Douglas Eben Jones

Graduate Theses and Dissertations

A digital geologic map of the Rockhouse quadrangle, Carroll and Madison counties, Arkansas, was created on a 1:24,000 scale using ArcMap 10 and Photoshop CS4. The data obtained in the field are digitized onto the United States Geological Survey (USGS) digital raster graphic (DRG) of the Rockhouse quadrangle. The geology in the Rockhouse quadrangle consist entirely of sedimentary rocks that are Paleozoic ranging from Lower Ordovician to Mississippian in age. The Ordovician System is represented by the Cotter, Powell, Everton, and St. Peter Formations. The Cotter and Powell are the prominent bluff forming units throughout the quadrangle and along the …


Origin And Provenance Of Spherules And Magnetic Grains At The Younger Dryas Boundary, Yingzhe Wu, Mukul Sharma, Malcom A. Lecompte, Mark N. Demitroff, Joshua D. Landis Sep 2013

Origin And Provenance Of Spherules And Magnetic Grains At The Younger Dryas Boundary, Yingzhe Wu, Mukul Sharma, Malcom A. Lecompte, Mark N. Demitroff, Joshua D. Landis

Dartmouth Scholarship

One or more bolide impacts are hypothesized to have triggered the Younger Dryas cooling at ∼12.9 ka. In support of this hypothesis, varying peak abundances of magnetic grains with iridium and magnetic microspherules have been reported at the Younger Dryas boundary (YDB). We show that bulk sediment and/or magnetic grains/microspherules collected from the YDB sites in Arizona, Michigan, New Mexico, New Jersey, and Ohio have (187)Os/(188)Os ratios ≥1.0, similar to average upper continental crust (= 1.3), indicating a terrestrial origin of osmium (Os) in these samples. In contrast, bulk sediments from YDB sites in Belgium and Pennsylvania exhibit (187)Os/(188)Os ratios <<1.0 and at face value suggest mixing with extraterrestrial Os with (187)Os/(188)Os of ∼0.13. However, the Os concentration in bulk sample and magnetic grains from Belgium is 2.8 pg/g and 15 pg/g, respectively, much lower than that in average upper continental crust (=31 pg/g), indicating no meteoritic contribution. The YDB site in Pennsylvania is remarkable in yielding 2- to 5-mm diameter spherules containing minerals such as suessite (Fe-Ni silicide) that form at temperatures in excess of 2000 °C. Gross texture, mineralogy, and age of the spherules appear consistent with their formation as ejecta from an impact 12.9 ka ago. The (187)Os/(188)Os ratios of the spherules and their leachates are often low, but Os in these objects is likely terrestrially derived. The rare earth element patterns and Sr and Nd isotopes of the spherules indicate that their source lies in 1.5-Ga Quebecia terrain in the Grenville Province of northeastern North America.


Carbon And Oxygen Isotope Study Of Carbonates From Watling's Blue Hole And Blue Hole Five, San Salvador, Bahamas, Elaine D. Flynn Aug 2013

Carbon And Oxygen Isotope Study Of Carbonates From Watling's Blue Hole And Blue Hole Five, San Salvador, Bahamas, Elaine D. Flynn

Mahurin Honors College Capstone Experience/Thesis Projects

Carbonate platforms, such as the Bahamas, formed through deposition and sea level fluctuations. These platforms contain records of rapid interglacial climate change and are useful in studying the impacts of climate change on similar tropical carbonate environments. Blue holes are dissolution lakes that may be beneficial for understanding climate change and anthropogenic impact. A δ13C and δ18O study was conducted on lake sediment core samples from Watling’s Blue Hole and Blue Hole Five on San Salvador Island, Bahamas. These lakes are located in a failed housing development and Watling’s Blue Hole was once part of an …


Cyclic Distributional Model Of The Late Moscovian Fusulinids In The Donets Basin (Ukraine) In Response To Eustatic Sea Level Fluctuations And Its Application In Biostratigraphy And Correlation, Rimma Khodjanyazova Aug 2013

Cyclic Distributional Model Of The Late Moscovian Fusulinids In The Donets Basin (Ukraine) In Response To Eustatic Sea Level Fluctuations And Its Application In Biostratigraphy And Correlation, Rimma Khodjanyazova

Boise State University Theses and Dissertations

The continuous Pennsylvanian shallow-marine, paralic, siliciclastic succession in the Donets Basin is pivotal for correlation of marine and continental strata in northern Pangaea with coeval shallow-marine mainly carbonate strata in the Moscow Basin, a historical type area of Moscovian Horizons. The details of the history of establishment, lithostratigraphy and current biostratigraphy of Podolskian and Myachkovian Horizons in the Moscow Basin that are not readily available in Western literature are reviewed.

A model of cyclic recurrence (~0.6 —1myr) of three main fusulinid assemblages in the Pennsylvanian siliciclastic-carbonate succession in the Donets Basin is proposed. A Hemifusulina-association (A) indicates the onset …


Dendrochronological Analysis Of Jones Homestead Jun 2013

Dendrochronological Analysis Of Jones Homestead

Historic Structures

Dating historical structures using dendrochronology. The Historical Structures collection consists of reports that are the result of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Dilyard, Jeff; Wiesenberg, Nicholas


Dendrochronological Analysis Of Four Sommerset Structures Jun 2013

Dendrochronological Analysis Of Four Sommerset Structures

Historic Structures

Dating historical structures in Somerset, Ohio 2013. The Historical Structures collection consists of reports that are the result of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Stewart, Alexander; Wiesenberg, Nicholas; Wiles, Greg


Petrified Wood Survey Of Land Adjacent To Petrified Forest National Park, Az, Kathleen Masterson Apr 2013

Petrified Wood Survey Of Land Adjacent To Petrified Forest National Park, Az, Kathleen Masterson

Collection of Engaged Learning

An intensive survey was conducted on HNZ land, a subsidiary of Hunt Inc., which owns the mineral rights to land located adjacent to the Petrified Forest National Park, Arizona, United States. The purpose of the survey was to log the position and characteristics of petrified wood to better protect the fossils from thieves and to assess the value of Hunt lands. A monetary value was assigned to each log based on color, condition, size, and other mitigating characteristics. Two broad categories of fossil logs were found on the land, alabaster and rainbow. Mineral composition and oxygen isotopes were analyzed to …


Geoanalytical Analysis Of Speleogenetic Development In The Owl Mountain And Nolan Creek Provinces: Fort Hood Military Installation, Texas (Abstract], Melinda G. Shaw-Faulkner, Kevin W. Stafford, Aaron W. Bryant Apr 2013

Geoanalytical Analysis Of Speleogenetic Development In The Owl Mountain And Nolan Creek Provinces: Fort Hood Military Installation, Texas (Abstract], Melinda G. Shaw-Faulkner, Kevin W. Stafford, Aaron W. Bryant

Faculty Presentations

No abstract provided.


Late Mississippian (Chesterian) Through Early Pennsylvanian (Atokan) Strata, Michigan Basin, U.S.A., Shannon M. Towne Apr 2013

Late Mississippian (Chesterian) Through Early Pennsylvanian (Atokan) Strata, Michigan Basin, U.S.A., Shannon M. Towne

Masters Theses

Over 2,000 linear feet of core material was analyzed to evaluate the stratigraphy and basin evolution of Carboniferous strata in the Michigan basin. Rock units were evaluated on the basis of lithofacies type, contact relationships, and existing regional geologic interpretations. The recovery of three distinct pollen and spore assemblages from core confirms the timing of deposition during the Late Mississippian Chesterian and Early-Middle Pennsylvanian Morrowan and Atokan regional stages within the Michigan basin.

The deposition of a marine carbonate succession with significant interstratified quartz sandstone occurred during the Chesterian regional stage. The Bayport interval (Bayport Limestone) is composed of seven …


Tree Ring Dating Of The Emerson Barn, Apple Creek, Ohio Jan 2013

Tree Ring Dating Of The Emerson Barn, Apple Creek, Ohio

Historic Structures

Dating historical structures in Wayne County, Ohio using dendrochronology. The Historical Structures collection consists of reports that are the result of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Nash, Andy; Vargo, Lauren; Wiesenber, Nick; Wiles, Greg


Bulletin No. 41: Trap Rock Ridges Of Connecticut: Natural History And Land Use, Penelope C. Sharp, Ralph S. Lewis, David L. Wagner, Cara Lee Jan 2013

Bulletin No. 41: Trap Rock Ridges Of Connecticut: Natural History And Land Use, Penelope C. Sharp, Ralph S. Lewis, David L. Wagner, Cara Lee

Bulletins

No abstract provided.


Biostratigraphy Of The Halgaito Formation, Cutler Group Near Mexican Hat, San Juan County, Utah, Kimberly Marie Scott Jan 2013

Biostratigraphy Of The Halgaito Formation, Cutler Group Near Mexican Hat, San Juan County, Utah, Kimberly Marie Scott

Theses Digitization Project

The purpose of this thesis is to develop a better understanding of the paleontology and biostratigraphy of the Halgaito Formation and the position of the Carboniferous-Permian Boundary (CPB) within the Halgaito Formation which would provide useful data that can be extrapolated to other terrestrial ecosystems of the southwestern United States of America that are of comparable age.


Stable Isotope Record Of Archean And Cambrian Serpentinizing Fluid Composition From Stichtite (Mg-Cr Carbonate Hydroxide), Amanda Lopez Jan 2013

Stable Isotope Record Of Archean And Cambrian Serpentinizing Fluid Composition From Stichtite (Mg-Cr Carbonate Hydroxide), Amanda Lopez

Theses Digitization Project

This study will focus on stichtite from two locations that contain the most abundant deposits of stichtite. The first location in Tasmania, Australia includes the Stichtite Hill locality (the type locality for stichtite) and the Tunnel Hill locality. The second location is at the New Amianthus Mine, Barberton District, South Africa. The broad geographical distribution of stichtite in deposits ranging from the Archean tho the early Cambrian, provides a window into the history and chemistry of serpentinizing environments on Earth through time.


Tree-Ring Evidence Of North Pacific Volcanically Forced Cooling And Forcing Of The Pacific Decadal Oscillation (Pdo), Lauren Vargo Jan 2013

Tree-Ring Evidence Of North Pacific Volcanically Forced Cooling And Forcing Of The Pacific Decadal Oscillation (Pdo), Lauren Vargo

Senior Independent Study Theses

Two large undocumented volcanic eruptions in 1698/9 and 1809 have been previously identified in ice cores as sulfate peaks, and in tree-ring latewood density data as low-density rings. These eruptions can also be recognized using tree-ring width data, and can be identified in the tree-ring record as narrow rings for several consecutive years. The first part of this study uses tree-ring width data from the Gulf of Alaska to provide further evidence that these eruptions occurred. The two eruptions also provide a natural experiment for investigating the effects large volcanic eruptions have on North Pacific climate, including the Pacific Decadal …


A Structural Analysis Of The El Kasr Structure In The Western Desert Of Egypt, Trevor Charles Ellis Jan 2013

A Structural Analysis Of The El Kasr Structure In The Western Desert Of Egypt, Trevor Charles Ellis

Masters Theses

"The El Kasr structure was studied in order to investigate the origins and evolution of the enigmatic Desert Eyes structures of the Western Desert due to its accessibility and uniqueness among the structures. The El Kasr structure, an elongate structural basin with low limb dips, is unique among the "Desert Eyes" structures in that it: 1) occurs in isolation in otherwise horizontal sedimentary rock, 2) the long dimension of the basin is oriented NNW, 3) it is closely spatially associated with the less common NNW fault zones, and 4) is composite in nature. The structure was investigated using remote sensing …


Ballistics Analysis Of Volcanic Ejecta: Miter Crater, Ice Springs Volcanic Field, Black Rock Desert, Utah, William Cary Jan 2013

Ballistics Analysis Of Volcanic Ejecta: Miter Crater, Ice Springs Volcanic Field, Black Rock Desert, Utah, William Cary

Senior Independent Study Theses

Ice Springs Volcanic Field, located in the Black Rock Desert west of Fillmore, Utah, is composed of three large craters, Crescent, Miter, and Terrace, and several smaller craters. Concern over the hazards of the volcanic field, ±660 years old, reactivating prompted the creation of a hazards model. This study focuses on Miter Crater in order to conduct a ballistic analysis of the blocks and bombs observed along the crater rim. Data analysis of Miter Crater ejecta was then used to create a hazards model for ballistic volcanic ejecta. Thirty-four blocks and bombs were recorded along the rim of Miter Crater. …


Volcanic And Tectonic Processes Along Anomalous Mid-Ocean Ridges, Julia Kathryn Howell Jan 2013

Volcanic And Tectonic Processes Along Anomalous Mid-Ocean Ridges, Julia Kathryn Howell

Theses and Dissertations

The morphological and structural characteristics of the global spreading ridge system are systematically related to spreading rate and magma supply (e.g. Macdonald, 1982). Because intermediate spreading-rate ridges (ISRs) spreading between 60 and 80 mm/yr have characteristics of both fast and slow spreading ridges, they are ideal environments to study the differences controlling upper crustal accretion. We examine the distribution of seamounts along spreading ridges to understand the relationship between seamount volcanism and axial morphology along four ISRs: the Juan de Fuca Ridge (JdFR), the Galápagos Spreading Centers (GSC), the Southeast Indian Ridge (SEIR), and the Eastern Lau Spreading Centers (ELSC). …


Tsunamis: Desprevenidos Por La Realidad De La Geología Un Estudio De La Posibilidad Y Precauciones Por Un Tsunami En Puerto López, Manabí, Ecuador, Abigail Eurich Oct 2012

Tsunamis: Desprevenidos Por La Realidad De La Geología Un Estudio De La Posibilidad Y Precauciones Por Un Tsunami En Puerto López, Manabí, Ecuador, Abigail Eurich

Independent Study Project (ISP) Collection

Tsunamis occur in the Pacific Ocean about once every 1.5 years (Berninghausen, 1962). Forty-nine Tsunamis are recorded to have hit the western coast of South America since 1562, though only 3 hit the coast of Ecuador specifically (Berninghausen, 1962). However, it is still important to recognize the possibility of having a tsunami in Ecuador and plan accordingly. On a very complex junction of the Nazca and South American plate, with the Nazca and Carnegie Ridges as well as the Galapagos hotspot, this part of the world is apt to many earthquakes, submarine landslides, and volcanic activity which all have the …


Evaluation Of Possible Source Rocks In Northern Nye County, Nevada: Implications For Hydrocarbon Exploration, Inessa Yurchenko Aug 2012

Evaluation Of Possible Source Rocks In Northern Nye County, Nevada: Implications For Hydrocarbon Exploration, Inessa Yurchenko

UNLV Theses, Dissertations, Professional Papers, and Capstones

The presence of oil outside of Railroad Valley, northern Nye County has sparked the interest of exploration companies in Nevada. The geology in this region is very complex and the level of petroleum exploration is low. In order to understand the distribution of oil, a complete petroleum systems analysis is required. Previous studies confirmed that the Mississippian Chainman Shale and Cretaceous to Paleocene Sheep Pass Formation, Member B are source rocks. However, a number of other possible source rocks exist in northern Nye County, but they are not confirmed because of incomplete datasets. The goal of this thesis project is …


Tree Ring Dating Analysis Of The Zane Trace Inn, 129 West Main Street Somerset, Oh 43783 Jun 2012

Tree Ring Dating Analysis Of The Zane Trace Inn, 129 West Main Street Somerset, Oh 43783

Historic Structures

Dating historical structures in Somerset, Ohio 2012. The Historical Structures collection consists of reports that are the resoult of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Appleton, Sarah; Cary, William; Nash, Andy; Wiles, Greg


Dendrochronological Analysis Of The Ridenour House And Barn, Somerset, Ohio 43783 Jun 2012

Dendrochronological Analysis Of The Ridenour House And Barn, Somerset, Ohio 43783

Historic Structures

Dating historical structures in Somerset, Ohio 2012. The Historical Structures collection consists of reports that are the resoult of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Appleton, Sarah; Cary, William; Nash, Andy; Wiles, Greg


Tree Ring Dating Analysis Of The Rouskoff Barn, Somerset, Ohio 43783 Jun 2012

Tree Ring Dating Analysis Of The Rouskoff Barn, Somerset, Ohio 43783

Historic Structures

Dating historical structures in Somerset, Ohio 2012. The Historical Structures collection consists of reports that are the resoult of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Appleton, Sarah; Cary, William; Nash, Andy; Wiles, Greg


Tree Ring Dating Analysis Of The Eliza James House And Barn, Somerset, Ohio 43783 Jun 2012

Tree Ring Dating Analysis Of The Eliza James House And Barn, Somerset, Ohio 43783

Historic Structures

Dating historical structures in Somerset, Ohio 2012. The Historical Structures collection consists of reports that are the resoult of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Appleton, Sarah; Cary, William; Nash, Andy; Wiles, Greg


Tree Ring Dating Analysis Of The Scot Barn, Somerset, Ohio 43783 Jun 2012

Tree Ring Dating Analysis Of The Scot Barn, Somerset, Ohio 43783

Historic Structures

Dating historical structures in Somerset, Ohio 2012. The Historical Structures collection consists of reports that are the resoult of dendochronological analysis of timbers from structures in Pennsylvania and Ohio. Contributors: Appleton, Sarah; Cary, William; Nash, Andy; Wiles, Greg


New Insights Into Troglotella Incrustans Wernli & Fookes, 1992, A Fascinating Upper Jurassic-Upper Cretaceous Foraminifer, Felix Schlagintweit May 2012

New Insights Into Troglotella Incrustans Wernli & Fookes, 1992, A Fascinating Upper Jurassic-Upper Cretaceous Foraminifer, Felix Schlagintweit

Studia UBB Geologia

New data about the highly variable test morphology of the benthic foraminifer Troglotella incrustans WERNLI & FOOKES (Oxfordian-Lower Cenomanian) are presented, permitting an emended species/genus diagnosis. This concerns mainly the existence of a large final chamber with fistulose extensions that may follow the uniserial or the irregular-branching test part. The way of life of T. incrustans (cryptoendolithic vs. euendolithic) is discussed against the background of different existing models in the literature. The study is based on material (thin-sections and provided photographs) mainly from the Upper Jurassic of Austria, Italy, Romania, Ukraine, and also the type-locality of France.


Mary Anning Of Lyme Regis: 19th Century Pioneer In British Palaeontology, Larry E. Davis May 2012

Mary Anning Of Lyme Regis: 19th Century Pioneer In British Palaeontology, Larry E. Davis

Headwaters

No abstract provided.


A Mineralogical Textural And Chemical Characterization Of A Hypothesized Kimberlite At White Mountain, Sunlight Basin, Wyoming, Stuart Kenderes May 2012

A Mineralogical Textural And Chemical Characterization Of A Hypothesized Kimberlite At White Mountain, Sunlight Basin, Wyoming, Stuart Kenderes

Mahurin Honors College Capstone Experience/Thesis Projects

Geologists have examined the causes and mechanisms responsible for the Heart Mountain detachment for over a century with much debate and discussion. White Mountain is a part of the upper plate, which was emplaced during the detachment event. Within White Mountain, there exist several andesitic dikes and carbonate ultra-cataclasite injectites, which were integral in the emplacement of the Heart Mountain detachment. This research involves the characterization and identification of an enigmatic vertical outcropping of brecciated rock located on White Mountain, Sunlight Basin, Wyoming, which was originally interpreted as a kimberlite. Samples were collected for geochemical and textural comparison, and cut …


Deciphering The Evolution Of Ore Fluids At The Batu Hijau Copper-~Gold Porphyry Deposit, Sumbawa, Indonesia, Jordan Thomas Armstrong May 2012

Deciphering The Evolution Of Ore Fluids At The Batu Hijau Copper-~Gold Porphyry Deposit, Sumbawa, Indonesia, Jordan Thomas Armstrong

UNLV Theses, Dissertations, Professional Papers, and Capstones

Fluid inclusions contained within quartz veins from the Batu Hijau Cu-Au porphyry deposit in Indonesia were analyzed to track the evolution of fluid temperature, pressure, and composition during the formation of the deposit to better understand the formation of this and other Cu-Au porphyry deposits in order aid future exploration. A combination of petrography, microthermometry, synchrotron x-ray fluorescence, and laser ablation-inductively coupled plasma-mass spectrometry were used to determine the temperature, pressure, and compositional aspects of the deposit.

Four types of fluid inclusions were recognized at Batu Hijau based on the volume percent of the vapor bubble; inclusions were classified as …


Muddy Creek Formation: A Record Of Late Neogene Tectonics And Sedimentation In Southern Nevada, Thomas William Muntean May 2012

Muddy Creek Formation: A Record Of Late Neogene Tectonics And Sedimentation In Southern Nevada, Thomas William Muntean

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Late Neogene Muddy Creek Formation (MCF), exposed in the vicinity of Lake Mead in southern Nevada, represents the youngest widespread Cenozoic sedimentary sequence in the region and is the focus of this study. Historically, the MCF has been largely ignored, with limited previous studies providing only regional-scale constraint on the age, stratigraphy, and mode of deposition for the formation; resulting in a data gap for our understanding of the Late Cenozoic tectonic and sedimentological evolution of southern Nevada.


The Behavior Of Zircon During Partial Melting In Anatectic Migmatites: Insights To Metamorphism, Deformation And Tectonism In The Central Santa Fe Range, Northern New Mexico, Michelle Renee Stropky May 2012

The Behavior Of Zircon During Partial Melting In Anatectic Migmatites: Insights To Metamorphism, Deformation And Tectonism In The Central Santa Fe Range, Northern New Mexico, Michelle Renee Stropky

UNLV Theses, Dissertations, Professional Papers, and Capstones

Three lithologic assemblages exposed in the central Santa Fe Range, northern New Mexico include (1) a septum of Proterozoic low temperature (~700oC, 5.5 kbars), semi-pelitic anatectic migmatites surrounded by (2) deformed megacrystic biotite granite that is intruded by (3) discrete plutons of largely undeformed hornblende biotite tonalite. Metamorphic fabrics in the migmatite record three deformation events (D1 - D3); a composite S1/S2 fabric (D1 and D2) that formed contemporaneous with anatexis and is folded about a southwest plunging map-scale (D3) antiform. The megacrystic granite exhibits a pervasive S1 subsolidus foliation that parallels the S1/S2 fabric in the migmatite and is …