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Strength Study Of Zircon Under High Pressure, Ievgeniia Morozova 2015 The University of Western Ontario

Strength Study Of Zircon Under High Pressure, Ievgeniia Morozova

University of Western Ontario - Electronic Thesis and Dissertation Repository

Zircon (ZrSiO4) is a strong accessory mineral that can retain U, Th and Hf within its structure. This makes zircon an important material in geochemical and geochronological studies. In addition, the strong thermal shock resistance of zircon allows for dating the formations of melt and impact events and to separate shocked and potentially shocked country rocks. However, the deformation mechanism and microstructure behavior of zircon at high pressure is poorly understood. Therefore, this work aims to study the deformation and texture of zircon in situ at high pressure and room temperature, and also to examine the microstructure of samples ...


Quantitative Hermeneutics: Counting Forestructures On A Path From W.M. Davis To The Concept Of Multiple-Permeability Karst Aquifers, H. L Vacher, Lee J. Florea 2015 University of South Florida

Quantitative Hermeneutics: Counting Forestructures On A Path From W.M. Davis To The Concept Of Multiple-Permeability Karst Aquifers, H. L Vacher, Lee J. Florea

International Journal of Speleology

Hermeneutics is the theory of interpretation. One of its major components is recognizing prejudgments, or forestructures, that we bring to our objects of study. In this paper, we construct a historical narrative of the evolution of thinking about the role of caves in relation to groundwater flow in limestone, and we tabulate forestructures as they appear in the story. This account consists of three overlapping time periods: the before and after of an incident that repelled hydrogeologists and students of karst from each other in the middle of the 20th century; a period, up to around the turn of ...


Preliminary Geophysical Characterization Of The Karst Within A Transverse Glade In The Atlantic Coastal Ridge, Miami-Dade County Florida, Usa, Lee J. Florea, Jeff Ransom, Dallas Hazelton 2015 Ball State University

Preliminary Geophysical Characterization Of The Karst Within A Transverse Glade In The Atlantic Coastal Ridge, Miami-Dade County Florida, Usa, Lee J. Florea, Jeff Ransom, Dallas Hazelton

Lee J Florea, PhD, P.G.

In this paper we present results of two DC Electrical Resistivity Tomography surveys at Deering Estate at Cutler in the Atlantic Coastal Ridge of Miami-Dade County, Florida. This County Natural Area encompasses Deering Glade and hosts one of the largest remaining tropical hardwood-hammock ecosystems in the USA. A canal extension, wetland restoration, and pump station recently constructed at Deering Estate by the South Florida Water Management District is designed to re-hydrate Deering Glade to pre-development conditions thus helping to sustain the hammock ecosystem and reverse trends in salt-water intrusion in this portion of the Biscayne aquifer.

For these transects, we ...


Analysis And Comparison Of Physical Properties And Morphology Of Impact Melt Flows On Venus And The Moon To Determine Atmospheric Controls, Christine Elizabeth Dong 2015 Bates College

Analysis And Comparison Of Physical Properties And Morphology Of Impact Melt Flows On Venus And The Moon To Determine Atmospheric Controls, Christine Elizabeth Dong

Geology Theses

Impact melt flows form when target material melted by an impact breaches the rim of the impact crater. The melt flows out and away from the crater, forming a lava flow. Such flows have been identified on Venus and the Moon by previous studies. This study aims to document impact melt flows on these two bodies to determine the differences, if any, between them, and to ascertain whether these differences are due to atmospheric conditions. Previously recorded morphological data from Robert Herrick of the Lunar and Planetary Institute and Neish et al. (2014) are used in conjunction with S-band (12 ...


Deformation Post-Doming: New Mapping Of The Oliverian Jefferson Dome, Mt. Dartmouth 7.5' Quadrangle, New Hampshire, Michelle Devoe 2015 Bates College

Deformation Post-Doming: New Mapping Of The Oliverian Jefferson Dome, Mt. Dartmouth 7.5' Quadrangle, New Hampshire, Michelle Devoe

Honors Theses

The Mt. Dartmouth 7.5’ Quadrangle, west of the Presidential Range, contains the southeastern portion of the Jefferson Dome, the largest of the Oliverian Domes. As part of a USGS NHGS EdMap StateMap project, the purpose of this study was to remap this part of the Jefferson Dome and perform a structural and mineralogical analysis of its rock units to develop a better understanding of the tectonic history of the Northeast. Structural analyses show dextral shear zones and folded foliation which suggest at least three phases of deformation post-doming. Literature claims shear zones exist throughout the Northeast, and this analysis ...


Petrogenesis And Paleostress Analysis Of The Mesozoic Mill Brook Dike Zone In The Mount Dartmouth 7.5' Quadrangle, New Hampshire, Graham Grear Oxman 2015 Bates College

Petrogenesis And Paleostress Analysis Of The Mesozoic Mill Brook Dike Zone In The Mount Dartmouth 7.5' Quadrangle, New Hampshire, Graham Grear Oxman

Honors Theses

Field mapping linked with petrogenetic and brittle structural studies of Mesozoic basalt dikes was performed in the Mount Dartmouth 7.5' Quadrangle, adjacent to the Presidential Range, NH. This was done in hopes of creating a better understanding of the intrusion setting and brittle deformational history of the basalt dikes, particularly in relation to the regional tectonic context. Field work done during the summer of 2014 revealed a 100 meter wide, 7.8 km long zone containing multiple mafic dikes that are exceptionally well exposed at the junction of NH Rt. 115 and the Cherry Mountain road. The largest dike ...


Nanodiamond Extraction At A Potential Impact Location, Joel Kathan 2015 DePaul University

Nanodiamond Extraction At A Potential Impact Location, Joel Kathan

DePaul Discoveries

Meteoritic or cometary impacts create the temperature and pressure conditions necessary to form nanodiamonds (NDs). The presence of extracted NDs from rocks of the time and locations of extinctions, fires, or known environmental changes are commonly used to confirm that a theorized cosmic impact occurred to trigger those events. Samples were obtained from an archeological site described in the Old Testament of the Bible as having been destroyed by the God of the Old Testament. To see if the historical description of Biblical events might have been triggered by a cometary impact or explosion, an attempt was made to isolate ...


Insights Into The Evolution Of The Great Plains Grassland Ecosystem Over The Last 5 Million Years From Paleotemperature And Paleovegetation Records, Anne Fetrow 2015 University of Puget Sound

Insights Into The Evolution Of The Great Plains Grassland Ecosystem Over The Last 5 Million Years From Paleotemperature And Paleovegetation Records, Anne Fetrow

Honors Program Theses

Over the last 10 million years, the Great Plains transitioned to the modern C4 grass dominated ecosystem. Well-preserved late Miocene to Holocene fossils and paleosols make the Meade Basin in southwest Kansas, USA a unique place to determine how paleoenvironmental conditions changed during C4 grassland evolution. δ18O values of paleosol carbonates (δ18Ocarb) in the Meade Basin decreased from the Miocene to Holocene while δ13C values increased; these trends were interpreted as an increase in temperature and/or in aridity coincident with an increase of C4 grass biomass on the landscape ...


Geothermobarometry And Petrographic Interpretations Of Christensen Ranch Meta- Banded Iron Formation From The Ruby Range, Montana, Jacob Hughes 2015 Western Kentucky University

Geothermobarometry And Petrographic Interpretations Of Christensen Ranch Meta- Banded Iron Formation From The Ruby Range, Montana, Jacob Hughes

Honors College Capstone Experience/Thesis Projects

The Ruby Range in southwestern Montana was tectonically uplifted during the mountain-building event of the Big Sky orogeny. Contained within the Christensen Ranch Formation, made up of sedimentary units metamorphosed during the Big Sky orogeny, are a small number of metamorphosed banded iron formations (BIFs). It is the presence and composition of these BIFs which is the focus of this research, principally their depositional origin, relationship to surrounding sedimentary packages, elemental and mineral compositions, and lastly, peak metamorphic conditions. Samples were collected, cut into thin sections, and powdered for textural and compositional analyses employing polarized light microscopy, Raman microscopy, scanning ...


Paleoenvironmental Reconstruction Of An Upper Ordovician Rocky Shoreline: The Lindsay Formation Of Heywood And Partridge Islands, Ontario, Hiba-tul Naseer Maheen 2015 The University of Western Ontario

Paleoenvironmental Reconstruction Of An Upper Ordovician Rocky Shoreline: The Lindsay Formation Of Heywood And Partridge Islands, Ontario, Hiba-Tul Naseer Maheen

University of Western Ontario - Electronic Thesis and Dissertation Repository

The islands of Heywood and Partridge, located northeast of Manitoulin Island in Georgian Bay, Ontario, preserve a major unconformity between the Paleoproterozoic Bar River and Lorrain Formation quartz arenite and Upper Ordovician Lindsay Formation carbonate and mudrock. The Lindsay Formation strata record two transgressive pulses of an epeiric sea that flooded the North American continent during the Late Ordovician. During this time, mountain building processes associated with the Taconic Orogeny were taking place to the present east, and the tectonic effects of this orogeny resulted in subsidence of the Michigan Basin. The Lindsay Formation of the Trenton Group was deposited ...


Nwa 8614: The Least Heated Winonaite, Karla Farley, Alex Ruzicka, Katherine Armstrong 2015 Portland State University

Nwa 8614: The Least Heated Winonaite, Karla Farley, Alex Ruzicka, Katherine Armstrong

Student Research Symposium

Northwest Africa 8614 is classified as a winonaite on the basis of oxygen isotope ratios, mineralogy, and highly reduced chemistry. Unlike other winonaites, it contains numerous and readily apparent chondrules. Here we discuss various features of NWA 8614 and the possible significance of the meteorite.

Petrological and chemical analyses were performed using optical microscopy with a DM2500 Leica petrographic microscope and a Zeiss Sigma VP-FEG scanning electron microscope (SEM) with a high-efficiency energy dispersive spectrometer (EDS). Oxygen isotopes were analyzed by Karen Ziegler at the University of New Mexico on acid-washed samples to remove terrestrial weathering products.

Owing to the ...


Structure From Motion Elevation Model For Adding Topographic Correction To Ground Penetrating Radar, Leslie A. Mowbray 2015 Portland State University

Structure From Motion Elevation Model For Adding Topographic Correction To Ground Penetrating Radar, Leslie A. Mowbray

Student Research Symposium

High resolution elevation models have become a standard tool in environmental, geological and archaeological investigations, however; the cost of acquiring Lidar in remote areas, on small project sites or over repeated time intervals remains prohibitively expensive. Here, open-source software and GIS are used to create a digital elevation model (DEM) from aerial photos in a process known as Structure from Motion (SfM). This process is a fraction of the cost of Lidar acquisition, and is shown to produce a model with comparable resolution. The photos used here were taken from a camera hung from a balloon flown at Mickey Springs ...


A Study On Photodegradation And The Fate Of Pyrogenic Carbon, John T. Howell 2015 University of Southern Mississippi

A Study On Photodegradation And The Fate Of Pyrogenic Carbon, John T. Howell

Master's Theses

Accounting for all possible sources of atmospheric CO2 is a pressing issue today due to the increasing effects of climate change. Estimates suggested that on the order of 1.3 million tons of dissolved pyrogenic carbon (pyDOC) could be entering the northern Gulf of Mexico annually. Assessing the fate of pyDOC in aquatic systems is crucial to understanding ecosystem impacts and potential feedback to climate change. Current research indicates that despite a generally lower susceptibility to biodegradation than their unpyrolyzed equivalents, pyrogenic carbon is not environmentally inert. While the role of microorganisms on the fate and transformation ...


Aerosol Size Distribution Measurements During The 2014 Nasa Sarp Campaign In The Central Valley And Sierra Nevada Mountains In California, Victoria A. Hampton 2015 Western Kentucky University

Aerosol Size Distribution Measurements During The 2014 Nasa Sarp Campaign In The Central Valley And Sierra Nevada Mountains In California, Victoria A. Hampton

Honors College Capstone Experience/Thesis Projects

Aerosols are directly and indirectly related to global climate by scattering radiation and also by seeding cloud formation. As a part of the 2014 NASA Student Airborne Research Program (SARP), research flights were conducted over the Central California region to better understand air quality in large urban California cities and also in the Central Valley. Using a Droplet Measurement Technologies Ultra High Sensitivity Aerosol Spectrometer (DMT-UHSAS), aerosol size distributions were measured across geographic regions of interest. Previous research has suggested that aerosols originating in the Central Valley may travel eastward to the Sierra Nevada and, once lifted orographically, could suppress ...


Stratigraphy And Depositional Environment Of The Mesaverde Group In The Northern Bighorn Basin Of Wyoming, Gordon Adams 2015 University of Nebraska-Lincoln

Stratigraphy And Depositional Environment Of The Mesaverde Group In The Northern Bighorn Basin Of Wyoming, Gordon Adams

Dissertations & Theses in Earth and Atmospheric Sciences

A sedimentological, stratigraphical and palynological study was conducted on the upper Cretaceous (Campanian) Mesaverde Group over 27.5 km of a north-south-orientated outcrop belt in the northern Bighorn Basin, Wyoming. During the Campanian, the study area lay in the western part of the Cretaceous Western Interior Seaway. The study aims to provide a stratigraphic and paleoenvironmental analysis of the Mesaverde Group and to integrate findings with data from outcrop belts to the south (southern Bighorn Basin), north (Montana) and east (Powder River Basin).

The Mesaverde Group (371 - 515 m thick) comprises a succession of mainly coarsening-upward stratal cycles, with some ...


Unraveling Controls On Fracture Stratigraphy In Carbonates: The Influence Of Regional Stress, Mechanical Properties, And Diagenesis, Matthew H. Peppers 2015 University of Nebraska-Lincoln

Unraveling Controls On Fracture Stratigraphy In Carbonates: The Influence Of Regional Stress, Mechanical Properties, And Diagenesis, Matthew H. Peppers

Dissertations & Theses in Earth and Atmospheric Sciences

Fracture characteristics analyzed from outcrops provide key insights into the migration pathways of subsurface hydrocarbons, and allow for a detailed understanding of the tectonic history in an area. This study looks to assess the impacts that various controlling factors have on the development of fracture characteristics. To complete this objective, a succession of Ordovician to Mississippian rocks was examined. The logged section includes the Cotter Dolomite, Chattanooga Shale, St. Joe Formation, and the Boone Formation (subdivided into informal Upper and Lower members). Located in northwestern Arkansas and southwestern Missouri, data were collected from roadcut exposures along Highway 71. Collected fracture ...


Paleoredox Geochemistry And Bioturbation Levels Of The Exceptionally Preserved Early Cambrian Indian Springs Biota, Poleta Formation, Nevada, Usa, Jonah Meron Novek 2015 University of Wisconsin-Milwaukee

Paleoredox Geochemistry And Bioturbation Levels Of The Exceptionally Preserved Early Cambrian Indian Springs Biota, Poleta Formation, Nevada, Usa, Jonah Meron Novek

Theses and Dissertations

The early Cambrian Indian Springs biota, western Nevada, USA exhibits Burgess Shale-type (BST) preservation of a diverse array of animal phyla, including the earliest definitive echinoderms. It therefore provides an important window on animal life during the Cambrian radiation. The objective of this study is to analyze the trace metal paleoredox geochemistry and bioturbation levels of this BST deposit in order to characterize the paleoenvironmental conditions in which these animals lived and their fossils were preserved. A total of 28 rock samples were collected from outcrops at three previously reported intervals of exceptional preservation at the Indian Springs locality, as ...


Microbially Induced Sedimentary Structures As An Ecological Niche In Subtidal Early Triassic Environments Of Eastern Panthalassa, Erin Wimer 2015 University of Wisconsin-Milwaukee

Microbially Induced Sedimentary Structures As An Ecological Niche In Subtidal Early Triassic Environments Of Eastern Panthalassa, Erin Wimer

Theses and Dissertations

Early Triassic microbially induced sedimentary structures (MISS) are a critical link in understanding the dynamics between changing environmental conditions and their effect on marine communities. The Permo-Triassic mass extinction (PTME) resulted in vacated ecospace and reduced bioturbation that allowed MISS to expand into Early Triassic subtidal environments. Data from southern Idaho and Montana indicate that MISS inhabited and proliferated in subtidal marine environments during the Griesbachian. This propagation led to changes in shallow substrate geochemical conditions that directly affected macrofaunal communities. The proliferation of microbial mats would have created anoxic and euxinic porewaters and made vertical bioturbation physiologically difficult. Geochemical ...


Paleoecology Of Glacial And Non Glacial Carboniferous Faunas During The Late Paleozoic Ice Age In Patagonia, Nicole Braun 2015 University of Wisconsin-Milwaukee

Paleoecology Of Glacial And Non Glacial Carboniferous Faunas During The Late Paleozoic Ice Age In Patagonia, Nicole Braun

Theses and Dissertations

The Late Paleozoic Ice Age (LPIA) records the only icehouse to greenhouse transition in Earth’s history that involved complex marine and terrestrial life and serves as an analogue for Quaternary climate change. Identifying biotic responses to paleoenvironmental variations during the LPIA is important in order to understand how our modern fauna may respond to contemporary climate change. Low-paleolatitude (far-field) marine faunas far from ice centers have been recognized and used as a global proxy for biotic responses to the LPIA, but the biotic responses in high-paleolatitude (near-field) regions close to Gondwanan ice centers have received much less attention. We ...


Hydrothermal Acid-Sulfate Alteration At Krafla And Námafjall, Ne Iceland: Implications For Gusev Crater And Meridiani Planum, Mars, George L. Carson 2015 University of Wisconsin-Milwaukee

Hydrothermal Acid-Sulfate Alteration At Krafla And Námafjall, Ne Iceland: Implications For Gusev Crater And Meridiani Planum, Mars, George L. Carson

Theses and Dissertations

Opaline silica, sulfate, and phyllosilicate-bearing deposits have been detected on Mars from both obiters and rovers, indicating extensive aqueous alteration of the basaltic surface, some of which likely occurred under hydrothermal conditions. Ongoing hydrothermal acid-sulfate alteration of Mars-like high-Fe (15.48-16.27 wt. % Fe2O3T) basalts and hyaloclastites in northeastern Iceland was studied to help interpret the products of alteration in analogous environments on ancient Mars. The Krafla and Námafjall areas feature intense surface alteration in gas- (fumarole) and fluid- (hot spring/mud pot) dominated settings. Influx of H2S gas (H2S + 2O2 = H2SO4) produced steam-derived acid-sulfate waters with pH values 1 ...


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