Geochemistry Commons^™

Predictive Modeling Of Terrestrial Radiation Exposure From Geologic Materials, Daniel A. Haber

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aerial gamma ray surveys are an important tool for national security, scientific, and industrial interests in determining locations of both anthropogenic and natural sources of radioactivity. There is a relationship between radioactivity and geology and in the past this relationship has been used to predict geology from an aerial survey. The purpose of this project

is to develop a method to predict the radiologic exposure rate of the geologic materials in an area by creating a model using geologic data, images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), geochemical data, and pre-existing low spatial resolution aerial surveys …

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.

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 …

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.

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 …

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

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 …

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 …

Geochemical Classification Of Placer And Lode Gold Deposits Within The Northern Dome Rock Mountains Of The Quartzsite Mining District, Az, Christina Marie Lopez Velasquez

Theses Digitization Project

In this study the geochemistry and distribution of placer and lode gold deposits of the northern Dome Rock Mountains near Quartzsite, Arizona wre studied. The primary objectives of this study were to geochemically classify the placer and lode gold deposits of the Quartzsite Mining District, Arizona. Additional objectives were to determine estimates of the economic value and quantity of production of placer and lode gold deposits. Addressing the economic geology of placer gold deposits, the ultimate goal for this geochemical study is to determine the source(s) of the placer gold and determining the economic potential.

Geochemistry, Geothermobarometry And Geochronology Of High-Pressure Granulites And Implications For The Exhumation History Of Ultrahigh-Pressure Terranes: Dulan, Western China, Benjamin David Joseph Christensen

All Master's Theses

The Dulan ultrahigh-pressure (UHP) rocks of the North Qaidam terrane, Western China, represent continental crust that has been subducted ~100 km during continental collision. Adjacent granulites representing burial to ~50 km could either be overprinted eclogites or a separate high-pressure-high-temperature (HP-HT) granulite unit. Overprinted eclogites and HP-HT granulites imply different P-T-t paths for UHP rocks. Metamorphic conditions for the granulites are 750–880 °C and 14–17 kbar. Zircon U-Pb geochronology, REE patterns and Ti-in-zircon thermometry indicate an increase in temperature from ~800 °C (449 Ma) to ~900 °C (418 Ma). This temperature increase could explain the presence of granulite leucosomes and …

Geochemical Fingerprinting Of Volcanic Airfall Deposits : A Tool In Stratigraphic Correlation, Soumava Adhya

Legacy Theses & Dissertations (2009 - 2024)

Chemical fingerprints of volcanic airfall deposits obtained from high-precision electron microprobe analysis of glass and phenocrysts phases provide geochemical correlations with temporal precision unattainable by other methods. In this research electron microprobe analysis (EMA) techniques, to fingerprint chemically and correlate fresh and altered volcanic airfall deposits, have been utilized to test the value of this tool for future research on stratigraphic correlation. The following samples were chosen from within a variety of sedimentary rocks widely separated spatially and temporally:

Origin Of Gabbroic Xenoliths Within The Lone Mountain Dacite Intrusion, Big Sky, Montana: A Field And Petrographic Analysis, Emily Clement

Undergraduate Review

No abstract provided.

Field, Petrographic, And Geochemical Characteristics Of Price Creek, Russ Mccormack

Undergraduate Review

No abstract provided.

The Origin Of Brucite In Hydrothermally Altered Limestone Near Devil Peak, Nevada, Rhonda L. Knupp

UNLV Theses, Dissertations, Professional Papers, and Capstones

Open-space brucite was identified in veins crosscutting hydrothermally altered limestone near the Devil Peak rhyolite plug in southern Nevada. The brucite occurs with serpentine, calcite, chalcedony, hydromagnesite, dolomite, and clinochlore.

Brucite usually forms as a replacement mineral, but textural evidence indicates that the brucite at Devil Peak precipitated in open space. The presence of chalcedony in veins indicates the temperature of the hydrothermal fluid was <180^oC during and after mineral deposition. Thermodynamic modeling shows this temperature is too low for replacement brucite to form, thus the low temperature of alteration may be a factor in this unusual occurrence of …

The Geology Of The Tuff Of Bridge Spring: Southern Nevada And Northwestern Arizona, Shirley Ann Morikawa

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Tuff of Bridge Spring (TBS) is a regionally-widespread, andesite to rhyolite (59.50 to 74.91 wt. %) ash-flow tuff of mid-Miocene age (ca. 15.2 Ma) that is exposed in the northern Colorado River extensional corridor of southern Nevada and northwestern Arizona. Determination of the areal distribution, geochronology, lithology, geochemistry, and internal stratigraphy of the TBS is important for its establishment as a reliable stratigraphic reference horizon for tectonic reconstructions of the extensional corridor during the middle Miocene. Based on reoccurring patterns of major and trace element variation, the TBS is divided into constant Cr/variable SiO₂ and variable Cr/variable SiO …

Mining In Maine : Past, Present, And Future, Carolyn A. Lepage

Maine Collection

Mining in Maine : Past, Present, and Future

by Carolyn A. Lepage, Michael E. Foley, and Woodrow B. Thompson

Maine Geological Survey, Department of Conservation, Augusta, Me., 1990.

Contents: Introduction / The Early Years: Pre-Civil War / The Civil War to World War II / The War Years of the 1940's / The Postwar Years: 1940's to 1960 / The 1960's / The 1970's / Maine Mineral Resources Association / The 1980's / Current Mining and Exploration / Future Potential / Acknowledgments / References

Structural, Remote Sensing And Multivariate Correlation Methods As Aids To Mineral Exploration, Central Ireland, D.W. Coller, M.F. Critchley, J.M. Dolan, Ciaran Mcdonnell, C.J. Murphy, W.E.A. Phillips, D.J. Sanderson

Books/Book chapters

This work discusses structural, remote sensing and multivariate correlation methods as aids to mineral exploration in West Central Ireland. The work was performed as part of the EU-funded CREST project.

Peat Resources Of Maine - Volume 4: Southern And Western Maine, Cornelia C. Cameron, Michael K. Mullen, Carolyn A. Lepage

Maine Collection

Peat Resources of Maine - Volume 4: Southern and Western Maine

by Cornelia C. Cameron, Michael K. Mullen, Carolyn A. Lepage & Walter A. Anderson

Bulletin 31 - Maine Geological Survey, Department of Conservation, Augusta, Maine (1984).

Preparation of this report was supported by funds furnished by the U.S. Department of Energy, Grant No. DE-FG18-79ET14690, the Maine Office of Energy Resources, the Maine Geological Survey, and the U.S. Geological Survey.

Contents: Introduction / The Maine Peat Resource Evaluation Program / Geologic Setting of Maine Peat Deposits / Formation of Peat Deposits in Maine / Methods of Investigation / Identification of …

Report Of The State Geologist 1953-1954, Maine Geological Survey

Maine Collection

Report of the State Geologist 1953-1954.

Maine Geological Survey - Maine Development Commission, Augusta, Maine - July 1955.

Contents: Joseph M. Trefethen -- Review of Maine Mineral Outlook / Henry W. Allen -- Limestone Investigations, 1953-54 / Wm.T. Forsyth -- Airbourne Magnetometer Survey in Eastern Maine / Gary M. Boone -- Petrology of the Farmington, Maine Area / Joseph M. Trefethen, Henry Allen, and Wm. T. Forsyth -- Scheelite Occurrences in Maine / Wm.T. Forsyth -- Beneficiation Tests on the Warren Sillimanite Gneiss / Wm. T. Forsyth -- Pyrrhotite Mineralization at Iron Hill, Gardiner, Maine / Joseph M. Trefethen -- …

Report Of The State Geologist 1951-1952, Maine Geological Survey

Maine Collection

Report of the State Geologist 1951-1952.

Maine Geological Survey - Maine Development Commission, Augusta, Maine - December, 1953.

Contents: Joseph M. Trefethen -- New England Mineral Resources / Henry Allen -- Progress Report of Limestone Survey, Knox County / Wm. Forsyth -- Mineralogical Variations of the Ellsworth Schist in Blue Hill, Maine / Lawrence A. Wing -- Preliminary Report on Eastern Maine Granites / Kern Jackson -- A Preliminary Report on the Geology of a Portion of the Rumford Quadrangle, Maine / Robert M. Zink -- Certain Aspects of the Ecology of Venus and Mya at Bunganuc and at Morgan …

Report Of The State Geologist 1947-1948, Maine Geological Survey

Maine Collection

Report of the State Geologist 1947-1948.

Maine Geological Survey - Maine Development Commission, Augusta, Maine - March 1949.

Contents: Activity of the Maine Geological Survey, 1947-48 / Joseph M. Trefethen -- Review of the Aroostook County Manganese Deposits / Joseph M. Trefethen -- Notes on Ground Water Conditions in Maine / Joseph M. Trefethen -- The Desert of Maine / Henry Allen and Elbert Pratt -- Reconnaissance Surveys of Limestones in Franklin County, Maine / Lawrence Wing and Arthur Dawson -- Preliminary Report on Asbestos and Associated Rocks of Northwestern Maine / Lawrence Goldthwait -- Clay Survey 1948 / Earl …

Third Report Of The Geological Survey In Kentucky, Made During The Years 1856 And 1857, David Dale Owen

Administrative Report--KGS

Third report. Assisted by Robert Peter (geochemist), Sidney S. Lyon (topographer), Leo Lesquereux (paleontologist), and Edward T. Cox (paleontologist).