Geology Commons^™

Geochemical Systematics Among Amphibolitic Rocks In The Central Blue Ridge Province Of Southwestern North Carolina, Nathan Collins

USF Tampa Graduate Theses and Dissertations

The Central Blue Ridge sub-province of the southern Appalachian Mountains preserves an unique and complex geologic history. The Cartoogechaye terrane is the westernmost terrane of the Central Blue Ridge sub-province, and is characterized by extensive olistostromal sequences, including mafic-ultramafic massifs, isolated mafic units, and block-in-matrix structures of varying scales. This study investigates the genetic and tectonic relationships, and regional chemical and metamorphic trends of the amphibolitic rocks entrained within units of the Cartoogechaye and nearby terranes, toward constraining the origins of these regional sequences, and examining the rationale for the current Blue Ridge terrane designations.

A distinct compositional variation exists …

Petrogenesis Of The Greenwater Range: Comparison To The Crater Flat Volcanic Field And Implications For Hazard Assessment, Ashley Kaye Tibbetts

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pliocene basalts of the Greenwater Range, California erupted from 24 volcanic vents now represented by volcanic plugs, craters and scoria mounds. Basaltic magmas originated in the asthenospheric mantle, but show evidence of a lithospheric component. Depths and temperatures of melting calculated using a silica activity geobarometer are 54.3–89.6 km and 1367-1435oC, placing melting in the asthenosphere. The preferred petrogenetic model involves melting of lithospheric mantle thermally and mechanically, but not chemically, converted to asthenospheric mantle. Melting depths correspond to low velocity zones in the mantle as revealed in seismic profiles. Chemical and lithologic similarities between basalt in the Greenwater Range …

Origin Of Blue Ridge Basement Rocks, Dellwood Quad, Western Nc: New Evidence From U-Pb Zircon Geochronology And Whole Rock Geochemistry, Donald Franklin Loughry Jr.

University of Kentucky Master's Theses

Terrane discrimination in polycyclic continental basement rocks is challenging due to high-grade metamorphism and intense deformation. Based on early USGS mapping the Blue Ridge basement in the Dellwood quadrangle of the eastern Great Smoky Mountains was proposed to consist of augen orthogneisses of Laurentian (Grenvillian) affinity interfolded with migmatitic hornblende and biotite paragneisses (“Carolina Gneiss”) and amphibolites of uncertain affinity. However, detailed study reveals that the hornblende gneiss of Hadley and Goldsmith (1963) is a heterogeneous map unit consisting of (1)metaplutonic rocks; (2) variably foliated and folded felsic orthogneisses; (3) strongly migmatitic, folded Hbl+Bt-bearing gneisses; (4) foliated and lineated garnet …

The Mississippian Section At Paddys Bluff, Crittenden County, Kentucky, Ron Counts, F. Brett Denny, James C. Hower, Zakaria Lasemi, Rodney D. Norby, Paul E. Potter, Scott Waninger, David A. Williams

Map and Chart--KGS

Paddys Bluff (Figs. 1-3) is located on the south side of the Illinois Basin on the Cumberland River, 1.7 miles downstream from Dycusburg in Crittenden County, Ky., in Carter coordinate section 23-I-16 and ecoregion 71f of the Western Highland Rim of Kentucky (Woods and others, 2002). This bluff is on a right-descending bend 18 liver miles above its junction with the Ohio River at Smithland, Livingston County. The bluff (Figs. 4A, B) is locally famous as the location for a scene from the classic 1962 film, "How the West Was Won,' a winner of three Academy Awards, starling James Stewart, …

Temporal And Geochemical Insights Related To Volcanic And Plutonic Activity Within Big Bend National Park, Texas, Daniel Paul Miggins

Open Access Theses & Dissertations

Big Bend National Park located in the southeastern part of the Trans-Pecos Magmatic Province in west Texas contains a diverse suite of volcanic and intrusive rocks. Ongoing geologic mapping, geochronology, and geochemical studies have focused on the timing and geological relationships associated with these volcanic and intrusive rocks. Igneous activity within Big Bend National Park occurred from 46.5 to 22.0 Ma. Precise 40Ar/39Ar and U-Pb zircon geochronology has resolved the timing of this activity into five discrete episodes: 1) eruption and emplacement of both intrusive and volcanic mafic rocks at 46.5 Ma followed by ~42.0 Ma mafic volcanic pulse; 2) …

Geochemistry And Nd - Isotopic Composition Of High Silica Rhyolites In The Neoarchaean Musoma-Mara Greenstone Belt, Northern Tanzania: Evidence For The Presence Of Older Continental Crust, S Manya

Tanzania Journal of Science

The high silica rhyolites of the Kibasuka Hill, although volumetrically minor, constitute a part of the greenstone sequence in the northern Musoma-Mara Greenstone Belt (MMGB). They are characterized by high silica contents (63.38 – 81.65 wt %), very low CaO (! 0.05 wt %), variable to unusually high K2O (2.24 – 13.43 wt %) most likely attributed to strong sericite alteration, and their major element composition are similar to those of melts derived from partial melting of metapelites. The samples have very low concentration of the transition elements, Sr (3.13 – 48.4 ppm) and very large negative Europium anomalies (Eu/Eu* …

Origin And Paleoclimatic Significance Of Late Quaternary Loess In Nebraska: Evidence From Stratigraphy, Chronology, Sedimentology, And Geochemistry, Daniel R. Muhs, E. Arthur Bettis Iii, John N. Aleinikoff, John P. Mcgeehin, Jossh Beann, Gary Skipp, Brian D. Marshall, Helen M. Roberts, William C. Johnson, Rachel Benton

United States Geological Survey: Staff Publications

Loess is one of the most extensive surficial geologic deposits in mid-continental North America, particularly in the central Great Plains region of Nebraska. Last-glacial-age loess (Peoria Loess) reaches its greatest known thickness in the world in this area. New stratigraphic, geochronologic, mineralogic, and geochemical data yield information about the age and provenance of Peoria Loess, as well as evaluation of recent climate models.

An Investigation Of Meromixis In Cave Pools, Lechuguilla Cave, New Mexico, David B. Levy

International Journal of Speleology

Chemical characteristics of permanent stratification in cave pools (meromixis) may provide insight into the geochemical origin and evolution of cave pool waters. The objective of this study was to test the hypothesis that some pools in Lechuguilla Cave may be subject to ectogenic meromixis, where permanent chemical stratification is induced by input of relatively saline or fresh water from an external source. However, because organic C concentrations in Lechuguilla waters are low (typically < 1 mg L^-1), biogenic meromixis resulting in O₂(g)-depleted subsurface waters is not expected. Four pools at various depths below ground surface (0 m) were studied: (1) …

Shallow Slab Fluid Release Across And Along The Mariana Arc-Basin System: Insights From Geochemistry Of Serpentinized Peridotites From The Mariana Fore Arc, Ivan P. Savov, Jeffrey G. Ryan, Massimo D'Antonio, Patricia Fryer

Geology Faculty Publications

Shallow slab devolatilization is not only witnessed through fluid expulsion at accretionary prisms, but is also evidenced by active serpentinite seamounts in the shallow fore-arc region of the Mariana convergent margin. Ocean Drilling Program (ODP) Leg 195 recovered serpentinized peridotites that present a unique opportunity to study the products of shallow level exchanges between the upper mantle and slab-derived fluids. Similar to samples recovered during ODP Leg 125, the protoliths of these fore-arc serpentinized peridotites are mantle harzburgites that have suffered large volume melt extraction (up to 25%) prior to interactions with fluids released from the downgoing Pacific Plate. Samples …

Outcrop Analog For Lower Paleozoic Hydrothermal Dolomite Reservoirs, Mohawk Valley, Ny, Brian E. Slater

Geology Theses and Dissertations

Geochemical analysis and field relations of linear dolomite bodies occurring in outcrop in the Mohawk Valley of New York suggest that they have undergone significant fault-related hydrothermal alteration. The dolomite occurs in the Lower Ordovician Tribes Hill Formation, which is regionally an early Ordovician shaley limestone with patchy dolomitization. The outcrop has an en echelon fault, fracture, and fold pattern. A 3D ground penetrating radar survey of the quarry floor has helped to map out faults, fractures, anticlines, synclines and the extent of dolomitization. Most of the dolomitization occurs in fault-bounded synclines or “sags” flanked by anticlines. The dolomite structures …

The Impact Of Host Rock Geochemistry On Bacterial Community Structure In Oligotrophic Cave Environments, Hazel A. Barton, Nicholas M. Taylor, Michael P. Kreate, Austin C. Springer, Stuart A. Oehrle, Janet L. Bertog

International Journal of Speleology

Despite extremely starved conditions, caves contain surprisingly diverse microbial communities. Our research is geared toward understanding what ecosystems drivers are responsible for this high diversity. To asses the effect of rock fabric and mineralogy, we carried out a comparative geomicrobiology study within Carlsbad Cavern, New Mexico, USA. Samples were collected from two different geologic locations within the cave: WF1 in the Massive Member of the Capitan Formation and sF88 in the calcareous siltstones of the Yates Formation. We examined the organic content at each location using liquid chromatography mass spectroscopy and analyzed microbial community structure using molecular phylogenetic analyses. In …

Induced-Polarization Measurements On Unconsolidated Sediments From A Site Of Active Hydrocarbon Biodegradation, Gamal Z. Abdel Aal, Lee D. Slater, Estella A. Atekwana

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To investigate the potential role that indigenous microorganisms and microbial processes may play in altering low frequency electrical properties, induced-polarization (IP) measurements in the frequency range of 0.1 to 1000 Hz were acquired from sediment samples retrieved from a site contaminated by hydrocarbon undergoing intrinsic biodegradation. Increased imaginary conductivity and phase were observed for samples from the smear zone (contaminated with residual-phase hydrocarbon), exceeding values obtained for samples contaminated with dissolved-phase hydrocarbons, and in turn, exceeding values obtained for uncontaminated samples. Real conductivity, although generally elevated for samples from the smear zone, did not show a strong correlation with contamination. …

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.

Thermochronology And Provenance Of The Yakutat Terrane, Southern Alaska Based On Fission-Track And U/Pb Analysis Of Detrital Zircon, Stephanie Ellen Perry

Geology Theses and Dissertations

Northward transport of the Yakutat terrane along the Transition and Queen Charlotte-Fairweather transform faults led to Neogene collision of the Yakutat terrane with the southern continental Alaska margin. Northward translation resulted in a stratigraphy that records the erosion of thermotectonic terranes along its path. The strata of the Yakutat terrane includes the Lower Oligocene to Lower Eocene Kulthieth Formation, the Upper Eocene to Lower Miocene Poul Creek Formation and the Miocene-Pleistocene Yakataga Formation. Detrital zircon fission-track (DZFT) ages from stratigraphically coordinated samples collected in the Northern Robinson Mountains yield provenance information of the units that can shed light on their …

Geochemistry Of Serpentinized Peridotites From The Mariana Forearc Conical Seamount, Odp Leg 125: Implications For The Elemental Recycling At Subduction Zones, Ivan P. Savov, Jeffrey G. Ryan, Massimo D'Antonio, Katherine Kelley, Patrick Mattie

Geology Faculty Publications

Recent examinations of the chemical fluxes through convergent plate margins suggest the existence of significant mass imbalances for many key species: only 20–30% of the to-the-trench inventory of large-ion lithophile elements (LILE) can be accounted for by the magmatic outputs of volcanic arcs. Active serpentinite mud volcanism in the shallow forearc region of the Mariana convergent margin presents a unique opportunity to study a new outflux: the products of shallow-level exchanges between the upper mantle and slab-derived fluids. ODP Leg 125 recovered serpentinized harzburgites and dunites from three sites on the crests and flanks of the active Conical Seamount. These …

Geochemistry Of Ground Water - Surface Water Interactions And Metals Loading Rates In The North Fork Of The American Fork River, Utah, From An Abandoned Silver/Lead Mine, Neil I. Burk

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The aqueous geochemistry and hydrology of the North Fork of the American Fork River, its tributaries, and the ground water in the vicinity of the Pacific Mine site were investigated in order to determine what impact ground water entering the North Fork has on toxic metal loads in the river. Toxic metal contamination in the North Fork is great enough that brown and cutthroat trout have absorbed lead, cadmium, and arsenic in their tissues at concentrations that are hazardous to human health if consumed. Ground water that flows through the mine site flows directly through the mine tailings before entering …

Complexity Of Devonian K-Bentonites In The Appalachian Foreland Basin: Geochemical And Physical Evidence Supporting Multi-Layered K-Bentonite Horizons, Lucas Benedict

Geology Theses and Dissertations

Detailed analysis of Lower to Middle Devonian K-bentonites in the Appalachian Basin reveals physical and geochemical characteristics within supposed single eruptive event deposits that indicate a more complex depositional history is recorded in many of these volcanic beds. Variations in bedding showing multiple coarse and fine-grained layers within a K-bentonite layer can be seen in some Devonian K-bentonite beds. Microscopic irregularities show variations in the orientation of volcanic grains, and subtle phenocryst layers within a K-bentonite suggest changes in depositional environment where changing water and wave regimes rework and redeposit material on the sea floor. The presence of fossil layers …

In-Situ Apparent Conductivity Measurements And Microbial Population Distribution At A Hydrocarbon-Contaminated Site, Estella A. Atekwana, D. Dale Werkema, Joseph W. Duris, Silvia Rossbach, Eliot A. Atekwana, William A. Sauck, Daniel P. Cassidy, Jay Means, Franklyn D. Legall

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

We investigated the bulk electrical conductivity and microbial population distribution in sediments at a site contaminated with light nonaqueous-phase liquid (LNAPL). The bulk conductivity was measured using in-situ vertical resistivity probes; the most probable number method was used to characterize the spatial distribution of aerobic heterotrophic and oil-degrading microbial populations. The purpose of this study was to assess if high conductivity observed at aged LNAPL-impacted sites may be related to microbial degradation of LNAPL. The results show higher bulk conductivity coincident with LNAPL-impacted zones, in contrast to geoelectrical models that predict lower conductivity in such zones. The highest bulk conductivity …

Sedimentological And Geochemical Characterization Of East Pond, Belgrade Lakes Watershed, Central Maine, Robin H. Nesbeda

Honors Theses

The present study focuses on East Pond, the head of the lake-chain system. East Pond is roughly oval in shape with several coves along the margins; it has an average 3 depth of 4.5 m, a maximum depth of 7.3 m, and a total volume of 26.35 x 10 6 m . The lake is surrounded by North temperate hardwood forest and a marshy outlet to the other lakes exists in the northwest comer. East Pond has suffered severe yearly algal blooms during the late summer and into the fall since 1993. This project aims to develop a baseline for …

Petrology And Lithogeochemistry Of The Mineralized Tanzanite-Grossular Bearings Rocks In The Merelani-Lelatema Area, Northeastern Tanzania, Ep Malisa

Tanzania Journal of Science

The Merelani-Lelatema area, which is occupied by late Proterozoic metasedimentary rocks, lies along the Lelatema fault zone. The rocks are mainly pelitic and semi-pelitic gneisses, psammitic gneisses, hydrothermally altered rocks, crystalline dolostones, pegmatites and quartz veins. The occurrence of gem-quality tanzanite and grossular has been found to occur mainly in boudinaged pegmatitic veins and hydrothermal fracture fillings. These fracture fillings occur in brecciated and hydrothermally altered graphite-bearing gneiss in a mineral association containing glass-clear quartz, diopside, zoisite, graphite and calcite. The psammitic gneisses are more siliceous and enriched in feldspars. They are grouped into graphite-kyanite gneiss with thin interlayers of …

The Middle Cambrian Wheeler Formation: Sequence Stratigraphy And Geochemistry Across A Ramp-To-Basin Transition, Elizabeth S. Langenburg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Middle Cambrian Wheeler Formation is interpreted as having been deposited in the shallow ramp and deeper basin environments of the House Range embayment (HRE), presumably, during a single third-order sequence. In the Drum Mountains, the Wheeler Formation (295 m thick) is dominated by proximal and distal ramp deposits; at Marjum Pass, the Wheeler Formation (190m thick) is dominated by basinal shale deposits. The Wheeler Formation contains only one biozone marker; the first appearance of Ptyhagnostus atavus. Lack of other chronostratigraphic markers and distinctive stratal patterns in the basinal facies makes correlation along this ramp-to-basin transect difficult. Therefore, carbon-isotope …

Strontium Isotope Geochemistry In The Central Part Of The Great Plains (Dakota) Aquifer, U.S.A.. Applied Geochemistry, D. C. Gosselin, F. E. Harvey, C. Frost, R. Stotler, P. A. Macfarlane

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Thermochronological Evolution Of Calcite Formation At The Potential Yucca Mountain Repository Site, Nevada: Part 2 Fluid Inclusion Analyses And Upb Dating, Jean S. Cline, Amy J. Smiecinski, Robert Bodnar

Publications (YM)

The presence of two-phase fluid inclusions in thin secondary mineral crusts at the potential Yucca Mountain nuclear waste repository has raised questions regarding the origin, timing, and temperature of past fluid flow through the repository horizon. The geologically recent passage of fluids with high temperatures would call into question the suitability of the site for the storage of high level nuclear waste. This study determined the thermal history of fluid flow through the site using fluid inclusion analyses and constrained the timing of thermal fluids by dating silica minerals spatially associated with the fluid inclusions using U-Pb techniques. Results provide …

Field Relations, Structural Geology, And Geochemistry Of The Jonestown Volcanic Field, Lebanon County, Southeastern Pennsylvania, Tristan J. Ashcroft

Geology Theses and Dissertations

The Jonestown Volcanic Field is a five kilometer by fifteen kilometer area of volcanic and hypabyssal rocks, basalt and diabase, located in southeastern Pennsylvania. These igneous rocks presently occur within an allochthonous belt of Ordovician deep water sedimentary rocks and Taconic flysch rocks known collectively as the Hamburg Klippe. Detailed field mapping during this project has revealed that the contacts between the igneous rocks and the flysch are not conformable. The volcanic rocks are associated with the Ordovician limestone that is adjacent to these volcanics. This limestone also is not conformable to the Hamburg Klippe sediments, rather it shares outcrop …

The Use Of A Synthetic Binary Solid Solution To Model Igneous Textural Evolution, Elizabeth Scott

Geology Theses and Dissertations

Crystallization experiments using a synthetic igneous analog have shown that grain boundary migration can take place in melt-present environments (Means and Park, 1994). In order to evaluate the importance of metamorphic processes during the textural evolution of a crystal mush, microstructural evidence is needed to link them with final igneous textures. In natural magmatic systems, plagioclase may provide a microstructural link; plagioclase solid solution enables the process of chemical zoning and preserves a record of crystal morphology (and chemistry) during growth. If metamorphic processes are common, they should affect the zoning patterns of plagioclase crystals.
A petrographic stage heater apparatus …

The Geochronology And Geochemistry Of The Bearhead Rhyolite, Jemez Volcanic Field, New Mexico, Leigh Justet

UNLV Theses, Dissertations, Professional Papers, and Capstones

Around 82% of mapped Bearhead Rhyolite (Main Cluster) and Peralta Tuff appears to have been derived from a relatively long-lived (~680 ka), large, shallow (Earth's surface) magma chamber that did not produce a caldera-forming eruption. Although volatile contents were great enough (~ wt.% H₂O), no large-scale explosive eruptions occurred because magma may have been tectonically vented. The lack of systematic chemical variation within the Main Cluster with time during this ~680 ka interval may imply that erupted magmas were physically separated from each other by fault-formed cupolas in the roof of the magma chamber. These results are significant …

Compositional Variations In The Fire Clay Coal Bed Of Eastern Kentucky: Geochemistry, Petrography, Palynology, And Paleoecology, Cortland F. Eble, James C. Hower, William Morton Andrews Jr.

Report of Investigations--KGS

Bench samples of the Fire Clay coal bed, collected from 28 localities in a study area of eight 7.5-minute quadrangles in the Eastern Kentucky Coal Field, were analyzed geochemically, petrographically, and palynologically to determine any spatial or temporal trends among the studied parameters.

At most sample sites the Fire Clay is split by a flint-clay parting of probable volcanic origin. The upper bench of the Fire Clay coal generally is thick, laterally continuous, low in ash yield and sulfur content, has a moderate to high calorific value, and is high in total vitrinite content. In contrast, the lower bench generally …

Identification Of Past Climate Variability Of The Eastern Pacific Ocean Using Both D13c And D18o Records In Corals From Clipperton Atoll (1994-1906), Lei Ren

Geology Theses and Dissertations

The ENSO (El Nino and the Southern Oscillation) is a fundamental ocean-atmosphere phenomenon that dominates interannual global climate variability. Reconstructing past ENSO events is therefore important for documenting and understanding the past behavior of the global climate system and enabling us to predict future climate change. However, the present understanding of ENSO events has been mainly based on the instrumental record of Pacific climate which provides detailed data only for the past few decades. Recent studies have shown that the stable isotope record in coral skeletons can be used as a valuable indicator of paleoclimatic changes in tropical regions, and …

Geochemical, Petrologic, And Structural Characterization At Multiple Scales Of Deformation Associated With The Punchbowl Fault, Southern California, Steven E. Schulz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three traverses across the exhumed trace of the Punchbowl fault zone in the Pelona Schist, southern California, were examined at the millimeter to kilometer scales to determine the morphology, deformation mechanisms, and geochemistry of the fault zone in schistose rocks. The Pelona Schist is predominantly a quartz-albite-muscovite-actinolite schist with associated minor metabasalts. The Punchbowl fault zone, which is exhumed 2-4 km, has 44 km of right lateral slip, and is composed of a fault core enveloped by a damaged zone.

The fault core is a region of extreme slip localization that records most fault displacement. Deformation in the fault core …

Geochemical Evolution Of A Mid-Miocene Synextensional Volcanic Complex: The Dolan Springs Volcanic Field, Northwestern Arizona, Scott Michael Mcdaniel

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Dolan Springs volcanic field (DSV), of northwestern Arizona, is dominated by andesite and basaltic-andesite flows and breccias, with minor amounts of basalt, rhyolite, and ash-flow tuff. Geochemistry is used here as a tool to evaluate the roles and contributions of the lithospheric and asthenospheric mantles to magmatism related to Miocene extension in the Colorado River extension corridor (CREC). The majority of synextensional volcanic rocks in the DSV are geochemically similar to regional trends, but rare tholeiitic basalts erupted near the end of extension. The tholeiites have trace element signatures similar to ocean island basalt (OIB), but have isotopic values …