Physical Sciences and Mathematics Commons^™

The Fate Of Carbonate Rocks During Hypervelocity Impacts: Case Studies From Three Impact Structures On Earth, Nicolas D. Garroni

Electronic Thesis and Dissertation Repository

Approximately 28% of all hypervelocity impact structures discovered on Earth exist in a carbonate-dominated target sequence. Despite decades of research, how carbonate rocks and minerals react to shock metamorphism is still poorly understood. In this contribution, three impact structures on Earth were studied to determine the effects of shock metamorphism on carbonate minerals: Chicxulub, Crooked Creek and Jebel Waqf as Suwwan.

At Chicxulub, carbonates from the impact-melt bearing breccia of drill core, M0077A were characterized petrographically and geochemically. Calcite was the only carbonate mineral present and is abundant throughout the impact breccia in five distinct varieties: limestone clasts …

Depositional Conditions, Stratigraphic Evolution, And Allo- And Autogenic Controls Of Lower Permian Non-Marine Carbonate Rocks, Lucaogou Low-Order Cycle, Bogda Mountains, Nw China, Yiran Lu

Doctoral Dissertations

"The overall objective of this study is to interpret the depositional conditions of lacustrine carbonate deposits of the lower Permian Lucaogou low-order cycle in the greater Turpan-Junggar continental rift basin, NW China. The depositional environments of ten carbonate lithofacies in the Tarlong-Taodonggou half graben and the Zhaobishan section were interpreted. Allo- and autogenic factors were identified. They controlled characteristics and distribution pattern of carbonate deposits in regional and local scale, respectively. Allogenic factors include the amount and direction of regional siliciclastic input, basin geometry, cyclic humidity/aridity oscillation, temperature, and regional tectonics. Autogenic factors include local siliciclastic input, local topography, local …

Using Geochemical Composition To Determine Paleo Environmental Conditions And Source Inputs In Paleozoic Rocks Within The Central Kansas Uplift Usa, Christiana Fumnanya Eziashi

Master's Theses

Paleoenvironmental conditions, sediment characteristics and lateral continuity using chemostratigraphy are not well established for stratigraphic units associated with some small fields within the Central Kansas Uplift (CKU). Samples of drill cuttings recovered from six wells (Hottman #1, and Hottman-Furthmeyer#1, Yocemento #1, Mong Benno #2, Rhian #3 and Worcester #1) at 10 ft intervals between 3150 ft and 3900 ft below ground level, were processed and analyzed using X-ray fluorescence (XRF) and X-Ray diffraction (XRD). The XRF technique was used to determine elemental compositions, and XRD was used to determine mineral content. The composition of the rock cuttings was used to …

Impact Of Calcium Carbonate Reactant Size And Mineralogy On Dolomite Stoichiometry, Katharine G. Rose

Masters Theses

Dolomite is a common, diagenetic, Mg-Ca carbonate mineral. Dolomitization occurs by a dissolution-precipitation reaction between a CaCO₃ precursor (calcite or aragonite) and Mg bearing fluids. The amount of Mg in dolomite, referred to as dolomite stoichiometry (mol% MgCO₃), varies in natural dolomites (38-50 mol% MgCO₃). Laboratory experiments have shown that dolomite stoichiometry is dependent on physiochemical factors of the diagenetic fluids (i.e., temperature, salinity, and Mg/Ca). The impact of the CaCO₃ precursor on stoichiometry, however, has not been studied directly. This study tests how the CaCO₃ precursor size (sieve size) and mineralogy (calcite …

Investigating The Impact Of Meteoric Diagenesis On The Geochemistry Of Carbonate Eolianites, Eleuthera And Water Cay, The Bahamas, Graham S. Bonnot

LSU Master's Theses

The geochemical signatures imparted in major, minor, and trace elements, combined with light isotopes, suggest promising applications regarding the stabilization of meteorically altered limestone eolianites. Previous high-resolution studies have indicated that elements associated with carbonate diagenesis such as Mg and Sr can be valuable proxies for salinity and aragonite dissolution, respectively. In addition to testing these proxies, the analyses of several temperature-, diagenetic-, bioactive-, and redox-sensitive elements were evaluated using laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) to identify additional indicators during carbonate diagenesis. Two geochemical drivers of U were identified; (1) aragonite dissolution similar to Sr and (2) oxidation …

The Sedimentology Of Cay Sal Bank - An Incipiently Drowned Carbonate Platform, Luis Ramirez

HCNSO Student Theses and Dissertations

Sediment on Cay Sal Bank (CSB) is characterized by its coarse-grain size, poor sorting, predominance of skeletal fragments, and relatively depleted d¹⁸O isotope values. CSB is an incipiently drowned platform in close proximity to the Great Bahama Bank (GBB), a carbonate platform which is not incipiently drowned and characterized by fine-grained, non-skeletal sediment. The GBB has locally well-developed oolitic grainstone facies and coral reef margins, which are both lacking on CSB. Platform-top water depths on the GBB are typically 10 m or less, but CSB depth ranges between 7 and 30 m. CSB is devoid of mud, whereas …

A New Chronostratigraphic Framework For The Silurian (Wenlockian) Niagara And Salina Units Of The Michigan Basin, Matthew Rine

Dissertations

Constraining the ages of sedimentary strata is challenging and is the principle source of stratigraphic uncertainty in sedimentary basins worldwide. The story is no different in the Michigan Basin, where our current understanding of the Silurian Niagara-Lower Salina stratigraphic record is based in large part on limited sedimentological and chronological data, resulting in a collection of models that disagree about the timing of deposition. This disagreement marks the starting point for the dissertation research presented here. The studies included in the dissertation integrate conventional and novel approaches to address the stratigraphic uncertainty that has plagued Silurian reef researchers for decades. …

Depositional Environment And Facies Analyses Of The Owl Mountain Province, Fort Hood Military Installation, Bell And Coryell Counties, Texas, Jacob Meinerts

Electronic Theses and Dissertations

The Owl Mountain Province is a plateaued, karst landscape located in the eastern section of the Fort Hood Military Installation and is characterized by Lower Cretaceous Fredericksburg Group carbonates. The topography is capped by thick sequences of the Edwards limestone; steep scarps and incised valleys along the edges of the plateaus host inter-fingering outcrops of the Edwards and Comanche Peak limestones, and the lower valleys are covered by alluvial sediments and intermittent outcrops of the Walnut Clay. These formations were deposited to the north and west of the main Edwards trend, and are thought to be part of a series …

Environmental Changes Across The Early Mississippian Carbon Isotope Excursion, Dev Krishna Maharjan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Early Mississippian K–O (Kinderhookian-Osagean) δ13C excursion or TICE (mid-Tournaisian carbon isotope excursion) is characterized by an anomalous carbonate carbon isotope value of ≥5‰ that has been documented from numerous stratigraphic sections across the globe. This δ13C excursion coincides with global cooling and sea-level fall and predicts a significant change in seawater chemistry. However, sulfate sulfur isotope data across the K-O δ13C excursion reported in previous studies seem not to be responsive to the carbon cycle. Likewise, a recent study has documented a unidirectional increase in nitrogen isotopes across this excursion, which is not anticipated considering the amount of organic …

Depositional Facies And Sequence Stratigraphy Of Niagaran-Lower Salina Reef Complex Reservoirs Of The Guelph Formation, Michigan Basin, Matthew J. Rine

Masters Theses

Hydrocarbon reservoirs in the Niagara-Lower Salina Reef Complex in the Michigan Basin have been extensively studied since the early 1960’s. These reservoirs host an immense hydrocarbon resource, existing as closely-spaced, highly-compartmentalized reservoirs that have produced >500 million barrels of oil and 2.9 trillion cubic feet of natural gas. Previous studies depict these “pinnacle reefs” as tall, symmetrical towers with a random distribution of facies. This study utilizes abundant core data (32 cores, 20-acre spacing), thin-section petrography, and petrophysical wire-line logs to reconstruct the geometry, facies distributions, depositional history, and sequence stratigraphy of the Columbus III Reef Complex within the Southern …

Detrital Carbonates In A Sequence Stratigraphic Framework: An Example From The Furongian Slope Environment In The Hot Creek Range Of Central Nevada, Leon Taufani

UNLV Theses, Dissertations, Professional Papers, and Capstones

An integrated sedimentological study of detrital carbonates of the late Cambrian (Furongian) Hales Limestone in central Nevada was conducted in order to model facies distribution and controlling mechanisms of carbonate gravity-flow deposits. Seven closely-spaced sections and numerous traceable short sections were measured to investigate temporal and spatial changes of detrital carbonates within a high-resolution stratigraphic framework supported by biostratigraphic and carbon isotope chemostratigraphic constraints and by key physical surfaces. Polished slabs and thin section petrographic analysis were used to identify micro- and macro-scale textures and diagenesis.

Ten lithofacies are identified from the Hales Limestone. Lateral tracing of these facies reveals …

Architecture And Stratigraphy Of The Lower Silurian Guelph Formation, Lockport Group, Southern Ontario And Michigan, Candace Brintnell

Electronic Thesis and Dissertation Repository

The Lower Silurian Lockport Group in Ontario and Michigan comprises, in ascending order: Gasport, Goat Island, Eramosa, and Guelph formations. Guelph facies architecture reveals deposition on an underlying carbonate ramp of Eramosa and/or Goat Island carbonates that dipped towards the Appalachian Basin. Temporally, Guelph facies reflect initial open marine transgressive phases that become increasingly restricted marine and karstic upward. Spatially, the facies display the most restricted marine and karstic fabrics in the central portion of the ‘Michigan Basin’ and are most open marine to the east. Newly acquired regional data supports the re-interpretation of the classic Guelph-pinnacle reef models as …

Evaluating The Effects Of Lithofacies And Thin Shales On The Lateral Distribution Of Hydrothermal Dolomite Reservoirs In The Michigan Basin, Peter J. Feutz

Masters Theses

The southern Michigan Basin contains numerous hydrothermal dolomite hydrocarbon fields, including the giant Albion-Scipio Field. The fields typically encompass narrow zones of faulting and fracturing which have been altered from a tight host limestone into a more porous and permeable dolomite by upward-moving hydrothermal fluids. Alternating layers of dolomite that spread laterally away from the main vertical fault conduits imply that structure alone may not define the resulting reservoir architectures within the region. A detailed analysis of primary depositional facies and thin shale seams suggests that secondary stratigraphic controls play a significant role in the development of reservoir rock within …

Sequence Stratigraphy Of The Lower Pennsylvanian (Bashkirian, Morrowan) Round Valley Limestone, Split Mountain Anticline (Dinosaur National Monument) And In The Eastern Uinta Mountains, Utah, Nathan Robert Davis

Theses and Dissertations

The Early Pennsylvanian (Bashkirian/Morrowan) Round Valley Limestone of northeastern Utah was deposited on the Wyoming shelf, a slowly subsiding depositional surface located between the Eagle and Oquirrh basins. The 311-foot-thick Round Valley Limestone displays a distinct cyclicity formed by stacked, meter-scale parasequences, comprised of a limited suite of open- to restricted-marine limestones with minor interbeds of siltstone and shale. Open-marine deposits are characterized by mudstone and heterozoan wackestone-packstone microfacies (MF1-4) and comprise the lower portions of parasequences. Rocks of these microfacies were deposited during maximum high-order transgression of the shelf. As sediment filled the limited accommodation, the shelf became restricted, …

Trace Elements In Northern Virginia Middle Ordovician Carbonates: Implications For Diagenesis, Ruth Ann Strauss

OES Theses and Dissertations

Ninety-three carbonate rock samples collected from four of the major lithofacies types present in the Middle Ordovician limestone sequence of northwestern Virginia were analyzed to investigate whether the lithofacies bear the geochemical signature of the depositional and/or the diagenetic environment. Significant variations in Cr, Fe, Mg, Mn and Sr concentrations exist among the major lithofacies types. Low levels of Sr in both New Market lithofacies are indicative of an open system during diagenesis. Dissimilar Fe and Mn concentrations between these, however, reflect water chemistry differences in the depositional environment. Increasingly greater Cr, Fe, Mn, and Sr concentrations in the Lincolnshire …

Depositional And Diagenetic History Of The Middle Ordovician Carbonates Of The Shenandoah Valley, Northern Virginia, Lynn Ellen Weyenberg

OES Theses and Dissertations

An examination of the Middle Ordovician carbonates in northwest Virginia has revealed a particularly sensitive record of deposition and subsidence. Two-hundred acetate peels from six measured stratigraphic sections in Shenandoah County, Virginia were examined to interpret the depositional and diagenetic history. Two major lithofacies have been recognized within the New Market Limestone and three have been recognized in the Lincolnshire Formation. These five lithofacies represent an overall transgressive sequence. This transgression was not uniform but paused several times to allow carbonate deposition to reach sea-level. These shoaling events suggest a slowly subsiding basin in this region. The carbonate rocks within …