Geology Commons^™

Phosphate Mineralogy And Paragenesis Of The Fletcher Pegmatite, North Groton, New Hampshire, Susanna T. Kreinik

University of New Orleans Theses and Dissertations

Investigation of phosphate assemblages selectively collected at the Fletcher Mine pegmatite, North Groton, New Hampshire, yielded eighteen discrete secondary phosphate species. Secondary phases were formed via metasomatic (high temperature) and hydrothermal (low temperature) alteration of primary triphylite and fluorapatite. Mineral associations bear proximal phases known to occur under contrasting conditions, both oxidizing and reducing, suggesting the formation of microenvironments during concomitant mineral generation. Late-stage hydrothermal fluids provide ions taken up in low temperature secondary phases with calcium and magnesium most prevalent in these suites. High iron to manganese ratios in analyzed specimens establish the relative evolution of the pegmatite host. …

Fine Grained Delta Front Sediment Transport, Sarah Noel

University of New Orleans Theses and Dissertations

Insights into transformative coastal processes are unlocked though understanding sediment transport mechanisms in fine-grained delta front environments. Movement of fine-grained sediments on delta fronts is not wholly explained through advection settling models. While advection settling models generally assume deposition into a still body, numerical modeling of sediment re-entrainment suggests there may be tidal, wave, and/or non-steady hydrograph influences allowing particles to reach greater distances by altering the decelerating velocity field. This research explores both an advection settling model and a mass conservation Rouse profile model to understand the irreducible delta front processes controlling sediment deposition. Using field data collected on …

Machine Learning Model Selection For Predicting Global Bathymetry, Nicholas P. Moran

University of New Orleans Theses and Dissertations

This work is concerned with the viability of Machine Learning (ML) in training models for predicting global bathymetry, and whether there is a best fit model for predicting that bathymetry. The desired result is an investigation of the ability for ML to be used in future prediction models and to experiment with multiple trained models to determine an optimum selection. Ocean features were aggregated from a set of external studies and placed into two minute spatial grids representing the earth's oceans. A set of regression models, classification models, and a novel classification model were then fit to this data and …

“Enriching Lives Within Sedimentary Geology”: Actionable Recommendations For Making Sepm A Diverse, Equitable And Inclusive Society For All Sedimentary Geologists, R.C. Mahon, A.M. Fernandes, A. Abeyta, R. Martindale, K.D Bergman, C. Jackson, Et Al

Earth and Environmental Sciences Faculty Publications

Innovative science benefits from diversity of thought and influence at all waypoints along the scientific journey, from early education to career-length contributions in research and mentorship. Scientific societies, like the Society for Sedimentary Geology (SEPM), steward their innovators and the direction of the science, thereby defining the societal impact and evolution of a discipline. They are uniquely positioned to promote the representation and success of all scientists, including those from minoritized populations, through proactive advocacy, and inclusive mentorship, awards, and leadership. We introspectively review available records of SEPM membership, leadership, awardees, and editorial boards to identify areas for growth and …

Probability Distributions Of Particle Hop Distance And Travel Time Over Equilibrium Mobile Bedforms, Robert C. Mahon, Ashley C. Thomas, Suleyman Naqshband, Kate C. P. Leary, Brandon Mcelroy

Earth and Environmental Sciences Faculty Publications

The joint probability distribution of streamwise particle hop distance, lateral particle hop distance, and travel time constrains the relationships between topographic change and sediment transport at the granular scale. Previous studies have investigated the ensemble characteristics of particle motions over plane bed topography; however, it is unclear whether reported distributions remain valid when bedforms are present. Here, we present measurements of particle motion over bedform topography obtained in a laboratory flume and compare these to particle motions over plane bed topography with otherwise similar conditions. We find substantial differences in particle motion in the presence of bedforms that …

Evolution And Stratigraphic Architecture Of Tidal Point Bars With And Without Fluvial Input: Influence Of Variable Flow Regimes On Sediment And Facies Distribution, And Lateral Accretion, Pricilla Souza

University of New Orleans Theses and Dissertations

Tide-influenced point bars represent a significant proportion of shallow-marine deposits, commonly developed along meandering channels in most backbarrier and estuarine systems. However, sedimentological studies to characterize this type of deposit are still emerging. They often present very heterogeneous internal architectures which development is controlled by the complex flow patterns operating in tidal environments. The study of the sedimentological and morphological characteristics of these features provides better understanding of the hydrodynamic processes that shape coastal systems and control their evolution as well as it contributes to better reservoir potential prediction and production strategy optimization, as tidal point bars may represent hydrocarbon …

Middle Miocene To Holocene History Of The Delacroix Island Fault System, Jarrett Leigh Levesh

University of New Orleans Theses and Dissertations

An in-depth field study of the Delacroix Island producing field illustrates the evolution of the east-trending Delacroix Island Fault during the last 13 My. Well log correlations and 3-D seismic interpretation of 22 subsurface bio-stratigraphic horizons across the fault reveal variable stratigraphic thicknesses and displacement. Wells, with well log curve data as shallow as 31 m (100 ft) below the surface, were used to calculate interval thicknesses, expansion indices, sediment accumulation rates, burial history and magnitudes of displacement. Through these analyses, a correlation was found between the positioning of ancient Miocene depocenters over Delacroix Island and a period of increased …

Seamless Lidar Surveys Reveal Rates And Patterns Of Subsidence In The Mississippi River Delta, Celeste E. Woock

University of New Orleans Theses and Dissertations

Light Detection and Ranging (Lidar) data are used to report the temporal and spatial patterns of subsidence as well as the potential contributors to subsidence within the Barataria and Terrebonne Bays. In recent decades, subsidence in southeast Louisiana has become a topic of substantial and growing concern to the scientific community, the local residents, and all those invested in the region. Lidar data were acquired from the United States Geological Survey (USGS) and the LSU Center for Geoinformatics. The data has been manipulated to map the differenced Lidar, complete an instantaneous slope analysis, and determine the thickness of the Holocene …

Geomorphology Of Shell Ridges And Their Effect On The Stabilization Of The Biloxi Marsh, East Louisiana, Frances R. Crawford

University of New Orleans Theses and Dissertations

Extensive shell ridges frame the edges of marsh platforms in parts of the Biloxi Marsh of southeast Louisiana. The exact sources of the shells in these accumulations have not been clearly identified but the most likely source is a combination of shells from modern offshore and shells excavated from buried St. Bernard delta deposits. Larger or fetch-protected ridges remain stable through time, whereas ridges facing open water are more mobile, moving as much as 38 m inland from July 2017 to January 2018. Behind stable ridges, marsh platform biomass is relatively unaffected. When ridges are mobile, vegetation is smothered, leaving …

Coupled Barrier Island Shoreline And Shoreface Dynamics, Benjamin S. Beasley

University of New Orleans Theses and Dissertations

In Louisiana, barrier islands are undergoing morphological change driven by high rates of relative sea-level rise and interior wetland loss. Previous works utilized historical region-scale bathymetry and shoreline change analyses to assess coastal evolution. However, more localized assessments considering the role of sediment transport processes in regional evolution are lacking. This is essential to predicting coastal change trajectories and allocating limited sand resources for nourishment. Using bathymetric and shoreline data, 100-m spaced shore-normal transects were created to track meter-scale elevation change for 1880s, 1930s, 1980s, 2006, and 2015. An automated framework was used to quantify and track parameters such as …

Hydrodynamic Controls On The Morphodynamic Evolution Of Subaqueous Landforms, Timothy L. Nelson

University of New Orleans Theses and Dissertations

The southern Chandeleur Islands are an ideal setting to study shoal evolution given their history of submergence and re-emergence. Here, numerical models shed light on the attendant processes contributing to shoal recovery/reemergence following a destructive storm event. Simulations of a synthetic winter storm along a cross-shore profile using Xbeach shows that convergence of wave-induced sediment transport associated with repeated passage of cold-fronts initiates aggradation, but does not lead to reemergence. A Delft3d model of the entire island chain shows that as these landforms aggrade alongshore processes driven by incident wave refraction on the shoal platform, backbarrier circulation and resulting transport …

Seismic Facies Classification Of An Intraslope Minibasin In The Keathley Canyon, Northern Gulf Of Mexico, Lamine Meroudj

University of New Orleans Theses and Dissertations

This work examines several volume attributes extracted from 3D seismic data with the goal of seismic facies classification and lithology prediction in intraslope minibasins. The study area is in the Keathley Canyon protraction (KC), within the middle slope of the Northern Gulf of Mexico (GOM). It lays within the tabular salt and minibasins province downdip of the main Pliocene and Pleistocene deltaic depocenters. Interaction between sedimentation and mobile salt substrate lead to the emergence of many stratigraphic patterns in the intraslope minibasins. Interest in subsalt formations left above salt formations poorly logged. Facies classification using Artificial Neural Network (ANN) was …

Evidence Of Fault Movement During The Holocene In Southern Louisiana: Integrating 3-D Seismic Data With Shallow High Resolution Seismic Data, Joseph P. Frank

University of New Orleans Theses and Dissertations

The Baton Rouge fault system of Louisiana is a well-known recently active system consisting of en echelon, east trending, down-to-the-south normal faults across the northeast periphery of the Mississippi River delta plain. Two, industry-donated, 3-D seismic surveys across 860 km² image deep-seated faults below Lake Borgne, along an east strike that parallels previously well mapped segments of the Baton Rouge system. Four major faults (> 6 km fault trace) are imaged within the seismic surveys across the Lake. The industry seismic data were not processed for reliable imaging at depths (m). To bridge the depth gap in seismic, high …

Overwash Controls On Barrier Island Morphodynamics During Storms, Joshua H. Alarcon

University of New Orleans Theses and Dissertations

Overwash, shoreface retreat, and barrier migration are common processes occurring in transgressive barrier island systems, the scale of which is exacerbated by sea level rise, subsidence and the frequency and magnitude of tropical and extratropical storms. Barrier morphology also clearly plays a key role in determining a morphological response to these processes. Using a hydrodynamic and sediment transport model (MIKE21) and selected barrier island and shoreface templates, informed by deltaic and coastal plain systems in the northern Gulf of Mexico, I performed simulations to determine barrier morphology in response to storms. A low dune with a gentle shoreface slope, characteristic …

Paleohydrology And Paleoecology Of The Neogene Siwalik Rocks, Nepalese Himalaya Using Multi-Proxy Lipid Biomarker Isotopic Study, Prabhat Chandra Neupane

University of New Orleans Theses and Dissertations

This study deploys compound-specific multi-proxy isotopic study of lipid biomarkers to understand Neogene climatic and ecological variabilities in the Himalayan foreland. The investigation of compound-specific carbon and hydrogen isotopes along with glycerol dialkyl glycerol tetraether (GDGT) is the first of its kind for the Nepalese Siwalik. A total of 49 mudstone (and some paleosol) samples were collected from the paleomagnetically age-constrained Siwalik strata in the Surai Khola and Karnali River sections.

δ¹³C results suggest a domination of C₃ trees between 12 and 8.5 Ma, and a stepwise expansion of C₄ grasses starting gradually at 8.5 Ma …

Validating A Universal Model Of Particle Transport Lengths With Laboratory Measurements Of Suspended Grain Motions, Robert C. Mahon, Brandon Mcelroy, Suleyman Naqshband

Earth and Environmental Sciences Faculty Publications

t The mechanics of sediment transport are of fundamental importance for fluvio-deltaic morphodynamics. The present study focuses on quantifying particle motions and trajectories across a wide range of flow conditions. In particular, a continuous model is presented that predicts particle travel distances for saltation and suspension based on Rouse number and relative grain roughness. By utilizing a series of eight video cameras in a plexiglass flume direct measurements of the distributions of particle travel distances (excursion lengths) were obtained. To this end, experiments were carried out in dark under black lights with fluorescent painted plastic and quartz sand particles. For …

An Investigation Into The Origin, Composition, And Commercial Significance Of A Sedimentary Subsalt Formation: Keathley Canyon, Gulf Of Mexico, David Aaron Brassieur

University of New Orleans Theses and Dissertations

Sub-salt oil and gas formations in deep-water northern Gulf of Mexico are high priority targets. Advances in seismic processing allow for high-resolution, below-salt imaging. Understanding the modes of salt emplacement provide insight into sub-salt traps and potential drilling hazards.

A sub-salt sedimentary unit lies in the Keathley Canyon protraction. Autosutures created the transport-parallel lineaments of the upper surface of the unit. In addition, highly variable sediment aggradation rates created ramps, flats, and basal cutoffs along the base of the allochthon as salt and sediment competed for space. Seismic models identify modes of salt emplacement, salt/sediment interactions, and mechanisms responsible for …

Barrier Spit Evolution And Primary Consolidation Of Backbarrier Facies: West Belle Pass Barrier, La, John N. Kramer Iii

University of New Orleans Theses and Dissertations

West Belle Pass Barrier is a barrier spit that formed during the last delta lobe progradation associated with the Lafourche delta complex. Located on the western flank of the Caminada-Moreau Headland, West Belle Pass Barrier and Raccoon Pass are located downdrift of the Belle Pass jetties. Morphological changes stemming from storms, jetty infrastructure, and an expanding tidal inlet are evaluated using historical shoreline data and imagery. Littoral transport around the jetties combined with inlet growth created a framework wherein sediment is transported through Raccoon Pass and sequestered as a flood-tidal delta. These events aided in the landward migration of West …

High-Frequency Tectonic Sequences In The Campanian Castlegate Formation During A Transition From The Sevier To Laramide Orogeny, Utah, U.S.A., David B. Cross

University of New Orleans Theses and Dissertations

Though stratigraphic correlations are abundant in the Cordilleran basin-fill, they rarely include along-strike transects providing a spatio-temporal sense of deformation, sediment-supply and subsidence. A new, high-resolution, regional strike-correlation of the Castlegate Formation reveals progressive northward-growth of the San Rafael Swell during two embryonic episodes of Laramide-style deformation in central Utah. The intrabasinal deformation-events produced gentle lithospheric-folding punctuated by erosional-truncation of upwarped regions. The earliest episode occurred at 78 Ma in the southern San Rafael Swell likely causing soft-sediment deformation and stratal-tilting. Following this the alluvial-plain was leveled and rapid, extensive-progradation took place. A second episode, at 75 Ma, where deformation …

Applying Modern Interpretation Techniques To Old Hydrocarbon Fields To Find New Reserves: A Case Study In The Onshore Gulf Of Mexico, U.S.A., Josiah D. Hulsey

University of New Orleans Theses and Dissertations

This study shows how the use of modern geological investigative techniques can reopen old, “drained” hydrocarbon fields. Specifically, it looks at the White Castle Field in South Louisiana. This field has pay sections ranging from late Oligocene to late Miocene. The late Oligocene package is underexplored and understudied and contains 3 primary reservoirs (Cib Haz (CH), MW, and MR). This study established the depositional history of these reservoirs. During most of the late Oligocene, the White Castle Salt Dome was located in a minibasin on the continental slope. The CH and MW deposited in this minibasin. The CH is an …

Submarine Channel Evolution Linked To Rising Salt Dome, Mississippi Canyon, Gulf Of Mexico, Rachel C. Carter

University of New Orleans Theses and Dissertations

By examining halokinetics and channel evolution in a deep-water system, we investigate how submarine channel morphology is affected by changing seascape linked to diapirism. The study area is located in Mississippi Canyon, Gulf of Mexico (GOM), situated directly off the continental slope in a prominent salt dome region. Interactions of salt domes with submarine channels in the GOM are poorly documented. Utilizing 3D seismic data and seismic geomorphology techniques, a long-lived Plio-Pleistocene submarine channel system has been investigated to develop a relationship between variable phases of salt movement and plan-form morphology of preserved channels.

We suggest that halokinetics acts as …

Petroleum Play Study Of The Keathley Canyon, Gulf Of Mexico, Jean Pierre Malbrough

University of New Orleans Theses and Dissertations

Beneath Keathley Canyon (KC) off the Southern Coast of Louisiana and Texas, allochthonous salt bodies have attained thicknesses of over 7620 m (25000 feet), providing excellent seals and migration pathways for hydrocarbons produced by post-rift sedimentary deposition. This study analyzes a small portion of the KC area, utilizing Petrel Seismic software and well information from the KC102 (Tiber) well.

An intra-Miocene wedge, expressed beneath salt, may provide information about movement of allochthonous salt over Wilcox sands, sediment compaction, and hydrocarbon pathways. Progradational sedimentation is the driving force which leads to faulting in the early Miocene, allowing Jurassic salt to rise, …

Mineralogy And Geochemistry Of Late Archean And Paleoproterozoic Granites And Pegmatites In The Northern Penokean Terrane Of Marquette And Dickinson Counties, Michigan, Christopher M. Johnson, Christopher M. Van Daalen

University of New Orleans Theses and Dissertations

This thesis focuses on mineralogy, geochemistry, and origin of eight pegmatites and two spatially associated granites of Late Archean and Paleoproterozoic ages located in Marquette and Dickinson Counties, Michigan. Biotite geochemistry reveals that both granites and all pegmatites are peraluminous and have an orogenic signature. However, bulk composition reveals the Humboldt granite is a peraluminous A-type granite and the Bell Creek granite is a peraluminous mix between I-, S-, and A-type granites. The Republic Mine pegmatite appears to be geochemically similar to the Bell Creek granite and Grizzly pegmatite. The Crockley pegmatite is genetically related to the Humboldt granite. The …

Quantifying The Stratigraphic Completeness Of Delta Shoreline Trajectories, Robert C. Mahon, John B. Shaw, Katherine R. Barnhart, Daniel E. J. Hobley, Brandon Mcelroy

Earth and Environmental Sciences Faculty Publications

Understanding the incomplete nature of the stratigraphic record is fundamental for interpreting stratigraphic sequences. Methods for quantifying stratigraphic completeness for one-dimensional stratigraphic columns, defined as the proportion of time intervals of some length that contain stratigraphy, are commonplace; however, quantitative assessments of completeness in higher dimensions are lacking. Here we present a metric for defining stratigraphic completeness of two-dimensional shoreline trajectories using topset-foreset rollover positions in dip-parallel sections and describe the preservation potential of a shoreline trajectory derived from the geometry of the delta surface profile and the kinematics of the geomorphic shoreline trajectory. Two end-member forward models are required …

The Garnet Line In Oxford County, Maine Pegmatites., Myles Mathew Felch, Myles M. Felch

University of New Orleans Theses and Dissertations

The garnet line is a planar fabric occuring within the intermediate and core zone in many of the Oxford County, Maine pegmatites. This study focuses primarily on the textural and chemical characteristics of the garnet line within the Mt. Mica and western Mt. Apatite quarries. Smaller, but similarly textured garnet line analogs from the Bennett, Emmons, Havey and Tamminen quarries are also investigated. All of these textures represent specific fractionation events within their respective dikes. In some of these locations, multiple stages of crystallization occur and appear to be post-magmatic, related to late stage metasomatism. These late stage fluids are …

Contact Zone Mineralogy And Geochemistry Of The Mt. Mica Pegmatite, Oxford County, Maine, Kimberly T. Clark

University of New Orleans Theses and Dissertations

This study focuses on exocontact mineral assemblages to determine composition, thermal signatures, and the extent of exomorphism that occurred between the Mt. Mica pegmatite and the migmatite host rock at the contact. Biotite-garnet thermometry of country rock samples resulted in an average temperature estimate of 630 °C. Measured biotite Fe/(Fe+Mg) ratios were used to calculate an fO2 of -18. The results indicate that the country rock and pegmatite formed under similar oxidizing conditions near the quartz-fayalite-magnetite (QFM) equilibria buffer. Whole rock (REE) analysis indicates an interaction trend between the country rock and pegmatite. Exomorphism does not appear to have …

An Analysis Of The Green Knoll Salt Dome, Located In The Southeast Green Canyon, Deep Water Gulf Of Mexico, Randal J. Broussard

University of New Orleans Theses and Dissertations

The western portion of the Mississippi/Atwater fold belt in the Gulf of Mexico contains what is known as The Green Knoll Salt Dome. The creation and growth of this salt diapir is punctuated by salt deposition, salt migration, sediment loading, and is linked to the “Frampton” fold belt. An indicator of these growth periods is exhibited in an angular unconformity (halo-kinetic sequence boundary) that flanks the diapir. This unconformity developed during the Miocene-Pliocene chronostratigraphic boundary. The “Redwood” (Green Canyon 1001) prospect was drilled after the discovery of middle Miocene sands containing hydrocarbons in the Mad Dog field (GC 826). The …

Mineralogy And Geochemistry Of The Erongo Granite And Interior Quartz-Tourmaline Orbicules And Nyf-Type Miarolitic Pegmatites, Namibia, Andrew P. Boudreaux

University of New Orleans Theses and Dissertations

The early Cretaceous anorogenic Erongo Granite of Namibia is known to host abundant boron mineralization in rounded, quartz-tourmaline clusters and in NYF-type miarolitic, pegmatitic cavities. Rock and mineral samples were taken from the bulk granite, tourmaline nests, and miarolitic cavities and analyzed using a variety of modern analytical techniques. Geochemical and mineralogical data suggest substantial input from the metasedimentary rocks of the Damara orogen was important in the genesis of the Erongo Granite magma. The geochemical signature of the Damara orogen is most evident in the tourmaline clusters and miarolitic cavities, where fractional crystallization accumulated volatile and incompatible elements enough …

Geochemistry, Mineralogy And Evolution Of Mica And Feldspar From Within The Mount Mica Pegmatite, Maine, Usa, Karen L. Marchal

University of New Orleans Theses and Dissertations

Mount Mica is a poorly zoned sodic LCT-type pegmatite consisting dominantly of quartz, albite and muscovite in the outer portions. Potassium feldspar and lepidolite are restricted to the core zone. Micas in the wall zone are chemically homogeneous, but abruptly evolve into higher Cs + Rb bearing lithian muscovites and lepidolites in the core zone. The abrupt increase of the Cs, Rb in K-feldspar, and Cs, Rb and F in muscovite, and lepidolite combined with the occurrence of highly evolved species lepidolite, pollucite, elbaite, beryl and spodumene in the core zone suggests that incompatible elements were retained in residual …

Geochemical Evidence For Vertical Migration Of Deep Formation Fluids Through The Baton Rouge -Denham Springs Fault System, Lesley C. Prochaska

University of New Orleans Theses and Dissertations

Accumulations of brackish groundwater exist across south Louisiana within the shallow, south-dipping Pleistocene to Upper Miocene Baton Rouge Aquifer System (BRAS). This research investigates the source of brackish groundwater through geochemical analysis of representative groundwater samples by comparing the following geochemical ratios along with other trace elements. Low Bromide (Br)/Chloride (Cl) and Potassium (K) /Cl ratios, high Sodium (Na) /Cl ratios, trace Magnesium (Mg) concentrations, and low Strontium (Sr) ⁸⁷/Sr⁸⁶ in brackish waters from the BRAS are inconsistent with in situ saline water from marine formation fluids of similar age. The ratios are consistent with in situ saline-water …