Geochemistry Commons^™

Snapshots Of Coastal Ecology During Glacial And Deglacial Intervals: A Multiproxy Assessment Of Northern Gulf Of Mexico Sediment Cores, Kendall Emilie Brome

LSU Master's Theses

Terrestrial ecosystems along exposed continental shelves during times of relatively low sea level and glaciation are rarely preserved due to the mechanically erosive nature of marine transgression and regression. In this study, I investigate the geochemical and palynological characteristics of two well-preserved sites in the northern Gulf of Mexico (NGOM) to determine the ecologic settings and subsequent mechanisms of preservation in this region. Both sites contain preserved terrigenous sediments of previously exposed coastal margins; the first is located at the Alabama Underwater Forest (~13 km south of Gulf Shores, AL, at ~15 mbsl), and optically stimulated luminescence dates to 72–56 …

Preliminary Geochemical And Mineralogical Assessment Of The Beach Sand, Vieques, Puerto Rico, Nazrul I. Khandaker

Publications and Research

PRELIMINARY GEOCHEMICAL AND MINERALOGICAL ASSESSMENT OF THE BEACH SAND, VIEQUES, PUERTO RICO

ROBBINS, Kathy H., KHANDAKER, Nazrul, SINGH, Andrew, and MUNRO, Toralv, Geological Society of America Abstracts with Programs, Vol 54, No. 5, https://doi.org/10.1130/abs/2022AM-379886

ROBBINS, Kathy H., Bronx Early College Academy for Teaching and Learning, 250E 164 STREET, Bronx, NY 10456, KHANDAKER, Nazrul, Geology Discipline, York College of CUNY, 9420 Guy R Brewer Blvd, AC-2F09, Jamaica, NY 11451-0001, SINGH, Andrew, Earth and Physical Sciences, York College of CUNY, 9420 Guy R Brewer Blvd, AC-2F09, Jamaica, NY 11451-0001 and MUNRO, Toralv, 10911 164th St Apt 1, Jamaica, NY 11433-2921 …

Antler Foreland Basin Evolution Recorded In Detrital Zircon U-Pb Geochronology, James Duncan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Antler orogeny was a Devonian-Mississippian (375-320 Ma) mountain building event that occurred along the western Laurentian margin. The initiation of the Antler orogeny is marked by the emplacement of the Roberts Mountain Allochthon (RMA) that thrust Cambrian-Devonian deep water marine siliciclastic rocks 100 km eastward onto the western Laurentian margin. Shortening related to the Antler orogeny deformed RMA strata and caused a flexural response in the continental crust that resulted in the formation of the adjacent Antler Foreland basin. The paleogeographic history of the RMA strata and tectonic drivers for the Antler orogeny are still debated. Proposed models suggest …

Distribution Of Particulate Organic Carbon – Fluxes And Inventories – In Growth-Faulted Coastal Wetlands, Samuel Joel Whitehead

Theses and Dissertations--Earth and Environmental Sciences

Coastal wetlands along the Northern Gulf of Mexico (NGOMx) are critically important but threatened environments which provide significant and diverse economic, social, and environmental value. These environments are essential components to the global carbon cycle, serving as one of the most efficient terrestrial carbon sinks. Since onset of the Industrial Revolution increasing rates of coastal wetland loss have been documented due to a variety of anthropogenic activities, neotectonic processes, subsidence, and rising sea-levels. This research utilized an array of methods and sedimentological analyses to test the hypothesis that growth-fault induced changes at Earth’s surface affects the delivery to, and storage …

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 or Doctor of Nursing Practice

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 …

Stratigraphic Analysis Of The Capps Limestone In The North Norton Oil Field In Runnels County, Texas, William Thompson

Electronic Theses and Dissertations

The Desmoinesian (Middle Pennsylvanian) Capps Limestone Member of the Mineral Wells Formation is a carbonate reservoir located in North Central Texas. It consists of interbedded limestone, sandstone, and shale units. Much of the Capps Limestone exists in the subsurface of Brown, Coleman, Runnels, Coke, Nolan, and Taylor counties, however, the Capps Limestone outcrops on the surface in Brown, Eastland, and Palo Pinto counties.

The cored interval from Runnels County was deposited in a marginal marine environment during the Middle Pennsylvanian Period. Although the Capps Limestone was first described in the 1890s, there is still much to be discovered about its …

Revisiting The Cretaceous-Paleogene Boundary In Western Kentucky, Usa, Jarred Asselta

Scholars Week

This study revisits a Cretaceous-Paleogene (K-Pg) sedimentary section in western Kentucky to determine the nature of this boundary and the depositional environments. Although previous pollen work identified the boundary over four decades ago, to our knowledge no work has been carried out at this important K-Pg boundary site. A combination of stratigraphy and sedimentology were used to characterize the section in detail. Bulk and oriented samples were collected for grain-size, geochemical, and petrographic analysis. We relocated the site and measured 1.5m of section that includes the K-Pg boundary. Four distinct units were identified and from base to top of section …

Palynology And Paleoclimatology Of The Chicxulub Impact Crater In The Early Paleogene, Vann Smith

LSU Doctoral Dissertations

At the end of the Cretaceous Period, a large bolide impacted the Earth and formed the Chicxulub impact crater in the Yucatán Peninsula, Mexico. In 2016, International Ocean Discovery Program (IODP) Expedition 364 Site M0077 drilled into the buried peak ring of the crater, recovering a marine Paleocene to early Eocene post-impact section deposited on top of the impact breccia. Palynological analysis of 195 samples from the post-impact section has yielded the first pre-Holocene vegetational record from inside the Chicxulub impact crater and the first palynological record of the recovery of life following the end-Cretaceous mass extinction from inside the …

Carbon-Isotope Chemostratigraphy And Fluvial Sedimentology Of The Moenave Formation, Utah, Jordan Oefinger

Graduate Theses and Dissertations

The end Triassic extinction (ETE) is one of the largest mass extinction events of the Phanerozoic, and it has been hypothesized that this event, as well as the Triassic-Jurassic (TJ) boundary, are preserved within the Moenave Formation of the Colorado Plateau. Identification of this boundary within southwest Utah sections of the Colorado Plateau region is critical for better understanding the relationship between climate change and the ETE in terrestrial, low latitude paleoenvironments. The Moenave Formation is well exposed in Blacks Canyon of Zion National Park and in the nearby Warner Valley, where detailed sedimentologic observations and carbon isotope sampling have …

Diversity – Independent Factors Predict Elevated Extinction Rates, Dustin Perriguey, Corinne Myers, Jason Moore, Louis Scuderi

Earth and Planetary Sciences ETDs

Multiple linear regression was used to determine the relationships between diversity-independent factors (i.e., abiotic, climatic) 2, 5, and 10 Myrs-prior to the most elevated Phanerozoic extinctions. We constructed five abiotic variables from Phanerozoic proxy records1–5 to compare to extinction rates: mean temperature, temperature instability, carbon cycle instability, continental weathering rates, and habitat instability. All three models were statistically significant (P < 0.05) and explained > 70% of the variation in Alroy’s6 three-timer generic extinction rates. However, the 2 Myr-prior model explained the most variance in extinction rates and had the most predictive power, based on adjusted and predictive R2 (~ 72% and 41%, respectively). Carbon …

Characterization Of Uranium, Lead, And Rare Earth Element Pollution In Natural Soils And Sediments, Hope Rasmussen

Civil and Environmental Engineering Theses and Dissertations

Heavy metals in the environment add to the global burden of pollution, negatively impacting public health and ecosystem resilience. This study included projects regarding uranium (U), lead (Pb), and rare earth elements (REE) in natural samples, due to their known toxicity, ubiquity, and relevance in context to recent pollution trends. The first project focused on testing the potential of using a hydroxyapatite product as a remediation solution for U-contaminated groundwater and soil at an EPA Superfund site. The results showed that the U was sequestered in a highly crystalline mineral form within the solids, guiding the EPA to specify the …

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 …

Coastal Watershed Monitoring And Management: Geomorphology, Geochemistry, And Hydrologic Modeling Of Los Peñasquitos Creek, Ca, Ravleen Khalsa-Basra

Theses

Rivers in semi-arid climates are directly influenced by local geographic and hydrologic conditions and impacted by modifications to hydrology via urbanization. Changes can influence erosion, morphology, habitat sustainability, and watershed health. In highly urbanized southern California coastal regions, these rare open spaces provide vital ecosystem services. Los Peñasquitos Creek in San Diego County is one such watershed. Using stream surveying and laboratory methods we quantified channel characteristics, grain size distribution, total metal concentration [M], organic carbon (%OC), and phosphate to longitudinally characterize the creek for improved management. Results identified three distinct reaches in the watershed (upper, middle, lower). Downstream, depth …

Detrital Zircon Petrochronology For Sedimentary Provenance Analysis: Source To Sink Of The Mississippi/Missouri River Drainage Basin, Sage Denali Muttel

Graduate Theses/Dissertations

Detrital petrochronology can provide a detailed look into sedimentary provenance through integrated mineral radioisotopic ages with corresponding mineral chemistry. By combining U-Pb ages and Th/U values of detrital zircon from 13 samples collected from Quaternary sand deposits in the Upper Missouri, Yellowstone, Bighorn, Platte, Kansas, Arkansas, Mississippi, Red and Brazos Rivers, an interpretation of detailed signatures that record evidence of the evolution of the Mississippi/Missouri River drainage and the tectonic events that shaped it were observed. Low Th/U values in zircon correlate temporally to convergent magmatism, whereas, higher and more variable Th/U zircon are coeval with known extensional tectonism. Using …

Chemostratigraphy Of Carbonate Gravity Flows Of The Wolfcamp Formation In Crockett County, Midland Basin, Texas, Alex Blizzard, Julie Bloxson

Electronic Theses and Dissertations

Sediment gravity flows into deep-water environments are important stratigraphic traps in lithologically diverse reservoirs generating multiple plays for hydrocarbon exploration. These highly heterogeneous deposits can be studied by utilizing chemostratigraphy and higher-order sequence stratigraphy; being an accurate method for reservoir characterization. Studying these gravity flows along a carbonate platform’s slope can further expand an understanding of the stratigraphy that is filling adjacent basins. The application of elemental analyses can support in identifying mineralogy that impact reservoir quality, especially when conventional testing cannot be applied.

This study utilizes five cores containing the Wolfcamp Formation from the southeastern slope of the Central …

Comparative Geochemical Analysis Of Ordovician And Mississippian Cherts In Relation To The Northern Arkansas And The Tri-State Mississippi Valley-Type Ore Districts, Jonathan T. Chick

Graduate Theses and Dissertations

It has been hypothesized that Ordovician, Mississippian, and younger carbonate and clastic formations found within the Ouachita Basin of west-central Arkansas and northward onto the Ozark Dome have experienced interaction with hydrothermal fluids due to tectonic forces produced by the Ouachita Orogeny. Lead (Pb) isotope analyses and resulting values produced through previous and concurrent geochemical studies of several formations indicate that the Mississippi Valley-type (MVT) ores were produced from a mixing and cooling of these sedimentary basinal brines by meteoric or connate waters. Reduction of sulfate to sulfide is one of the possible mechanisms by which MVT ore precipitation may …

“The Tale Of 3,000 Zircons”: An Investigation Of Grenville Sedimentation In Amazonia Using U/Pb Detrital Zircon Geochronology, Felicia R. Harris

Theses and Dissertations--Earth and Environmental Sciences

The continental collision between Laurentia and Amazonia that generated Rodinia and the Grenville Orogen is proposed to be one of the largest, hottest and longest-lived orogens in Earth history. Subsequent erosion and weathering led to a mountain range’s worth of sediment recycled into clastic systems across North America, otherwise known as the “Great Grenville Sedimentation Event”. The Sunsas orogeny in Amazonia is correlative to the Grenville in North America and is proposed to be the result of final Rodinian collision at 1200-1000 Ma. Despite the connection between the two ranges and the robust sedimentary record in North America, little work …

A Multi-Method Investigation Of The Modern Sedimentation And Late Holocene Paleolimnology Of June Lake (Mono County, Ca), And A Survey-Based Analysis Of Ninth Graders’ Attitudes Towards Geology, Eva Lyon

Theses and Dissertations--Earth and Environmental Sciences

Three distinct manuscripts comprise this dissertation. The first analyzes the modern sedimentary basin of June Lake, a small glacial lake in the eastern Sierra Nevada of California (USA) using a number of data sets, including bathymetry, surface sediment composition, and seismic stratigraphy. The seismic survey revealed sublacustrine morphological features that suggest the basin originated due to ice scour, as well as four acoustically distinct stratigraphic units that reflect the history of sedimentation following glacial scouring. Corroborating the seismic record, sediment cores from the youngest unit are composed of hemipelagically deposited, organic-rich, laminated diatomaceous oozes alternating with coarse tephra beds. The …

Crystalline Architecture And Stratigraphy Of Coral Skeletal Density Banding: A Geobiological Record Of Changing Coral Reef Ecology, Kyle Fouke

Honors Theses

Coral skeletal density banding (CSDB), composed of alternating high density band (HDB) and low density band (LDB) layers that comprise the CaCO₃ (aragonite) skeleton of scleractinian corals, are used as chronometers for global paleoclimatic reconstructions of sea surface temperature (SST). Scleractinian coral skeletons have been intensively studied for centuries with detail analysis of the macro- and microscale skeletal structure to establish taxonomic and evolutionary relationships of coral species, mechanisms of biomineralization, and seafloor physical, chemical and biological alteration (diagenesis) of the skeleton. This study is the first to determine the crystalline architecture of HDBs and CSDB stratigraphic …

Physical And Chemical Properties Of Clastic Sediments From Two Caves In The Northern Karst Region Of Puerto Rico, Autum R. Downey

Graduate Theses, Dissertations, and Problem Reports (ETD)

Geochemical properties and organic characteristics are essential to understanding the general depositional dynamics of a cave. Most work on clastic cave sediments focuses on physical properties of sediments. Little work has been done on bulk organic matter and geochemical properties.

This project reports physical and geochemical characterization of cave sediments from two caves in the northern karst region of Puerto Rico: El Tallonal Cave and Cueva Clara. Core and grab samples were collected and analyzed for particle size, total organic carbon, total nitrogen, organic matter characteristics using fluorescence spectroscopy, and major and minor elements using X-ray fluorescence (XRF). The sediments …

Reconstructing Hydrologic Conditions And Metals Supplied By The Peace River To The Peace-Athabasca Delta, Jelle André Faber

Theses and Dissertations (Comprehensive)

The Peace-Athabasca Delta (PAD) in northern Alberta, Canada, is recognized internationally for its ecological, historical, and cultural significance. The delta is mostly within Wood Buffalo National Park, a UNESCO World Heritage Site, and is a Ramsar Wetland of International Importance. The construction of the WAC Bennett Dam (1967) and the Site C Dam (ongoing, 2024) on the Peace River, and expansion of the Alberta Oil Sands industry along the Athabasca River have raised concerns over water quantity and quality in the delta. When industry operations began, effective monitoring had not been implemented. Consequently, pre-industrial reference conditions are unknown and can …

Reinterpreting The Tectonic Model Of The Southern Part Of The Taconic Orogeny Through A Provenance Study Of Late Ordovician Sandstones, Juan Carlos Guerrero

LSU Master's Theses

A provenance study of quartz arenites that stratigraphically are closely associated with major Ordovician K-bentonites has been conducted in order to further our understanding of the tectonic setting of eastern Laurentia during the Late Ordovician. Using laser ablation ICP-MS, detrital zircons separated from Ordovician sandstone samples in the southeastern Appalachian Mountains (Virginia to Alabama) were dated using U-Pb geochronology. Analytical results show three dominate age ranges for the zircons from these sandstones: ~440-490 Ma, ~900-1300 Ma, and ~1300-1500 Ma. In addition, some zircon ages grouped into older ranges of ~1600-1800 Ma, ~1800-1900 Ma, and ~2600-2800 Ma. Zircon ages from ~900-2800 …

Neogene Chemical Weathering And Provenance Records Of The Western Himalaya Preserved In The Arabian Sea, Peng Zhou

LSU Doctoral Dissertations

Some tectonic models for the Himalaya emphasize the importance of surface processes in controlling the structural evolution. To investigate this tectonic–climatic interactions, and the weathering and erosion of the western Himalaya, International Ocean Discovery Program (IODP) Expedition 355 drilled two sites (site U1456 and U1457) in Laxmi Basin, which located in the Eastern Arabian Sea. In my research project, I plan to use a series of geochemical and geochronological methods on the sediment samples from the cores of these two sites, and sediments from an industrial borehole Indus Marine A-1, which near the Indus river mouth, to reconstruct a climatic …

A Terrestrial Reconstruction Of Gona, Ethiopia Before And During The African Humid Period, Marie N. White, Gary E. Stinchcomb

Posters-at-the-Capitol

The African Humid Period (AHP) resulted in more humid conditions across Northern and Eastern Africa from 15 to 5 thousand years ago (ka). This wetter climate affected flora, fauna and the Homo sapiens living in East Africa. The lack of terrestrial paleoenvironmental reconstructions is a problem in East Africa, especially during the AHP, where most are done utilizing lacustrine or marine proxies. In the case of Gona, Ethiopia, terrestrial proxies are desired due to the rich archaeological and fossil concentrations that occur in the area. Paleosols provide more direct, localized reconstructions that provide context for these finds. This study utilizes …

Improving Thorium-230 Determination In Marine Sediment, Katherine Mateos

Independent Study Project (ISP) Collection

Our oceans are intimately related to the climate of our planet. Paleoceanographic approaches aim to study oceans through geologic time to improve models of future climate. Radioisotopes provide us with chemical tracers that help us understand change through time. The uraniumseries decay chain contains thorium-230, a decay product of uranium-234. This isotope is useful to paleoceanographers in its disequilibrium to its parent isotope and in determining the flux of sediment falling to the ocean floor. In order to use 230Th to study oceans, we must be able to accurately measure the amount of thorium in sediment samples. Thorium is found …

Provenance And Maximum Depositional Age Analysis Of The Moenave Formation Using Detrital Zircon U-Pb Geochronology And Sandstone Petrography, Asher Rea Boudreaux

Graduate Theses and Dissertations

In southwestern Utah and northeastern Arizona, Moenave Formation (latest Triassic(?)-Jurassic) is bracketed by well-studied Mesozoic units extensively sampled for detrital zircon geochronology and is poorly documented in regard to provenance, representing an important gap in knowledge. The Moenave Formation provides a unique opportunity to employ detrital zircon U-Pb geochronology and sandstone petrography relevant to completing the paleogeographic, evolutionary, and climatic story of the region. This study aims to characterize the sedimentary provenance of the Moenave Formation and to identify, or at least improve constraints on, the stratigraphic position of the Triassic-Jurassic boundary (TJB) and placement of the end-Triassic extinction (ETE), …

The Paleozoic Sedimentary Rocks Of The Ouachita Mountains And Their Genetic Relationship To The Mississippi Valley-Type Mineralization In The Southern Ozark Region: Insights From Radiogenic Pb Isotopes And Trace Elements Studies, Christophe Wakamya Simbo

Graduate Theses and Dissertations

Cluster of Pb and/or Zn deposits of the well-known Tri-State and Northern Arkansas Mississippi Valley Type (MVT) districts located north of the Arkoma basin and the Ouachita fold-thrust belt in north America are genetically connected to the Pennsylvanian-Permian Ouachita orogeny which triggered a South-North topographic gradient flow of basinal brines, leaching metal rich sediments en route. The objective of the research is twofold. First, to ascertain whether the organic-rich shales and sandstones from the study area provided metals during the mineralization event, which was coeval with the Ouachita orogeny. Second, to assess the depositional environment of the potential source rocks, …

Geochemical Analysis Of Mississippian Cherts And Devonian-Mississippian Novaculites, Southern Midcontinent Region, Julie Mary Cains

Graduate Theses and Dissertations

This study uses trace elements and radiogenic isotopes (Pb, Sr, and Nd) to investigate the origin and mode of formation for the siliceous deposits in the Lower Mississippian Boone Formation and the Devonian-Mississippian Arkansas Novaculite in the southern midcontinent. Mississippi Valley-type Pb-Zn ore deposits in the Tri-State District and the Northern Arkansas District were deposited by hydrothermal fluids, and highly radiogenic Pb isotope ratios suggest a genetic relationship between the Boone Formation chert (206Pb/204Pb ~ 21.59, 207Pb/204Pb ~ 15.87, 208Pb/204Pb ~ 40.10) and the MVT ores. Due to the very low concentration of Pb in the Boone chert (~2 ppm) …

A Joint Xrf-Δ13CCarb Chemostratigraphic Approach For Characterizing Paleo-Environmental Processes In The Mudstone-Dominated Wolfcamp Formation Of West Texas, Frank Tamakloe

Theses and Dissertations--Earth and Environmental Sciences

The Late Paleozoic Ice Age represents a dynamic period in Earth system history recording a shift from icehouse to greenhouse conditions. Concomitant with this change was a series high-frequency, high-amplitude sea level fluctuations leading to the deposition of “Kansas type” cyclothems in the Mid-Continent, and a similar rhythmic expression of interbedded shales and carbonates in the Midland Basin. Stable isotope geochemistry is a particularly powerful tool when examining these mud-rich successions because changes in organic matter partitioning may be recorded first in δ¹³C_DIC of sea-water and consequently in δ¹³C_carb of marine rocks. The δ …

The Forestry Reclamation Approach: Measuring Sediment Mass Accumulation Rates In Reclaimed Mine Lands And Naturally Regenerated Logged Forests Of Eastern Kentucky, William E. Bond

Theses and Dissertations--Earth and Environmental Sciences

The spread of surface coal mining has resulted in loss of forests in the Appalachian region. The Forestry Reclamation Approach (FRA) was developed to provide guidance for restoring forests on reclaimed mined land. This study hypothesizes that the FRA will result in larger magnitude of sediment accumulation rates in reclaimed mine sites compared to those reclaimed using grassland reclamation. Three sediment cores and six trenches were sampled within four reclaimed mined and three previously logged sites in eastern Kentucky. Samples were processed for radionuclides, grain-size, stable isotopes (δ¹³C), and POC. LIDAR data were used to identify valley …