Given the drastic rise in renewable energy investment across the US and globally, along with global sustainable development goals, it is important to develop techniques for renewable resource assessment. The study aims to identify the most suitable areas for renewable energy development in Texas by analyzing various geospatial factors that influence renewable energy production, such as terrain and land use. Resource-specific data such as surface direct normal irradiance (DNI) and wind speed and power density were used to ensure resource availability. Proximity to important infrastructure was also considered, access to infrastructure is an important economic consideration for utility-scale installation. Products generated use an integration of remote sensing data, geospatial analysis, and machine learning algorithms to develop a spatially-explicit multi-criteria decision analysis (MCDA) for solar and wind resources in Texas.

This study will develop (livable) suitability index for areas within Fort Worth with respect to the availability of various amenities (walkability, parks, etc.), public transport, proximity to fresh produce and entertainment (restaurants, etc.), and other relevant services. This is important as the City of Fort Worth has some of the lowest transit scores compared to major cities across the US especially with those having similar population as Fort Worth. Several spatial analysis techniques including proximity and overlay analysis will be undertaken using tools in ArcGIS Pro and ArcGIS Online to attain the objectives of the study.

As the nature and quantity of new/novel nanomaterials continue to expand to meet industrial, medical, and domestic demands, their accidental or intentional release becomes inevitable. To this end, an evolving understanding of the interaction dynamics between nanomaterials and naturally occurring geomaterials is central to supporting continued sustainable development and use of nanomaterials. The current study explores the chemodynamics of the organic nanomaterial, polyamidoamine (PAMAM) dendrimers, binding to (and debinding from) ferrihydrite. Specific focus is placed on how PAMAM size and pH affects the reaction between three carboxyl-terminated PAMAMs (Gx.5-COOH) sorbing/desorbing to/from the variably-charged ferrihydrite (FFH). Since both ferrihydrite and PAMAM exhibit pH-dependent variation of speciation, it is expected that binding/debinding dynamics of differing sizes of PAMAM will vary. Investigating the quantity, rate, and dynamics of these reactions provides insight into the type of bonding occurring (physiosorption, electrostatic bonding, or hydrogen bonding) and the location of bonding (surface versus micropore spaces). The information gained from this study will help to develop a more holistic picture of the environmental fate of synthetic nanomaterials.

In Tarrant County, Texas, food deserts affect approximately 275,000 residents. Chronic health conditions affect households living in food-insecure communities, leading the government to spend billions of dollars treating preventable diseases. Implementing sustainable urban agriculture in areas of high need to produce food using geospatial technology to aid in soil management can play an important role in helping farmers. The objective is to create an urban soil analysis map from the data collected on the soil properties, distribution, and variability of how these properties affect landscapes.

The aim for this project is centered around understanding carbon sequestration and the potential for carbon capture, utilization, and storage (CCUS) in the United States of America. An in depth look at the CO2 emissions for given areas of the U.S. will be looked at to gain an idea of where localized hotspots for emissions are located and how the impact of these emissions can be reduced using CCUS. By coupling emission data with existing infrastructure data (such as active and abandoned wells, pipelines, storage facilities, etc.) an outlook on the possibility of CCUS and reduction of emissions can be achieved. Geologic formations also play a specific role in how CCUS works. Understanding the various rock formations below and how the injected CO2 will be sealed away deep in the ground is a vital piece for any CCUS project. Combining the geological data with the emissions and infrastructure data will piece together a variety of information to better understand the possibility of reducing carbon emissions in various areas around the United States.

The Middle Cenomanian Woodbine sandstones act as a major reservoir system for many large oil fields throughout East Texas. Although numerous studies have been completed on Woodbine outcrops within DFW Metroplex, none have used modern techniques or tools, or utilized facies model concepts to study their reservoir characteristics or environment of deposition. Prior studies interpreted these outcrops as a shelf-strandplain coastal setting or a fluvial-dominated delta plain. However, this study of Woodbine outcrops along Lake Grapevine identified evidence of significant tidal influence.
The focus of this project was to determine the depositional environment and obtain a better understanding of the reservoir characteristics of the upper Woodbine (Lewisville) sandstones found in outcrop along the southeastern shores of Lake Grapevine in Tarrant County, TX. A detailed study of the lithofacies, ichnofacies, and biofacies, along with handheld spectral gamma ray and permeameter analyses, from 8 measured sections were conducted to identify representative lithofacies. Oversized thin-sections were made to estimate porosity ranges for each lithofacies, and to identify the types and extent of cement in the sandstones. Photomosaics were utilized to delineate sand body geometries by tracing out the lateral extent of the units and identifying significant surfaces and potential fluid barriers or baffles.
Seven lithofacies were distinguished in the outcrops of the study area: Bioclastic, massive bioturbated sandstone, mudstone, heterolithic sandstone and mudstone, crossbedded sandstone, flaser-bedded sandstone, and cemented sandstone. Two of the most common and laterally continuous lithofacies, the massive bioturbated and crossbedded sandstones, also had the best reservoir characteristics, with average porosities of 26% and 27%, and average measured permeabilities of 6,300 mD and 10,700 mD, respectively. The lower permeabilities in the massive bioturbated sandstone are related to clay-rimmed burrows. The bioclastic, mudstone, and cemented sandstone lithofacies are potential barriers to fluid flow, as they all have low porosities (less than 2%) and permeabilities (less than 200 mD).
The data acquired during this study were all consistent with an interpretation of a tidally-influenced estuarine to shallow marine depositional environment for the upper Woodbine in the study area, which differs from previous studies. The high abundance of trace fossils that are commonly found in tidally-influenced depositional systems, including Conichnus/Bergaueria, Cylindrichnus, Planolites, Palaeophycus, Rosselia, Rusophycus, Skolithos, and Thalassinoides, coupled with the presence of heterolithic deposits and common oyster shells led to this interpretation.
This study is the first to analyze outcrops of the Lewisville (upper Woodbine) sandstones in their type area specifically for their reservoir characteristics, and to document tidal influences during deposition. Considering the considerable volumes of hydrocarbons that have been produced from the Woodbine in the adjacent East Texas Basin, this study could provide valuable data for building reservoir models of upper Woodbine sandstones for both hydrocarbon production and potential CO2 sequestration.

This research will examine the change in size of local aquifers in Texas to determine how drought affects crop yield in Texas, for the aquifers scattered about Texas are the major source of irrigation for farmers in the state. This will be demonstrated by assessing conditions in the San Antonio area (as a case study) due to the severe drought that has affected the area for the past couple of months. Several spatial datasets including remote sensing datasets and results derived using different analysis tools in GIS will be utilized to demonstrate the change in aquifer size and volume during the investigated period.

More meteorites are found in North-West Africa every year than in any other location on the earth’s surface. These meteorites are sold and will either enter a scientific collection, or that of a private collector. In the latter case, a meteorite may never be officially classified, which means that it is not recognized by the scientific community as a new meteorite find.. The meteorite classification process is led by the Meteoritical Society, who nominate meteorite researchers to serve on the Meteorite Nomenclature Committee. This committee is responsible for the peer review of all meteorite classification submissions, and to ensure the donation of a scientific repository sample. After this, an official name is assigned and the meteorite is entered into the Meteoritical Bulletin Database (MetBull). MetBull is an archive of all meteorites recognized by the Meteoritical Society and contains basic information about each meteorite; for example, its classification, the location it was found, and a brief description of the sample studied.

The Monnig Meteorite Collection at TCU contains a number of unclassified meteorite samples. In this study, we will examine three unknown meteorites and determine the meteorite type in terms of: (1) the type of body they come from, (2) the minerals and textures they contain, (3) their mineral compositions and, (4) their thermal history. This data will then be submitted to the Meteorite Nomenclature Committee for official classification.

Excessive greenhouse gas emissions that result from unregulated energy exploitation contribute to climate change and air pollution. One way to restore the carbon balance within the earth’s systems is to increase carbon inputs by capturing atmospheric carbon and storing it in stable reservoirs, also known as Carbon Sequestration. Using the process of photosynthesis, plants absorb carbon dioxide from the atmosphere and convert it to organic carbon that is relatively more stable than gaseous carbon. The ability to sequester carbon varies across different vegetation species and the environments in which they grow. Using ArcGIS tools and free-access remote sensing data, this study will survey the spatial distribution of plant biomass and their effective carbon storage capacity in a case study located in Africa. The results from this study will i) identify facilities with the most effective carbon sequestration potential ii) help conservation programs in making landscaping decisions for future urban developments.

The 1.2 Ga Barby Formation located in SW Namibia is comprised of basaltic andesites and shoshonites from oblique subduction in a volcanic arc setting. Recent mapping and whole-rock geochemistry within the Barby Formation has been completed by previous TCU graduate students. Clinopyroxenes (CPX) from samples collected during these studies were analyzed using an Electron Microprobe (EMP) at Fayetteville State University, North Carolina. Data collected from CPX phenocrysts corresponds with previous findings that the samples can be divided into two groups. Group 1 samples show an enrichment in rare earth elements (REE) and light rare earth elements (LREE) Th, Zr, La/Yb, Nb, with a smaller Ti anomaly as compared to Group 2 (Lehman, 2019; Orhmundt, 2020). CPX phenocrysts within Group 1 have higher TiO2 wt% concentrations. Differences between the two groups are attributed to different source rock compositions and partial melting (Lehman, 2019; Orhmundt, 2020). Mineral compositions and cation ratios from EPMA data were also used to determine geothermobarometric conditions of the formation’s magma plumbing system. Single-clinopyroxene thermometry and barometry equations from Wang et al. (2021) and Purtika (2008) were utilized in this study. Wang et al. (2021) calculations resulted with average pressures between 1-3 ± 1.5 kbar and average temperatures between 1100-1200 °C. Purtika (2008) calculations resulted with overall higher pressures averaging at 3-5 kbar and slightly hotter temperatures at 1200 ± 50°C. Overall temperatures are higher than what would be expected in the basaltic andesitic system and variations could be due to the low-grade metamorphism the area has experienced that has affected the geochemistry.

Subsidence is a downward sinking of earth materials that creates a large or small circular surface, but it may produce linear or irregular failure patterns. The highly dissolved calcium carbonate or evaporite rocks allow acidic rainwater to permeate its strata. Near or underlying rock can easily be dissolved in water and create space and caverns underground, making a sudden catastrophic collapse of the land surface. Highly soluble bedrocks are a widespread geologic phenomenon in the West Texas Permian Basin. The majority of the area has been impacted by the subsurface dissolution gypsum layers, which is a cause of the active sinkhole formation from a few meters to 100 m wide. This geohazard has caused damage on infrastructure and civilian property. It can cause environmental problems when it alters the local hydrology. Sinkhole detection using field surveying is expensive, time-consuming, labor-intensive, and not easily accessible, and it might be potentially dangerous for the surveyor. In this paper, I detect, map, and thus analyze anthropogenic triggering factors of sinkholes in Wink, Texas, using open-source high-resolution LiDAR (Light Detection and Ranging) data. Methods involve Generating Digital Elevation Model (DEM), extracting the depressions from DEM, identifying sinkhole boundary contour, and then converting the delineated sinkhole to a polygon shapefile, analyzing the shape and geometric properties. False alarm sinkhole depression eliminates based on the threshold value. Finally, human-induced factors have been investigated.

Distributive fluvial systems (DFS) are cited to be one of the most dominant fluvial depositional systems seen in continental basins. This system can now be defined by five common characteristics seen in many continental basins: 1) channels that radiate from an apex; 2) a channel size decrease downstream; 3) an increase in preservation of floodplain deposits relative to downstream deposits; 4) a decrease downstream in channel grain size; 5) a change from amalgamated channel deposits in proximal areas to more separated and smaller channels in distal areas. DFSs have been heavily studied in the Morrison Formation near the Four Corners of the United States, however, they have not been tested in eastern New Mexico. The above set of parameters are tested in the Morrison Formation in East New Mexico against the Salt Wash DFS to see how the two systems compare.
Completing this study will provide quantitative analysis over a potential ancient DFS with the goal of providing a dataset that can be used to compare with other DFSs. Additionally, analyzing an unknown area of the Morrison Formation will ultimately open up studies to be worked on in the future. Correlating the East Morrison Formation DFS with the Colorado Plateau Morrison Formation DFS will bridge the gap for determining similarities and differences between these exposures and set the stage for future studies. Additionally, this work will also help us better understand the wider Morrison basin and facies distributions within.

The Upper Jurassic Morrison Formation has been extensively studied in the Western-Interior United States since it contains economic resources of uranium, vanadium, and some of the most well-preserved dinosaur fossils in the United States. Covering over 450,000 square miles from southern Canada to New Mexico, the Morrison Formation's enormous extent presents a unique opportunity to understand the processes happening on Earth's surface during the Late Jurassic. Studies of the Morrison Formation have primarily focused on areas where there are large concentrations of the aforementioned economic resources within its strata. The geologic community has largely overlooked Morrison Formation outcrops in northeastern New Mexico compared to the exhaustively studied outcrops in and around the Colorado Plateau. The absence of recent studies in the Morrison Formation in northeast New Mexico provides a chance to explore it with a level of detail unobtainable until recently. This study will undergo a detailed architectural analysis of two to three extensive outcrops of the Morrison Formation in northeastern New Mexico. This Study will do detailed bedding and facies diagrams of these outcrops from drone images to constrain fluvial style and fluvial history of these rocks. Studying the Morrison Formation in a high level of detail will, in all likelihood, produce new information on the climate and fluvial morphology of the environment in the Late Jurassic. With a new detailed understanding of this all but forgotten piece of the Morrison Formation, the groundwork will be laid for the potential to correlate this piece of the Morrison Formation with other understudied or non-correlatable pieces elsewhere across its vast depositional extent and to piece this part of the Late Jurassic fluvial story into the larger puzzle.

Martian meteorites provide us with a window into the processes occurring during the formation and evolution of the terrestrial planets, such as: accretion and differentiation, emplacement and formation of magmatic rocks, the behavior and content of volatile compounds, and the effects of impact events. Here, we present the initial results from a two-phase study on a presumed Martian meteorite, hereafter referred to as NWA X. First, the 800g main mass of NWA X was imaged prior to cutting using 3D laser scans and photogrammetry to produce 3D models of the meteorite’s exterior, and computed tomography (CT) to provide scans of the interior. The main mass was cut and a 175g end piece was donated to the Monnig Meteorite Collection, along with a 5g chip for scientific analysis. In the second phase of the study, we will characterize NWA X in terms of its texture, modal mineralogy, and mineral chemistry. Results from this study will allow us to confirm if NWA X is of Martian origin and, if so, place it in context within the existing dataset for Martian meteorites.

Mesosiderites are a group of stony-iron meteorites that contain roughly equal amounts of core material (metal) and crust (silicates) from one or more asteroid parent body. The core material is predominantly Fe,Ni-metal, with some troilite (FeS), and is found as clasts and/or intimately mixed within the meteorite matrix. Silicate clasts are basaltic or gabbroic in origin, representing different formation depths within the crust, and are predominantly plagioclase and pyroxene. The formation of mesosiderites is not fully understood, but observed features require a three stage process: (1) formation of asteroidal silicate crust; (2) metal-silicate mixing, where molten metal is injected into the solid silicates; (3) deep burial, as reflected by the extremely slow cooling rates of less than 1ºC/My. Mesosiderites are classified by pyroxene content and degree of metamorphism, which focuses only on the silicate phases. That not only ignores half of their mineralogy, but also the third stage of their formational history. Additionally, only 15% of known mesosiderites have been studied in detail. This research aims to 1) investigate five previously understudied and ungrouped mesosiderites and 2) determine if metal within mesosiderites can be used to refine current classification schemes.

Fort Worth, Texas has become one of the most populated areas in the United States. With a growing influx of commuters on a daily basis, there is no doubt that there will be a large amount of car crashes in the city. According to the Texas Department of Transportation, in 2020 there were over 15,000 car crashes while in 2021 there were over 17,000 car accidents. In 2022 alone there have been over 3000 car crashes already. Many of these car crashes are likely avoidable and finding the areas that are most susceptible to these accidents will be valuable knowledge for drivers and the city. Applying ESRI ArcGIS Pro’s spatial analysis extension to the Texas Department of Transportation's car accident the roads of Fort Worth with high crash and fatality rates will be found and mapped accordingly.

Debris flow is a landslide with a quick velocity of displacement that involves risk and damages to life and property. It can be triggered by periods of intense rain usually on steep slopes. Also, a second triggering factor is the influence of wildfire. Wildfire can increase drastically the probability of this type of landslide because the fire burned the vegetation which helps to stabilize the soil and the slope. The research uses geographical information system (GIS) for the development of mapping landslide susceptibility, with a particular interest in the evaluation of areas vulnerable to debris flow natural hazards that may be triggered after a wildfire, with the effects of intensive periods of precipitation. The method has been applied to Montecito city, which was exposed to a massive mudslide in January 2018. The spatial landslide susceptibility response in this study area is correlated to different factors, such as vegetation, lithology, slope gradient, and distance to streams networks which are considered the control of the probability of incidence of a landslide event in this area. Obtained by using the methodology of the multi-criteria decision evaluation (MCE) model. The results obtained from this study indicate that the GIS-based model is valuable and appropriate for the scale used in this study. The model helped to identify areas that still are affected by the wildfire, which can be vulnerable to a new process of debris flow impacting the population closer to the rivers downhill.

The city of Austin and its surrounding area is experiencing tremendous growth and expansion as a consequence of fast urban development and population growth. This has led to increased constructions and other anthropogenic alterations of the environment to accommodate the growing population and economy. These activities, coupled with the natural conditions and forcings, have made areas within the metropolis susceptible to the threats of landslides. The present study aims to identify zones in the study area that are susceptible to the threats of slow-moving creep/slow-slide landslide hazards and understand the factors and processes that control the occurrence of these events through an integrated study approach. This includes: (1) generating a landslide susceptibility (LS) map through a combination of the triggering factors including local geology and tectonic features, land use/cover, elevation/slope, and precipitation; (2) detecting active deformation processes that could lead to landslide failure using Interferometric Synthetic Aperture Radar (InSAR) analysis techniques applied on Sentinel-1 SAR datasets (2015 – 2020) and validated through datasets from campaign GPS surveys and permanent stations; and (3) identify the factors and processes that directly or indirectly constrain the occurrence of the phenomenon through spatial analysis of relevant datasets. Our findings show: (1) the main concentration of vertical displacement (-1 to -6 mm/yr) is around the northern region of the study area; (2) zones with a moderate subsidence rate coincide with urbanized areas (up to -2 mm/yr) whereas pockets of high displacement rates (up to -6 mm/yr) are noted on NW parts; (3) most of the areas experiencing subsidence are underlain by the Comanche Series characterized by alternating beds of harder and softer limestones interbedded with beds of marly/clayey layers, and formations of marine marl, sandstone, and carbonaceous shale from the Gulf Series; (4) there is a high spatial correspondence between areas with high subsidence rates and high LS index; and (5) efforts are currently underway to analyze relevant datasets to determine factors and processes that control the occurrence of the hazard.

Nationally groundwater supplies 30% of the freshwater while within Texas that number increases to 60%. As population increases across the United States, Texas being the 7th fastest-growing state, there is immense pressure on freshwater resources. It is important to monitor the quality of groundwater reservoirs to ensure continuous and sustainable use of these reservoirs for current and future populations.
This study assesses the water quality of all nine major aquifers in Texas, with a focus on investigating the water chemistry change across shallow wells (below 300 feet) in these aquifers. This study used a distributed analysis to extrapolate the pH and Total Dissolved Salts (TDS) distribution across Texas major aquifers and revealed that all the shallow wells exhibit signs of water chemistry change. Decadal analysis of data from the Pre-1960s up to 2016 indicates that the pH of these shallow wells had sudden salinization between 1975-1985, followed by significant acidification from 1985 to 2016, where all aquifers followed this trend with the exception of Carrizo Wilcox in the far East and Hueco Mesilla Bolsons in the far West of Texas. On the other hand, TDS increased consistently statewide.
Added effort will be geared towards finding a correlation between the long-term groundwater chemistry change and the land use/land cover change around the major aquifers of Texas. The results of this project will help to determine the possible origin and causes of the change in groundwater chemistry of shallow aquifers in Texas.

For this research project, geospatial analysis will be utilized to study tornado outbreaks in Alabama, and to analyze the impact of major tornado events at different times (1974-2020) in the specified study regions and analyze that as well. This project is significant because these tornado outbreaks resulted in many deaths and lots of devastation in the region. By studying these tornadoes closely, a better understanding of the tornado events will be developed .
The goal of the study is to compare the relationship of elevation to the severity of the tornadoes (EF Scale) as well as look into how surface modification has amplified the effect of the tornadoes to analyze results more closely. Other primary goals are to 1) map the tornado track and 2) to analyze the change in the impact of tornadoes over time, taking land surface changes, elevation, and EF values into consideration to better understand the relation between them. In terms of the time series analysis, I will look into major tornado outbreaks that affected the study sites from 1974-2020. All of this will be accomplished using ArcMap, Google Earth Engine, and possibly other programs/tools. Relevant datasets are coming from LANDSAT, Sentinel 1 and 2, Digital Elevation Model (DEM), and from other possible sources.

The Austin Chalk is a rhythmically bedded sequence of chalk and marl that represents pelagic to hemipelagic carbonate deposition in the ancestral Gulf of Mexico during the Upper Cretaceous. The Austin Chalk differs from traditional chalk deposits due to its relatively high abundance of clay and volcanic ash. Outcrops of the chalk stretch from north-central Texas to west Texas and surface exposures mirror the subsurface trend of the Ouachita orogen. Deformation of the heavily fractured Austin Chalk is caused by the normal faults associated with the Balcones Fault Zone.
Historically, the Austin Chalk has been exploited as a conventional hydrocarbon reservoir produced from natural porosity and permeability without large hydraulic stimulations. More recently, the Austin Chalk has been explored as a combination fractured and unconventional reservoir, relying on natural porosity and permeability combined with induced hydraulic fracturing to generate new fracture permeability to release hydrocarbons trapped in microscopic pores. In addition to its reservoir properties, much of the city of Dallas is built within the outcrop trend of the chalk. Thus, understanding the properties and deformation features of the Austin Chalk is also important to the construction industry in north-central Texas.
Deformation of the Austin Chalk in Ten-Mile Creek is characteristic of normal faulting seen in platform carbonate sequences. Faults are identified by the presence of slickenlines and fault gouge, and are surrounded by a damage zone defined by synthetic faulting, jointing, and folding. Deformation is concentrated near the fault core and decreases with distance from the fault core. Here, we present a structural analysis of Church of the Nazarene section of Ten-Mile Creek. The mechanical properties of stratigraphic units are quantified using a Schmidt hammer. Fracture parameters, such as fracture density and intensity, are quantified using scanline surveys. Additionally, spectral gamma ray measurements are made in the field using the RS-230 spectrometer. Spectral gamma ray properties are combined with fracture parameters to create an integrated structural and petrophysical analysis.

The Sierra Nevada in California has a rich Cenozoic volcanic history including important arc sequences related to the southern Ancestral Cascades dating as far back as 30 Ma (du Bray et al., 2014). The present study focuses on Pliocene volcanic debris-avalanche deposits in the northern Sierra Nevada that fill paleocanyons west and northwest of Lake Tahoe. The paleocanyons trend west, west-southwest, and west- northwest from an unknown volcanic source to the east (Berkebile, 2003; Harwood et al., 2014). The main objective of this study is to examine petrogenetic relations of the debris-avalanche deposits and obtain isotopic ages for them. Another purpose is to determine if the three debris-avalanche deposits are from the same eruptive event or possibly the result of separate eruptions and multiple source vents. To acquire detailed data for this study, I am using whole-rock chemistry of both major and trace elements, electron microprobe analysis of phenocryst phases, and analysis of melt inclusions for magmatic volatile contents. Isotopic ages will be obtained using 40Ar/39Ar dating. Clinopyroxenes (CPX), orthopyroxenes (OPX), and plagioclase phenocrysts from samples collected have been analyzed using an electron microprobe (EMP) at Fayetteville State University, North Carolina under supervision of Dr. Steven Singletary. Data from these phenocrysts phases will be used to determine geothermobarometric conditions of the parental magma chamber or chambers.

Organic matter, a complex mixture of organic compounds, is responsible for the cycling of global carbon and nutrients in aquatic and terrestrial ecosystems. Understanding the sorption and desorption dynamics of organic matter on mineral surface is then important in determining the mechanisms of carbon, pollutants and nutrients cycling in the environment. This project assess the energetics and dynamics of sorption and desorption of natural organic matter from different sources with 2-line ferrihydrite. To understand how theses interaction occur on mineral surfaces, we studied the sorption and desorption behavior of various fraction of organic matter such as humic acid, fulvic acid, natural organic matter as well as water-extracted organic matter from charred plant biomass. Result thus far show the differences in energy, quantity and the kinetics of sorption and desorption involved in these interactions. The energy and rate involved in the binding and de-binding of natural organic matter with the surface of 2-line ferrihydrite is greater than those associated with charred ashe juniper. Additionally, the energy of sorption and desorption decrease with increasing pH conditions. In contrast, the rate of reaction increase with increasing pH. This presentation will link the chemical properties of organic matter as well as the surface properties of ferrihydrite and their influence on the sorption and desorption dynamics across different environmentally relevant pH conditions.

As the nature and quantity of new/novel nanomaterials continue to expand to meet industrial, medical, and domestic demands, their accidental or intentional release becomes inevitable. To this end, an evolving understanding of the interaction dynamics between nanomaterials and naturally-occuring geomaterials is central to supporting continued sustainable development and use of nanomaterials. The current study explores the chemodynamics of the organic nanomaterial, polyamidoamine (PAMAM), binding to (and debinding from) ferrihydrite. Specific focus is placed on how PAMAM size affects the quantity, kinetics and dynamics for three carboxyl-terminated PAMAMs (Gx.5-COOH) sorbing/desorbing to/from the variably-charged ferrihydrite (FFH). Early results suggest that at pH 5, the smaller PAMAM G1.5-COOH sorbed/desorb to/from FFH in similar quantities but at slower rates than G3.5-COOH. Sorption/desorption was also found to occur via 1- or 2-steps with a faster surface-mediated step being followed by a slower diffusion-mediated step and the proportion of surface-mediated: diffusion-mediated sorption/desorption increasing with PAMAM size (i.e. G1.5-COOH<G3.5-COOH). This presentation will further cover results obtained with G5.5-COOH PAMAM.

A flow adsorption microcalorimtery-UVvis spectroscopy method was used to directly measure high temporal resolution energetics and energy dynamics of Adenosine triphosphate disodium (ATP) at the ferrihydrite-water interface. Ferrihydrite is amongst the most reactive and ubiquitous form of Fe-oxide minerals in the geosphere known to exhibit controlling effects on the bioavailability and cycling of nutrients such as Phosphorous. Fe-oxide minerals are known catalysts in the phase transformation from organic phosphate (Po) to inorganic phosphate (Pi) depending on the surface and organic molecule speciation. Interactions of ATP and ferrihydrite at pH 2, 5, and 8 were conducted to quantify the effect of pH on energetics and energy dynamics. At pH 2, 5, and 8 where the speciation of ATP was cation, uncharged, and anion respectively, its interactions with nitrate (NO3-) saturated ferrihydrite were exothermic with 13.8 J g-1, 11.4 J g-1, and 8.7 J g-1 respectively. Nitrate’s interactions with ATP saturated ferrihydrite were endothermic with 13.8 J g-1, 11.5 J g-1, and 45. 4 J g-1 at pH 2, 5, and 8 respectively. Post ATP anion exchange indicated that the interaction of ATP and ferrihydrite decreased by a factor of ≈ 1.8 (6.51 ± 0.38 J g-1 to 3.63 ± 0.23 Jg-1), ≈ 1.6 (0.13 ± 0.01 J g-1 to 0.08 ± 0.02 Jg-1 ), ≈ 2 (0.15 ± 0.05 J g-1 to 0.07 ± 0.02 Jg-1 ) at pH 2, 5, and 8 respectively. In addition to ATP’s speciation and ferrihydrite’s surface charge, differences in interaction energetics and dynamics were attributable to the Pi produced by hydrolysis of ATP. A decrease in post ATP anion exchange suggested partial reversibility by NO3- pointing to inner sphere interactions with ferrihydrite. The presentation will further discuss the molar heats of inner sphere interactions of the ATP and Pi with ferrihydrite at pH 2, 5, and 8.

Beginning in the Late Mississippian to Early Pennsylvanian, southern Laurentia experienced a major tectonic regime change. Progressive closure of the Rheic Ocean and collision between Laurentia and Gondwana along the Ouachita-Marathon fold and thrust belt drove deformation and subsidence within a series of basins along the southern Laurentian margin. Few provenance studies in the Ardmore Basin have been conducted mainly based on facies distribution, and heavy mineral and petrographic analyses. There are two opposing ideas regarding regional sediment deposition; 1.) a transcontinental system with headwaters from the Appalachian Orogen region and minor inputs from uplifts associated with the Ouachita Orogen, and 2.) a dominant transport from a southern source, likely accreted Gondwanan terranes. Here I propose a detailed U-Pb detrital zircon geochronology study to document the provenance of major upper Mississippian (Chesterian) to lower Pennsylvanian (Atokan) sandstones in the Ardmore Basin. I hypothesize that due to increased regional tectonic activity to the east and south, the Ardmore Basin experienced a major source shift from the Late Mississippian to Early Pennsylvanian with sediment transitioning from mature sand, mainly derived from Laurentia, to less mature sediments likely sourced from the Appalachian and Ouachita Orogens and local uplifts. Results of this study will provide critical evidence for the debate between previously proposed transcontinental vs. locally-derived sediment dispersal models, and contribute to the understanding of paleogeography during the collision of Laurentia and Gondwana.