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.
Meander bend theory has been around since Albert Einstein popularized it in the 1920s. Since then, many geologists and physicists have grappled to understand the mechanics and concepts that cause rivers to meander in the ways that they do. Through the years, scientists have learned that bedload, slope, and flow velocity are all major drivers of cutbank erosion and bar building. However, one answer that has eluded scientists to this point is whether bar building (bar push) or bank scour (bank pull) causes meander bend migration. This study aims to analyze meander bend patterns in an 88 Km unchannelized stretch of the Missouri River between Yankton, SD and Sioux City, IA. Landsat images of this stretch over the last 30 years have been processed in remote sensing software to track bank, bar, and channel changes over this span of time. Extensive remote sensing processing (ESRI ArcMap and ArcGIS Pro) and statistical analyses will be performed on the river with respect to bank vs. bar movement, mid-channel bar migration, bar growth, and bar life cycles.
The Red River of the South is a highly understudied fluvial system with limited mapping. Early work, however, did map four fluvial terraces along the flanks of the modern river valley. These terraces record a period of time in which the ancestral Pleistocene Red River was a continent-scale river, sourcing from the Rockies and the volcanic uplands of New Mexico and depositing into the Gulf of Mexico. The ages of these terraces, though, are poorly understood. With these four known terraces, spanning the “terrace zone” (a ~5 km radius from the modern valley), and with surface areas of the terraces ranging between ~3 km2 and ~8.8 km2—there exists the potential to document the deposits of these four distinct periods of lateral migration—as well as to characterize various paleochannels and other fluvial features preserved within these terraces through hand auger sampling.
I aim to track the evolution of the Red River both physiologically and geochronologically, utilizing allostratigraphic methods to reconstruct some of the River’s past through the floodplain’s lithology and optically stimulated luminescence (OSL) dating of preserved terraces. I aim to construct detailed cross-sections of the valley fill by sampling the deposits of each of the various ancient terraces, as well as the modern floodplain, running roughly perpendicular to the axis of the current stretch of the Red River. Ideally, I would encounter paleochannels while drilling so as to potentially assess the features of the paleochannel belt. To maximize the likelihood of encountering paleochannels and related assemblages, I have begun to process and analyze Lidar and satellite data in an effort to identify remnants of these paleo-structures. I will collect sealed samples containing silica grains to send for OSL dating. In doing so, I can ascertain definitive dates on when the deposits associated with specific terraces were laid down.
(Presentation is private)
The Mississippi River Delta is the 7th largest river delta on Earth that consists of the Mississippi River and the Gulf of Mexico. Additionally, it contains 40% of the wetlands in the contiguous United States and over two million hectares (4,942,108 acres), an area equivalent to the size of two football fields, of agricultural lands. Due to fertilizer runoff from agricultural lands, the river delta has been experienced excess levels of nitrogen and phosphorus. The excess levels of these nutrients have contributed to water pollution in the delta and the hypoxia zone in the Gulf of Mexico. This research will focus on mapping the levels of nitrogen and phosphorous across the river delta to determine where the highest levels are
Author(s): Meagan Alexander Environmental Sciences Benite Ishimwe Environmental Sciences Olivia Jones Environmental Sciences Manyiel Mel Geological Sciences Montreal Taylor Geological Sciences
Advisor(s): Omar Harvey Geological Sciences
Location: Zoom Room 6, 01:10 PM
(Presentation is private)
Agricultural soils require the presence of three basic plant nutrients: Nitrogen, phosphorus, and Potassium (NPK). Each nutrient has its role in plant growth and their deficiencies have adverse effects. Therefore, detailed analysis was required to analyze whether soils from a lake were sufficient in terms of these nutrients and could be suggested for use as an agricultural soil amendment on a particular plot of land. Experimental study by way of specific chemical analysis methods (LOI, spectroscopy, etc.) looked at water content, pH, EC, SOC (Soil Organic Carbon), phosphorus and nitrogen content in the lake sediments; these values were used to determine what contents/nutrients in the lake sediments would need to be optimized for crops of interest. Results from the concluding experimental procedures would allow the property owner to effectively make use of their resources.
(Presentation is private)
The Louisiana coast is prone to power tropical storm systems, known as hurricanes, which commonly cause significant damage to the environment and financial infrastructure in coastal states, such as Louisiana. Using landsat data acquired from the USGS, determining land cover degradation from seasonal low-pressure storms that span different decades can be made possible. This GIS-based study also takes into account elevation models (DEMs) to provide an accurate portrayal of how coastal vegetation influences the impact of these storms, as well as how storm intensity influences the morphology of coastlines.
(Presentation is private)
Hawaii’s most active volcano, Kilauea, poses many threats to the surrounding infrastructure of the Big Island. Surface deformation from eruptions and underground magma tunnels have produced a growing lava lake within the Eastern Rift Zone, located on the Southeast tip of the island, since 2018. Using remote sensing techniques and GIS, I will use recent data collected from Kilauea’s eruptions and Halema’uma’u lava lake to create a volcanic hazards map of the region. A volcanic hazards map gives us insight to where the safest place are to inhabit on the surface of the island.
(Presentation is private)
There are many major geologic units that outcrop in various regions of the Dallas-Fort Worth metroplex. A major unit that will be discussed in the current study is the Eagleford Shale. Previous studies have generated geologic maps that illustrate where this unit crops-out within the study region. The goal of this study is to create a modern geologic hazard zonation map of the Dallas-Fort Worth metroplex focusing on areas where the Eagleford crops-out. On this map, I will include the spatial distribution of discovered Eagleford outcrop locations and will integrate photographs that illustrate the stratigraphy of this formations using GIS.
Subsequently, I will use the map to calculate the area of all Eagleford surficial deposits within the study region. This shale is a mudrock that is primarily made up of soft-sediments and clays and can pose a geological hazard where it reaches the surface due to shrinking and swelling. This can cause major foundation issues to infrastructure that is built on this unit. Therefore, this map can be used for the purpose of taking precautionary measures when planning the construction of new buildings and road networks within the Dallas-Fort Worth metroplex.
The Lower Cenomanian Maness Shale is an argillaceous mudrock that occurs between the Buda Limestone and Woodbine Sandstone in the East Texas Field, and was originally placed within the Washita Group based on its biostratigraphy. It regionally extends throughout the East Texas Basin in tandem with the overlying Woodbine Group and displays considerable thickness and facies variations. The Maness interval is significant because previous studies indicate that it may be a hydrocarbon source rock.
Although this mudrock has been studied for several decades, the sediment source of the Maness remains in question. Prior studies have indicated that the sediment comprising the Maness could have come from multiple sources, one of them being the southern side of the Sabine Uplift. In the current study, I will correlate well logs through the south side of the Sabine Uplift from Polk and Tyler counties through Rusk county. I will then generate an isopach map of the study area and will compare thickness trends to those shown on the composite isopach map constructed by English (2020). Lastly, I will examine a core from Tyler or Polk counties that could potentially reveal clastic sandstones occurring within the Maness. The findings will be used to test my hypothesis that the Maness Shale is sourced from the southern portion of the Sabine Uplift.
The Atlantic Forest, which extends over 17 Brazilian States, is one of the richest biomes in the world. Historically it has been a hot spot for biodiversity including endangered and endemic species. Despite this, only 15% of the forest’s original range remains. This loss is disproportionally distributed as 4 of the 17 states accounts for 90% of the loss. The source of this deforestation can be attributed primarily to logging developments and eucalyptus plantations. Through using public geodatabases, satellite imagery, and ArcGIS Pro we will show this forest loss and fragmentation in a visually accessible way.
Hardness, defined as resistance to surface deformation, is an intrinsic property of all materials including sedimentary rocks. The variables responsible for a sedimentary rock’s hardness are not completely understood. By understanding which variables control hardness, we may gain a better understanding of related rock strength. Rock strength, defined as a rock’s resistance to plastic deformation under loading, is an important parameter for many industries such as mining, civil engineering, and hydrocarbon exploration.
Numerous tests such as triaxial tests or uniaxial tests are used to quantify rock strength, but are often expensive, time consuming, or require substantial investment in laboratory setup. To circumvent these issues, other devices have been employed to determine rock strength. For example, the Proceq Equotip Bambino micro-rebound hammer (Bambino) has been used for decades to test the hardness of materials such as concrete, steel, and ceramics. These hardness values have been used to determine material strength. Selected studies on rocks empirically correlate between Bambino-derived hardness value (called Leeb hardness) and uniaxial compressive strength (UCS). However, significant scatter in the data suggest that certain intrinsic (e.g., density, bulk mineralogy, etc.) or extrinsic factors (e.g., sample volume, surface the sample rests on) need to be considered for a better correlation.
In this study, I examined the relations between Leeb hardness and UCS values, while examining lithologic variations and other properties such as bulk mineralogy, water loss, volume, density, and effective porosity. I found that bulk mineralogy, density, effective porosity, and water content correlated with a sample’s mechanical hardness. Also, a sample’s UCS is related to its density, effective porosity, and mechanical hardness. Ultimately, these data validated previous studies and shed new insight on the controlling properties of a rock’s hardness and strength.
The Kittanning coal seams run underneath West Virginia, southeast Ohio, and southwestern Pennsylvania. It is part of a sequence that underlies the Freeport and Pittsburgh coals. All three seams are of Pennsylvanian Age. Of the seams in the Northern Appalachian Basin, the Kittanning has the among the largest extents. For that reason, it will most likely be the greatest influencer on population patterns. Since the early 1800s, the people of the region mined and used coal to produce their energy. As such, it is the goal of this research is to determine the spatial relationship between the economic coal sources and population centers.
(Presentation is private)
Anxiety related to academics, especially with regards to testing, is a rapidly growing mental health issue impacting all undergraduates at TCU. High levels of test anxiety have been shown to inhibit memory recall, reduce exam scores, and promote poor study habits. Expressive writing is a form of test anxiety intervention consisting of a type of free response developed to allow students to release their minds of anxious thoughts and emotions related to exams. Expressive writing has been shown to reduce test anxiety and improve exam performance. However, the effectiveness of expressive writing may be mitigated by a students’ level of emotional intelligence. Emotional intelligence is defined as the capacity to be aware of, control, and express one’s emotions. In order to better understand the connection between emotional intelligence and expressive writing, I conducted an exploratory mixed-methods study using quantitative survey data to inform our selection of interview participants and the initial development of my interview protocol. Initially, to gain insight into students’ responses to the expressive writing prompt, I collected and coded expressive writing samples from GEOL 10113 students during the Fall of 2020. Prior to the beginning of the semester, I asked the students to complete a Trait Emotional Intelligence Questionnaire-Short Form (TEIQue-SF) to assign a numerical value to their approximate emotional intelligence levels. Next, I stratified students by quartiles into high (Q3), medium (Q2), and low (Q1) emotionally intelligent groups. Then, GEOL 10113 students were asked to participate in focus group interviews, and volunteers were subsequently grouped by their TEIQue-SF score into three focus groups relating to the high, medium, and low emotional intelligence bins. Finally, using the focus group interview data and the selected student’s responses from the initial expressive writing exercise, I found that all of the student responses showed consistent differences between the three focus groups. Highly emotionally intelligent students had more positive experiences with the expressive writing exercise while lower emotionally intelligent students tended to have neutral or negative experiences with the activity. Overall, these data suggest that the level of emotional intelligence relates to how willing students were to convey their thoughts and emotions during the activity, which helped the higher emotionally intelligent students to have positive experiences with the writing exercise. The implications of my study are that while the efficacy of the expressive writing exercise is assumed, emotional intelligence is a confounding variable. Students must engage with it in some sort of authentic manner if they are to benefit from the exercise.
Solar energy is a significant contributor to the renewable energy mix. Many urban developments are making investments to install solar systems across feasible areas. The allocation of solar systems relies on the land’s geography and the amount of solar radiation received. The purpose of this study is to apply to determine the best sites for solar installations in urban areas. Using the TCU area of Fort Worth, Texas as a case study, this study will use ESRI’s ArcMap and ArcGIS Pro to estimate the solar power potential of different residential rooftops. The results will be useful in showing what households are most suitable for solar installation based on their expected energy yield.
Landslides may be caused naturally or triggered by human activities and have enormous societal and economic impacts. Detecting and mapping landslides through the generation of landslide susceptibility maps (LSM) and understanding the factors that trigger these processes will be helpful in land use planning and risk assessments. Moreover, it will also assist landslide mitigation efforts by controlling anthropogenic-led processes that induce landslides. This study deals with the analysis to identify slow-moving landslides in Travis County, Texas. It combines geographic information systems(GIS) and remote sensing datasets and techniques to generate an LSM of the study area and identify ground displacements. Remote sensing data provide key information about the topography and land uses, combined with controlling factors for a landslide occurrence such as slope, geology/soil and geological structures, and vegetation/land uses to perform an empirical approximation to map and assess landslide susceptibility. Once the susceptible areas are identified, analysis for ground displacement is applied using a Synthetic Aperture Radar Interferometric (InSAR) technique referred to as the Small Baseline Subset (SBAS) and field-based multitemporal Real-Time Kinematic (RTK) GPS measurements.
The Ouachita Trough is a basin that formed along a passive margin on the southern border of Laurentia caused by the Precambrian–Cambrian rifting of Rodinia and the opening of the Iapetus Ocean. The collision of Laurentia and Gondwana and the closing of the Iapetus Ocean thrust sediments from the Ouachita Trough onto the southern portion of the North American craton to form the Ouachita Mountains. The Ouachita Trough transitioned from a sediment-starved basin into an area of rapid sediment accumulation during the Mississippian. The Stanley Group, of interest in this study, was deposited prior to the collision of the encroaching Gondwana continent to the south. Although there have been many previous studies aiming to determine the provenance history of the Stanley Group, the results are inconclusive. In this study, nine samples from turbidite deposits of the Stanley Group were processed using both U-Pb age dating and core rim analysis. Laurentia and Gondwana have similar aged terranes that are difficult to differentiate. Using core rim analysis allowed us to date both the age of the core and rim of individual zircon grains. We were then able to correlate zircon grains of similar ages to their sources. By analyzing a large area of the Ouachita Mountains, this study shows that the Stanley Group consists of sediments sourced from both Laurentia and Gondwana terranes to the south.