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ENSC2019HUDGENS33438 GEOL

Monarch Butterfly Population Decline

Type: Graduate
Author(s): andrew hudgens Geological Sciences
Advisor(s): Tami Morgan Geological Sciences
Location: Session: 2; Basement; Table Number: 2

poster location

Monarch butterfly populations in North America have declined by approximately 80% over the last 20 years. Many contributing factors are responsible for this decline, however the loss of Milkweed has been identified as a major factor. Milkweed is the primary food source for Monarch caterpillars. A GIS analysis was performed to identify milkweed resources in the North Texas area.

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GEOL2019CAVES50910 GEOL

Understanding Metal-Silicate Mixing in Mesosiderites

Type: Graduate
Author(s): Lindsay Caves Geological Sciences
Advisor(s): Rhiannon Mayne Geological Sciences
Location: Session: 1; 1st Floor; Table Number: 5

poster location

Mesosiderites are meteorites composed of equal parts metal and crustal silicate material, which have been linked to the HED parent body 4Vesta. The metal portion of mesosiderites is also compositionally similar to the IIIAB irons. Mesosiderite silicates were mixed with metal, recrystallized and rapidly cooled. The slow metallographic cooling rates recorded by mesosiderite metal indicate mixing followed by deep burial within an asteroidal body. Several models for the formation of mesosiderites have been proposed, but no single model can completely explain their multi-stage history. Oxygen isotope compositions of mesosiderites and eucrites are identical, consistent with the HEDs and mesosiderites originating from a common parent body. However, there are notable differences between the two groups. These include the differing Fe-Mn-Mg systematics in mesosiderite pyroxenes, which reflect an FeO reduction trend and not the magmatic trend seen in the HEDs. Phosphates and tridymite are also more abundant in mesosiderites than howardites and eucrites. These differences have been attributed to redox reactions that occurred during the metal-silicate mixing stage of mesosiderite formation. As previous work focused mainly on the silicate portion, this study examines the metal of five mesosiderite samples of varying petrologic class and degree of metamorphism. Thick sections of each meteorite containing both matrix metal and metal nodules were requested on loan from the National Meteorite Collection, located in the National Museum of Natural History, Department of Mineral Sciences. Electron microprobe (EMP) analyses of both silicate and metal portions of each mesosiderite were collected, as well as LA-ICP-MS analyses of the matrix metal and metal nodules within each section. The dataset will be analyzed for evidence of redox reactions and other processes that may have been occurring during the metal-silicate mixing phase of mesosiderite formation. If redox reactions occurred between the metal and silicate portions of mesosiderites, then: 1) the matrix metal within mesosiderites may be depleted in readily oxidizable elements (e.g. P, W) relative to the metal nodules that are not in contact with the silicate phase; or, 2) all metal in mesosiderites is depleted in readily oxidizable elements. This depletion should be visible when compared to IIIAB irons of a similar composition.

(Poster is private)

GEOL2019CHEN17381 GEOL

Geomimicry as a solution to high atmospheric CO2 levels

Type: Undergraduate
Author(s): Guangshun Chen Geological Sciences
Advisor(s): Omar Harvey Geological Sciences
Location: Session: 2; 2nd Floor; Table Number: 4

poster location

Carbon Dioxide (CO2) emissions are a huge problem that plagues our planet. It causes numerous health and environmental issues that are already causing long term damage. This project was designed to combat those issues by using geomimicry to extract and convert CO2 from the air into the rock mineral, calcium carbonate (CaCO3) which is the main way carbon is naturally sequestered on Earth. We first built an apparatus that could: pump carbon dioxide in, measure carbon dioxide levels, and become airtight. We then poured 1 gallon of water and 6 grams of calcium hydroxide (CaOH2) into this apparatus and shook it to thoroughly dissolve the CaOH2 into solution. After that we bubbled in Carbon Dioxide for 2, 4, 5 or 6 seconds. After recording our results we determined the k-value or efficacy of the reaction, this value is also known as as the rate constant. This showed us that the experiment is most effective at lower concentrations. To further prove the viability of this approach we redid the experiment at 2 seconds and then weighed the Calcium Carbonate produced. Because the reaction has a 1:1:1:1 molar ratio we were able to determine the moles of Carbon Dioxide that were removed from the system. We found that our system worked incredibly (Approximately 95-99%) well at removing added Carbon Dioxide from the apparatus.

GEOL2019CORONA14323 GEOL

Coltan Mining in Democractic of Republic of the Congo and Its Relation with War

Type: Undergraduate
Author(s): Genesiss Corona Geological Sciences
Advisor(s): Tammie Morgan Geological Sciences
Location: Session: 1; Basement; Table Number: 10

poster location

Coltan Mining Sites and Conflict for Technology
There has been ongoing conflict in the African country of the Democratic Republic of the Congo. The source of conflict is due to a highly valued mineral known as coltan. The mineral is found within the Kivu regions, near the border of Rwanda. The mineral coltan also known as tantalum which is “Tantalum is used to store the electricity in cell phones and other devices, and it is referred to, by those in the industry and by human rights groups, as one of the “3 Ts” (tantalum, tungsten, and tin) that, along with gold, are present in nearly every digital device” (Smith, 18). The extraction of this mineral has brought much social unrest and violence within the country for the sake of technology. There has been constant war within this region which has forced many people to flee from their homes, resulted in deaths, violence and forced child labor. A GIS analysis was done to show correlation between the location of the mining sites in Kivu and its effects on the environment and population.

GEOL2019DEBONE30636 GEOL

Newly discovered old volcano in Big Bend National Park

Type: Graduate
Author(s): Kristin DeBone Geological Sciences Tamie Morgan Geological Sciences
Advisor(s): Richard Hanson Geological Sciences
Location: Session: 2; Basement; Table Number: 8

poster location

Recent field work has discovered a volcanic complex within the Paleocene Black Peaks Formation in the northwestern part of Big Bend National Park in west Texas. This is the only known Paleocene volcano in west Texas. We have identified pyroclastic deposits consisting of ash-sized and coarser clasts, including volcanic bombs and blocks, which were erupted explosively from a nearby vent. Margins of the volcanic complex have been mapped using remote sensing because the volcanic rocks are distinctly different in color from the adjacent shale. Characteristics of the pyroclastics suggest derivation from phreatomagmatic eruptions, which occurred when magma and groundwater violently interacted in the shallow subsurface.

(Poster is private)

GEOL2019DONAHOO65357 GEOL

Using Non-Invasive Geophysical Techniques in Near-Surface Infrastructure and Agricultural Planning and Management

Type: Graduate
Author(s): Michaela Donahoo Geological Sciences
Advisor(s): Omar Harvey Geological Sciences
Location: Session: 2; 3rd Floor; Table Number: 7

poster location

Using Non-Invasive Geophysical Techniques in Near-Surface Infrastructure Planning and Management

Michaela Donahoo1, Karim Ouamer-ali2,3, Youcef Daoud2, Kaddour Djili3, Omar R. Harvey1
1Department of Geological Sciences, Texas Christian University, Fort Worth, Texas, USA.
2 National Institute of Agronomic Research of Algeria (INRAA), El-Harrach, Algeria.
3Ecole Nationale Supérieure Agronomique (ENSA), El-Harrach, Algeria.

Understanding soil characteristic variability geospatially as a function of depth and time is key to the optimal implementation of subsurface infrastructure planning and expansion. The soils physical behavior as well as its interaction with piping and road materials determine where such a system could divert and predict future maintenance frequency. Central to the development of site-specific, precision management strategies is the quantification and mapping of the geospatial variability in soil properties at significantly higher resolutions than provided in current soil surveys. The presentation will cover results from ongoing collaborative research efforts between researchers at Texas Christian University and two Algerian institutions in using non-invasive measurements of bulk apparent electrical conductivity (ECa) to quantify and map 3-D soil variability in semi-arid and arid areas of Algeria, Northern Africa. The focus will be on the derivation and application of depth-specific ECa-ECe (saturated paste), ECa-clay content and ECa-water content relationships for use in understanding seasonal salinity and water dynamics within potential depths of construction interest.

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GEOL2019FERRARI22030 GEOL

GIS as a Tool for Mapping Potential Locations of Geologic Outcrops in the Ouachita Mountains

Type: Undergraduate
Author(s): Bennett Ferrari Geological Sciences
Advisor(s): Tamie Morgan Geological Sciences Xie Xiangyang Geological Sciences
Location: Session: 2; 2nd Floor; Table Number: 2

poster location

A GIS analysis was conducted to analyze digital map layers of soils, bedrock geology and topography including slope looking for differences in erosional topography that would result in an exposed geologic outcrop. This study was conducted in the region of the Ouachita Mountains that extends from North Central Texas through Oklahoma into Arkansas. For this study, know geologic outcrop locations were mapped and used as test sites.

GEOL2019HOLLAND18000 GEOL

DFW Interpolation Study of Pollution Congregation Insight for Real Estate Market Analysis

Type: Undergraduate
Author(s): Claire Holland Geological Sciences
Advisor(s): Tamie Morgan Geological Sciences
Location: Session: 2; Basement; Table Number: 3

poster location

Pollution is a distinguished and growing environmental issue among urban centers across the world. GIS interpolation methods can allow visualization of air toxics data that is intuitive and insightful. This data can be collected and aggregated to produce pollution density maps. I will be working with interpolation methods for the DFW metroplex over a specific time period to determine areas where pollution has become a major growing issue. I will use this information to assess the overall effect on DFW property values, and what this means in regards to future real estate market analysis. By knowing where the pollutants are congregating, I can effectively predict which property values will rise and fall due to the overall effects of pollution.

GEOL2019JACKSON44843 GEOL

Evolution of the Trinity River - Fort Worth, TX

Type: Undergraduate
Author(s): Blake Jackson Geological Sciences
Advisor(s): Tamie Morgan Geological Sciences
Location: Session: 1; 1st Floor; Table Number: 3

poster location

The past 20 years has seen significant change in urbanization and commercial development along the Trinity River of Fort Worth, Texas. Significant projects such as Panther Island and the Trinity River Project are major proposals here. A GIS analysis using historical aerial photography and satellite imagery was conducted to examine the impact of urbanization on green space, tree-cover, overall greenness, and vegetation patterns at Fort Worth’s Trinity River.

GEOL2019LAMB52985 GEOL

A Source to Sink Analysis of the Dockum Group in the West Texas Highplains

Type: Graduate
Author(s): Grayson Lamb Geological Sciences
Advisor(s): John Holbrook Geological Sciences
Location: Session: 1; 3rd Floor; Table Number: 9

poster location

The fundamental understanding of any geologic basin stems from ascertaining the relationship between its source and sink. Every basin is therefore identified as a “sink” and has a provisional “source.” The investigation of this fundamental relationship is the preliminary exploration step to further basin development.
The Late Triassic Dockum Group of the west Texas high plains is an understudied group that begs investigation into the source to sink relationship. A comprehensive study of the Dockum Group as a “sink” is here undertaken in order to better understand the paleoclimate and its implications on the Dockum group depositional style. This study focuses on the northern most section of the Dockum group outcrop system. Within the study area it is subdivided into three main formations, the Tecovas mud, Trujillo sand, and Cooper Canyon sand-mud mix system.
This study showcases a forward stratigraphic modeling software, Dionisos Flow. From field based outcrop work: grain size, channel thickness, water discharge, and lithofacies assemblages were quantified as model inputs in Dionisos Flow.
The study aims to model Dockum Group sedimentation in order to determine the plausible paleoclimate, and its related depositional environment and depositional style. To do so, an outcrop study and fluvial architecture analysis was completed to serve as model input variables. Then a forward stratigraphic Dionisos Flow model of the three main Dockum Group formations was generated. It was then analyzed and coupled with the outcrop study to draw conclusions on the necessary Triassic climate conditions to produce the Dockum Group deposits.
Per the modeling exercise and outcrop study it is concluded that the Triassic climate was highly variable, shifting between semi-arid to humid. Its variability has been underemphasized in previous studies. Climate alterations are on a scale of 103 years. Additionally, the Dockum Group’s sedimentation style has been a forum of contradicting theories. This study has concluded that Dockum sands were deposited in a predominantly upper flow regime environment during humid climate cycles, while its abundant muds were deposited in lower flow during semi arid climate cycles.

(Poster is private)

GEOL2019MEL8440 GEOL

A GIS Analysis of Seasonal Trends in Atmospheric Particulate Matter across Texas from 2017-2018

Type: Undergraduate
Author(s): Manyiel Mel Geological Sciences
Advisor(s): Tamie Morgan Geological Sciences Omar Harvey Geological Sciences
Location: Session: 2; Basement; Table Number: 7

poster location

A variety of health studies have established an association between exposure to particle pollution and an array of significant health risks. For individuals with pre-existing heart or lung disease, older people, and children, exposure to particle pollution can result in increased hospital admissions, emergency room visits, absences from school or work, and restricted activity. A GIS analysis was conducted to map the distribution of particular matter (PM2.5) across the state of Texas, looking at seasonal variations over the period of 2017 and 2018. Ambient temperature data were also collected, interpolated and analyzed. Data was collected from TCEQ for different monitoring stations across Texas and mapped to visualize the areas in Texas that might be exposed to higher levels of PM2.5. The data were analyzed looking for trends based on season variations and locations in Texas.

GEOL2019MIRKIN10373 GEOL

Background Color Matching in Texas Horned Lizards

Type: Graduate
Author(s): Stephen Mirkin Biology
Advisor(s): Tamie Morgan Geological Sciences
Location: Session: 2; Basement; Table Number: 1

poster location

Texas horned lizards are a threatened species in the state of Texas with declines attributed to a variety of factors including: habitat conversion, pesticide use and red imported fire ants. These cryptic lizards in their natural habitats utilize a variety of anti-predator defense mechanisms. The primary defensive adaptation to avoid predators is often cited as their cryptic coloration, which is often suggested to color match the background substrates of the regions where they are found. Although background color-matching is purported to be an important factor in horned lizard defensive strategies it has never been empirically tested. Here we present the first known study of background color matching of Texas horned lizards in the state of Texas. We used a GIS analysis using soils and satellite imagery data to test how well Texas horned lizards match the soils and substrate in different regions of Texas.

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GEOL2019PEREZ40118 GEOL

Area Growth of Fort Worth, Texas in Zip Codes 76131, 76177, 76137, and 76244

Type: Undergraduate
Author(s): Dylan Perez Geological Sciences
Advisor(s): Tamie Morgan Geological Sciences
Location: Session: 2; 3rd Floor; Table Number: 1

poster location

Over the last 20 years significant growth has occurred in the northern part of Fort Worth, Texas defined by the zip codes 76131, 76137, 76177, and 76244. Using GIS analysis, this project measured the amount of open area lost and the growth of residential and commercial areas.

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GEOL2019STIEFFEL51148 GEOL

Evidence for an Old Parana delta and Diachroneity in Global Highstands

Type: Graduate
Author(s): Rodney Stieffel Geological Sciences
Advisor(s): John Holbrook Geological Sciences
Location: Session: 1; 2nd Floor; Table Number: 4

poster location

The highstand deltas of the Holocene tend to each initiate with the peaking of eustatic sea level rise at about 7000 y.b.p. While generally tied to this time, the initiation of highstand shorelines is not necessarily synchronous. Local impacts on relative sea level can impact this timing. In particular, the Parana Delta, Argentina, appears to have initiated as early as 8100 y.b.p., well before the global sea level peak and potentially before any comparable highstand shorelines. The Parana Delta encompasses an area of ~17,400 km2 enclosed in the Rio de la Plata estuary, growing steadily at a rate of approximately 2 km2 yr-1 for roughly the past 6000 yrs. This deltaic system has shifted from fluvial, to wave-dominated, and then back to its present day fluvial dominated system. Aerial and satellite imagery, shallow boreholes, radiometric dating of shells and sand, and Ground Penetrating Radar are used to define the distinctive sedimentary features of the delta. New data from the upper part of the delta indicates the Parana Delta initiated well before the 6000 y.b.p. previously reported. Sediment cores collected from across the upper delta are used to identify sedimentary facies and construct a stratigraphic framework. Three OSL samples collected from the oldest set of beach ridge s indicate the first ridges formed approximately 8100 years ago. These beach ridges are <3 m above sea level and argue for an early peak in relative sea level. Highstand strata are about 6 m thick above a thin (1-2 m) condensed section above transgressive shoreface deposits. The Parana delta initiated at least 1500 years before the sea level peak. Assumptions of synchronicity of highstands with eustatic sea level accordingly must be tempered with comparable allowance for local error.

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GEOL2019TALBERT42796 GEOL

Lower Permian and Pennsylvanian Stratigraphy and Shale Gas Potential of the Palo Duro Basin

Type: Graduate
Author(s): Brendan Talbert Geological Sciences
Advisor(s): Cheyenne Xie Geological Sciences
Location: Session: 2; Basement; Table Number: 11

poster location

The Palo Duro Basin is a northwest-southeast trending cratonic basin in the Texas Panhandle that formed from uplift of the Amarillo/Wichita Mountains during the Pennsylvanian, and subsequent subsidence during the Permian. Sediments were deposited in a number of environments, the most prominent being fan-delta, carbonate shelf, and deep basin settings. Major lithologies in the Pennsylvanian are granite wash, shelf-margin carbonates, and basinal shales, while the Permian hosts the same lithologies, as well as numerous evaporites and red-bed sequences.
This study analyzes log data from 100+ wells in the Palo Duro Basin to correlate and determine the lateral extent of different facies throughout the basin during the Pennsylvanian and Permian. Cross-sections made will help to generate isopach, structure, and other geological maps to identify areas where further geochemical and/or petrophysical analyses can be performed to evaluate Pennsylvanian and lower Permian shale gas potential of the Palo Duro Basin. This project will establish a more detailed stratigraphic framework of Pennsylvanian and lower Permian aged sediments of the basin, as well as determine source rock quality and thermal maturity for potential shale gas plays within the Palo Duro Basin, with a more thorough look along the southern fringes of the basin near the Matador Arch.

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GEOL2019TERRELL64068 GEOL

Pennsylvanian and Mississippian Stratigraphy, Little Hoss Ranch, Johnson County, Fort Worth Basin, Texas

Type: Graduate
Author(s): Aro Terrell Geological Sciences
Advisor(s): Richard Denne Geological Sciences
Location: Session: 1; 2nd Floor; Table Number: 7

poster location

The primary objective of this study is to test my hypothesis that the stratigraphy within Little Hoss Ranch is very complex and diverse but correlative to the surrounding strata of similar depth and characteristics. The second objective is to identify characteristics of the stratigraphic facies to better aid in the production via recompletion or other determined methods within the Little Hoss area. Seismic data that will be analyzed within Little Hoss Ranch are made available by TEP Barnett. Seismic analysis will be done using Kingdom and will be assisted by the TEP geophysicist when possible. The goal is to use these data to better identify faults and other significant structural features within the area as well as the Barnett Shale stratigraphy for LHR. A map will be made using the seismic data and logs will be included in the map for reference and quality check purposes. The seismic, well log, and cutting data for the LHR that will be analyzed was originally acquired by Chesapeake as early as 2008 and is now owned by TEP, Barnett. 127 well logs will be analyzed using PETRA, within and immediately adjacent to the Little Hoss Ranch area, to better correlate and map the stratigraphy within the Little Hoss Ranch and will be tied to the LHR wells with surrounding wells in Johnson County and Tarrant County to create regional cross-sections. An additional cross-section will be created with the wells to the north in Tarrant County to display structural trends and stratigraphic facies correlation. The 127 LHR wells will be used to create a detailed structure map that can be compared to the seismic time structure map. The BHT will be used from the well logs as well as production data (oil to gas ratio) to determine if differential thermal maturity occurred within the area The overall goal of this project is to analyze the stratigraphy and structure of the Barnett Shale play within the Little Hoss Ranch confines and to identify any geologic effects or geologic solutions to marginal production for the area of study. Seismic data, well-logs, core and cuttings, mud-log descriptions, and background literature research will be used to conduct a thorough investigation into the stratigraphy affecting the LHR. The wells in the LHR will be used with wells in northern parts of the Fort Worth Basin to create a cross section spanning a larger area. This will help to better correlate the stratigraphy for the basin and help identify depositional and erosional changes in the Fort Worth Basin. Additionally, the OGIP data and calculations will be used to help define what the remaining hydrocarbon value is for the Barnett Shale within LHR.

(Poster is private)

GEOL2019TOTZ51136 GEOL

A GIS Analysis of Crustal Stress Directions and Orientation of Horizontal Drilling in the Permian Basin in West Texas

Type: Undergraduate
Author(s): Samuel Totz Geological Sciences
Advisor(s): Tamie Morgan Geological Sciences Helge Alsleben Geological Sciences
Location: Session: 1; 2nd Floor; Table Number: 6

poster location

The World Stress Map (WSM) is a global compilation of information on the stress field of the present-day earth crust and is maintained since 2009 at the Helmholtz Center Potsdam GFZ German Research Center for Geosciences. This database uses data from earthquake focal mechanisms, well bore breakouts, drilling induced fractures, and geologic data to generate a map of the stresses in the Earth. Using GIS, the data was mapped and examined for the Permian Basin area of West Texas which is currently one of the largest and most active oil fields in the United States. This database in conjunction with data collected on the direction of horizontal well bores was examined to determine if or how stress directions in the Earth influenced the drilling bore direction. This data was also used to see if there is a correlation between stress direction and a company’s decision to place a well in a certain location or orientation.

(Poster is private)

GEOL2018ALVAREZ29418 GEOL

Regional Chemostratigraphy and Mechanical Stratigraphy of the Barnett Shale, Fort Worth Basin, Texas

Type: Graduate
Author(s): John Alvarez Geological Sciences
Advisor(s): Helge Alsleben Geological Sciences

Although multiple localized chemostratigraphic and strength studies have been completed on the organic-rich Barnett Shale in the Fort Worth basin (Montgomery et al., 2005; Pollastro et al., 2007; Jarvie et al., 2007; Rowe et al., 2008; Williams et al., 2016; Taylor, 2017; Alsleben, unpublished), basin-wide correlations have not been completed. Basin-wide correlation of chemostratigraphy and mechanical stratigraphy could enhance the understanding of regional variations in chemical composition and rock competence. Therefore, this study is going to test multiple hypotheses to identify regional trends and correlations within the Barnett Shale, based on variations in the formations chemical makeup and rock strength. The purpose is to start establishing a more comprehensive, basin-wide characterization of the mechanical stratigraphy and chemostratigraphic framework of the Barnett Shale in the Fort Worth Basin. Results will start to establish possible regional variations such as rock strength and help determine what controls those variations. Ultimately, the data compilation may provide a better understanding of the Barnett Shale and start to address the complex interactions between marine sediment flux, terrestrial sediment flux, and geochemistry throughout the basin at the time of deposition.

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GEOL2018BURNS41328 GEOL

Geomechanical Relationship Between the Maness Shale and Lower Eagle Ford, San Marcos Arch, Texas

Type: Undergraduate
Author(s): Alec Burns Geological Sciences
Advisor(s): Richard Denne Geological Sciences

The geomechanical properties of Eagle Ford cores from the San Marcos Arch were measured by hardness tools to test that calcareous rocks are stiffer than the clay-rich shales. Results were quantified and graphed to reinforce the idea that the Maness shale could be more ductile than the superimposing Eagle Ford Shale.

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GEOL2018BURNS56887 GEOL

Facies modeling of the Lower Williams Fork, Piceance Basin, CO

Type: Undergraduate
Author(s): Alec Burns Geological Sciences
Advisor(s): Xiangyang Xie Geological Sciences Tamie Morgan Geological Sciences

Lithology and facies of the Lower Williams Fork in the Piceance Basin, Colorado were interpreted using spectral gamma ray logs on Petrel. Models were created using this correlated data to predict the facies in an area with no well data. Different modeling methods will be used, such as object modeling and sequence indication simulation to compare and search for the best fit. Published outcrop measurements were used to constrain subsurface geobody geometry. Models were also used to estimate reservoir rock potential in the Lower Williams Fork.

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GEOL2018DEBONE1535 GEOL

Energetics of Dissolved Organic Matter at the SiO2-Water Interface

Type: Graduate
Author(s): Kristin DeBone Geological Sciences
Advisor(s): Omar Harvey Geological Sciences

Silica oxides (SiO2) come in a variety of forms including quartz, opal, silica gel and phytoliths. This study will focus on the binding and debinding energetics of sodium benzoate, sodium butyrate and sodium acetate on these various silica oxides. The direct measurement and analysis of binding and debinding energies should provide valuable data and insights into the dynamics of organic molecules at the oxide-water interface. The study will focus on the systematic collection and analysis of experimental data that can be used to support the development, validation and refinement of computational models of interactions involving natural organic matter at the metal oxide-water interface, while facilitating the further development of experiment-driven understanding of binding-debinding dynamics of organic molecules onto mineral surfaces.

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GEOL2018FUNDERBURG1151 GEOL

Metasomatism in Eucrites

Type: Graduate
Author(s): Rebecca Funderburg Geological Sciences
Advisor(s): Rhiannon Mayne Geological Sciences

METASOMATIC FEATURES IN EUCRITES. R. L. Funderburg1, R. G. Mayne, N. G. Lunning2, and S. Sin-gletary3, 1Monnig Meteorite Collection, 2950 West Bowie Street, SWR 244, Texas Christian University, Fort Worth, TX 76109. (r.funderburg@tcu.edu), 2Department of Mineral Sciences, Smithsonian Institution, National Museum of Natural History, 10th and Constitution NW, Washington, DC 20560-0119. 3Robeson Community College, 5160 Fayetteville Road, Lumberton, NC 28360.

Introduction: The breakdown of pyroxene to silica and troilite was first identified as an alteration process in eucrites by Duke and Silver [1]; however, metasomatism was not iden-tified as a potential cause of these features until the 1990s [2] and has been increasingly identified in the last 10 years [3, 4, 5, 6, 7]. Many eucrite studies were conducted prior to this time and, while metasomatic features may have been identified, they were not attributed to this process.

Barrat et al. [4] proposed a three-stage alteration process to explain the products of metasomatic alteration found in eu-crites:
(1) Fe-enrichments along cracks in pyroxenes
(2) Fe-rich olivine deposits in cracks and troilite
(3) Al-depletion coincident with Fe-enrichment of pyroxene

While metasomatism within eucrites is now commonly identified within the literature, the mechanism for this altera-tion is not well understood. Possible mechanisms proposed in-volve hydrous fluid alteration [4] or sulfurization from a S-rich vapor [6, 7]. The addition of sulfur is required to produce troilite from the breakdown of pyroxene, which has been ob-served in several eucrites [3, 4, 5, 6, 7]. Zhang et al. [5] sug-gested that the sulfur may have been present in the form of a dry S-O-P vapor, formed by the volatilization of pre-existing S- and P-rich material as a result of impacts. Additional petro-logical studies are needed to test if metasomatism was consist-ently driven by S-O-P vapors or if some metasomatism lacks the P-component expected for impact derived vapor.

Metasomatism has been directly investigated for only a handful of eucrites. This study will investigate metasomatism in both Stannern and Main-Group-Nuevo-Laredo (MGNL) eucrites to investigate the com-position of the altering fluid/vapor and overarching processes that drive metasoma-tism on the eucrite parent body. Our preliminary work is fo-cused on the Stannern-trend eucrites Bouvante and LEW 88010, the main group eucrite Béréba, and the polymict eu-crite NWA 4834.

Methods: The samples from this study are on loan from the following: Béréba (USNM 5745-2, USNM 6003-2; Na-tional Meteorite Collection, Smithsonian Institution), Lewis Hills 88010 (LEW 88010) (LEW 88010,4; Meteorite Working Group), Bouvante and Northwest Africa 4834 (NWA 4834) (M1224.3, M1224.5, and M2049.2; Monnig Meteorite Collection). Petrographic analysis was conducted via optical micros-copy with an Olympus BX51 polarizing light microscope at the Oscar Monnig Meteorite Collection at Texas Christian University. Backscatter electron (BSE) maps and major ele-ment data for pyroxenes in Bouvante, LEW 88010, and NWA 4834 were measured by a JEOL JXA-8530F HyperProbe elec-tron microprobe analyzer (EMPA) at Fayetteville State Uni-versity’s Southeastern North Carolina Regional Microanalyti-cal and Imaging Consortium. Backscatter maps were gener-ated for each thin section and energy dispersive x-ray spec-trometry (EDS) point analyses were performed.

Results and Discussion: Of the four samples selected for this study so far, one is unbrecciated (LEW 88010), two are monomict (Béréba and Bouvante), and one is polymict (NWA 4834). These samples were selected as they were observed to contain possible metasomatic features during our petrographic survey, but have not been included in the current literature re-garding metasomatism. They include members of both the Stannern- and MGNL- trends (S: Bouvante and LEW 88010; MGNL: Béréba). All samples are either falls or were observed to show little to no terrestrial alteration. Mineralogically, they are typical eucrites, being dominated by pyroxene and plagio-clase, with lesser phases including troilite, chromite, ilmenite, Fe-rich olivine, and silica.
Preliminary results suggest that Fe-enrichment of pyrox-ene rims, along with an associated Al-depletion, is occurring due to metasomatism in the three samples examined using EMPA. Fe-rich olivine was observed in NWA 4834. Petrographic analysis identified the breakdown of pyroxene into troilite and silica in all four samples.

Future Work: Quantitative pyroxene and plagioclase data for all four samples will be collected prior to the conference. This will allow for further assessment of the Al-depletion along with Fe-enrichment in pyroxenes. We will also investigate the presence of phosphates in these samples to investigate the P-component that would be present in an impact derived vapor. We will assess if there are any differences in metasomatism between MGNL and Stannern-trend eucrites. A survey of previously identified residual eucrites for metasomatic features will also be conducted, so that all three geochemical groupings are represented, if possible.

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GEOL2018HARRISON25027 GEOL

Facies Characterization, Architecture Analysis, and Depositional Environment of Cretaceous-Paleogene Coal Beds and Surrouding Strata within the Raton Basin of Colorado and New Mexico, USA

Type: Graduate
Author(s): Ross Harrison Geological Sciences John Holbrook Geological Sciences Sean Horne Geological Sciences
Advisor(s): John Holbrook Geological Sciences

The Raton Basin of Colorado and New Mexico is a Laramide foreland basin that has been important to coal geology since its first identification as a coal resource in 1821, and as a major Coal Bed Methane resource in the modern era. Raton Basin contains Cretaceous to Paleogene strata representative of the major transgression and subsequent regression of the Western Interior Seaway. The interaction between the distal and proximal lithosomes of strata within the Raton Basin is not fully understood. The coaly, fine-grained rocks of the lower and upper coal zones of the Upper Cretaceous to Paleogene Raton Formation are indicative of deposition in wet, distal lowlands, whereas the coarser grains of the barren series of the Raton Formation indicate that this unit was deposited in a highland setting proximal to the source. While the basin has been explored and produced for petroleum and coal in the past (specifically the Cretaceous Vermejo Formation and Raton Formation), vertical and lateral interaction, geometries, and potential communication between the coal deposits and surrounding fluvial deposits is not well-understood. This project has served as an investigation into the depositional model of the coal deposits and their surrounding fluvial deposits, specifically by: analyzing outcrops using architecture analysis, performing core descriptions and interpretations, conducting coal palynology, organic petrology, and chemical analysis. It has been proposed that the Upper Cretaceous to Paleogene strata of the Raton Basin were deposited within a Distributive Fluvial System (DFS), and that the coal-rich zone is the down-dip expression of this system. Initial results (vertical and lateral relation of facies in core and outcrop, organic petrology, and palynology) reveal that the extensive and laterally continuous coals formed in a woody low-lying fluvio-lacustrine depositional environment, and humid subtropical climate.

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GEOL2018HORNE32182 GEOL

Interaction Between the Upland and Lowland Lithosomes of Late Cretaceous and Paleogene Strata of the Raton Basin

Type: Graduate
Author(s): Sean Horne Geological Sciences Ross Harrison Geological Sciences John Holbrook Geological Sciences
Advisor(s): John Holbrook Geological Sciences

The Raton Basin of Colorado and New Mexico is a Laramide foreland basin that has been important to coal geology since its first identification as a coal resource in 1821, and as a major Coal Bed Methane resource in the modern era. Raton Basin contains Cretaceous to Paleogene strata representative of the major transgression and subsequent regression of the Western Interior Seaway. The interaction between the distal and proximal lithosomes of strata within the Raton Basin is not fully understood. The coaly, fine-grained rocks of the lower and upper coal zones of the Upper Cretaceous to Paleogene Raton Formation are indicative of deposition in wet, distal lowlands, whereas the coarser grains of the barren series of the Raton Formation indicate that this unit was deposited in a highland setting proximal to the source. While the basin has been explored and produced for petroleum and coal in the past (specifically the Cretaceous Vermejo Formation and Raton Formation), vertical and lateral interaction, geometries, and potential communication between the coal deposits and surrounding fluvial deposits is not well-understood. It has been proposed that the Upper Cretaceous to Paleogene strata of the Raton Basin were deposited within a Distributive Fluvial System (DFS), and that the coal-rich zone is the down-dip expression of this system. This hypothesis was tested by integrating results from well log correlations, measured sections, architecture analysis of outcrops from drone photogrammetry, core descriptions, and coal palynology and microscopy. Initial results reveal the presence of three distinct, repeating lithosomes (valley-fill sandstones, mixed terminal splays, and very extensive and laterally continuous coals) that are identifiable and correlatable in well logs, are cyclically represented, and suggest basin-scale swings in depositional environment consistent with shifting components within a basin-wide DFS system, consistent with the DFS hypothesis.

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GEOL2018LEHMAN53009 GEOL

Insights into the Sources and Tectonic Setting of Magmatism in a Complex Arc Setting: Major and Trace Element Variations in the ~1.2 Ga Barby Formation in SW Namibia

Type: Graduate
Author(s): Katelyn Lehman Geological Sciences
Advisor(s): Richard Hanson Geological Sciences

The ~1.2 billion-year-old-Barby Formation is located in SW Namibia and has been argued to represent a continental volcanic arc. Previous studies on these rocks primarily relied on mobile-element data, which can be altered by secondary processes and therefore is unreliable for constraining petrologic processes. In an effort to establish the Barby Formation's petrotectonic history, 20 samples were analyzed using XRF and ICP-MS to determine whole-rock major and trace element concentrations. These data were used to answer two questions: (1) Do the samples represent one unique magma series that came from a single source? (2) If the Barby Formation is indeed a volcanic arc, did it form from normal, flat-slab, or oblique subduction? These questions were answered using a combination of geostatisical analyses (distribution, cluster, and outlier analyses), trace-element tectonic discrimination diagrams, and geospatial analyses (see other poster by Lehman et al.). This study supports previous interpretations that the Barby Formation formed in a continental arc setting, with rock samples displaying steeply dipping, light-rare-earth-element enriched patterns, negative Nb/Ta anomalies, and calc-alkaline andesitic to shoshonitic compositions. Major and trace element data indicate at least two magma series from two distinct mantle sources. These two groups are controlled by enrichment differences and variations in the high-field-strength element ratios. The presence of shoshonitic rocks is consistent with flat-slab or oblique subduction.

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