Earth Sciences Commons^™

Blending Rudists With Technology; Non-Destructive Examination Of The Internal And External Structures Of Rudists Using High Quality Scanning And Digital Imagery, Ann Molineux, Robert W. Scott, Jessie Maisano, Richard Ketcham, Louis Zachos

Turkish Journal of Earth Sciences

Certain formations within the Cretaceous of Texas include zones of silicified rudists. Such diagenetic alteration, combined with the timing of alteration, has preserved many structural features of the rudist suitable for computed tomography (CT scanning). The excellent density differences between those skeletal structures (silica) and the internal sediment (calcitic mud) or later crystallization (calcite), fulfill a fundamental requirement for such analysis. The Jackson School of Geosciences at The University of Texas provides access to a high resolution computed tomography scanning system. This equipment, not identical to medical scanners, provides higher resolution and sophisticated software to analyze the imagery. Several rudist …

Geophysical Analysis Of Seasonal Montandon Gravel Ridge Water Table Fluctuation And Moisture Gradient Variation Due To Storm Events, Annie Strader

Honors Theses

The purpose of this research project is to continue exploring the Montandon Long-Term Hydrologic Research Site(LTHR) by using multiple geophysical methods to obtain more accurate and precise information regarding subsurface hydrologic properties of a local gravel ridge,which are important to both the health of surrounding ecosystems and local agriculture. Through using non-invasive geophysical methods such as seismic refraction, Direct Current resistivity and ground penetrating radar (GPR) instead of invasive methods such as boreholedrilling which displace sediment and may alter water flow, data collection is less likely to bias the data itself. In addition to imaging the gravel ridge subsurface, another …

Miocene Fluctuations Of The West Antarctic Ice Sheet And The Influence Of Meltwater On The Ross Sea Outer Continental Shelf: Seismic-Stratigraphic Based Interpretations, Sean Francis Kerrin

LSU Master's Theses

The changing extents of the West Antarctic Ice Sheet (WAIS) and the manifestation of meltwater discharge on the outer shelf during the Miocene were deduced using seismic stratigraphy and seismic facies interpretations. Deep Sea Drilling Project (DSDP) Leg 28 drill sites were used for chronologic constraints of the outer continental shelf (OCS) seismic stratigraphy to establish correlations to coeval strata at the inner shelf SMS-ANDRIL drill site. The evidence indicates that grounded ice sheets periodically existed on the OCS during the early and middle Miocene and in section inferred to have been deposited in the late-Miocene. Large-scale grounding events occurred …

A Petrophysical Evaluation Of Factors That Control Cap Rock Seal Quality, Andrew Tyler Harrison

LSU Master's Theses

Textural and mineralogical variations within 33 shale samples were analyzed to provide a model for predication of hydrocarbon top-seal efficiency. Variation in mineral abundances in the subsurface influences petrophysical properties and other characteristics of hydrocarbon sealing sequences and reservoirs. In geophysical well logs, various proxies, such as gamma ray emission and neutron absorption, are used to assess changes in mineral composition. This study directly compares X-ray diffraction measurements of mineral percentages and geophysical responses from Middle Miocene cored intervals in the Santa Cruz Well; Mississippi Canyon block 519, Gulf of Mexico with those derived from well logging. Distinct textural differences …

Riparian Conundra, David Weaver

Conference papers and presentations

Riparian vegetation is established or restored on the basis that it physically filters and traps hillslope derived particulate nutrients in surface runoff. Whilst many studies support this conventional model of riparian function, few test this models embedded assumptions. The assumptions are that catchments are surface runoff dominated, that most surface derived nutrients are transported in particulate form, and that riparian management targets locations that will result in the greatest change in water quality. This paper reviews studies in south west Western Australia that challenge these assumptions. Plots measuring leaching and runoff of nutrients showed that 20 times more water and …

Bioturbation, Habitat Partitioning, And Tiering In Tropical Intertidal Callianassid Mounds: An Example From The Bahamas, H. Allen Curran

Geosciences: Faculty Publications

Abstract from 2010 Workshop on Crustacean Bioturbation — Fossil and Recent held in Lepe, Spain.

Editors: Jordi M. deGibert, Fernando Muñiz, Eduardo Mayoral, Zain Belaústegui

Oxygen And Hydrogen Diffusion In Minerals, John Richard Farver

School of Earth, Environment and Society Faculty Publications

This chapter provides a summary and review of experimentally determined oxygen and hydrogen volume diffusion in minerals. A very extensive and detailed review of stable isotope exchange processes including oxygen and hydrogen volume diffusion can be found in Cole and Chakraborty (2001) and a detailed review of hydrogen diffusion in minerals, especially nominally anhydrous minerals, can be found in Ingrin and Blanchard (2006). In addition, a detailed review of oxygen and hydrogen diffusion in silicate melts is provided by Zhang and Ni (2010), and oxygen and hydrogen diffusion rates can also be found in the chapters, in this volume, on …

A Real Time Optical Biosensor Assay For Amoxicillin And Other Β-Lactams In Water Samples, Israel M. Scott, Lewis J. Kraft, Jonathan D. Parker, Kathryn Daniel, Sarah Kustick, Diana Kennen, Jonathan L. Mcmurry

Faculty Articles

Antibiotic contamination of drinking water and sewage is a matter of environmental and public health concern. Traditionally, ELISA or HPLC methods have been used to detect and measure antibiotic contamination. By applying an optical biosensing method, biolayer inteferometry (BLI), we have developed a kinetic competition binding assay capable of quantitating less than lppm (~33 μM) amoxicillin. Similar to surface plasmon resonance, BLI senses changes that occur upon binding of one molecule to another near a surface to measure association and dissociation. Immobilized amoxicillin was used to screen for binding against an analyte solution of anti-amoxicillin equilibrated with amoxicillin-containing water samples, …

Spatial Variations Of Salinity, Temperature And Pressure On The Flank Of A Salt Dome, Offshore Louisiana: Implications For Mechanisms Of Fluid Flow, Andrew Kevin Steen

LSU Master's Theses

Salt dome dissolution in the Gulf of Mexico sedimentary basin is a primary cause for elevated pore water salinities in the subsurface. Temperature, pressure, salinity, lithology and fluid density are parameters often used to identify preferential conduits and driving forces for fluid migration. These parameters were calculated using 20 wireline logs covering 40 km² on the south flank of a salt dome on the continental shelf, offshore Louisiana. 3-D seismic has been utilized to determine location of faults, to aid in sand correlation, and to provide a structural overview of the dome. Vertical and lateral variations in lithology, salinity, temperature, …

Concentrations, Distributions And Chemical Speciation Of Zinc And Cadmium In The Equatorial And South Atlantic Ocean, Gonzalo G. Carrasco

OES Theses and Dissertations

Certain trace metals are important cofactors in enzymatic systems and are thus, essential for life in the world's oceans. Two of these metals, Zn and Cd, are required by phytoplankton for enzymes that facilitate carbon uptake (Morel and Price, 2003). In seawater the total dissolved concentration of a metal (MTD) is distributed among different chemical species and this chemical speciation dictates a metal's bioavailability. Strong organic metal-binding ligands greatly affect the metal's chemical speciation in the ocean, potentially limiting phytoplankton growth by reducing the concentrations of Zn²⁺ and Cd²⁺, the bioavailable forms of these two metals to …

Hydrogeochemistry Of Caves Drip Water At Selected Caves In Peninsular Malaysia., Nor Bakhiah Baharim

Student Works (2010-2019)

This preliminary study represents the study on hydrogeochemical of caves drip water throughout Peninsular Malaysia. All samples were analysed for pH, Total Dissolved Solid (TDS), Dissolved Oxygen (DO), Conductivity, cation and anion. Despite local hydrological and geological differences among sampling sites, the monitoring revealed significant synchronous intersite variations that related to rainfall variation and control the volume of water input. The constant hydraulic pressure is expected in karst system as a result of moist condition of tropical region and rainfall throughout the year. Drip sites were classified into to two classifications which are seepages flow and seasonal flow. A simplified …

Inversion Of 2d And 3d Dc Resistivity Imaging Data Forhigh Contrast Geophysical Regions Using Artificial Neuralnetworks., Ahmad Neyamadpour

Student Works (2010-2019)

In electrical resistivity imaging surveys, the field data along a profile are normally acquired as a subsurface distribution of apparent resistivity. One common method to obtain the true resistivity distribution is by inverting the apparent resistivity values. However, the inversion of DC resistivity imaging data is complex due to its non-linearity. This is especially true for regions with high resistivity contrast. For the complicated subsurface structure, especially when regions of high resistivity contrast exist, a conventional inversion technique based on least squares methods may not be able to invert the DC resistivity data with adequate accuracy. Therefore, in this study, …

Lacustrine Sediment Record Of Multiple Quaternary Lava Dams On The Owyhee River, Southeastern Oregon, Caitlin Anne Orem

All Master's Theses

Multiple lava dams and correlating lakes impacted the Quaternary evolution of the Owyhee River. Sediment records from lava-dammed lakes were investigated to understand effects of the West Crater (WC) lava dam (~70 ka), the Saddle Butte 2 lava dam (~144 ka), and the Bogus Rim lava dam (~1.9 Ma). Evidence from the WC lava dam and related features indicates that dam duration consisted of five stages (1) dam and lake formation at ~70 ka; (2) dam overflow and lake sedimentation from ~70–46 ka; (3) removal of lava dam and lake termination from ~46 ka to at least 36 ka; (4) …

Fluid Budget Of Metasedimentary Rocks From A Tertiary Accretionary Prism And Connections To Seismicity, Olympic Peninsula, Northwest Washington State, Holly Makena Macfadden Rotman

All Master's Theses

Metamorphic dehydration reactions and fluid movement in accretionary prisms have been linked to the recently discovered episodic tremor and slip (ETS) earthquake events along subduction zones, but prior studies lack the detail to effectively test the hypothesis that fluid flow triggers ETS events. I conducted field work along a 52.5 km transect on the Olympic Peninsula metasedimentary accretionary prism of the Cascadia subduction zone, and collected approximately 40 representative samples of sandstone and mudrock that were buried to 6–15 km. This depth range intersects the 10–50 km depth range of ETS events. My objectives are to quantify the water flow …

Bala (Ankara) Earthquakes: Implications For Shallow Crustal Deformation In Central Anatolian Section Of The Anatolian Platelet (Turkey), Onur Tan, Mustafa Cengi̇z Tapirdamaz, Semi̇h Ergi̇ntav, Sedat İnan, Yildiz İravul, Ruhi̇ Saatçilar, Beki̇r Tüzel, Adi̇l Tarancioğlu, Sali̇h Karakisa, Recai̇ Feyi̇z Kartal, Sami̇ Zünbül, Kenan Yanik, Mehmet Kaplan, Fuat Şaroğlu, Ali̇ Koçyi̇ği̇t

Turkish Journal of Earth Sciences

Central Anatolia is quiet in terms of seismic activity, and rarely earthquakes up to magnitude 5.6 occur in the inner part of the Anatolian block or Anatolian platelet. Southeast of Ankara, the capital city of Turkey, two earthquake sequences with maximum magnitude of 5.6 occurred in 2005 and 2007. We discuss these shallow crustal deformation in the Anatolian platelet, in the light of seismological data from these earthquakes (M_L= 5.6) and their aftershocks. Following the earthquake of December 20, 2007 near Bala town, Ankara, we installed seven temporary stations in the first 24 hours to observe the aftershock activity and …

Miocene - Quaternary Tectonic Evolution Of The Northern Eastern California Shear Zone, Kurt L. Frankel, Jeffrey Lee, Kim Bishop, Nancye Dawers, Plamen Ganev, Jeff Unruh, Lewis A. Owen

All Faculty Scholarship for the College of the Sciences

The northern eastern California shear zone is an important component of the Pacific– North America plate boundary. This region of active transtensional deformation east of the San Andreas fault extends from the Garlock fault northward along the east side of the Sierra Nevada and into western Nevada. The eastern California shear zone is thought to accommodate nearly a quarter of relative plate motion between the Pacific and North America plates. Recent studies in the region, utilizing innovative methods such as cosmogenic nuclide geochronology, airborne lidar, structural mapping, and (U-Th)/He geochronology, are helping elucidate deformation histories for many of the major …

Phosphorus For High Rainfall Pastures, Mike Bolland, Bill Russell, David Weaver

Bulletins 4000 -

Soil testing for phosphorus provides a reliable indication of when the level of phosphorus in a soil is likely to be adequate for pasture production in the next growing season. It is a waste of money to apply phosphorus fertiliser when soil testing indicates none is required, or to acidified soils, or to undergrazed pastures, or to pastures dominated by poorly productive species.

Legumes have higher phosphorus requirement than grasses.

Critical soil test phosphorus values do not change when nitrogen fertiliser is applied.

Taphonomy And Sedimentology Of Two Miocene Vertebrate Fossil Sites On Fort Polk, Louisiana, Julie Lynn Hill

LSU Master's Theses

The discovery of a terrestrial mammalian fauna in the Miocene deposits on Fort Polk, Louisiana, fills a geographic gap in the Gulf Coast paleontological framework, but the provenance of the fossils, nature of the depositional environments, and relationships between the sites is still debated. This is especially true for the TVOR site cluster. TVOR SE has a mixture of marine and terrestrial vertebrates in association with a partly dissolved, in situ bed of articulated oyster shells, which stands in contrast to the fully terrestrial and freshwater assemblage at TVOR, and the indeterminate site TVOR S. Although limited outcrop may bias …

Glacial Deposits, Vol. 38, 2009-2010, Department Of Geography-Geology

Glacial Deposits

Newsletter of the Department of Geography-Geology

Palynological Analysis Of Tiger And Trinity Shoals, Louisiana Continental Shelf, Russell Ryan Crouch

LSU Master's Theses

Forty sediment samples taken from twenty-six vibracores collected from Holocene shoals (Tiger and Trinity) were processed for palynomorphs and analyzed to characterize the terrestrial and marine paleo-environments of southern Louisiana at the time of deposition of each shoal. Abundant and diverse pollen assemblages were recovered while marine microplankton were sparse (< 2% relative abundance). Pollen species were grouped by plants of similar environmental significances including arboreal, non-arboreal, aquatic, and shrub categories. Palynological signals were compared in detail between each core, as well as along strike and dip transects, to help determine whether or not these shoals were deposited coevally or in distinct depositional cycles. Evidence shows that Tiger and Trinity Shoals carry remarkably similar palynological profiles, indicating that sediments of these shoals areS from the same source, and that deposition extended over an interval of time such that climate change was not sufficient enough to alter the vegetation response (hence palynological signal). Pollen profiles show source sediments are predominantly from the lower Mississippi River drainage basin and exhibit species similar to those present in modern Louisiana coastal marshes and swamps (i.e., Taxodium distichum, Cyperaceae, Graminae, Chenopodiaceae, and Asteraceae), and coastal to upland hardwood forests of the Mississippi River alluvial valley (i.e., Pinus, Quercus, Carya, and Liquidambar styraciflua).

Delineation Of A Produced Water Plume In Pointe Coupee Parish, Louisiana, Matthew C. Smith

LSU Master's Theses

Three pits were excavated in the 1960’s at the Fordoche Oil Field in Lottie, Louisiana, as evaporation pits for oil well produced brines. The pits were closed and completed in the 1980’s. Previous studies indicate that produced water has leached into the subsurface within the area to the south and southeast of the pits. Ground penetrating radar (GPR) was utilized in an attempt to delineate the present location of the plume as well as test the feasibility of GPR within a clayey soil in south Louisiana. In addition to collection of GPR data, electrical conductivity logs and soil cores (including …

Using Inoceramid Bivalve Taphonomy As A Paleoenvironmental Indicator Across The Cenomanian/Turonian Horizon At The Pueblo, Colorado Gssp, Jacob Frederick Grosskopf

LSU Master's Theses

Recent paleoenvironmental and geochemical studies indicate that benthic conditions during Oceanic Anoxic Event II (OAE II) (93.5 Mya) in the Cretaceous Interior Seaway (CIS) were dysoxic rather than anoxic. In this thesis, dysoxic benthic conditions were tested for by observing patterns in taphonomic alteration of the calcite portions of inoceramid bivalve shells during and after OAE II. Inoceramid valves were extracted from beds that spanned OAE II at the Cenomanian/Turonian Global Boundary Stratotype Section and Point (GSSP) in Pueblo, Colorado: beds 62 (Hartland Shale), 72 (Bridge Creek Limestone), and 115 (Bridge Creek Limestone). Degree of alteration was tallied using categorical …

Geothermal Resource Assessment Of The Gueydan Salt Dome And The Adjacent Southeast Gueydan Field, Vermilion Parish, Louisiana, Taylor Austin Gray

LSU Master's Theses

The fluids heated by the high thermal conductivity and vertical geometry of salt domes in South Louisiana have the potential to be an economic source of geothermal energy. The Gueydan dome is a piercement salt diapir in Southwest Louisiana lying along the Vermilion and Acadia Parish border. Isotherms indicate a thermal anomaly at the crest of the dome with formation temperatures of 62 ˚C recorded at 1346 m, which is too cold for a geothermal prospect. The shallowest salt encountered is at a depth of 1475 m, and the surrounding strata are Cenozoic sand and clay deposits. Previous geothermal assessments …

Evaluation Of Microfacies Controls On Hydrocarbon Seal Quality, Nchekwube Mbamalu

LSU Master's Theses

A microfacies based approach is proposed for the petrophysical prediction of the most effective hydrocarbon seals. Four distinct microfacies types deposited by different deep water depositional processes have been identified based on textural and mineralogical characteristics. Individual microfacies types include: 1) finely laminated, silt poor to slightly silty hemipelagic claystones; 2) faintly laminated, slightly to moderately silty distal hemiturbiditic claystones; 3) weakly laminated, moderately silty to slightly sandy intermediate hemiturbiditic mudstones; and 4) very silty and sandy proximal hemiturbiditic mudstones. Hemipelagic and distal hemiturbiditic claystones (microfacies types 1 and 2) containing well to modestly organized fabric, high total clay contents, …

New Age Control On A Mid-Shelf Grounding Event In Eastern Basin, Ross Sea, Amy Noelle Cone

LSU Master's Theses

It is widely accepted that the West Antarctic Ice Sheet (WAIS) was grounded at the continental shelf edge in Eastern Ross Sea during the Last Glacial Maximum (LGM), but the precise chronology is debated. Existing post-LGM ice retreat chronologies are considered suspect because nearly all have been developed using radiocarbon dating of acid-insoluble organics (AIO). Foraminifer tests yield more accurate radiocarbon dates than AIO because unlike loose sediment, foram tests are unlikely to be contaminated by allochthonous carbon, but unfortunately forams are sparse in Antarctic marine sediment cores. Here I utilized a new 3-D multibeam survey of a mid-continental-shelf grounding …

Variations In Synechococcus Cell Quotas Of Phosphorus, Sulfur, Manganese, Iron, Nickel, And Zinc Within Mesoscale Eddies In The Sargasso Sea, Benjamin S. Twining, Daliangelis Nunez-Milland, Stefan Vogt, Rodney S. Johnson, Peter N. Sedwick

OES Faculty Publications

The quotas of P, S, Mn, Fe, Ni, and Zn in individual Synechococcus cells collected from the surface and deep chlorophyll maximum (DCM) layer of three mesoscale eddies in the Sargasso Sea were measured using synchrotron X-ray fluorescence microscopy. Cells in a mode-water eddy had significantly higher P (57 +/- 10 amol) and Mn (28 +/- 7 zmol) cell quotas than cells collected from a cyclone (22 +/- 2 amol and 10 +/- 1 zmol, respectively) or anticyclone (25 +/- 3 amol and 18 +/- 3 zmol, respectively). Conversely, Ni and Zn quotas were significantly higher in the cells from …

Origin Of Pyrite Nodules At The Top Of The Nantuo Diamictites, Southern China, Changjie Liu

LSU Master's Theses

Pyrite nodules up to 20 cm in diameter are found at the top of the Marinoan (~635 Ma) Nantuo glacial diamictite as well as in the cap dolostones and shale/siltstones in the lower Doushantuo Formation in eastern Guizhou, southern China. Earlier studies on the occurrence and stable sulfur and triple oxygen isotope composition of barite in the cap dolostones concluded that seawater sulfate concentrations in shallow oceans in the South China Block were low during the deposition of the cap dolostones. Therefore, the occurrence of pyrite nodules suggests two scenarios: 1) Formation before the precipitation of the cap dolostone, when …

Geothermal Energy Potential Of South Bossier Parish, Louisiana, John Adam D'Aquin

LSU Master's Theses

Northwestern Louisiana sits atop a geothermal anomaly that stretches across Eastern Texas and into Southern Arkansas. Geothermal gradients are observed in this area that are greater than the Gulf Coast average of 22-26oC/km. South Bossier Parish, in particular, could be an ideal location for economic production of electricity by conventional geothermal or enhanced geothermal projects due to ideal geothermal production temperatures of 120-180oC at a relatively shallow depth of approximately 3-5 km. A localized geothermal of 35oC/km gradient was determined using bottom-hole temperatures (BHTs) from 147 wells. At approximately 3.2 km depth, temperatures of approximately 130oC within the geopressured sands …

The Influences Of Microbial Diversity On Carbonate Geochemistry Across A Transition From Fresh To Saline Water In The Edwards Aquifer, Texas, Cassie Jo Gray

LSU Master's Theses

Microbially-mediated karstification through the production of metabolic byproducts has been well-documented in cave environments, but less is known about deep karstic settings. This research aimed to distinguish between microbial and geochemical influences on carbonate dissolution in the Edwards Aquifer, a prolific karst aquifer in central Texas, specifically from a transect of six wells across a transition from fresh to saline water in New Braunfels. For the first time, a portion of the aquifer’s bacterial diversity was examined from molecular 16S rRNA gene sequence analyses, which revealed that Alphaproteobacteria, Gammaproteobacteria, and Betaproteobacteria dominated the aquifer, with rare Bacteroidetes, Nitrospirae, and Firmicutes …

A Dynamic Physical Model For Soil Temperature And Water In Taylor Valley, Antarctica, H. W. Hunt, Andrew G. Fountain, Peter T. Doran, Hassan J. Basagic

Geography Faculty Publications and Presentations

We developed a simulation model for terrestrial sites including sensible heat exchange between the atmosphere and ground surface, inter- and intra-layer heat conduction by rock and soil, and shortwave and longwave radiation. Water fluxes included snowmelt, freezing/thawing of soil water, soil capillary flow, and vapour flows among atmosphere, soil, and snow. The model accounted for 96-99% of variation in soil temperature data. No long-term temporal trends in soil temperature were apparent. Soil water vapour concentration in thawed surface soil in summer often was higher than in frozen deeper soils, leading to downward vapour fluxes. Katabatic winds caused a reversal of …