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Articles 331 - 360 of 423
Full-Text Articles in Earth Sciences
Do Laminated Sediment-Gravity-Flow Deposits On The Antarctic Peninsula Continental Shelf Record Ice Sheet Grounding Events?, Vincent Clyde Adams
Do Laminated Sediment-Gravity-Flow Deposits On The Antarctic Peninsula Continental Shelf Record Ice Sheet Grounding Events?, Vincent Clyde Adams
LSU Master's Theses
Barker and Camerlenghi (2002) proposed that drifts on the continental rise of the Antarctic Peninsula may record a high-resolution record of ice-sheet expansions on the adjacent continental shelf. In their view, laminated sediments were deposited during glacial periods, whereas during interglacial periods, sediment supply to drifts was negligible. As a consequence of low sediment supply, the tops of laminated sequences were bioturbated. Therefore, a bioturbated-laiminated couplet should represent a complete glacial cycle. Bioturbated and laminated (B-L) sediment couplets were compiled from cores at two drift sites obtained from Ocean Drilling Program (ODP) Leg 178 Sites 1095, 1096, and 1101. If …
Role Of Shelf Morphology In Grounding-Line Stability: A Numerical Approach, Rhonika Robinson
Role Of Shelf Morphology In Grounding-Line Stability: A Numerical Approach, Rhonika Robinson
LSU Master's Theses
The main concern of this study is to discover how the transition from a shallow to an overdeepened, foredeepened shelf might affect grounding-line translation of the West Antarctic Ice Sheet (WAIS). Deep shelves permit a larger influx of relatively warm Circumpolar Deep Water (CDW), which melts the ice at grounding lines, and thereby, create a potentially unstable situation in which ice retreat may accelerate. Numerical analysis of the responses of marine ice sheets on various shelf profiles confirmed that a change in shelf morphology changes ice sheet dynamics. Ice sheet retreat on an overdeepened, foredeepened shelf is, at least, 3 …
Holocene Evolution And Avulsion History Of The Lower Mississippi River, Yazoo Basin, Ms, Eric Prokocki
Holocene Evolution And Avulsion History Of The Lower Mississippi River, Yazoo Basin, Ms, Eric Prokocki
LSU Master's Theses
Optically stimulated luminescence dates coupled with paleohydrological estimations from lower Mississippi River (LMR) meander belts within the Yazoo Basin, MS provide new insight into the geochronological and hydrologic history of the LMR throughout the Holocene period. According to OSL dates, there are only three temporally equivalent LMR meandering river regime sediment packages, and not five as previously assumed from past geochronological research initiatives within the lower Mississippi Valley (LMV). The three geochronological sediment packages from oldest to youngest are thus represented by the following LMR meander belts: Early Holocene Chronostratigraphic Package – ca. 9.19 to 8.07 ka represented by the …
Environmental Influences On The Mobility And Speciation Of Arsenic In The Geothermal Waters Of El Tatio Geyser Field, Chile, Lindsey R. Johnson
Environmental Influences On The Mobility And Speciation Of Arsenic In The Geothermal Waters Of El Tatio Geyser Field, Chile, Lindsey R. Johnson
LSU Master's Theses
El Tatio geyser field, northern Chile, impacts regional water quality, policy, and agricultural commerce due to the geothermal waters containing high concentrations of naturally-occurring arsenic (As). In the circumneutral pH, non-sulfidic thermal waters at El Tatio, dissolved arsenite [As(III)] dominates geyser discharge water upstream, but dissolved arsenate [As(V)] dominates downstream. Microbial mats and sediments were analyzed for changes in As speciation using X-ray spectroscopy methods, such as XANES and EXAFS at both the As and Fe K-edges, combined with ATR-FTIR spectroscopy and molecular genetics, to understand As cycling. The sediments and microbial mats were dominated by As(V) speciated as both …
Source(S) Of Salinity In The Mississippi River Alluvial Aquifer, Iberville Parish, Louisiana, Stephanie Erin Welch
Source(S) Of Salinity In The Mississippi River Alluvial Aquifer, Iberville Parish, Louisiana, Stephanie Erin Welch
LSU Master's Theses
The Mississippi River Alluvial Aquifer extends from Southern Illinois to the mouth of the Mississippi and is comprised of fluvial sands and gravels of Late Pleistocene age. Several areas of the aquifer in Arkansas, Mississippi, and Louisiana are affected by elevated levels of salinity. One such area occurs in Iberville Parish, LA, where the aquifer is 150-240 m in thickness and is capped by 23-38 m of clay. Recharge of the aquifer from the Mississippi River on the east is fresh, but salinity is high in the western portions of the aquifer and chloride levels are as high as 1,000 …
A Multi-Proxy Approach To Investigating The Latest Holocene (~4,500 Yrs. Bp) Vegetational History Of Catahoula Lake, Louisiana, Rebecca Ann Tedford
A Multi-Proxy Approach To Investigating The Latest Holocene (~4,500 Yrs. Bp) Vegetational History Of Catahoula Lake, Louisiana, Rebecca Ann Tedford
LSU Doctoral Dissertations
A multi-proxy investigation of sediments examined from Catahoula Lake, Louisiana has provided a record of late-Holocene vegetational changes, related to both hydrology and climate. This study integrates data from phytoliths, pollen, stable isotopes, magnetic susceptibility, and core sediment analysis. A modern phytolith analog assessed the phytoliths production in local plants and their modern soil sample distribution within the established lake vegetation zones. Fifty of the 76 species produced both distinctive and redundant phytoliths. The modern soil sample database indicates that phytoliths produced from both monocotyledon and dicotlyledon plant groups prove useful in distinguishing between forest and grassland communities and identifying …
Miocene Herpetofaunas From The Central Gulf Coast Usa: Their Paleoecology, Biogeography, And Biostratigraphy, Michael John Williams
Miocene Herpetofaunas From The Central Gulf Coast Usa: Their Paleoecology, Biogeography, And Biostratigraphy, Michael John Williams
LSU Doctoral Dissertations
The late Barstovian Fort Polk herpetofauna represents the most diverse herpetofauna on the Gulf Coast, USA, and includes 15 genera from ten families. The herpetofaunal composition of Fort Polk and Miocene east Texas localities is similar enough to Great Plains localities that they are all considered to be one biogeographical province during the Barstovian. The use of ternary diagrams, ratios of herpetological elements to kg matrix screened, and natricine-colubrine indices, has allowed determining the wetness of the Fort Polk sites. Development of a composite stratigraphic section for North American fossil snakes has allowed recognition of two extinctions of fossil snakes …
Late Quaternary Geochronologic, Stratigraphic, And Sedimentologic Framework Of The Trinity River Incised Valley: East Texas Coast, Matthew Gene Garvin
Late Quaternary Geochronologic, Stratigraphic, And Sedimentologic Framework Of The Trinity River Incised Valley: East Texas Coast, Matthew Gene Garvin
LSU Master's Theses
Optically stimulated luminescence dates from the last glacial period falling–stage and lowstand Deweyville deposits along the Trinity River valley in Texas provided insight to their timing of deposition and allogenic controls on fluvial processes. Three distinguishable periods of incision and lateral channelbelt migration were the effect of both lowered sea levels and climate controlling factors within the drainage basin. Valley widening and deposition of the High, Middle, and Low Deweyville units were constructed and subsequently preserved as fluvial terraces during oxygen isotope stages (OIS) 3 through 2, from 65–32.5 ka, 32.5–23 ka, and 23–16 ka respectively. Although numerous workers using …
Deciphering Controls On Polyphase Intraplate Deformation In The Ertomiao Region, Lang Shan, North-Central China, Michael Blevins
Deciphering Controls On Polyphase Intraplate Deformation In The Ertomiao Region, Lang Shan, North-Central China, Michael Blevins
LSU Master's Theses
The Ertomiao region of the Lang Shan, China, is located approximately 700 km west of Beijing, in the north-central portion of the North China block. This area is characterized by multiple periods of deformation, including periods of extension and contraction, spanning from Permian through Cenozoic time. This setting provides the structural relationships necessary to decipher the controls of polyphase crustal deformation. During fieldwork key structural observations and crosscutting relationships were established. Beginning with a period of contraction, northeast striking post Jurassic, pre Early Cretaceous (123 ma) thrust faults place Precambrian gneiss (unit PCB) onto Jurassic/Cretaceous sandstone and conglomerate (unit Jr/K). …
Characterization Of The Lucinid Bivalve-Bacteria Symbiotic System: The Significance Of The Geochemical Habitat On Bacterial Symbiont Diversity And Phylogeny, Angela Marissa Green-Garcia
Characterization Of The Lucinid Bivalve-Bacteria Symbiotic System: The Significance Of The Geochemical Habitat On Bacterial Symbiont Diversity And Phylogeny, Angela Marissa Green-Garcia
LSU Master's Theses
Extensive characterization of a single lucinid bivalve habitat was conducted to characterize the relationship between host bivalve and thiotrophic bacterial endosymbionts. For lucinids, the ecological and evolutionary relationships between hosts and endosymbionts are poorly understood. Reconstructing the evolutionary history of lucinid endosymbiosis, and the geologic significance of the association, has been hampered by insufficient knowledge of endosymbiont ecology and taxonomic diversity. Host organisms (Lucinisca nassula and Phacoides pectinatus) were collected from Cedar Keys, Florida, within the top 15-20 cm of the sediment in sea grass beds. PCR amplification and sequencing of bacterial 16S rRNA genes from lucinid gills and sediment …
Komatiitic Flows Of The Pioneer Ultramafic Complex Of The 3.3ga Weltevreden Formation, Barberton Greenstone Belt, South Africa: Stratigraphy, Petrology, And Geochemistry, Marc Romain Cooper
Komatiitic Flows Of The Pioneer Ultramafic Complex Of The 3.3ga Weltevreden Formation, Barberton Greenstone Belt, South Africa: Stratigraphy, Petrology, And Geochemistry, Marc Romain Cooper
LSU Master's Theses
The 3.29 Ga Pioneer Ultramafic Complex (WPC) is a 1 km thick east-northeast trending tilted (90° dip) section of layered ultramafic rock in the Weltevreden Formation in the west-northwest region of the Barberton Greenstone Belt (BGB). It was originally interpreted as an intrusive complex with slaty zones that have a linear horizontal fabric produced by shear. However, a recent study identifies these slaty zones as komatiitic tuffs and attributes their horizontal fabric to plane and cross bedding. The present study suggests the non-slaty zones are extrusive komatiitic flows with abundant pyroxene spinifex tops, normal volcanic textures and crystal sizes, and …
Long-Term Subsidence And Compaction Rates: A New Model For The Michoud Area, South Louisiana, Clint H. Edrington
Long-Term Subsidence And Compaction Rates: A New Model For The Michoud Area, South Louisiana, Clint H. Edrington
LSU Master's Theses
This study examined the stratigraphic record of the Michoud area in East New Orleans, Louisiana to address questions concerning the magnitude of, and processes leading to land-surface subsidence. The hypotheses under review are based on recent geodetic studies, which challenge the widely held position that modern subsidence is primarily a function of shallow sediment compaction. Testing these hypotheses involved constructing a structural cross section of the Michoud area using well logs, chronostratigraphic data, and fault picks, so as to evaluate differential motion along specific faults through time. Employing ages and corrected depths for three key subsurface horizons, long-term (Middle Miocene …
Dactyls Reveal Evolutionary Patterns In Decapod Crustaceans, Jeffrey Guy Agnew
Dactyls Reveal Evolutionary Patterns In Decapod Crustaceans, Jeffrey Guy Agnew
LSU Doctoral Dissertations
Because of their high preservation potential and uses in foraging and defense, decapod crustacean dactyls (movable fingers of claws) are potentially excellent test subjects for an ongoing debate concerning the relative importance of top-down (predators) and bottom-up (prey) controls on morphologic diversification and evolution. The utility of dactyls for inferring evolutionary patterns were evaluated using living and subfossil xanthoid crabs sampled from the southeast U.S. Atlantic and Gulf of Mexico coasts, and were used to: (1) distinguish the roles of selection and constraint on dactyl morphology through allometric and shape comparisons in the context of the crab’s phylogenetic relationships and …
Evolution Of An Allochthonous Salt System, Southern Mars-Ursa Basin, Northern Gulf Of Mexico, Angela Bordelon Pell
Evolution Of An Allochthonous Salt System, Southern Mars-Ursa Basin, Northern Gulf Of Mexico, Angela Bordelon Pell
LSU Master's Theses
This study examines the evolution of an allochthonous salt system in the southern Mars-Ursa basin. A seismic stratigraphic framework and biostratigraphic markers provided constraints on basin development and sediment accumulation from late Miocene to middle Pliocene time. External geometries of tectonostratigraphic packages are identified in the study area and are combined with analyses of brittle deformation to track salt evacuation in the study area. External geometries identified in the study include: wedge, layer and trough. Fifty-nine faults were mapped in basin and suprasalt strata and five phases of brittle deformation were identified. Eight evolutionary stages were identified for the time …
Heavy Mineral Analysis Of The Pecan Island Complex, Louisiana Chenier Plain, Southwest Louisiana, Cherie' Jenae Lee
Heavy Mineral Analysis Of The Pecan Island Complex, Louisiana Chenier Plain, Southwest Louisiana, Cherie' Jenae Lee
LSU Master's Theses
This study reports the results of a heavy mineral analysis of samples from Pecan Island and associated ridges on the Louisiana Chenier Plain. The goal of the study is to provide additional insight on the origins of the sand comprising the ridges. Chenier plains are multi-membered, progradational ridge-interridge mudflat sequences (Augustinus, 1989). The various suggested sources of the sand grains include: the Mississippi River, especially the Teche sub-delta; the Mermentau and Calcasieu Rivers; and the reworking of older mudflat and chenier ridges. Several liters of sand were collected from a depth of 0.5 to 2.0 meters at locations near the …
Tourmalinities In Neoproterzoic Metaevaporitic Deposit Of Duruchas Formation, Damar Belt, Central Namibia, Haiting Sun
Tourmalinities In Neoproterzoic Metaevaporitic Deposit Of Duruchas Formation, Damar Belt, Central Namibia, Haiting Sun
LSU Doctoral Dissertations
Tourmalinites from a well-developed meta-evaporite sequence in the Neoproterozoic Duruchaus Formation of central Namibia contain tourmalines with chemical and textural features that are excellent recorders of their environment of formation. Unlike most other meta-evaporitic deposits, this tourmalinite locality exhibits only minor deformation. The tourmalinites form as finely laminated units ca. 1 m thick within a sequence of quartzites, mica schists, dolomitic marbles, and carbonate breccias. Well-preserved pseudomorphs are considered to replace a variety of evaporitic minerals. The meta-sedimentary rocks of the Duruchaus Formation have been interpreted as representing lacustrine, playa lake, fluvial, and non-marine evaporite deposition in an intracontinental rift …
Analysis Of Miocene Stratigraphy And Sedimentology In The Ross Sea, Antarctica: A First Order Test Of Proxy Based Climate Interpretations, Samuel Gray
LSU Master's Theses
During the Cenozoic, the climate progressed from global warmth into an icehouse world. This study investigates the links between the development of the climate and cryosphere using sediment flux and stratal geometries. The current polar conditions are characterized by dry basal conditions, which due to minimal melt water produce significantly less sediment than their temperate counterparts. Therefore, the transition from temperate to polar conditions should have resulted in marked decrease in sediment flux and change in stratal geometries in adjacent marine margins. Regional seismic stratigraphic evidence clearly suggests that ice has been intermittently grounded on the Ross Sea outer continental …
Fluid Flow In The Central North Slope Foreland Basin, Alaska, Anna Marie Bélanger
Fluid Flow In The Central North Slope Foreland Basin, Alaska, Anna Marie Bélanger
LSU Master's Theses
Previous studies of the areal variations in heat flow and spatial variations in formation water salinity and hydraulic head are consistent with the existence of a currently active, topographically-driven regional fluid flow regime in the National Petroleum Reserve Alaska (NPRA) portion of the western North Slope foreland basin. This conclusion is also supported by the results of numerical modeling of fluid flow and heat transport in the area. This work has now been extended to the east. The results of this study demonstrate that the Permian though Cenozoic age sediments of the central North Slope foreland basin have been significantly …
Empirical Modeling Of Late Quaternary Sediment Supply To The Gulf Of Mexico Shelf Margin In A Cool Lowstand World, Jill Hattier Womack
Empirical Modeling Of Late Quaternary Sediment Supply To The Gulf Of Mexico Shelf Margin In A Cool Lowstand World, Jill Hattier Womack
LSU Master's Theses
During the last glacial period, river systems responded to the lowering of sea level by incising valleys, extending across the continental shelf, and depositing deltas on the shelf margin and upper slope of surrounding basins. These deltas represent important repositories for sediment delivered to the coastal ocean and provide partial records of sediment discharged from continental landmasses. Over relatively short time scales, like that of the last glacial-interglacial cycle, hinterland drainage areas, relief and lithology can be considered constants while the primary variable of significance is climate change (Syvitski and Milliman, 2007). It is reasonable to assume, therefore, that supply …
Carbonated Sections From Komatiite Flow- Top Alteration Zones In The Barberton Greenstone Belt: Implications For Near-Surface Archean Environments, Judith E. F. Stoute
Carbonated Sections From Komatiite Flow- Top Alteration Zones In The Barberton Greenstone Belt: Implications For Near-Surface Archean Environments, Judith E. F. Stoute
LSU Master's Theses
Over a dozen komatiitic flows in the 3.2-3.5 Ga Barberton Greenstone Belt are topped with unique green silica- and carbonate-rich rocks, which likely formed from interaction of the cooling lava flow with seawater shortly after deposition. This study focuses on an alteration zone in the Mendon Formation. Two styles of alteration are observed in this alteration zone: silicification and carbonation. The goal of this study is to characterize the carbonates in the alteration zone, constrain the timing of alteration, test whether the alteration zones are due to interaction with seawater after deposition, and estimate the elemental fluxes between the rock …
Paleoceanography Of The Gulf Of Papua Using Multiple Geophysical And Micropaleontological Proxies, Lawrence A. Febo
Paleoceanography Of The Gulf Of Papua Using Multiple Geophysical And Micropaleontological Proxies, Lawrence A. Febo
LSU Doctoral Dissertations
Recent marine and late Pleistocene sediments examined from the Gulf of Papua (GoP), Papua New Guinea investigate the flux and fate of detrital sediments and organic carbon over the last glacial-interglacial cycle. Based on surface sediment magnetic susceptibility (MS) and calcium carbonate concentrations, recent marine sediment is exported off the narrow shelf and into deeper regions via the Kerema Canyon of the northern Pandora Trough. Detrital clastic sediment is then dispersed deeper into the central and southern Pandora Trough. Except for pelagic deposition, very little detrital material reaches the Ashmore Trough and Eastern Plateau adjacent to the Great Barrier Reef. …
Shelf-Margin Delta Morphology As A Paleo Sea Level Indicator: Implications On Late Quaternary Relative Sea-Level Changes In The Northeast Gulf Of Mexico, Swati Ghoshal
LSU Doctoral Dissertations
A new technique to determine relative sea level history at siliciclastic settings is proposed in this dissertation. The clinoform break (defined as the topset-foreset transition point) of the modern Mississippi River Delta shows a direct relationship with sea level elevation. The analysis of Holocene lobes 8 and 9 belonging to the St. Bernard delta complex of the Mississippi Delta suggests that delta clinoforms can be significantly modified by post-abandonment processes, and hence a detailed stratigraphic evaluation is necessary to determine whether the clinoform geometry is a result of wave erosion or any other post-abandonment processes. The strategy was tested on …
Genetic Stratigraphy And Geochronology Of Last Interglacial Shorelines On The Central Coast Of South Carolina, Russell Willis
Genetic Stratigraphy And Geochronology Of Last Interglacial Shorelines On The Central Coast Of South Carolina, Russell Willis
LSU Master's Theses
This study investigated the shallow subsurface of the Lower Coastal Plain of South Carolina in order to determine the sea-level history and stratigraphic architecture preserved within several emergent shoreline complexes. The absolute age of each shoreline complex was estimated using single-aliquot regenerative-dose (SAR) optically stimulated luminescence (OSL) techniques. The resulting geochronology was incorporated into a high-resolution stratigraphic framework defined by ground penetrating radar calibrated with deep sediment cores, many of which contain a complete sequence of highstand deposition. Three emergent barrier complexes were identified within the Lower Talbot, Pamlico, and Princess Anne terraces, and assigned to sea-level highstands during interglacial …
Assessing The Potential Impact Of Microbes In The Edwards And Trinity Aquifers Of Central Texas, Kelli Willson Randall
Assessing The Potential Impact Of Microbes In The Edwards And Trinity Aquifers Of Central Texas, Kelli Willson Randall
LSU Master's Theses
The Edwards Aquifer in central Texas is one of the largest carbonate aquifers in the United States, supplying nearly two million people with water. The role of microorganisms in the development of deep carbonate aquifers has not been thoroughly investigated. The Edwards Aquifer is composed of a freshwater zone and a sulfidic, saline water zone. Down-well video surveys show an abundance of white filamentous and planktonic biomass floating in the water column, indicating that the saline water may serve as a habitat for microbes and provide a unique opportunity to investigate microbially enhanced deep subsurface karstification. A combination of geochemical …
Caliche As A Geologic Repository For Atmospheric Sulfate, Katie Jane Howell
Caliche As A Geologic Repository For Atmospheric Sulfate, Katie Jane Howell
LSU Master's Theses
Recent studies demonstrate that important information on sulfur source, oxidation pathway, transport pattern, and reaction kinetics of the oxidation reactions of reduced sulfur gases in the atmosphere may be uncovered by measuring multiple sulfur and oxygen isotope compositions of the oxidation product — secondary atmospheric sulfate (SAS). SAS from Earth’s distant past, however, is rarely preserved in the rock record because of its high solubility and small quantity. Caliche, a pedogenic carbonate formed in arid to semi-arid continental settings and common in the geologic record, could serve as a repository for ancient SAS. Two major groups of caliche samples: 1) …
Ice Sheet Grounding Zone Deposits On Ross Sea Continental Shelf (Antarctica): Seismic Facies Analysis And P-Wave Reflectivity Attributes, Adeniyi Adewumi Saanumi
Ice Sheet Grounding Zone Deposits On Ross Sea Continental Shelf (Antarctica): Seismic Facies Analysis And P-Wave Reflectivity Attributes, Adeniyi Adewumi Saanumi
LSU Master's Theses
Subglacial till and overlying glaciomarine deposits are difficult to distinguish because the physical properties of subglacial till may vary depending on the drainage conditions of the rock directly beneath the ice sheet. Based on approximately 120 kilometers of multi-channel seismic data, detailed seismic facies analysis and amplitude variation with offset (AVO) analysis are carried out to examine the distribution of ice sheet grounding zone deposits on the continental shelf of the Northern Basin, Ross Sea (Antarctica) and infer the physical properties of interpreted subglacial till. Seismic facies analysis led to the differentiation of distinct sub-environments around a grounded ice sheet: …
Muscovite Pseudomorphs After Staurolite As A Record Of Fluid Infiltration During Prograde Metamorphism, Jennifer Kaye Whittington
Muscovite Pseudomorphs After Staurolite As A Record Of Fluid Infiltration During Prograde Metamorphism, Jennifer Kaye Whittington
LSU Master's Theses
Pressure-temperature conditions encountered by metamorphic rocks are often used to constrain tectonic environments of formation. Evidence of the prograde path during metamorphism is often obliterated by peak metamorphic conditions. However, pseudomorphs that form during prograde metamorphism may provide insights into heat and mass transport along this portion of the P-T-X-t path. Seventeen sillimanite zone samples, each containing 2-5 muscovite-rich pseudomorphs after staurolite, were investigated from pelitic schists of the Farmington Quadrangle, west-central Maine, USA. Pseudomorphs are easily recognized by an increase in average grain size (~cm) and change to randomly oriented muscovite-rich (~45-75%) modal mineralogy relative to the rock matrix …
The Twiggs Clay: Mineralogy, Origin, And Industrial Properties Of An Upper Eocene Opaline Claystone In The Coastal Plain Province Of Georgia, U.S., Lori G. Eversull
The Twiggs Clay: Mineralogy, Origin, And Industrial Properties Of An Upper Eocene Opaline Claystone In The Coastal Plain Province Of Georgia, U.S., Lori G. Eversull
LSU Doctoral Dissertations
The Twiggs Clay is an upper Eocene claystone found as discontinuous deposits downdip of the Fall Line in the Coastal Plain Province of eastern and central Georgia. A distinctive facies of the Twiggs is found in two lenses near the town of Wrens. The nature, origin, and potential commercial application of this resource are examined. Four strata and two mineralogic assemblages are recognized in the Wrens deposit. The lower three strata are near white in color and very low in density. These strata are mineralogically similar and are composed predominantly of disordered silica and smectite. The smectite is dioctahedral, and …
Diagenesis Of Mudstones, Offshore Texas And Southwestern Louisiana, Maria Antonieta Pacheco
Diagenesis Of Mudstones, Offshore Texas And Southwestern Louisiana, Maria Antonieta Pacheco
LSU Master's Theses
Predicting the effects of mudstone diagenesis on reservoir quality is an important component of successful petroleum exploration and production programs. A regional study using chemical analyses from mudstone core cuttings and SP logs from 15 wells from the western Gulf of Mexico, including the Matagorda, Brazos, Mustang offshore areas, indicates that chemical changes with depth such as overall depletion of quartz and calcite; the illite-smectite conversion; and K2O enrichment occur in the mudstone Miocene interval of the study area. Mixing of depositional sources has been suggested to be the cause of similar chemical and mineralogical changes observed in Paleocene-Eocene and …
Quantitative Clay Mineralogy Of Several Louisiana Soils, Johan Forsman
Quantitative Clay Mineralogy Of Several Louisiana Soils, Johan Forsman
LSU Master's Theses
A method was developed to simplify the approach to obtaining a better quantitative representation (QR) of complex clay mineral assemblages by XRD analysis. The method has eight steps: 1) preparation of samples with preferred orientation; 2) qualitative identification of phases; 3) peak decomposition to obtain precise locations of individual peaks contained within broad diffraction bands; 4) creation of a library of theoretical XRD patterns by modeling of one-dimensional XRD patterns; 5) selection of experimental library patterns; 6) employing the LINEST function found in common spreadsheet software to fit library patterns to experimental patterns; 7) evaluation of results to determine needed …