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Varietal Differences In Perennial Ryegrass For Fructan Metabolism And Their Relationship To Grazing Tolerance, B. Lasseur, J. Lothier, A. Morvan-Bertrand, M. O. Humphreys, M. P. Prud'homme Apr 2023

Varietal Differences In Perennial Ryegrass For Fructan Metabolism And Their Relationship To Grazing Tolerance, B. Lasseur, J. Lothier, A. Morvan-Bertrand, M. O. Humphreys, M. P. Prud'homme

IGC Proceedings (1977-2023)

Perennial ryegrass (Lolium perenne L.) is the most important grass in Europe; it often is defoliated. The link between fructan metabolism and defoliation tolerance has been studied in 2 Lolium perenne varieties, Aurora (high sugar perennial) and Perma (low-to-normal sugar perennial) (Turner et al., 2002).


Variability In Quantity And Composition Of Water Soluble Carbohydrates Among Irish Accessions And European Varieties Of Perennial Ryegrass, S. Mcgrath, S. Barth, A. Frohlich, M. Francioso, S. A. Lamorte, T. R. Hodkinson Apr 2023

Variability In Quantity And Composition Of Water Soluble Carbohydrates Among Irish Accessions And European Varieties Of Perennial Ryegrass, S. Mcgrath, S. Barth, A. Frohlich, M. Francioso, S. A. Lamorte, T. R. Hodkinson

IGC Proceedings (1977-2023)

The objective of this study was to identify perennial ryegrass accessions displaying high fructose and glucose contents and an improved ratio between fructose and glucose fractions across different time points throughout the year. Fructose and glucose are the main constituents of the water soluble carbohydrate (WSC) fraction in perennial ryegrass. For animal nutrition the amount of WSC is crucial as it is the primary energy source available to metabolise the intake of plant protein. The ratio between fructose and glucose fractions is important since fructosan chains, which are an excellent energy source for ruminants, are built from fructose. Furthermore the …


Breeding Of Cms-F1-Hybrids In Lolium Perenne With Improved Nitrogen Use Efficiency, W. Luesink, B. Ingwersen, L. Wolters, J. De Riek Apr 2023

Breeding Of Cms-F1-Hybrids In Lolium Perenne With Improved Nitrogen Use Efficiency, W. Luesink, B. Ingwersen, L. Wolters, J. De Riek

IGC Proceedings (1977-2023)

The environmental pollution by nitrogen losses from dairy farms can be reduced by improving the nitrogen use efficiency (NUE) of grass varieties. The main goal is to develop varieties with a better nitrogen utilisation. These low input varieties can produce acceptable yields at a low level of N-fertilisation. High input varieties express their high yield potential only at high N-supply. These varieties are less preferable, because N- losses increase at higher levels of nitrogen application. The breeding of CMS-F1-Hybrids can be a successful strategy for developing varieties with a higher NUE. In F1-Hybrid varieties higher heterosis effects can be achieved …


A Survey Of European Regional Adaptation In Italian Ryegrass Varieties, T. J. Gilliland, A. J. P. Van Wijk Apr 2023

A Survey Of European Regional Adaptation In Italian Ryegrass Varieties, T. J. Gilliland, A. J. P. Van Wijk

IGC Proceedings (1977-2023)

Ryegrass is widely adapted to cool temperate eco-zones and breeders often submit individual varieties for testing in a number of EU countries. National testing programmes often combine data from several trial sites that may differ climatically, but not from sites in other member states, despite the possibility of high ecological similarity. Given increasing interest in animal value characters (soluble sugars, lipids, sward geometry), additional testing for these would be valuable but is prohibited by capped or declining funding. Data sharing between EU national authorities could be advantageous but is inhibited by the lack of statistically valid data on the sensitivity …


Milk Production Potential Of Different Dairy Pasture Types In Southern Australia, J. Tharmaraj, D. F. Chapman, Z. N. Nie, A. P. Lane Apr 2023

Milk Production Potential Of Different Dairy Pasture Types In Southern Australia, J. Tharmaraj, D. F. Chapman, Z. N. Nie, A. P. Lane

IGC Proceedings (1977-2023)

The growth rate of traditional perennial ryegrass-based pastures commonly fails to meet herd feed requirements through winter and summer in non-irrigated dairy systems in southern Australia. Alternative pasture species can improve seasonal feed supply in this region (Tharmaraj & Chapman, 2005). However, the feeding value and milk production of these pastures must at least match perennial ryegrass if they are to be adopted successfully on dairy farms. This paper reports results of a comparison of the milk production potential of pasture types similar to those investigated by Tharmaraj & Chapman (2005) for their agronomic performance.


Effect Of Strain Of Holstein-Friesian Cow And Feed System On Reproductive Performance In Seasonal-Calving Milk Production Systems Over Four Years, B. Horan, J. F. Mee, Myles Rath, P. O'Connor, P. Dillon Apr 2023

Effect Of Strain Of Holstein-Friesian Cow And Feed System On Reproductive Performance In Seasonal-Calving Milk Production Systems Over Four Years, B. Horan, J. F. Mee, Myles Rath, P. O'Connor, P. Dillon

IGC Proceedings (1977-2023)

In Ireland most dairy farms operate seasonal calving grass-based milk production systems. Feed demand and supply are matched by having calving highly concentrated in spring. This requires high pregnancy rates within a short time following the start of mating in late April or early May, but has become increasingly difficult to achieve due to declining fertility in Irish dairy herds (Mee, 2004). In New Zealand, cows of North American Holstein-Friesian origin have poorer fertility than New Zealand Holstein-Friesians on pasture-based seasonal calving systems (Harris & Kolver, 2001). The present study sought to determine the effect of strain of Holstein-Friesian (HF) …


Phenotype X Herbage Allowance Interactions In Reproduction Of First Calf Heifers Grazing Semiarid Rangeland, J. W. Holloway, B. G. Warrington, M. K. Owens Apr 2023

Phenotype X Herbage Allowance Interactions In Reproduction Of First Calf Heifers Grazing Semiarid Rangeland, J. W. Holloway, B. G. Warrington, M. K. Owens

IGC Proceedings (1977-2023)

Cattle are differentially adapted to nutritional environments. The most sensitive measure of adaptation is reproduction of first-calf heifers. We studied the role of maturation rate and milk production on reproductive performance of first-calf heifers allowed different levels of herbage in semiarid rangeland.


The Impact Of The Level Of Feed-On-Offer Available To Merino Ewes During Winter-Spring On The Wool Production Of Their Progeny As Adults, Chris Oldham, M. Ferguson, B. Paganoni, A. Thompson, G. Kearney, M. A. Van Burgel Apr 2023

The Impact Of The Level Of Feed-On-Offer Available To Merino Ewes During Winter-Spring On The Wool Production Of Their Progeny As Adults, Chris Oldham, M. Ferguson, B. Paganoni, A. Thompson, G. Kearney, M. A. Van Burgel

IGC Proceedings (1977-2023)

New opportunities for developing optimum ewe management systems, based on achieving liveweight and body condition score (CS) targets at critical stages of the reproductive cycle, have emerged from the acceptance that nutrition during pregnancy can have substantial impacts on the lifetime wool performance of the progeny (Kelly et al,. 1996). However, most studies of the impacts of nutrition on foetal growth and development tended to focus on late pregnancy and have also only considered extreme nutritional regimes often outside the boundaries of commercial reality. Hence, the Lifetime Wool team (Thompson & Oldham, 2004) conducted dose-response experiments to determine the …


Effects Of Forage Chicory (Cichorium Intybus) On Farmed Deer Growth And Internal Parasitism, S. O. Hoskin, P. R. Wilson, W. E. Pomroy, T. N. Barry Apr 2023

Effects Of Forage Chicory (Cichorium Intybus) On Farmed Deer Growth And Internal Parasitism, S. O. Hoskin, P. R. Wilson, W. E. Pomroy, T. N. Barry

IGC Proceedings (1977-2023)

Internal parasitism (particularly lungworm - Dictyocaulus sp) significantly limits post-weaning growth of deer. Endoparasite control using anthelmintics may be unsustainable, due to the increasing risk of anthelmintic resistance and the risk or perception of chemical residues in animal products. Chicory has a high feeding value and contains sesquiterpene lactones and low levels of condensed tannins, both with anti-parasitic activity (Molan et al., 2003). Grazing chicory during autumn may reduce the requirement for anthelmintic treatment of young deer compared with grazing ryegrass-based pasture (Hoskin et al., 1999). The objective of this study was to investigate the effect of withholding …


Earthquake Resistant Buildings, Admin Stem For Success Apr 2023

Earthquake Resistant Buildings, Admin Stem For Success

STEM for Success Showcase

Students learn about earthquakes and engineering by building a structure that can survive an earthquake.


Lesson Plans In Astronomy, Ecology And Biology, Admin Stem For Success Apr 2023

Lesson Plans In Astronomy, Ecology And Biology, Admin Stem For Success

STEM for Success Showcase

This document contains various lesson plan ideas for concepts within the fields of biology, ecology, astronomy, and geology.


Testing Pedagogical Approaches To Online Lecture: Effects Of Background Music And Interactive Video Series On Student Retention Of Prior Conception-Correcting Information On Climate Change, Roya Franseth Apr 2023

Testing Pedagogical Approaches To Online Lecture: Effects Of Background Music And Interactive Video Series On Student Retention Of Prior Conception-Correcting Information On Climate Change, Roya Franseth

Honors Projects

Climate change is a pervasive element in our modern lives, yet many harbor ideas about climate change and associated climate mechanisms that are misinformed or incorrect. Ideas like these – prior conceptions (ideas that people carry with them into learning experiences about a subject) – are studied in varying degrees across fields. The geosciences do not have a particularly robust collection of research on the subject of geoscience-specific prior conceptions. At the same time, due to the COVID-19 pandemic, alternatives to in-person lecture such as online lecture have become normalized. The original aim of this paper was to determine if …


Permian Trilobites And The Applicability Of The “Living Fossil” Concept To Extinct Clades, Melanie J. Hopkins, Peter Wagner, Katherine J. Jordan Apr 2023

Permian Trilobites And The Applicability Of The “Living Fossil” Concept To Extinct Clades, Melanie J. Hopkins, Peter Wagner, Katherine J. Jordan

Department of Earth and Atmospheric Sciences: Faculty Publications

Some taxa occupy our imaginations as “living fossils” because they were known from the fossil record before being discovered alive today. Other taxa are considered “living fossils” because modern relatives bear a strong morphological resemblance to fossil relatives, or because they occupy a contracted geographic range or have less diversity now than in the past, or because they represent phylogenetic diversity that requires conservation. A characterizing feature of living fossils–and thus an implicit assumption of all criteria–is that the “living fossil” of interest is extant. However, the general research questions that “living fossils” inspire–Why do rates of evolution vary across …


Water Erosion In The South-West Of Western Australia, Department Of Primary Industries And Regional Development, Western Australia Apr 2023

Water Erosion In The South-West Of Western Australia, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

The averaged annual direct cost of water erosion to dryland farming in Western Australia is estimated to be $10 million, but the costs are much higher in years of severe summer storms.

Water erosion occurs when water flowing over the land surface moves soil particles downslope. Water erosion is a natural process, but is accelerated under agriculture, especially on cropped land. Water erosion causes loss of topsoil, reduced crop yields, damaged infrastructure, weed dispersal, eutrophication (algal blooms) and silting of dams and natural waterways.


Organic Matter Quality Influences Aerobic And Anaerobic Respiration Rates In Peatland Soils, Rachel Shaw, Lauren Bryan, Madison Smith, Christian Lundy, Alexis Koehl, Grace Behrens, Mackenzie Dole, Madeleine O'Donnell Apr 2023

Organic Matter Quality Influences Aerobic And Anaerobic Respiration Rates In Peatland Soils, Rachel Shaw, Lauren Bryan, Madison Smith, Christian Lundy, Alexis Koehl, Grace Behrens, Mackenzie Dole, Madeleine O'Donnell

22nd Annual Celebration of Undergraduate Research and Creative Activity (2023)

The vulnerability of peatland carbon reservoirs to decomposition in a warming climate remains a key uncertainty in Earth System Models. This will be determined in part by the "quality" of the peatland organic matter, i.e. the ease by which it is decomposed by the microbial community. We developed an index of organic matter quality based on the biochemical composition of the peat. The index uses a principal components analysis of proxies based on the carbohydrate composition, hydrolysable amino acids, C:N, pH, and nutrient availability in the peat porewater. The index was compared with measurements of aerobic and anaerobic respiration rates …


Temperature Sensitivity Of Nitrogen Mineralization In Peat From A Southwestern Michigan Bog, Madison Smith, Lauren Bryan, Rachel Shaw, Mackenzie Dole, Madeleine O'Donnell Apr 2023

Temperature Sensitivity Of Nitrogen Mineralization In Peat From A Southwestern Michigan Bog, Madison Smith, Lauren Bryan, Rachel Shaw, Mackenzie Dole, Madeleine O'Donnell

22nd Annual Celebration of Undergraduate Research and Creative Activity (2023)

In this study, we measured inorganic nitrogen (nitrate and ammonium) released from peat cores from Miner Lake bog at two temperatures to analyze the impact of climate warming on the peatland nitrogen cycle. We hypothesized a higher nitrogen release in samples incubated at warmer temperatures. Furthermore, previous research indicates shallow peat decomposes faster than deeper peat. Therefore, we hypothesized faster nitrogen mineralization in shallow samples. We collected peat cores from two locations from Miner Lake Bog in Allegan County, Michigan: a plot in the center of the bog and a sedge meadow site near the edge. Two samples for each …


Glass: The Material That Defines Us, Madisyn Rex Apr 2023

Glass: The Material That Defines Us, Madisyn Rex

Honors Projects

This Honors Project is an exploration of the intersections between glass science, geology, glass art, and my own personal experience with glass.


Soil Nutrient And Invertase-Producing Bacteria Relation Impact On Cilembu Sweet Potato (Ipomoea Batatas L.) Growth: A Study Based On Upland And Wetland Cultivation In Cilembu Village Sumedang District, Eso Solihin, Syaiful Anwar, Dwi Andreas Santoso, Budi Nugroho, Purwono, Rija Sudirja, Haris Maulana, Nadia Nuraniya Kamaluddin, Agung Karuniawan Apr 2023

Soil Nutrient And Invertase-Producing Bacteria Relation Impact On Cilembu Sweet Potato (Ipomoea Batatas L.) Growth: A Study Based On Upland And Wetland Cultivation In Cilembu Village Sumedang District, Eso Solihin, Syaiful Anwar, Dwi Andreas Santoso, Budi Nugroho, Purwono, Rija Sudirja, Haris Maulana, Nadia Nuraniya Kamaluddin, Agung Karuniawan

Jurnal Kultivasi

Environment is one important factors that must be considered in supporting sweet potato productivity. Environmental factors can be biotic and abiotic, including the availability of nutrients and microbes in the soil. This study aimed to identify the nutrient content of the soil in paddy fields and dry fields, identify the total invertase microorganisms in paddy fields and dry fields, and identify the relationship between soil nutrients and microorganisms during the growth of Cilembu sweet potato in dry and paddy fields agroecosystems. This research was conducted on dry fields and paddy fields in Cilembu Village, Sumedang Regency. The experimental design used …


Interspecies Differences In Food Sources For The Tropical Callichirid Shrimp Neocallichirus Spp. On San Salvador Island, Bahamas, Koji Seike, H. Allen Curran Apr 2023

Interspecies Differences In Food Sources For The Tropical Callichirid Shrimp Neocallichirus Spp. On San Salvador Island, Bahamas, Koji Seike, H. Allen Curran

Geosciences: Faculty Publications

At least 4 species of callichirid shrimp coexist in the shallow marine settings of San Salvador Island, an isolated, small platform of the all-carbonates Bahama Archipelago, implying that interspecific competition or trophic niche segregation occurs between these shrimp species. Carbon and nitrogen stable isotope analyses were conducted on soft tissues of 3 callichirid species, Neocallichirus cacahuate, N. grandimana, and N. maryae, to determine the food sources for each species. These analyses revealed that the isotopic trophic niches for these 3 species do not overlap. The most important food source for all 3 species was manatee grass Syringodium filiforme …


Igneous Petrology Of Rumicolca Lavas From The Peruvian Altiplano: Controls On Compositional Variability And Source Characteristics, Jacob Ladner Apr 2023

Igneous Petrology Of Rumicolca Lavas From The Peruvian Altiplano: Controls On Compositional Variability And Source Characteristics, Jacob Ladner

Student Research Symposium

Lava flow samples from the Peruvian Altiplano plateau described petrologically, mineralogically, and geochemically for investigation of of genetic relation, compositional variability, and melt source characteristics. Reflective of a metasomatically altered mantle resulting from subduction of the Nazca plate under the western margin of South America.


Carbonate Microfacies Of The Middle To Upper Pennsylvanian Cache Creek Group At Meadow Lake, British Columbia, Canada, Brennen Leidy Apr 2023

Carbonate Microfacies Of The Middle To Upper Pennsylvanian Cache Creek Group At Meadow Lake, British Columbia, Canada, Brennen Leidy

Undergraduate Research Conference

No abstract provided.


Phosphate Availability, P-Uptake, Phosphatase, And Yield Of Maize (Zea Mays L.) Affected By Kaolin Based P-Solubilizer And P Fertilizer In Inceptisols, Betty Natalie Fitriatin, Muhammad Nafariz Budiman, Pujawati Suryatmana, Nadia Nuraniya Kamaluddin, Dedi Ruswandi Apr 2023

Phosphate Availability, P-Uptake, Phosphatase, And Yield Of Maize (Zea Mays L.) Affected By Kaolin Based P-Solubilizer And P Fertilizer In Inceptisols, Betty Natalie Fitriatin, Muhammad Nafariz Budiman, Pujawati Suryatmana, Nadia Nuraniya Kamaluddin, Dedi Ruswandi

Jurnal Kultivasi

Inceptisols have problem in phosphate availability. Soil P content is very low available to plants because it is bound by soil colloids. One of the efforts to increase the P nutrient in the soil in a sustainable way by using P-Solubilizers that can dissolve phosphate in the soil so that it is available for plants. The purpose of experiment was to determine the effect of the combination dose of kaolin based P-Solubilizer and P fertilizer for improving P availability, P uptake, phosphatase, and maize yield on Inceptisols. The kaolin-based P-Solubilizer was used a consortium of phosphate solubilizing microbes (PSM) consisting …


Effect Of Npk And Bacillus-Coated Npk Fertilizer On Biomass, Nutrient Content In Soil And Nutrient Uptake By Lettuce, Reginawanti Hindersah, Mieke Rochimi Setiawati, Pujawati Suryatmana, Betty Natalie Fitriatin, Fasa Aditya, Gita Bina Nugraha, Rara Rahmatika Risanti, Priyanka Asmiran Apr 2023

Effect Of Npk And Bacillus-Coated Npk Fertilizer On Biomass, Nutrient Content In Soil And Nutrient Uptake By Lettuce, Reginawanti Hindersah, Mieke Rochimi Setiawati, Pujawati Suryatmana, Betty Natalie Fitriatin, Fasa Aditya, Gita Bina Nugraha, Rara Rahmatika Risanti, Priyanka Asmiran

Jurnal Kultivasi

The Inoculation of beneficial soil microbes is an effective method for lowering doses of inorganic fertilizers. This study was aimed to observe and compare the effect of doses and formulas of Bacillus-coated NPK (BCN) and conventional NPK fertilizers on biomass, major macro-nutrient in soil and their uptake by shoots of lettuce (Lactuca sativa L.); as well as evaluate the potency of BCN for decreasing doses of NPK fertilizers. The greenhouse experiment was set up in a randomized block design with seven treatments and five replications. The treatments included one and a half doses of recommended NPK fertilizer and two BCN …


Seasonal Seepage Fluid Flow And Pressure Detection Beneath Flood Protection Levees In The Lower Mississippi River Valley Using Non-Invasive Geophysical Methods, Daniel Locci Apr 2023

Seasonal Seepage Fluid Flow And Pressure Detection Beneath Flood Protection Levees In The Lower Mississippi River Valley Using Non-Invasive Geophysical Methods, Daniel Locci

LSU Doctoral Dissertations

This study explores the use of shear-wave seismic reflection and electrical resistivity techniques to complement our understanding of seepage pore pressure variations and soil type estimation beneath earthen levees in the Mississippi River floodplain. The seasonal variations of water level in the river create changes in pore pressure in the adjacent aquifer, which can be detected using time-lapse shear-wave velocity analysis. The seismic reflection patterns during these pressure variations show changes in velocity that can be translated into changes in effective pressure, allowing us to distinguish between confined and leaky aquifers.

In addition, the integration of geophysical methods such as …


Ecological Stability Of Late Pleistocene-To-Holocene Lesotho, Southern Africa, Facilitated Human Upland Habitation, Robert Patalano, Charles Arthur, William Christopher Carleton, Sam Challis, Genevieve Dewar, Kasun Gayantha, Gerd Glexiner, Jana Ilgner, Mary Lucas, Sara Marzo, Rethabile Mokhachane, Kyra Pazan, Diana Spurite, Mike W. Morley, Adrian Parker, Peter Mitchell, Brian A. Stewart, Patrick Roberts Apr 2023

Ecological Stability Of Late Pleistocene-To-Holocene Lesotho, Southern Africa, Facilitated Human Upland Habitation, Robert Patalano, Charles Arthur, William Christopher Carleton, Sam Challis, Genevieve Dewar, Kasun Gayantha, Gerd Glexiner, Jana Ilgner, Mary Lucas, Sara Marzo, Rethabile Mokhachane, Kyra Pazan, Diana Spurite, Mike W. Morley, Adrian Parker, Peter Mitchell, Brian A. Stewart, Patrick Roberts

Biological and Biomedical Sciences Department Faculty Journal Articles

Investigation of Homo sapiens’ palaeogeographic expansion into African mountain environments are changing the understanding of our species’ adaptions to various extreme Pleistocene climates and habitats. Here, we present a vegetation and precipitation record from the Ha Makotoko rockshelter in western Lesotho, which extends from ~60,000 to 1,000 years ago. Stable carbon isotope ratios from plant wax biomarkers indicate a constant C3-dominated ecosystem up to about 5,000 years ago, followed by C4 grassland expansion due to increasing Holocene temperatures. Hydrogen isotope ratios indicate a drier, yet stable, Pleistocene and Early Holocene compared to a relatively wet Late Holocene. Although relatively …


Effectiveness Of Water Hyacinth Compost And N, P, K, S Fertilizer On S-Available, S Uptake, Protein Content, And Yield Of Shallot In Inceptisols From Jatinangor, Emma Trinurani Sofyan, Fajar Akbar Gumelar, Anni Yuniarti, Benny Joy, Fiky Yulianto Wicaksono Apr 2023

Effectiveness Of Water Hyacinth Compost And N, P, K, S Fertilizer On S-Available, S Uptake, Protein Content, And Yield Of Shallot In Inceptisols From Jatinangor, Emma Trinurani Sofyan, Fajar Akbar Gumelar, Anni Yuniarti, Benny Joy, Fiky Yulianto Wicaksono

Jurnal Kultivasi

. Water hyacinth (Eichhornia crassipes) is a source of organic matter that can be used as compost to improve the soil quality and productivity of shallots. Shallots are horticultural commodities that have various benefits. Inceptisol soils dominate Indonesia, with an area of 37.5% of Indonesia's land area but have low soil fertility. Soil fertility can be increased by optimal fertilization. This experiment aimed to determine the dose of water hyacinth compost and nitrogen (N), phosphor (P), potassium (K), sulfur (S) fertilizer which gave the best effect on increasing available S, S uptake, protein content, and yield of shallots. The experiment …


Evaluating Fungal Population Response To The Miocene Climatic Optimum: High-Resolution Palynological Insights From The South China Sea And Mcmurdo Sound, Antarctica, Mallory Pilie Apr 2023

Evaluating Fungal Population Response To The Miocene Climatic Optimum: High-Resolution Palynological Insights From The South China Sea And Mcmurdo Sound, Antarctica, Mallory Pilie

LSU Master's Theses

Fungi play key and specific roles in ecosystems, specifically as many have restricted geographic distributions, known host/substrate preferences, and are important local environmental indicators due to their short dispersal distances. This study of fossil fungi from a time interval of pronounced global warming, the Miocene Climatic Optimum (MCO), allows analysis of fungal response to an analogue for future climate change scenarios. The research presented herein is part of a larger project, Fungi in a Warmer World (FiaWW), which is using globally-distributed sediment samples to provide foundational information on fungal community distribution patterns and will provide the first fungi-based climatological reconstructions …


New U–Pb Geochronology For The Central Atlantic Magmatic Province, Critical Reevaluation Of High-Precision Ages And Their Impact On The End-Triassic Extinction Event, Alisson L. Oliveira, Mark D. Schmitz, Corey J. Wall, James L. Crowley, Antomat A. Macêdo Filho, Maria Helena B. M. Hollanda Apr 2023

New U–Pb Geochronology For The Central Atlantic Magmatic Province, Critical Reevaluation Of High-Precision Ages And Their Impact On The End-Triassic Extinction Event, Alisson L. Oliveira, Mark D. Schmitz, Corey J. Wall, James L. Crowley, Antomat A. Macêdo Filho, Maria Helena B. M. Hollanda

Geosciences Faculty Publications and Presentations

The end-Triassic extinction (ETE) event represents one of the ‘big five’ episodes of mass extinction. The leading hypothesis for the cause of the ETE is the intrusion of voluminous magmas of the Central Atlantic Magmatic Province (CAMP) into carbon-rich sediments of two South American sedimentary basins, around 201.5 Ma. The timing of dikes and sills emplacement, however, must be considered in light of age models from CAMP rocks occurring in North America. In this work, we present new high-precision ages for critical samples in NE Brazil (201.579 ± 0.057 Ma) and Canada (201.464 ± 0.017 Ma), in order to evaluate …


Quantifying Mud Settling Velocity As A Function Of Turbulence And Salinity In A Deltaic Estuary, Michael W. Mcdonell Apr 2023

Quantifying Mud Settling Velocity As A Function Of Turbulence And Salinity In A Deltaic Estuary, Michael W. Mcdonell

LSU Master's Theses

Mud settling velocity is controlled by flocculation, which in turn strongly depends on turbulence and on the chemistry and biology of the water-sediment mixture. As a result, mud settling velocity can be poorly constrained in coastal areas and vary in space and time by orders of magnitude. Here we quantified mud settling velocity in Barataria Basin, a deltaic estuary in Louisiana (USA), using three independent methods: eddy covariance (one station for 200 days), floc cameras (4 stations at one time), and Rouse profile inversion (14 stations, replicated 10-30 times each). Eddy covariance indicates that settling velocity increases with turbulence, at …


Snow Distribution And Influence In Taylor Valley, Antarctica, Using Remote Sensing, Katherine Mcnulty, Peter Doran, Mark Salvatore, Suniti Karunatillake Apr 2023

Snow Distribution And Influence In Taylor Valley, Antarctica, Using Remote Sensing, Katherine Mcnulty, Peter Doran, Mark Salvatore, Suniti Karunatillake

LSU Master's Theses

The McMurdo Dry Valleys is the largest ice-free area in Antarctica, but seasonal snow covers the valley floors sporadically throughout the year. In this study, a model to estimate areal snow coverage from satellite imagery was created. An area-volume model was created to estimate the amount of snow water equivalent (SWE) from the snow area extracted from the imagery. Snow cover influences the total albedo, the hydrologic budget, and the soil moisture and soil temperature in Taylor Valley (TV). Quantifying snow precipitation in TV is challenging because snow redistributes with winds, sublimates, or melts within a short period. Previous estimates …