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Articles 151 - 180 of 1925

Full-Text Articles in Sedimentology

Sediment Transport And Geomorphological Evolution In The Northern Gulf Of Mexico, Kelli Moran Jan 2023

Sediment Transport And Geomorphological Evolution In The Northern Gulf Of Mexico, Kelli Moran

LSU Doctoral Dissertations

This dissertation explores the mechanisms driving sediment transport and deposition on the continental shelf and within the bays of the northern Gulf of Mexico via a suite of geophysical methods and sediment cores on a variety of timescales. This dissertation is comprised of three main chapters, each focusing on a different location, environment, and process but tied together using geophysical survey, a thematic focus on geomorphic change and sediment transport within the deltaic cycle and deltaic plain environments, and the implications this change poses for both past and future sediment transport and environmental change in response to sea level change. …


Mid-20th Century Land-Use Change Greatly Reduced Flood Intensity In The Southeastern Us Dataset, Zhixiong Shen, Nicholas William Conway Jan 2023

Mid-20th Century Land-Use Change Greatly Reduced Flood Intensity In The Southeastern Us Dataset, Zhixiong Shen, Nicholas William Conway

Marine Science Faculty Publications

This dataset presents laser-diffraction grain-size distribution data of the sediment core, SBL2, taken from an oxbow lake in the Pee Dee River floodplain South Carolina, USA (33.8453 °N, 79.3507°W).


Organic Matter Content And Grain Size Analysis In Seagrass Sediments, Adriana Amrhein, Rip Hale Jan 2023

Organic Matter Content And Grain Size Analysis In Seagrass Sediments, Adriana Amrhein, Rip Hale

College of Sciences Posters

Anthropogenic stresses including increased water temperatures, decreased water quality, sea level rise, ocean acidification and sediment biogeochemical processes have caused a significant loss in seagrass meadow acreage. Seagrass meadows provide coastal protection from storms and recently have been emphasized for their importance in sequestering and storing “Blue Carbon” from the atmosphere and ocean. Seagrass meadows can trap this blue carbon in their sediment as organic carbon, and it can be stored for hundreds to thousands of years. Restoration efforts of seagrass meadows in the Virginia coast started in the 1990s and effects of increasing seagrass density can be observed in …


Sediment Delivery To Sustain The Ganges-Brahmaputra Delta Under Climate Change And Anthropogenic Impacts, Jessica L. Raff, Steven L. Goodbred Jr., Jennifer L. Pickering, Ryan S. Sincavage, John C. Ayers, Md. Saddam Hossain, Carol A. Wilson, Chris Paola, Michael S. Steckler, Dhiman R. Mondal, Jean-Louis Grimaud, Celine Jo Grall, Kimberly G. Rogers, Kazi Matin Ahmed, Syed Jo Grall, Kimberly G. Rogers, Kazi Matin Ahmed, Syed Humayun Akhter, Brandee N. Carlson, Elizabeth L. Chamberlain, Meagan Dejter, Jonathan M. Gilligan, Richard P. Hale, Mahfuzur R. Khan, Md. Golam Muktadir, Md. Munsur Rahman, Lauren A. Williams Jan 2023

Sediment Delivery To Sustain The Ganges-Brahmaputra Delta Under Climate Change And Anthropogenic Impacts, Jessica L. Raff, Steven L. Goodbred Jr., Jennifer L. Pickering, Ryan S. Sincavage, John C. Ayers, Md. Saddam Hossain, Carol A. Wilson, Chris Paola, Michael S. Steckler, Dhiman R. Mondal, Jean-Louis Grimaud, Celine Jo Grall, Kimberly G. Rogers, Kazi Matin Ahmed, Syed Jo Grall, Kimberly G. Rogers, Kazi Matin Ahmed, Syed Humayun Akhter, Brandee N. Carlson, Elizabeth L. Chamberlain, Meagan Dejter, Jonathan M. Gilligan, Richard P. Hale, Mahfuzur R. Khan, Md. Golam Muktadir, Md. Munsur Rahman, Lauren A. Williams

OES Faculty Publications

The principal nature-based solution for offsetting relative sea-level rise in the Ganges-Brahmaputra delta is the unabated delivery, dispersal, and deposition of the rivers’ ~1 billion-tonne annual sediment load. Recent hydrological transport modeling suggests that strengthening monsoon precipitation in the 21st century could increase this sediment delivery 34-60%; yet other studies demonstrate that sediment could decline 15-80% if planned dams and river diversions are fully implemented. We validate these modeled ranges by developing a comprehensive field-based sediment budget that quantifies the supply of Ganges-Brahmaputra river sediment under varying Holocene climate conditions. Our data reveal natural responses in sediment supply comparable to …


Systemic Analyses Of Radiocarbon Ages Of Coexisting Planktonic Foraminifera, Jörg Lippold, Julia Gottschalk, Jean Lynch-Stieglitz, Matthew W. Schmidt, Sönke Szidat, Andre Bahr Jan 2023

Systemic Analyses Of Radiocarbon Ages Of Coexisting Planktonic Foraminifera, Jörg Lippold, Julia Gottschalk, Jean Lynch-Stieglitz, Matthew W. Schmidt, Sönke Szidat, Andre Bahr

OES Faculty Publications

We compare radiocarbon (14C) ages of coexisting planktonic foraminifera species from sediment cores VM12-107 and KNR166-2-26JPC from the Equatorial Atlantic Ocean for three time periods (Holocene, Heinrich Stadial 1, last glacial maximum). We find a maximum inter-species difference of 1200 14C yr. On average, the 14C ages deviate by ∼300 yr between Globigerinoides ruber and other species. In most cases, this exceeds the analytical uncertainty range of the measurements and thus renders the choice of species for generating age models as important as sample weight. While modern stratified water-column profiles imply an increase in 14C …


Using 3-Dimensional Mapping To Determine The Possibility Of Structural Control On Development Of The Upper Ordovician Lexington Limestone, Central Kentucky, U.S.A., Sean Davis Jan 2023

Using 3-Dimensional Mapping To Determine The Possibility Of Structural Control On Development Of The Upper Ordovician Lexington Limestone, Central Kentucky, U.S.A., Sean Davis

Theses and Dissertations--Earth and Environmental Sciences

The upper Lexington Limestone of Late Ordovician age has been interpreted to represent a structurally controlled, complex, facies mosaic. This facies mosaic has historically been interpreted to be a carbonate buildup of shoal complexes with interbedded shale units with intertonguing facies. Due to relatively recent advances in geographic-information-systems (GIS) mapping technologies, it is possible to generate three-dimensional (3-D) compatible maps to offer insight to the complexities of the upper Lexington Limestone and to determine if structural control affected the distribution of members. The resulting two-dimensional (2-D) and 3-D maps show that basement faults likely exerted a significant influence on facies …


A Source-To-Sink Analysis Of The Pantanal Basin (Brazil): Implications For Weathering, Erosion, And Landscape Evolution In The World's Largest Wetland, Edward L. Lo Jan 2023

A Source-To-Sink Analysis Of The Pantanal Basin (Brazil): Implications For Weathering, Erosion, And Landscape Evolution In The World's Largest Wetland, Edward L. Lo

Theses and Dissertations--Earth and Environmental Sciences

Large back-bulge retro-arc basins have limited information about the sediment composition, yet they comprise important parts of the stratigraphic rock record. The exorheic Pantanal Basin is the world's largest continental wetland that regulates many valuable ecosystem services (water storage, nutrient cycling, agriculture, ranching, tourism, and transportation). This dissertation is composed of three studies that utilize a suite of tools to examine the most fundamental basin-wide source-to-sink sediment processes and controls that affect the characteristics and distribution of modern sediments.

The first paper consists of a metadata analysis of 76 shallow tropical floodplain lakes in the literature with bathymetric data and …


Berriasian–Valanginian Geochronology And Carbon-Isotope Stratigraphy Of The Yellow Cat Member, Cedar Mountain Formation, Eastern Utah, Usa, Robert M. Joeckel, Celina A. Suarez, Noah M. Mclean, Andreas Möller, Gregory A. Ludvigson, Marina B. Suarez, James I. Kirkland, Joseph Andrew, Spencer Kiessling, Garrett A. Hatzell Jan 2023

Berriasian–Valanginian Geochronology And Carbon-Isotope Stratigraphy Of The Yellow Cat Member, Cedar Mountain Formation, Eastern Utah, Usa, Robert M. Joeckel, Celina A. Suarez, Noah M. Mclean, Andreas Möller, Gregory A. Ludvigson, Marina B. Suarez, James I. Kirkland, Joseph Andrew, Spencer Kiessling, Garrett A. Hatzell

Conservation and Survey Division: Faculty and Staff Publications

The Early Cretaceous Yellow Cat Member of the terrestrial Cedar Mountain Formation in Utah, USA. has been interpreted as a “time-rich” unit because of its dinosaur fossils, prominent paleosols, and the results of preliminary chemostratigraphic and geochronologic studies. Herein, we refine prior interpretations with: (1) a new composite C-isotope chemostratigraphic profile from the well-known Utahraptor Ridge dinosaur site, which exhibits δ13C features tentatively interpreted as the Valanginian double-peak carbon isotope excursion (the so-called “Weissert Event”) and some unnamed Berriasian features; and (2) a new cryptotephra zircon eruption age of 135.10 ± 0.30/0.31/0.34 Ma (2σ) derived from the CA-ID-TIMS …


Closing The Modern Seismic Gap Along The Teton Fault Via Seismic Mapping Of Mass Transport Deposits In Jackson Lake, Wy, Callia Jacqueline Cortese Jan 2023

Closing The Modern Seismic Gap Along The Teton Fault Via Seismic Mapping Of Mass Transport Deposits In Jackson Lake, Wy, Callia Jacqueline Cortese

Theses and Dissertations--Earth and Environmental Sciences

Terrestrial paleoseismological records along the Teton fault have historically indicated two-to-three major post-Pinedale (~14 ka) earthquake events, leaving an unresolved 6-9 m offset along the modern scarp. Recent studies of Jenny Lake have augmented this record, but the triggering mechanism is still equivocal until new paleo-earthquake records are developed. The earthquake record of the Teton fault is complicated by quiescence from ~5 ka to present, demonstrating the need for additional paleoseismic investigations. Compressed, high-intensity radar pulse (CHIRP) reflection data from Jackson Lake indicates multiple potentially seismically-induced mass transport deposits (MTDs). At least six MTD Groups representing chronostratigraphic intervals were interpreted …


Hydrologic And Geomorphic Investigations Of Two Engineered Stream Crossings Under Interstate 90 In Washington State, Catherine Mast Jan 2023

Hydrologic And Geomorphic Investigations Of Two Engineered Stream Crossings Under Interstate 90 In Washington State, Catherine Mast

All Master's Theses

The importance of stream restoration in providing a healthy ecosystem is widely recognized. The Washington State Department of Transportation (WSDOT) has implemented environmental changes to facilitate habitat restoration and wildlife passage along the Interstate 90 Highway (I-90) corridor where it passes over the Cascade Mountains. Prior to the I-90 corridor expansion, Price and Noble Creeks passed under the highway though culverts, limiting passage of aquatic species or wildlife below the highway. In 2019 the stream channel crossings were expanded, and the size/shape of these creeks were engineered to mirror what would be seen in a natural environment. Since construction, erosion …


Natural Fracture Evolution: Investigations Into The Middle Devonian Marcellus Shale, Appalachian Basin, Usa, Natalie Abigail Mitchell Jan 2023

Natural Fracture Evolution: Investigations Into The Middle Devonian Marcellus Shale, Appalachian Basin, Usa, Natalie Abigail Mitchell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Optimizing recovery from unconventional shale reservoirs has generated considerable research into optimal recovery methods through hydraulic fracturing design and shale reservoir characterization in the development of long-term hydrocarbon producers. Permeability at multiple scales from nanometer-scale pore sizes and nano-darcy permeability to completion-induced fractures defining a 100’s of meter stimulated reservoir volume plays a significant role in hydrocarbon flow during production in shale reservoirs. Preexisting cemented fractures in unconventional shale reservoirs are abundant and preferentially reactivate during induced hydraulic fracturing treatment to create necessary large-scale permeability. While previous investigations have significantly improved our knowledge of shale reservoirs, it has also highlighted …


Using Soil And Forest Type To Map Bedrock In Nemo, South Dakota, Madison R. Isaac Jan 2023

Using Soil And Forest Type To Map Bedrock In Nemo, South Dakota, Madison R. Isaac

Williams Honors College, Honors Research Projects

Bedrock mapping can be used to locate economic deposits, assess natural disaster (e.g., mass wasting) risk, and decipher the geologic history of a region. This study examines a site at Nemo, South Dakota to assess whether two contrasting types of bedrock produce different soil that result in different types of forest cover. Although bedrock varied, other soil forming factors were uniform. Within an approximately 1 km2 area, quartzite and metagabbro bedrock, ponderosa pine and quaking aspen forests were mapped. The soil above the quartzite bedrock is thinner and sandier and is dominated by ponderosa pine (Pinus ponderosa). …


Hydrogeologic Field Trip Of Northeast Nebraska, Sue Olafsen Lackey, Kathleen Cameron, Matt Marxsen Jan 2023

Hydrogeologic Field Trip Of Northeast Nebraska, Sue Olafsen Lackey, Kathleen Cameron, Matt Marxsen

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


2023 Nebraska Water Leaders Academy, Mark E. Burbach, Robert Matthew Joeckel Jan 2023

2023 Nebraska Water Leaders Academy, Mark E. Burbach, Robert Matthew Joeckel

Conservation and Survey Division: Faculty and Staff Publications

Eighteen participants completed the 2023 Water Leaders Academy bringing the total number of graduates to 186 since the inception of the program in 2011. Assessments of participants’ transformational leadership skills, champion of innovation skills, water knowledge, engagement with water issues, civic capacity, entrepreneurial leadership behaviors, boundary spanning skills, and curiosity increased significantly over the course of the year, according to both the participants and their raters. Feedback from the participants was highly positive and constructive. Academy planners are addressing participant concerns. Results of the program assessment indicate that the curriculum is meeting the Academy’s objectives. Therefore, only minor changes are …


Telescopic Megafans On The High Plains, Usa Were Signal Buffers In A Major Source-To-Sink System, Jesse T. Korus Dr., Robert Matthew Joeckel Jan 2023

Telescopic Megafans On The High Plains, Usa Were Signal Buffers In A Major Source-To-Sink System, Jesse T. Korus Dr., Robert Matthew Joeckel

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


3d Hydrostratigraphic And Hydraulic Conductivity Modeling Using Supervised Machine Learning, T. A. Tilahun, Jesse T. Korus Dr. Jan 2023

3d Hydrostratigraphic And Hydraulic Conductivity Modeling Using Supervised Machine Learning, T. A. Tilahun, Jesse T. Korus Dr.

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Nebraska's Water, Nawaraj Shrestha, Ann Briggs, Aaron R. Young, Robert Matthew Joeckel Jan 2023

Nebraska's Water, Nawaraj Shrestha, Ann Briggs, Aaron R. Young, Robert Matthew Joeckel

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Conservation And Survey Division 2023 Annual Report, R. M. Joeckel, M. M. Waszgis Jan 2023

Conservation And Survey Division 2023 Annual Report, R. M. Joeckel, M. M. Waszgis

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Continental Saline Environments Interpreted From Bedded Gypsum Of The Triassic Red Peak Formation (Chugwater Group), Northcentral Wyoming, Maya Yamei Bradford Jan 2023

Continental Saline Environments Interpreted From Bedded Gypsum Of The Triassic Red Peak Formation (Chugwater Group), Northcentral Wyoming, Maya Yamei Bradford

Graduate Theses, Dissertations, and Problem Reports (ETD)

Bedded evaporites and associated red bed siliciclastics record saline lake and groundwater systems from Permo-Triassic Pangea. A major component of these red bed and evaporite systems is bedded gypsum. However, little attention has been paid to the textures of ancient gypsum. Observations of gypsum textures can refine interpretations of depositional environment and diagenetic history. This project describes textures of bedded gypsum from an outcrop of the Triassic Red Peak Formation (Chugwater Group) near Greybull, Wyoming.

This thesis uses fieldwork, petrography, and x-ray diffraction to describe an outcrop of the upper Red Peak Formation, with a focus on textures of bedded …


Numerical Study Of Sediment Suspension Affected By Rigid Cylinders Under Unidirectional And Combined Wave-Current Flows, Sha Lou, Xiaolan Chen, Shengyu Zhou, Gangfeng Ma, Shuguang Liu, Larisa Dorzhievna Radnaeva, Elena Nikitina, Irina Viktorovna Fedorova Jan 2023

Numerical Study Of Sediment Suspension Affected By Rigid Cylinders Under Unidirectional And Combined Wave-Current Flows, Sha Lou, Xiaolan Chen, Shengyu Zhou, Gangfeng Ma, Shuguang Liu, Larisa Dorzhievna Radnaeva, Elena Nikitina, Irina Viktorovna Fedorova

Civil & Environmental Engineering Faculty Publications

Sediment transport modeling for flows with cylinders is very challenging owing to the complicated flow–cylinder–sediment interactions, especially under the combined wave-current flows. In this paper, an improved formulation for incipient sediment suspension considering the effect of cylinder density (i.e., solid volume fraction) is employed to simulate the bottom sediment flux in the flow with cylinders. The proposed model is calibrated and validated using laboratory measurements under unidirectional and combined wave-current flows in previous studies. It is proved that the effects of cylinders on sediment suspension can be accounted for through a modified critical Shields number, and the proposed model is …


An Eolian Dust Origin For Clastic Fines Of Devono-Mississippian Mudrocks Of The Greater North American Midcontinent, Austin J. Mcglannan, Alicia Bonar, Lily Pfeifer, Sebastian Steinig, Paul Valdes, Steven Adams, David Duarte, Benmadi Milad, Andrew Cullen, Gerilyn S. Soreghan Dec 2022

An Eolian Dust Origin For Clastic Fines Of Devono-Mississippian Mudrocks Of The Greater North American Midcontinent, Austin J. Mcglannan, Alicia Bonar, Lily Pfeifer, Sebastian Steinig, Paul Valdes, Steven Adams, David Duarte, Benmadi Milad, Andrew Cullen, Gerilyn S. Soreghan

School of Earth & Environment Departmental Research

Upper Devonian and Lower–Middle Mississippian strata of the North American midcontinent are ubiquitously fine-grained and silt-rich, comprising both so-called shale as well as argillaceous limestone (or calcareous siltstone) that accumulated in the Laurentian epeiric sea. Although long recognized as recording marine deposition, the origin and transport of the fine-grained siliciclastic material in these units remains enigmatic because they do not connect to any proximal deltaic feeder systems. Here, we present new data on grain size, whole-rock geochemistry, mineralogy, and U-Pb detrital-zircon geochronology from units across Oklahoma; we then integrate these data with models of surface wind circulation, refined paleogeographic reconstructions, …


Storm Intensity And Forward Speed Controls On Back-Barrier And Shoreface Sediment Dynamics Along The Louisiana Coast, Md Mohiuddin Sakib Dec 2022

Storm Intensity And Forward Speed Controls On Back-Barrier And Shoreface Sediment Dynamics Along The Louisiana Coast, Md Mohiuddin Sakib

LSU New Orleans Theses and Dissertations

High energetic storms import sediment to back-barrier bays and marshes and produce a perennial footprint that contributes to the long-term evolution of the inner shelf, bays, and marsh platform. The magnitude of sedimentation in back-barrier bays and marshes varies with storm characteristics (e.g., storm intensity, forward speed, size, and track). However, quantifying the impacts of storm characteristics on the sediment exchange between the inner shelf, bays, and marshes and documenting the resulting net sediment import and export patterns across these interfaces remains largely unexplored. Here we applied a calibrated Delft3D hydrodynamics and sediment transport model to a microtidal bay-marsh complex …


Along Strike Tectonic Evolution Of The Neogene Bermejo Foreland Basin And Eastern Precordillera Thrust Front, Argentina (30-32ºs), Zoey Catherine Plonka Dec 2022

Along Strike Tectonic Evolution Of The Neogene Bermejo Foreland Basin And Eastern Precordillera Thrust Front, Argentina (30-32ºs), Zoey Catherine Plonka

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Bermejo retroarc foreland basin system formed in flexural response to Miocene crustal thickening in the Andean orogenic system, specifically, the eastward propagation of the Precordillera fold-thrust belt and the basement-involved uplift of the Sierras Pampeanas. Previous work in the area has mainly focused on the mechanisms and expression of flat slab subduction and the structural geometry of the basement-involved Sierras Pampeanas and east-vergent Precordillera fold-thrust belt at depth. Much of this work has furthered the understanding of Bermejo basin evolution north of 31ºS, however debate still exists whether the N-S trending Bermejo basin evolved synchronously or asynchronously through time. …


Paleoenvironmental Changes Across The Devonian-Carboniferous Transition, Audrey M. Warren Dec 2022

Paleoenvironmental Changes Across The Devonian-Carboniferous Transition, Audrey M. Warren

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Devonian-Carboniferous (D-C) transition was a critical interval in earth history, witnessing profound environmental changes associated with plant and animal evolution and extinction. Two first-order mass extinctions occurred leading up to the D-C boundary: the Kellwasser Event at the Frasnian-Famennian (F-F) boundary (~371 Ma) and the D-C boundary Hangenberg Event (~359 Ma). Both events were associated with significant sea level changes and major carbon cycle perturbations, evidenced by widespread deposition of black shale and positive carbon isotope (δ13C) excursions, all of which have been used to correlate these events across the globe. Because preservation of black shale requires anoxic conditions, …


Sub-Recent Microfauna Within Allogenic Sediments At The Bottom Of A Deep Cave, Njemica (Biokovo Mt., Croatia), Tomislav Kurečić, Valentina Hajek Tadesse, Lara Wacha, Marija Horvat, Nina Trinajstić, Ivan Mišur Nov 2022

Sub-Recent Microfauna Within Allogenic Sediments At The Bottom Of A Deep Cave, Njemica (Biokovo Mt., Croatia), Tomislav Kurečić, Valentina Hajek Tadesse, Lara Wacha, Marija Horvat, Nina Trinajstić, Ivan Mišur

International Journal of Speleology

Clastic sediments deposited at the bottom of the vertical, nearly 1000 m deep Njemica Cave (Biokovo Mountain, Croatia) were analysed. Owing to the vertical morphology of the cave, the occurrences of clastic sediments are sparse. Small, up to decimetre-thick, undisturbed sediment accumulations situated near the siphon lake revealed interesting palaeontological and mineralogical data. These data are used as a useful proxy for discussing depositional processes, the provenance of the sediments and paleo-habitats of the subterranean fauna.

The sub-recent assemblages of ostracods were discovered within the sediment, and they were shown to be correlative to the known endemic species in the …


Inverting Passive Margin Stratigraphy For Marine Sediment Transport Dynamics Over Geologic Time, Charles Shobe, Jean Braun, Xiaoping Yuan, Benjamin Campforts, Boris Gailleton, Guillaume Baby, François Guillocheau, Cécile Robin Nov 2022

Inverting Passive Margin Stratigraphy For Marine Sediment Transport Dynamics Over Geologic Time, Charles Shobe, Jean Braun, Xiaoping Yuan, Benjamin Campforts, Boris Gailleton, Guillaume Baby, François Guillocheau, Cécile Robin

Faculty & Staff Scholarship

Passive margin stratigraphy contains time-integrated records of landscapes that have long since vanished. Quantitatively reading the stratigraphic record using coupled landscape evolution and stratigraphic forward models (SFMs) is a promising approach to extracting information about landscape history. However, there is no consensus about the optimal form of simple SFMs because there has been a lack of direct tests against observed stratigraphy in well-constrained test cases. Specifically, the extent to which SFM behaviour over geologic space and timescales should be governed by local (downslope sediment flux depends only on local slope) versus nonlocal (sediment flux depends on factors other than local …


Snapshots Of Coastal Ecology During Glacial And Deglacial Intervals: A Multiproxy Assessment Of Northern Gulf Of Mexico Sediment Cores, Kendall Emilie Brome Nov 2022

Snapshots Of Coastal Ecology During Glacial And Deglacial Intervals: A Multiproxy Assessment Of Northern Gulf Of Mexico Sediment Cores, Kendall Emilie Brome

LSU Master's Theses

Terrestrial ecosystems along exposed continental shelves during times of relatively low sea level and glaciation are rarely preserved due to the mechanically erosive nature of marine transgression and regression. In this study, I investigate the geochemical and palynological characteristics of two well-preserved sites in the northern Gulf of Mexico (NGOM) to determine the ecologic settings and subsequent mechanisms of preservation in this region. Both sites contain preserved terrigenous sediments of previously exposed coastal margins; the first is located at the Alabama Underwater Forest (~13 km south of Gulf Shores, AL, at ~15 mbsl), and optically stimulated luminescence dates to 72–56 …


Flow Regime Evolution Of A Major Cave System In The Eastern Alps (Hirlatzhöhle, Dachstein), Lukas Plan, Gottfried Buchegger, Eva Kaminsky, Gabriella Koltai, Tanguy Racine, Jacek Szczygieł Oct 2022

Flow Regime Evolution Of A Major Cave System In The Eastern Alps (Hirlatzhöhle, Dachstein), Lukas Plan, Gottfried Buchegger, Eva Kaminsky, Gabriella Koltai, Tanguy Racine, Jacek Szczygieł

International Journal of Speleology

The 116 km-long and 1560 m-deep Hirlatzhöhle is one of the major cave systems in the Northern Calcareous Alps (NCA; Austria). It is located in the NW part of the Dachstein, an extensive karst massif encompassing 576 km² with its highest point at 2995 m a.s.l. In contrast to most other caves in the NCA, Hirlatzhöhle comprises old (epi)phreatic passages located up to 1 km above the base level as well as two modern major drainage systems. The aim of this study is to define the palaeo- and the active flow conditions in combination with speleogenesis, and the age of …


Observations On Late Cretaceous Micrampulla (Corethrales, Bacillariophyceae) From The Campbell Plateau (Zealandia), Southwest Pacific Ocean, Kenta Abe, David M. Harwood, Richard W. Jordan Oct 2022

Observations On Late Cretaceous Micrampulla (Corethrales, Bacillariophyceae) From The Campbell Plateau (Zealandia), Southwest Pacific Ocean, Kenta Abe, David M. Harwood, Richard W. Jordan

Department of Earth and Atmospheric Sciences: Faculty Publications

Late Cretaceous (late Campanian) diatom assemblages from the Campbell Plateau (Zealandia), southwest Pacific Ocean, obtained from Deep Sea Drilling Project (DSDP) Leg 29 Site 275, contain well-preserved specimens of two enigmatic diatom species currently assigned to the genus Ktenodiscus; Micrampulla parvula originally described from the Maastrichtian-age Moreno Shale, California, and Pterotheca cretacea from DSDP Site 275. In general, the two species share a number of common features with modern Corethron (domed valves, probable heterovalvate frustules, T-shaped serrated articulated spines, marginal sockets), but differ in the location of the sockets (i.e. vertically at the base of the valve dome and …


Preliminary Geochemical And Mineralogical Assessment Of The Beach Sand, Vieques, Puerto Rico, Nazrul I. Khandaker Oct 2022

Preliminary Geochemical And Mineralogical Assessment Of The Beach Sand, Vieques, Puerto Rico, Nazrul I. Khandaker

Publications and Research

PRELIMINARY GEOCHEMICAL AND MINERALOGICAL ASSESSMENT OF THE BEACH SAND, VIEQUES, PUERTO RICO

ROBBINS, Kathy H., KHANDAKER, Nazrul, SINGH, Andrew, and MUNRO, Toralv, Geological Society of America Abstracts with Programs, Vol 54, No. 5, https://doi.org/10.1130/abs/2022AM-379886

ROBBINS, Kathy H., Bronx Early College Academy for Teaching and Learning, 250E 164 STREET, Bronx, NY 10456, KHANDAKER, Nazrul, Geology Discipline, York College of CUNY, 9420 Guy R Brewer Blvd, AC-2F09, Jamaica, NY 11451-0001, SINGH, Andrew, Earth and Physical Sciences, York College of CUNY, 9420 Guy R Brewer Blvd, AC-2F09, Jamaica, NY 11451-0001 and MUNRO, Toralv, 10911 164th St Apt 1, Jamaica, NY 11433-2921 …