Open Access. Powered by Scholars. Published by Universities.®
- Institution
-
- University of Nebraska - Lincoln (954)
- Old Dominion University (40)
- Central Washington University (18)
- University of Dayton (15)
- Western Washington University (10)
-
- Selected Works (9)
- The University of Southern Mississippi (9)
- University of Massachusetts Amherst (9)
- University of Nevada, Las Vegas (9)
- University of South Florida (9)
- University of Wisconsin Milwaukee (9)
- Claremont Colleges (8)
- University of Arkansas, Fayetteville (6)
- Western University (6)
- Fort Hays State University (5)
- Loma Linda University (5)
- City University of New York (CUNY) (4)
- East Tennessee State University (4)
- Florida International University (4)
- Liberty University (4)
- Louisiana State University (4)
- Portland State University (4)
- Boise State University (3)
- Cedarville University (3)
- College of Saint Benedict and Saint John's University (3)
- James Madison University (3)
- Montclair State University (3)
- Northern Illinois University (3)
- Stephen F. Austin State University (3)
- University of Montana (3)
- Keyword
-
- Nebraska (446)
- Groundwater (92)
- Geology (73)
- Test (73)
- Hole (72)
-
- Logs (72)
- Water (65)
- Map (61)
- Conservation and Survey Division (60)
- Water Survey Paper (53)
- Resource (46)
- Wells (45)
- Paleontology (36)
- Irrigation (32)
- Groundwater Nebraska (31)
- Water Nebraska (31)
- Level (28)
- Csd (26)
- News (26)
- Decline (20)
- Rise (20)
- Notes (17)
- Paleoecology (17)
- Resources (17)
- Foraminifera (16)
- Mineral operations (16)
- Report (16)
- Survey (16)
- Annual (15)
- Registered (15)
- Publication Year
- Publication
-
- Conservation and Survey Division (813)
- Bulletin of the University of Nebraska State Museum (113)
- Geology Faculty Publications (25)
- OES Theses and Dissertations (21)
- OES Faculty Publications (19)
-
- All Faculty Scholarship for the College of the Sciences (18)
- Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research (12)
- Theses and Dissertations (10)
- Master's Theses (9)
- UNLV Theses, Dissertations, Professional Papers, and Capstones (8)
- Electronic Theses and Dissertations (7)
- Robert F. Diffendal, Jr., Publications (7)
- WM Keck Science Faculty Papers (7)
- Doctoral Dissertations (6)
- USF Tampa Graduate Theses and Dissertations (6)
- Electronic Thesis and Dissertation Repository (5)
- Honors Theses (5)
- Loma Linda University Electronic Theses, Dissertations & Projects (5)
- Department of Earth and Atmospheric Sciences: Faculty Publications (4)
- FIU Electronic Theses and Dissertations (4)
- Marcus R. Ross (4)
- Masters Theses (4)
- Department of Earth and Environmental Studies Faculty Scholarship and Creative Works (3)
- Dissertations and Theses (3)
- Earth and Planetary Sciences ETDs (3)
- Graduate Research Theses & Dissertations (3)
- Graduate Theses and Dissertations (3)
- Journal of the Arkansas Academy of Science (3)
- Maine Collection (3)
- Umesh K. Haritashya (3)
Articles 1 - 30 of 1219
Full-Text Articles in Geology
Pre-Tertiary Subcrop Rocks In The Nebraska Panhandle, Conservation Annd Survey Division
Pre-Tertiary Subcrop Rocks In The Nebraska Panhandle, Conservation Annd Survey Division
Conservation and Survey Division
No abstract provided.
Inferred Areal Extent Of The Oligocene (White River Group) Chadron Basal Sand, Conservation And Survey Division
Inferred Areal Extent Of The Oligocene (White River Group) Chadron Basal Sand, Conservation And Survey Division
Conservation and Survey Division
No abstract provided.
Configuration Of The Base Of The Principal Aquifer, Conservation And Survey Division
Configuration Of The Base Of The Principal Aquifer, Conservation And Survey Division
Conservation and Survey Division
No abstract provided.
Theory Of An Automatic Seepage Meter And Ramifications For Applications, V. A. Zlotnik, D. K. Solomon, D. P. Genereux, T. E. Gilmore, C. E. Humphrey, A. R. Mittelstet, A. V. Zlotnik
Theory Of An Automatic Seepage Meter And Ramifications For Applications, V. A. Zlotnik, D. K. Solomon, D. P. Genereux, T. E. Gilmore, C. E. Humphrey, A. R. Mittelstet, A. V. Zlotnik
Conservation and Survey Division
No abstract provided.
Controls On Soft Tissue And Cellular Preservation In Late Eocene And Oligocene Vertebrate Fossils From The White River And Arikaree Groups Of Nebraska, South Dakota, And Wyoming, John E. Gallucci, Grace Woolslayer, Kelsey Barker, Brian Kibelstis, Allison R Tumarkin-Deratzian, Paul V. Ullmann, David E. Grandstaff, Dennis O. Terry
Controls On Soft Tissue And Cellular Preservation In Late Eocene And Oligocene Vertebrate Fossils From The White River And Arikaree Groups Of Nebraska, South Dakota, And Wyoming, John E. Gallucci, Grace Woolslayer, Kelsey Barker, Brian Kibelstis, Allison R Tumarkin-Deratzian, Paul V. Ullmann, David E. Grandstaff, Dennis O. Terry
School of Earth & Environment Faculty Scholarship
Previous studies on microtaphonomy have identified multiple types of organic microstructures in fossil vertebrates from a variety of time periods and past environmental settings. This study investigates potential taphonomic, paleoenvironmental, and paleoclimatic controls on soft tissue and cellular preservation in fossil bone. To this end, fifteen vertebrate fossils were studied: eight fossils collected from the Oligocene Sharps Formation of the Arikaree Group in Badlands National Park, South Dakota, and seven fossils from formations in the underlying White River Group, including the Oligocene Brule Formation of Badlands National Park, and the Eocene Chadron Formation of Flagstaff Rim, Wyoming; Toadstool Geologic Park, …
Groundwater In Nebraska, Troy E. Gilmore, Jesse T. Korus Dr.
Groundwater In Nebraska, Troy E. Gilmore, Jesse T. Korus Dr.
Conservation and Survey Division
What is groundwater? Groundwater is water that fills and moves between spaces in underground rocks, gravel, sand, or other materials.
Cambrian Trilobites From The Nounan Dolomite And Lower St. Charles Formation (Upper Marjuman To Lower Sunwaptan; Miaolingian To Furongian Series), Smithfield Canyon, Northern Utah, Frederick A. Sundberg, Hannah R. Cothren, Carol M. Dehler
Cambrian Trilobites From The Nounan Dolomite And Lower St. Charles Formation (Upper Marjuman To Lower Sunwaptan; Miaolingian To Furongian Series), Smithfield Canyon, Northern Utah, Frederick A. Sundberg, Hannah R. Cothren, Carol M. Dehler
Geosciences Faculty Publications
The trilobite faunas that occur with the Steptoean Positive Isotope Carbon Excursion (SPICE) at Smithfield Canyon, Utah, have been reported, but not illustrated. Given the importance of the SPICE at this section for international correlations, the trilobites from new collections from the upper Nounan Dolomite to lower St. Charles Formation at Smithfield Canyon are reported herein and integrated with the previously reported taxa. Trilobite assemblages indicate that the upper Cedaria to the Ellipsocephaloides biozones (Miaolingian Series, Guzhangian Stage to Furongian Series, Jiangshanian Stage) are present stratigraphically below or above the SPICE.
Some of the taxa reported herein may represent new …
Nebraska Statewide Groundwater-Level Monitoring Report 2023, Aaron R. Young, Mark E. Burbach, Sue Olafsen Lackey, Robert Matthew Joeckel, Nawaraj Shrestha, Jeffrey Westrop
Nebraska Statewide Groundwater-Level Monitoring Report 2023, Aaron R. Young, Mark E. Burbach, Sue Olafsen Lackey, Robert Matthew Joeckel, Nawaraj Shrestha, Jeffrey Westrop
Conservation and Survey Division
This report is a synthesis of groundwater-level monitoring programs in Nebraska. It is a continuation of the series of annual reports and maps produced by the Conservation and Survey Division (CSD) of the University of Nebraska in cooperation with the U.S. Geological Survey (USGS) since the 1950s. Groundwater-level monitoring began in Nebraska in 1930 to survey the state’s groundwater resources and observe changes in its availability on a regular basis. The CSD and USGS cooperatively developed, maintained, and operated an observation-well network throughout the state. These two agencies were responsible for collecting and archiving this information, and for making it …
Joint Interpretation Of Ert And Self-Potential Data To Characterize The Subsurface Geology And Hydrodynamics Along The Sutherland Supply Canal And Paxton Siphon Inlet, Paxton, Nebraska., M. K. Aboushanab, D. R. Hallum, R. M. Joeckel
Joint Interpretation Of Ert And Self-Potential Data To Characterize The Subsurface Geology And Hydrodynamics Along The Sutherland Supply Canal And Paxton Siphon Inlet, Paxton, Nebraska., M. K. Aboushanab, D. R. Hallum, R. M. Joeckel
Conservation and Survey Division
No abstract provided.
Leveraging High Resolution Classifications And Random Forests For Hindcasting Decades Of Mesic Ecosystem Dynamics In The Landsat Time Series, N. E. Kolarik, Nawaraj Shrestha, T. Caughlin, J. S. Brandt
Leveraging High Resolution Classifications And Random Forests For Hindcasting Decades Of Mesic Ecosystem Dynamics In The Landsat Time Series, N. E. Kolarik, Nawaraj Shrestha, T. Caughlin, J. S. Brandt
Conservation and Survey Division
No abstract provided.
Analyzing The Shark Paleoecology Of Coastal Georgia From The Miocene And Pliocene Epochs, Joshua Lee Clark, Benjamin Angalet
Analyzing The Shark Paleoecology Of Coastal Georgia From The Miocene And Pliocene Epochs, Joshua Lee Clark, Benjamin Angalet
Georgia Journal of Science
The field of shark paleoecology often yields indecisive conclusions based on the limited fossilization of their anatomical structures, with the exception of their teeth. The majority of the Atlantic coast has been studied regarding the presence of certain prehistoric shark species from the Miocene, Pliocene, and Pleistocene epochs. However, information pertaining to the Georgia coast and understanding its potential community structure is relatively understudied. This study was conducted in which thousands of fossil shark specimens and subsequent marine fauna were collected from dredge spoils created by the US Army Corps of Engineers (USACE): Savannah District. A total of 5,127 fossil …
Field Guide To Big Bone Lick, Kentucky: Birthplace Of American Vertebrate Paleontology, Glenn W. Storrs, H Gregory Mcdonald, Eric Scott, Robert A. Genheimer, Stanley E. Hedeen, Cameron E. Schwalbach
Field Guide To Big Bone Lick, Kentucky: Birthplace Of American Vertebrate Paleontology, Glenn W. Storrs, H Gregory Mcdonald, Eric Scott, Robert A. Genheimer, Stanley E. Hedeen, Cameron E. Schwalbach
Special Publication--KGS
Big Bone Lick is the birthplace of vertebrate paleontology in the Western Hemisphere and has a long and celebrated history in the exploration of the American colonial frontier and of the early United States. Notable European scientists of the 18th century such as Buffon, Cuvier, and Hunter discussed the fossils found there. Prominent Americans of the time, such as Boone, Washington, Franklin, and Jefferson are also part of the site’s history. It is the type locality for several extinct late Pleistocene megafaunal mammals, most notably the iconic American Mastodon, who were attracted to the area by salt licks dictated by …
History Of Ice-Rafting In The Arctic Ocean During Glacial Maxima Through Marine Isotope Stage 6, Shannon M. Cofield
History Of Ice-Rafting In The Arctic Ocean During Glacial Maxima Through Marine Isotope Stage 6, Shannon M. Cofield
OES Theses and Dissertations
Numerous studies attempted to reconstruct Arctic paleoclimate, specifically ice mass timing and locations, during glacial maxima. While some regions, like the Barents-Svalbard Ice Sheet (BSIS) are well-studied, they may benefit from a high-resolution paleo proxy. Other regions are highly contested, such as the East Siberian Sea or the presence of a central Arctic Ocean ice mass.
This research uses an Fe-grain provenance method to (1) define how the BSIS behaved during Marine Isotope Stage (MIS) 2, 4, and 6, and when it retreated; (2) determine the presence and ages of Shelf Ice Masses (SIMs) in the Beaufort Sea and East …
Nebraska Statewide Groundwater-Level Monitoring Report 2022, Aaron R. Young, Mark E. Burbach, Sue Olafsen Lackey, Robert Matthew Joeckel, Jeffrey Westrop
Nebraska Statewide Groundwater-Level Monitoring Report 2022, Aaron R. Young, Mark E. Burbach, Sue Olafsen Lackey, Robert Matthew Joeckel, Jeffrey Westrop
Conservation and Survey Division
No abstract provided.
The Anatomy And Phylogeny Of A New Large Plioplatecarpine Mosasaur From The Campanian Bearpaw Shale Of Montana (Usa), Richard A. Carr
The Anatomy And Phylogeny Of A New Large Plioplatecarpine Mosasaur From The Campanian Bearpaw Shale Of Montana (Usa), Richard A. Carr
Master's Theses
In 2018, a large and associated plioplatecarpine mosasaur skull, pectoral girdle, and rib cage, whose total body length may have exceeded five meters, was uncovered in the Late Campanian Bearpaw Shale of Northeast Montana (USA). Phylogenetic analysis of this specimen, MOR 10855, recovers this individual as a basal member of the genus Plioplatecarpus. This specimen, is unique in that it is estimated to be nearly twice the size of any of the other species of Plioplatecarpus found in the Western Interior Seaway during this part of the Cretaceous. While the included phylogenetic study suggests MOR 10855 represents a new …
Timing Of Diversification, Dispersal, And Biogeography Of Parrots In The Genus Amazona (Psittaciformes: Psittacidae) Throughout The Caribbean, Visualized In Gis, Christopher Kingwill
Timing Of Diversification, Dispersal, And Biogeography Of Parrots In The Genus Amazona (Psittaciformes: Psittacidae) Throughout The Caribbean, Visualized In Gis, Christopher Kingwill
Master's Theses
Avian fossil records from across the Caribbean (Greater and Lesser Antilles) demonstrate higher avian diversity prior to extinction events due to climate change at the end of the Pleistocene and human impact across the Caribbean throughout the Holocene. Amazon parrots (Amazona) are a diverse genus of New World parrots found throughout Central and South America, as well as the Caribbean. Their phylogeny and evolutionary history, specifically for Caribbean species, has been debated in terms of source areas in Central and South America and the timing of and number of colonization events to different islands that preceded diversification into …
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
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
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 …
2023 Nebraska Water Leaders Academy, Mark E. Burbach, Robert Matthew Joeckel
2023 Nebraska Water Leaders Academy, Mark E. Burbach, Robert Matthew Joeckel
Conservation and Survey Division
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 …
3d Hydrostratigraphic And Hydraulic Conductivity Modeling Using Supervised Machine Learning, T. A. Tilahun, Jesse T. Korus Dr.
3d Hydrostratigraphic And Hydraulic Conductivity Modeling Using Supervised Machine Learning, T. A. Tilahun, Jesse T. Korus Dr.
Conservation and Survey Division
No abstract provided.
Telescopic Megafans On The High Plains, Usa Were Signal Buffers In A Major Source-To-Sink System, Jesse T. Korus Dr., Robert Matthew Joeckel
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
No abstract provided.
Hydrogeologic Field Trip Of Northeast Nebraska, Sue Olafsen Lackey, Kathleen Cameron, Matt Marxsen
Hydrogeologic Field Trip Of Northeast Nebraska, Sue Olafsen Lackey, Kathleen Cameron, Matt Marxsen
Conservation and Survey Division
No abstract provided.
A Miocene Nannofossil Biostratigraphic Case Study: Alaminos Canyon Block 627 And Mississippi Canyon Block 555, And Sedimentation Rates In The Gulf Of Mexico, Bethany L. Cobb Faulk, Murlene W. Clark
A Miocene Nannofossil Biostratigraphic Case Study: Alaminos Canyon Block 627 And Mississippi Canyon Block 555, And Sedimentation Rates In The Gulf Of Mexico, Bethany L. Cobb Faulk, Murlene W. Clark
Gulf and Caribbean Research
The Miocene sediments of 2 deep—water boreholes from the northern Gulf of Mexico, from Alaminos Canyon (AC) Block 627 and Mississippi Canyon (MC) Block 555, have been biostratigraphically analyzed using calcareous nannofossils, revealing changes in sedimentation rates and depositional environments between these 2 areas. High nannofossil abundance values and low sedimentation rates generally recorded in the Alaminos Canyon region suggest a condensed section during much of the Miocene, associated with a basinal environment. Mississippi Canyon exhibits lower nannofossil abundance and higher sedimentation rates compared to Alaminos Canyon during the majority of the Miocene. Increased sediment volumes are largely attributed to …
Surficial Geologic Mapping Of The Starkville 7.5-Minute United States Geological Survey Quadrangle 33088d-7 In Oktibbeha County, Mississippi, Jonathan Leard
Surficial Geologic Mapping Of The Starkville 7.5-Minute United States Geological Survey Quadrangle 33088d-7 In Oktibbeha County, Mississippi, Jonathan Leard
Theses and Dissertations
The Starkville Quadrangle is a hotspot for geological research. The Late Cretaceous is represented by the Demopolis Formation in the northeast corner of the quadrangle, followed by the Ripley Formation, and the Prairie Bluff Formation. The K-Pg boundary is exposed in the quadrangle, and the remarkable paleontology is of global importance. The Clayton Formation is the first Paleocene unit. Where the Clayton Formation channel sands are in contact with the underlying Prairie Bluff Formation, springs occur. Springs were a rare source of water in the Black Prairie and spurred the settlement of the area over 10,000 years ago. The Paleocene …
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
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 …
Beyond Functional Diversity: The Importance Of Trophic Position To Understanding Functional Processes In Community Evolution, Roxanne M. W. Banker, Ashley A. Dineen, Melanie G. Sorman, Carrie L. Tyler, Peter D. Roopnarine
Beyond Functional Diversity: The Importance Of Trophic Position To Understanding Functional Processes In Community Evolution, Roxanne M. W. Banker, Ashley A. Dineen, Melanie G. Sorman, Carrie L. Tyler, Peter D. Roopnarine
Geoscience Faculty Research
Ecosystem structure—that is the species present, the functions they represent, and how those functions interact—is an important determinant of community stability. This in turn aects how ecosystems respond to natural and anthropogenic crises, and whether species or the ecological functions that they represent are able to persist. Here we use fossil data from museum collections, literature, and the Paleobiology Database to reconstruct trophic networks of Tethyan paleocommunities fromthe Anisian and Carnian (Triassic), Bathonian (Jurassic), and Aptian (Cretaceous) stages, and compare these to a previously reconstructed trophic network from a modern Jamaican reef community. We generated model food webs consistent with …
Soils Of The Central Nebraska Loess Hills And Central Loess Plains, Judith Turk, Rebecca Young, Nicolas A. Jelinsky, Amber D. Anderson, Ashlee Dere, Colby J. Moorberg, Rachel K. Owen
Soils Of The Central Nebraska Loess Hills And Central Loess Plains, Judith Turk, Rebecca Young, Nicolas A. Jelinsky, Amber D. Anderson, Ashlee Dere, Colby J. Moorberg, Rachel K. Owen
Conservation and Survey Division
Understanding soil systems that characterize a region is critical to natural resource management. However, the knowledge gained through intensive study of local soil systems, which takes place annually as part of collegiate soil judging contests, is often poorly preserved for future use. In this study, field descriptions and laboratory data for 16 soil profiles described for the 2019 Region 5 Soil Judging Contest were used to characterize the soil system of the Central Nebraska Loess Hills and Central Loess Plains. Three landscape components of this soil system were analyzed: the loess uplands and rainwater basins, the transitional zone, and bottomlands. …
Faunal Comparison And Analysis Of The Blufftown Formation-Cusseta Sand Contact At Hannahatchee Creek, Georgia, Seth Fradella
Faunal Comparison And Analysis Of The Blufftown Formation-Cusseta Sand Contact At Hannahatchee Creek, Georgia, Seth Fradella
Honors Theses
The origin of fossil material in the highly fossiliferous bed above the Upper Cretaceous (Campanian) Blufftown Formation-Cusseta Sand contact at Hannahatchee Creek, Georgia, has long been a subject of scientific curiosity; however, no research has yet been conducted to specifically investigate discrepancies between the fossil assemblages of the upper Blufftown Formation and the basal Cusseta Sand, which overlies it unconformably. In the most recent published hypothesis, Case and Schwimmer (1988) propose that the basal Cusseta Sand contains a mixture of original fauna as well as material reworked and redeposited from the underlying Blufftown Formation, resulting in a lag deposit above …
A Faunal Composition Of The Late Cretaceous Blue Springs Site In Northeastern Mississippi And Evidence For Potential Paleoenvironmental Differences Between Beds, Ginger Trochesset
A Faunal Composition Of The Late Cretaceous Blue Springs Site In Northeastern Mississippi And Evidence For Potential Paleoenvironmental Differences Between Beds, Ginger Trochesset
Honors Theses
The Maastrichtian-age Blue Springs locality of the Coon Creek Member of the Ripley Formation is known for abundant, well-preserved marine fossils, including many genera of microfossils, bivalves, gastropods, decapods, cephalopods, actinopterygians, and other vertebrate organisms. This research contributes to the understanding of the paleontology of the site, as well as the changing paleoenvironmental conditions of the beds throughout deposition.
This project analyzed bulk material collected in 2021 from three fossiliferous beds at Blue Springs: the Lower Corbula Bed (Bed C), the Pebble Bed (Bed G), and the Exogyra-Pycnodonte Bed (Bed J). Unconsolidated material from Beds C and J was processed …
The Diatom Dark Ages: Identification Of Mid-Cretaceous Arctic Platform Diatoms From The Basal Transgression Of The Kanguk Formation, Devon Island, Nunavut, Canada, Megan Heins
Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research
The lower part of the mid-Cretaceous Kanguk Formation (Lower Turonian interval) contains an important paleontological record crucial to the characterization of a poorly known interval of fossil marine diatoms history. Kanguk Formation mudstones are exposed in a ~200 m-thick section on Devon Island, Nunavut, Canadian High Arctic. Diatoms at this location are well-preserved due to shallow burial on this Arctic Platform site. The rock sequence was protected from glacial erosion that removed much of the Cretaceous record by being down-faulted in a linear graben. Study of these well-preserved fossil diatoms allows for a documentation of the assemblage, identification of potentially …
Complex Unicellular Microfossils From The 1.9 Ga Gunflint Chert, Canada, Ana L. González Flores
Complex Unicellular Microfossils From The 1.9 Ga Gunflint Chert, Canada, Ana L. González Flores
Electronic Thesis and Dissertation Repository
The presence of eukaryotic life during the early Paleoproterozoic has been a matter of debate because well-preserved fossils older than 1.8 Ga rarely exhibit eukaryotic cellular microstructures. In this study, microfossils from the 1.9 Ga Gunflint Chert were studied using the extended-focal-depth imaging technique, combined with scanning electron microscopy, resulting in recognition of three types of large (10–35 μm diameter) complex unicellular bodies (CUBs) and one type of “multicellular body” (< 50 μm diameter). The CUBs show the following eukaryotic cyst-like structures: (1) radially arranged internal strands similar to those in some acritarchs and dinoflagellates; (2) regularly spaced long tubular processes, stubby pustules, and/or robust podia on the cell surface; (3) reticulate cell-wall sculpturing such as pits, ridges, and scale-like ornaments; and (4) internal bodies that may represent membrane-bounded organelles. These morphological features provide strong evidence for the presence of protists in the late Paleoproterozoic.
Among the three types of CUBs from the Gunflint microbiota, a new species, Germinosphaera gunflinta sp. nov., was recognized. This species has the diagnostic characteristics of Germinosphaera, such …