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Articles 7351 - 7380 of 29940
Full-Text Articles in Geology
Geochemical Investigation Of Monogenetic Volcanoes From The Pribilof Islands, Bering Sea, Alaska, Clayton L. Reinier
Geochemical Investigation Of Monogenetic Volcanoes From The Pribilof Islands, Bering Sea, Alaska, Clayton L. Reinier
Graduate Theses/Dissertations
Small-volume basaltic magmas found at continental intraplate environments have not been as extensively studied compared to their polygenetic counterparts. Specifically, regions such as the Bering Sea basalt province, described as a diffuse igneous province, have commonly been overlooked. Assumptions that these systems are invoked by simple, single batches of magma has subsequently left a gap in understanding the processes responsible for primary magma generation away from plate boundaries with little tectonic influence. The following studies that constitute this thesis focus on an in-depth geochemical investigation at the crystal and sub-crystal scale to evaluate lithospheric mantle heterogeneities, processes that govern primary …
A 60- Year Record Of The Demotechnic Index Of States, 1960-2019, Gavin James Kellough
A 60- Year Record Of The Demotechnic Index Of States, 1960-2019, Gavin James Kellough
Graduate Theses and Dissertations
A country’s dependency on energy resources can be interpreted through the calculation of energy indices. The Demotechnic Index (DI) was used to determine the trajectory of energy efficiency of each state in the United States over the period 1960-2019. The DI serves as a measure of the energy intensity of states and a proxy for energy sustainability of each state.The DI is the ratio of total energy use to total metabolic energy demand of a population. Mathematically, DI = (E_T-E_M)/E_M E_T represents the total energy used (metabolic energy + technological energy in kilojoules annually, kJ/y), while EM represents the basic …
Factors Controlling Longshore Variations Of Beach Changes Induced By Hurricane Hermine Along Pinellas County Beaches, West-Central Florida, Wenhan Zhai
USF Tampa Graduate Theses and Dissertations
Hurricane Hermine, 2016, impacted the coast of west-central Florida and generated high waves superimposed on elevated wave levels which caused significant beach erosion. A total of 122 profiles, spaced about 300 m apart, were surveyed 2 weeks before and one week after the storm to examine the beach changes along three barrier islands along the coast of west-central Florida. including Sand Key, Treasure Island and Long Key. In order to investigates the longshore variations of beach/nearshore changes induced by storm, several parameters were defined and calculated including beach volume changes, berm height, beach width, foreshore slope, as well as sandbar …
Detrital Zircon U-Pb Geochronology Of Upper Mississippian Siltstone, Oklahoma And Arkansas, Linnea Johnson
Detrital Zircon U-Pb Geochronology Of Upper Mississippian Siltstone, Oklahoma And Arkansas, Linnea Johnson
Graduate Theses and Dissertations
Although Upper Mississippian strata have been characterized extensively using lithostratigraphy, sequence stratigraphy, and biostratigraphy across the North American midcontinent, the origin of the silt comprising the Meramec STACK (Sooner Trend Anadarko Basin, Canadian and Kingfisher counties) reservoirs of the Anadarko Basin in west-central Oklahoma and age equivalent units is not well understood, despite its economic importance as an unconventional petroleum reservoir. Previously published models have variously invoked fluvial, marine, and aeolian sediment transport for Upper Mississippian siltstone present along the paleo-shelf edge of the Laurentian craton. This study uses detrital zircon U-Pb geochronology and grain morphology, handheld x-ray fluorescence (hXRF) …
Machine Learning Applied To A Modern-Pleistocene Petrographic Dataset: The Global Prediction Of Sand Mineralogy (Gloprsm) Model, Isaac Johnson
Machine Learning Applied To A Modern-Pleistocene Petrographic Dataset: The Global Prediction Of Sand Mineralogy (Gloprsm) Model, Isaac Johnson
Graduate Theses and Dissertations
Petrography has long been used as a tool to decipher the sedimentary provenance of sand and sandstone from the relative proportions of framework grain types. Petrographers have also related the proportions of quartz (Q), feldspar (F), and lithic (L) grains to the processes that form and modify sediments within sediment routing systems. This past work has shown that factors including source lithology, climate, transport history, and tectonism work in concert to modify the framework mineralogy of sand. However, there is a lack of a quantitative understanding of the interactions and feedbacks between these factors and how they modify sand mineralogy. …
The Morphodynamic Interaction Of River Deltas And Their Marshes, Kelly M. Sanks
The Morphodynamic Interaction Of River Deltas And Their Marshes, Kelly M. Sanks
Graduate Theses and Dissertations
Globally, many of the largest river deltas contain vast marsh platforms that are currently threatened due to a combination of anthropogenic alterations to rivers and increasing relative sea level rise. Restoration and management plans for river deltas depend on optimizing riverine sediment accumulation in marsh platforms. However, the accumulation of organic material in marsh platforms is often neglected in predictive models and the interaction of ecogeomorphic processes governing marsh accumulation with the physical processes governing river delta growth is poorly understood.
Herein, I investigate this complex relationship through a combination of field and experimental studies. I show that in coastal …
Lithological And Geochemical Characterization Of Ramp Sediments And A Depositional Model Of The Ordovicain Garden City Formation, Northeastern Utah, Kenneth W. Kehoe
Lithological And Geochemical Characterization Of Ramp Sediments And A Depositional Model Of The Ordovicain Garden City Formation, Northeastern Utah, Kenneth W. Kehoe
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The Ordovician Garden City Formation is a mostly marine limestone rock formation deposited in what is known today as the Northern Utah Basin in North America ~485.5 million years ago. Previous research on the Pogonip Group, a time equivalent rock formation located in the Ibex Basin south of the Northern Utah Basin, has identified nine cycles of sea-level fall and rise. However, these nine sea-level cycles have proven difficult to identify within the Garden City Formation due to the limited contrast between rock types within the rock formation. Previous research on the Garden City has approximated these sea-level cycles through …
Speleogenesis In A Lens Of Metamorphosed Limestone And Ankerite: Ochtiná Aragonite Cave, Slovakia, Pavel Bella, Pavel Bosák, Petr Pruner, Helena Hercman, Katarína Pukanská, Karol Bartoš, Ľudovít Gaál, Dagmar Haviarová, Peter Tomčík, Šimon Kdýr
Speleogenesis In A Lens Of Metamorphosed Limestone And Ankerite: Ochtiná Aragonite Cave, Slovakia, Pavel Bella, Pavel Bosák, Petr Pruner, Helena Hercman, Katarína Pukanská, Karol Bartoš, Ľudovít Gaál, Dagmar Haviarová, Peter Tomčík, Šimon Kdýr
International Journal of Speleology
The Ochtiná Aragonite Cave (Western Carpathians) represents an unique natural phenomenon. It originated under particular lithological and hydrogeological conditions of the Ochtiná Karst in which several isolated lenses of Paleozoic crystalline limestone (marbles), partly metasomatically altered to ankerite, are enclosed by phyllites. Meteoric water seepage through non-carbonate rocks dissolved limestone and caused the oxidation of ankerite to Fe oxyhydroxides. Carbon dioxide produced during ankerite oxidation enhanced limestone dissolution. The maze cave consists of parallel fault-controlled linear passages and chambers interconnected by transverse horizontal passages. Phreatic and epiphreatic solution morphologies resulted from slowly moving or standing water. These include flat ceilings …
Community College Geoscience Faculty Perspectives On Critical Thinking Instructional Tools, Mariela Salas Bao
Community College Geoscience Faculty Perspectives On Critical Thinking Instructional Tools, Mariela Salas Bao
Dissertations and Theses
Research has shown that modern courses and programs designed to foster critical thinking vary in both content and delivery, in turn leading to differences in their effectiveness. Few studies have investigated critical thinking among nontraditional students at community colleges taking STEM courses, especially within the geosciences. Furthermore, such research has focused primarily on the students with few if any studies involving faculty. This study examined the perceptions held by community college geoscience faculty regarding critical thinking and how such perceptions influenced their choice of instructional strategies. This study used a basic qualitative methodology and a maximum variation sampling to select …
A New Phosphatized Ophiuroid From The Lower Triassic Of Nevada And Its Position In The Evolutionary History Of The Ophiuroidea (Echinodermata), Ben Thuy, Vivienne Maxwell, Sara B. Pruss
A New Phosphatized Ophiuroid From The Lower Triassic Of Nevada And Its Position In The Evolutionary History Of The Ophiuroidea (Echinodermata), Ben Thuy, Vivienne Maxwell, Sara B. Pruss
Geosciences: Faculty Publications
The Lower Triassic fossil record of brittle stars is relatively rich, yet most records published to date are based on poorly preserved or insufficiently known fossils. This hampers exhaustive morphological analyses, comparison with recent relatives or inclusion of Early Triassic ophiuroid taxa in phylogenetic estimates. Here, we describe a new ophiuroid from the Lower Triassic of Nevada, preserved as phosphatized skeletal parts and assigned to the new taxon Ophiosuperstes praeparvus gen. et sp. nov Maxwell, V. Pruss. S.B. This unusual preservation of the fossils allowed for acid-extraction of an entire suite of dissociated skeletal parts, including lateral arm plates, ventral …
Revisiting The Cretaceous-Paleogene Boundary In Western Kentucky, Usa, Jarred Asselta
Revisiting The Cretaceous-Paleogene Boundary In Western Kentucky, Usa, Jarred Asselta
Scholars Week
This study revisits a Cretaceous-Paleogene (K-Pg) sedimentary section in western Kentucky to determine the nature of this boundary and the depositional environments. Although previous pollen work identified the boundary over four decades ago, to our knowledge no work has been carried out at this important K-Pg boundary site. A combination of stratigraphy and sedimentology were used to characterize the section in detail. Bulk and oriented samples were collected for grain-size, geochemical, and petrographic analysis. We relocated the site and measured 1.5m of section that includes the K-Pg boundary. Four distinct units were identified and from base to top of section …
Detailed Structural And Stratigraphic Analysis Of The Salt-Sediment Interactions On Top Of The Wheeler Dome Salt Tongue, Mississippi Canyon Area, Gulf Of Mexico, Ryan Jaska
Electronic Theses and Dissertations
The Mississippi Canyon is in the northeastern part of the Gulf of Mexico, south of the state of Mississippi. In this area, there are many different salt structures present including salt canopies, diapirs, and salt pillows. The Callovian aged Louann Salt covers this area and is the cause of many of the salt structures and structures of the overlying formations seen in Gulf of Mexico today. Salt is mobile when subjected to stress from overlying sediment and gravity. Stress will force the salt to not only move upward, but to also move down slope deeper into adjacent basins through the …
Mgrre_Pureoilscouttickets_Miller, Martin_2_21127128770000, Mgrre
Mgrre_Pureoilscouttickets_Miller, Martin_2_21127128770000, Mgrre
Legacy Scout Tickets from Pure Oil Company
No abstract provided.
Mgrre_Pureoilscouttickets_Miller, Martin H_1_21127127420000, Mgrre
Mgrre_Pureoilscouttickets_Miller, Martin H_1_21127127420000, Mgrre
Legacy Scout Tickets from Pure Oil Company
No abstract provided.
Mgrre_Pureoilscouttickets_Neumann, Oscar P._1_21127119360000, Mgrre
Mgrre_Pureoilscouttickets_Neumann, Oscar P._1_21127119360000, Mgrre
Legacy Scout Tickets from Pure Oil Company
No abstract provided.
Mgrre_Pureoilscouttickets_Kyncl, Jos & Marie_1_21127118890000, Mgrre
Mgrre_Pureoilscouttickets_Kyncl, Jos & Marie_1_21127118890000, Mgrre
Legacy Scout Tickets from Pure Oil Company
No abstract provided.
The Birth And Incision History Of The San Juan River In The Past 5 Ma, Micael T. Albonico
The Birth And Incision History Of The San Juan River In The Past 5 Ma, Micael T. Albonico
Earth and Planetary Sciences ETDs
This study addresses the evolution of the San Juan River system and its confluence with the Colorado River, ~ 100 km above the regionally important Lees Ferry knickzone. The San Juan River is a 600-km-long continental-scale tributary of the Colorado River. From its headwaters in the San Juan Mountains in Colorado, the San Juan River flows across the Colorado Plateau, and into the Colorado River upstream of Grand Canyon. Published apatite fission track and apatite (U-Th)/He thermochronologic data show that rocks in Marble Canyon, as well as in middle and upper reaches of the San Juan River, were >75 °C …
Mgrre_Pureoilscouttickets_Newman, Lena C._1_21127113670000, Mgrre
Mgrre_Pureoilscouttickets_Newman, Lena C._1_21127113670000, Mgrre
Legacy Scout Tickets from Pure Oil Company
No abstract provided.
Mgrre_Pureoilscouttickets_Vander Leest, Joe_1_21127112940000, Mgrre
Mgrre_Pureoilscouttickets_Vander Leest, Joe_1_21127112940000, Mgrre
Legacy Scout Tickets from Pure Oil Company
No abstract provided.
Mgrre_Pureoilscouttickets_Vaughn, Thad_1_21127111290000, Mgrre
Mgrre_Pureoilscouttickets_Vaughn, Thad_1_21127111290000, Mgrre
Legacy Scout Tickets from Pure Oil Company
No abstract provided.
Soil Accretion And Mass Accumulation In A Scrub And Fringe Mangrove Forest In Biscayne Bay, Florida, Jessica A. Jacobs
Soil Accretion And Mass Accumulation In A Scrub And Fringe Mangrove Forest In Biscayne Bay, Florida, Jessica A. Jacobs
USF Tampa Graduate Theses and Dissertations
This study estimated soil accretion and mass (organic carbon (OC), total nitrogen (TN), and total soil) accumulation in a scrub and fringe mangrove forest in Biscayne Bay, FL, to assess how forests of different morphologies (scrub vs. fringe) have kept pace with recently accelerating rates of sea-level rise. Accretion rates (AR) were estimated using the Constant Initial Concentration (CIC) model of lead-210 deposition and it was determined that the scrub forest has accreted at 1.3 ± 0.2 mm yr-1 over 75 years and the fringe forest at 2.8 ± 0.4 mm yr-1 over 92 years. The fringe forest estimate met …
Mgrre_Pureoilscouttickets_Bowen, George W._1_21127120500000, Mgrre
Mgrre_Pureoilscouttickets_Bowen, George W._1_21127120500000, Mgrre
Legacy Scout Tickets from Pure Oil Company
No abstract provided.
Spatial Variations Of Stochastic Noise Properties In Gps Time Series, Xiaoxing He, Michael Simon Bos, Jean-Philippe Montillet, Rui Fernandes, Timothy I. Melbourne, Weiping Jiang, Wudong Li
Spatial Variations Of Stochastic Noise Properties In Gps Time Series, Xiaoxing He, Michael Simon Bos, Jean-Philippe Montillet, Rui Fernandes, Timothy I. Melbourne, Weiping Jiang, Wudong Li
Geological Sciences Faculty Scholarship
The noise in position time series of 568 GPS (Global Position System) stations across North America with an observation span of ten years has been investigated using solutions from two processing centers, namely, the Pacific Northwest Geodetic Array (PANGA) and New Mexico Tech (NMT). It is well known that in the frequency domain, the noise exhibits a power-law behavior with a spectral index of around −1. By fitting various noise models to the observations and selecting the most likely one, we demonstrate that the spectral index in some regions flattens to zero at long periods while in other regions it …
Interspecific And Local Variation In Tern Chick Diets Across Nesting Colonies In The Gulf Of Maine, Keenan Yakola, Adrian Jordaan, Stephen Kress, Paula Shannon, Michelle D. Staudinger
Interspecific And Local Variation In Tern Chick Diets Across Nesting Colonies In The Gulf Of Maine, Keenan Yakola, Adrian Jordaan, Stephen Kress, Paula Shannon, Michelle D. Staudinger
United States Geological Survey: Staff Publications
The Gulf of Maine, USA is home to four colonial co-nesting tern species: Least Tern (Sternula antillarum), Common Tern (Sterna hirundo), Arctic Tern (Sterna paradisaea), and the federally endangered Roseate Tern (Sterna dougallii). Over three decades of visual observations of chick provisioning were compiled for a comparative dietary study in the region, including the first detailed descriptions of Least and Roseate Tern chick diets. Three prey groups comprised the majority of chick diets among tern species between 1986–2017: hake (Urophycis spp. or Enchelyopus cimbrius) 28–37% frequency of occurrence (FO), sand lance …
Revisiting Darwin’S Little Pond As A Method To Liberate Phosphorus From Apatite Under Prebiotic Hadean Earth Conditions, Jennifer Lago
Revisiting Darwin’S Little Pond As A Method To Liberate Phosphorus From Apatite Under Prebiotic Hadean Earth Conditions, Jennifer Lago
USF Tampa Graduate Theses and Dissertations
Phosphorus is an essential element for life as we know it. Phosphorus, mainly in the form of phosphate, is key to biologic functions such as genetic material, energy production, and cellular framework. As phosphorus is key to so many important biological functions it is of no wonder the question of how phosphorus was incorporated into life initially is a fundamental question in how life began.
During this time a prebiotic phosphorus source would need to have originated in rock, as phosphorus has not volatile source on Earth. The most prevalent mineral source on a prebiotic Earth would likely have been …
Mgrre_Pureoilscouttickets_State Of Michigan_1_21127099460000, Mgrre
Mgrre_Pureoilscouttickets_State Of Michigan_1_21127099460000, Mgrre
Legacy Scout Tickets from Pure Oil Company
No abstract provided.
Mgrre_Pureoilscouttickets_Biegalle, Louis Et Ux_1_21127097150000, Mgrre
Mgrre_Pureoilscouttickets_Biegalle, Louis Et Ux_1_21127097150000, Mgrre
Legacy Scout Tickets from Pure Oil Company
No abstract provided.
Mgrre_Pureoilscouttickets_Benjamin, Emma & Michigan Trust Company_1_21127091500000, Mgrre
Mgrre_Pureoilscouttickets_Benjamin, Emma & Michigan Trust Company_1_21127091500000, Mgrre
Legacy Scout Tickets from Pure Oil Company
No abstract provided.
Mgrre_Pureoilscouttickets_Swett, Edward R._1_21127083310000, Mgrre
Mgrre_Pureoilscouttickets_Swett, Edward R._1_21127083310000, Mgrre
Legacy Scout Tickets from Pure Oil Company
No abstract provided.
Mgrre_Pureoilscouttickets_Branstrom, H._1_21127081840000, Mgrre
Mgrre_Pureoilscouttickets_Branstrom, H._1_21127081840000, Mgrre
Legacy Scout Tickets from Pure Oil Company
No abstract provided.