• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 9
  • 3
  • Tagged with
  • 14
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The mineralogy of glauconite,

Warshaw, Charlotte Marsh, January 1957 (has links)
Thesis (Ph. D.) - Pennsylvania State University, 1957. / Vita. Bibliography: leaves 139-143.
2

Mössbauer studies of iron in glauconite

Arnott, Robert Allen, January 1968 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
3

Deposition and diagenesis of Glauconite Sandstone, Berrymore-Lobstick-Bigoray area, South Central Alberta a study of physical chemistry of cementation /

Meshri, Indu D. January 1981 (has links)
Thesis (Ph.D.)--University of Tulsa, 1981. / Four folded enclosures in pocket. Bibliography: leaves 120-130.
4

The origin and distribution of glauconite from the sea floor off California and Baja California

Pratt, Willis Layton, January 1962 (has links)
Thesis (Ph. D. Geology)--University of Southern California. / Includes bibliographical references (leaves 236-242).
5

Investigation of Reactions between Glauconite and Carbon Dioxide, with Implications for Carbon Sequestration

Nguyen, Van Anh 10 August 2018 (has links)
The objective of this study was to develop a protocol to test the reactivity of glauconite, a Fe/Mg bearing aluminosilicate mineral, in carbon storage. A selected glauconite-rich sample from the Cambrian Riley Formation of Central Texas was used containing glauconite 38 wt%, quartz 58 wt%, and calcite 4 wt%. Ten experiments were conducted using two techniques where total pressure was: 1) controlled by delivering CO2 to a high-pressure apparatus; 2) kept at saturated vapor level in autoclaves. The treated glauconite samples were analyzed with Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (SEM), and X-ray Diffraction techniques (XRD). Although the reaction between glauconite and CO2 was not visible, calcite crystallized in solution when its pH exceeded the value of 6.88. The research provides a foundation to develop further investigations of rock reactions under CO2 saturated conditions.
6

Palaeoecology of the middle to late Cambrian Rogersville Shale, Conasauga Group, eastern Tennessee

Campbell, Leslie Ann January 2008 (has links)
Thesis advisor: Paul Strother / The Rogersville Shale of the Middle to Late Cambrian Conasauga Group was deposited on the margins of Laurentia, in what is now eastern Tennessee. Based on 21 thin section samples from the ORNL-Joy2, core five distinct microlithofacies are described, trace fossils characterized, and palynological data interpreted. This investigation concluded that the Rogersville Shale was deposited in a shallow, restricted marine or possibly estuarine environment that would have been exposed to terrestrial runoff. Previous work on the Conasauga Group placed deposition of the Rogersville Shale within an intercratonic basin in approximately 250m of water, perhaps significantly deeper. This investigation found that the Rogersville Shale was likely deposited in a lagoonal setting or restricted estuarine environment that had freshwater input. / Thesis (MS) — Boston College, 2008. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Geology and Geophysics.
7

Cool-water Carbonate Sedimentology and Sequence Stratigraphy of the Waitaki Region, South Island, New Zealand

Thompson, Nicholas Kim January 2013 (has links)
In the mid-Cenozoic, New Zealand underwent slow subsidence interspersed with unconformity development, however significant controversy exists around both the extent of submergence below sea level during this period of maximum drowning, as well as the causes of these unconformities. Detailed field observations, combined with extensive petrographic analyses, stable isotopes, cathodoluminescence, and thin section staining were used to develop lithofacies, depositional, and sequence stratigraphic models of the mid-Cenozoic succession in the Waitaki region, South Island, to address these controversies. Twelve facies types have been described for Late Eocene-Early Miocene sedimentary rocks, leading to the identification of two major (Mid Oligocene & Early Miocene) and one minor (Late Oligocene) sequence boundaries. Surtseyan volcanism in the east produced a palaeohigh, resulting in a submerged rimmed cool-water carbonate platform, with low-lying land to the west. This eastern palaeohigh developed karst during sea-level lowstands, which correlate with silty submarine bored hardgrounds in the west. Glauconitic and phosphatic facies deposited during early marine transgression suggest an authigenic factory supplied by terrigenous clays existed during lowered sea level that was progressively shut down in favour of a carbonate factory as sea level rose and terrigenous supply decreased. The eastern palaeohigh served to nucleate this carbonate factory by raising the sea floor above the influence of siliciclastic sediment supply and providing a shallow substrate for marine colonisation. The higher energy eastern facies display dissolution of aragonitic taxa, while deeper western facies retained an aragonitic assemblage. This early bathymetric high created a barrier to submarine currents, but was gradually reduced by erosion during subsequent lowstands. Calcareous facies were often subjected to minor seafloor cement precipitation to shallow burial diagenesis, while eastern facies developed some meteoric cement during subaerial exposure. Comparisons between sea-level change in the study area and the New Zealand megasequence indicate eustatic changes as the primary driver of water depth in the Waitaki region until the development of the modern plate boundary in the Early Miocene.
8

DEPOSITIONAL AND STRATIGRAPHIC SIGNIFICANCE OF MARINE, GREEN-CLAY, MINERAL FACIES IN THE LOWER-MIDDLE MISSISSIPPIAN BORDEN AND FORT PAYNE FORMATIONS, WESTERN APPALACHIAN AND EASTERN ILLINOIS BASINS, KENTUCKY

Udgata, Devi Bhagabati Prasad 01 January 2011 (has links)
Detailed study of strata associated with the glauconite-rich Floyds Knob Bed in the western Appalachian and eastern Illinois basins have corroborated previous interpretations that the unit is a widespread, largely synchronous marker horizon. However, in some areas there are multiple glauconite beds; in others a distinct bed is lacking, but the glauconite is dispersed throughout many beds, forming an interval rather than a distinct bed. In Kentucky and adjacent states, the Floyds Knob interval, in upper parts of the Lower-Middle Mississippian Borden-Grainger delta sequence and in lower parts of the Fort Payne carbonate sequence, was deposited at the end of loading-type relaxation during a flexural cycle in the Neoacadian (final) tectophase of the Acadian Orogeny. Tectonic influence, combined with a major late Osagean sea-level lowstand, created conditions that generated sediment starvation and shallower seas across widespread parts of the western Appalachian and eastern Illinois basins. In the absence of major sediment influx, glauconite was deposited uniformly across many major depositional settings, ranging from delta-platform to basinal environments. Especially important, however, is the newly reported occurrence of the Floyds Knob interval in basinal Fort Payne environments from south-central Kentucky, where it is represented by a thick, pelletal, glauconite-rich horizon that separates clastics at the base of the Fort. Payne Formation from carbonates at top. The study also provides the first-ever radiometric dating of the Floyds Knob glauconites, which suggests a late Osagean origin. These results support the existing biostratigraphic studies that point to a late Osagean origin for the Floyds Knob interval.
9

Glauconite as an indicator of sequence stratigraphic packages in a Lower Paleocene passive-margin shelf succession, Central Alabama

Udgata, Devi Bhagabati Prasad, January 2007 (has links) (PDF)
Thesis (M.S.)--Auburn University, 2007. / Abstract. Vita. Includes bibliographic references (ℓ. 91-96)
10

[en] CHEMICAL PROCESSING AND CHARACTERIZATION OF A GLAUCONITE CONCENTRATE IN ORDER TO SELECTIVELY PRODUCE POTASSIUM SULFATE / [pt] PROCESSAMENTO QUÍMICO E CARACTERIZAÇÃO DE UM CONCENTRADO DE GLAUCONITA VISANDO À PRODUÇÃO SELETIVA DE SULFATO DE POTÁSSIO

CARLOS LEONNY RAIMUNDO FRAGOSO 14 May 2019 (has links)
[pt] Íons de potássio (K+) são essenciais na nutrição das plantas e são, normalmente, fornecidos na forma de KCl ou K2SO4. Este cloreto de potássio é responsável por 90 por cento da quantidade de potássio oferecido pela indústria de fertilizantes. No entanto, alguns cultivos são sensíveis à presença de íons cloreto (Cl) ou exigem maior teor de enxofre, o que explica o interesse em fertilizantes contendo íons sulfato (SO42-). No contexto de um mercado de fertilizantes competitivo, a indústria está constantemente à procura de novos métodos para obtenção dos produtos desejados, assim como novas matérias-primas. Portanto, o concentrado mineral de glauconita pode ser visto como uma fonte potencial de matéria-prima para obtenção de Sulfato de Potássio, por ser este um mineral essencialmente constituído por óxidos e hidróxidos de Mg, Al, Si, Fe e K. Em geral, pode-se dizer que a glauconita tem um teor de potássio variando de 5 a 8 por cento de K2O, dando suporte à sua utilização em um processo de obtenção de K2SO4, para uso no enriquecimento de fertilizantes. Dentro dessa perspectiva, o trabalho proposto tem como objetivo apreciar o processamento químico de um concentrado de glauconita, baseado em uma rota que tem início numa digestão com H2SO4 seguida de separações seletivas. O trabalho também contempla a caracterização dos materiais envolvidos, tanto o concentrado inicial de glauconita bem como os produtos obtidos ao longo do processamento químico. Para isso foram utilizadas as técnicas de Microscopia Eletrônica de Varredura (MEV / EDS), Espectrometria de Infravermelho por Transformada de Fourier (FTIR), Difração de Raios X (XRD) e Fluorescência (FRX). Estudos preliminares indicam que a digestão com H2SO4 tem um comportamento seletivo em relação ao SiO2, que não é sensível ao ataque ácido. Desta forma, o produto resultante pode ser lavado com água e filtrado consecutivas vezes formando soluções ricas em Mg, Al, Fe e K, bem como os ânions de sulfato. Tais soluções foram, em seguida, submetidos a evaporações controladas, a fim de determinar as condições em que a precipitação seletiva de um precursor rico em K e Al (por exemplo, alúmen de potássio) seria viável. O material obtido foi calcinado a 800 graus C, de modo a estimular sua decomposição em K2SO4 e Al2O3. A separação final entre estes componentes foi levada a efeito por meio de solubilização seletiva com água, permitindo a separação do óxido insolúvel. Os resultados sugerem que a rota de processamento proposto caracteriza-se como um método em potencial para obtenção do K2SO4, de interesse para a indústria de fertilizantes, podendo ainda viabilizar a formação do Al2O3 que, preferencialmente, deve conter níveis baixos de ferro para ter uma eventual utilização, com atrativos ambientais, na indústria do alumínio. / [en] Potassium ions (K+) are essentials for plant nutrition and are, usually, supplied in the form of KCl or K2SO4. The former is responsible of 90 percent of the potassium amount offered by the fertilizer industry. However, some crops are sensitive to presence of chloride ions (Cl-) or require higher sulfur content, thereby keeping the interest in fertilizers with sulfate ions (SO42-). In the context of a competitive fertilizer market, the industry is constantly searching for new methods to obtain their desired products as well as new raw materials. Therefore, glauconite bearing ores can be seen as a potential source of raw material as this hydrate silicate mineral is essentially constituted by oxides and hydroxides of Mg, Al, Si, K and Fe. In general, it can be said that glauconita has a potassium content varying from 5 to 8 percent of K2O, encouraging its use in a process to obtain K2SO4 with fertilizers purposes. Within this perspective, the proposed work aims to appreciate the chemical processing of a glauconite concentrate based on a combined aqueous and pyro metallurgical route. The present work also incorporates the materials characterization of the received concentrate as well as of the obtained products by means of Scanning Electron Microscopy (SEM/EDS), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD) and Fluorescence (XRF). Preliminary studies have shown that H2SO4 digestion has a selective behavior towards SiO2 which is not sensible to the acid attack. It was also found that the resulting product can be washed with water forming solutions rich in Mg, Al, K and Fe as well as sulfate ions. These were then submitted to controlled evaporations in order to establish conditions in which the selective precipitation of a precursor rich in K and Al (e.g. potassium alúmens) is feasible. The obtained material was calcined at 800 degree C in order to stimulate decomposition in K2SO4 and Al2O3. The separation between these constituents was taken into effect through selective solubilization with water allowing the separation of the insoluble oxide. The results suggest that the proposed processing route characterize itself as a potential method to obtain K2SO4, of interest for the fertilizer industry, and Al2O3 which, in containing a small amount of iron, could be used, with environmental attractiveness, in the aluminum industry.

Page generated in 0.0364 seconds