Xenolith-bearing orthogneiss of Amazonian affinity discovered in the Dellwood quadrangle in the Blue Ridge basement complex represents the oldest crustal component of the southern Appalachians (1.33 – 1.37 Ga: Quinn, 2012). New U-Pb zircon ages for migmatitic paragneiss of the Cartoogechaye terrane exposed in the Dellwood quadrangle reveal two unique detrital zircon age signatures that indicate either a local eastern Laurentian margin source or an exotic source. Detailed mapping, whole rock geochemistry, and U-Pb zircon geochronology were conducted to determine whether this exotic crustal component extends farther south into the Hazelwood 7.5” quadrangle. Lithological similarities exist between paragneisses in the Dellwood quadrangle and those in the Hazelwood quadrangle. However, the increase in proportion of leucosome and polyphase folding prevent direct correlation of lithologies between the areas. Whole rock major element compositions overlap the composition of basement orthogneisses. Zircon ages of six paragneiss samples reveal multiple detrital zircon age modes that are dominated by two Grenville modes at ~1050 and 1150 Ma. Minor zircon populations exist at ~450 – 480, 700 – 900, and 1300 – 1500 Ma. Age distributions and compositional trends are evidence that the protolith of the paragneiss in the Hazelwood quadrangle was Neoproterozoic rift sediments with a dominant Laurentian margin source.

A series of late Tertiary rhyolitic and dacitic flows, domes, and minor pyroclastic rocks form an elongate volanic mass along the northwestern Utah-northeastern Nevada border . The structure of the flow banding and the linear arrangement of vents indicate that the mass represents a multi-sourced extrusive complex which erupted through many fissure-type conduits. A 39 km2 area at the southern end of the mass was studied in detail in order to gain a better understanding of the eruptive nature and history of these Tertiary volcanic rocks. Age dating reveals that volcanism in the study area was episodic, and covered a period of at least 4 to 5 million years. The silicic volcanic rocks in the study area are similar chemically and mineralogically to other eruptive units within the Rhyolite Mts., which range from dacite (Si0 2 69%) to high-silica rhyolite (SiOz 75-77%). They also exhibit chemical characteristics similar to other silicic volcanic rocks of bimodal association in the western United States. Two-feldspar high-K rhyolite is the dominant volcanic rock in the study area, commonly found overlying rhyolitic vitric tuffs and agglomerates. Rhyolite from the southern portion of the study area is dated at 7.6 to 8.6 m.y.b.p. Dacitic samples contain phenocrysts of plagioclase, quartz, biotite, hornblende, and orthopyroxene. Dacitic volcanism is dated at 12.4 m.y.b.p. By analogy with other "bimodal" volcanic fields in the western U.S., it is assumed that these si 1 icic magmas are products of partial melting of crustal rocks. Evidence from a least squares differentiation model, along with the overall geochemical characteristics, indicates crystal fractionation as the dominant mechanism for the transition from dacite to rhyolite, with plagioclase as the dominant fractionating phase.

The Cartoogechaye terrane (CT) is an enigmatic migmatite terrane within the Central Blue Ridge province of the southern Appalachians. Previous work identified exotic Pb isotope compositions within the CT (Quinn, 2012). More recent studies that mapped the extent of potentially exotic metaigneous lithologies yield U-Pb zircon ages consistent with a native Laurentian margin metasedimentary origin (Larkin, 2016). This study focused on the possible extent of similar lithologies in the Clyde quadrangle and provides further constraints on the crustal affinity of the CT. The Clyde quadrangle consists of four distinct lithologic packages: the CT, Ashe metamorphic suite, Great Smoky Group, and Grenville basement. Five samples within the Clyde quadrangle and one sample from Wayah Bald quadrangle were collected for detrital zircon (DZ) U-Pb geochronology and whole rock geochemistry for comparison similar anlayses from other bedrock units in the region. Dominant DZ age modes consist of the Grenville doublet (1050 Ma and 1150 Ma) or a modified version of it. Minor age modes exist at ~450 Ma, 600-750 Ma, and 1300-1550 Ma. Zircons for all but one sample display heterogeneous external and internal cathodoluminescence morphologies, consistent with a sedimentary protolith for the paragneisses. Whole rock compositions are consistent with weathering of and derivation from a local basement source. U-Pb age data are most consistent with an eastern Laurentian sedimentary provenance for five samples. The presence of 450-460 Ma grains is most consistent with high-grade Taconian regional metamorphism. The lack of a major Shawinigan age mode and zircon morphology for ca. 980-1050 Ma metamorphic zircons indicate that sample CLY16-1 is a syn-orogenic metasediment within the Grenville basement underlying the CT.

The Harrington Peak Quadrangle is located within the Caribou National Forest of southeast Idaho. Within this quadrangle are outcrops of olivine trachyte of Pliocene(?) age overlying sedimentary rocks of Mississippian to Tertiary age. The region contains thrust faults and later normal faults (generally trending north-south} formed during Basin and Range extension. The Largest outcrop of olivine trachyte (approximately1 1/2 X 3 km) probably formed as the result of a fissure eruption. Two other outcrop areas show evidence of being sites of local extrusion. Whole-rock chemical analyses revealed the olivine trachyte to have moderate amounts of SiO2 and Al2O3, high MgO and CaO, and K2O in excess over Na2O (approximately 2:1). Mineralogical characteristics include microphenocrysts of Mg-rich olivine and diopsidic augite in a groundmass of Ba-rich sanidine, diopsidic augite, Fe-Ti oxides, and less commonly phlogopite and/or plagioclase. The olivine trachyte closely resembles the ciminites from the Viterbo region of Italy and has some petrological and mineralogical similarities to many other continental potassic volcanic rocks. The olivine trachyte may have formed by partial melting of a heterogenous mica peridotite mantle source enriched in incompatible elements during a previous tectonic event.

Pomona College has professed a commitment to sustainable leadership and decreased water use, exemplified by shifts to garden areas with native landscaping. However, the central college green space, Marston Quadrangle, was renovated in the summer of 2012 and only a few native plants were added to the landscape. In this thesis, I explore Pomona’s Marston Quadrangle as a visual and symbolic space, attempting to better understand the intentions of the landscaped area. I first briefly examine recent campus dialogue surrounding sustainability, water issues, and native landscaping. Then, I look at the history and architectural iconography Marston Quadrangle is steeped in, as well as some of the ideas the architects and landscapers had. I found that Marston Quadrangle is deeply tied to Pomona College’s history and identity, representing the ways in which the college tried to establish itself as on par with the schools of the East coast and England. Attempts to renovate the Quadrangle have placed a priority on restoring the vision of Ralph Cornell, the landscape architect, when it is clear that late in his life he regretted the non-native landscaping decisions he had made. I conclude that Marston Quadrangle no longer serves its purpose of establishing Pomona College as unique and works against the college’s sustainability goals. In light of this, I make suggestions for planting changes that would allow the iconography of the architecture to interact with native plantings, creating a deeply symbolic gesture of sustainable leadership and uniquely Southern California identity.

The Wattis 7.5 Minute Quadrangle is located in central Utah, in the transition zone between the Basin and Range province and the Colorado plateau. Two small grabens, located in the quadrangle, are the easternmost evidence of Basin and Range faulting. Sedimentary units exposed are mainly Cretaceous in age and deposited in the Western Cretaceous Interior Seaway. This area is of economical importance due to its large coal deposits, coal bed methane, and groundwater. The Wattis Quadrangle provided an ideal opportunity to test, at a small scale, the applicability of a new groundwater model for stratified mountainous terranes. Water samples had 14C ages ranging from modern to 10,000 ± 500 years. Stable isotopes of oxygen and hydrogen showed that recharged precipitation fell when climate conditions were close to modern, or slightly colder. Three groundwater systems consist of one shallow groundwater system in the North Horn Formation, and two deeper aquifers located in the Blackhawk Formation and the Star Point Sandstone. Water in the North Horn Formation is modern, whereas the Blackhawk Formation and Star Point Sandstone waters are mixed systems, having tritium concentrations between 3 and 4 T.U., and 14C ages between 7,000 and 10,000 years. Geochemical modeling shows that there are no plausible reaction paths to evolve the North Horn Formation waters into waters contained in underlying units. Thus, water entering the top of the plateau does not flow through the stratified rocks to exit at its base. Instead, the waters represent discrete perched systems at various stratigraphic levels. The Star Point Sandstone has three parasequences with a single sequence boundary. The deposits show normal marine conditions containing lower shoreface biota of Skolithos and Ophiomorpha overlain by middle shoreface sedimentary structures. The Star Point Sandstone deltaic parasequences likely prograded into the basin during pulses of thrusting from the Sevier Orogeny. The Emery Sandstone Member of the Mancos Formation contains three parasequences all located in the lower shoreface, and also exhibits the normal marine biota of Skolithos and Ophiomorpha. The Emery Sandstone reflects density currents caused by major storm events, including Bauma C and D depositional structures. Thick sandstone bodies are restricted to paleochannels.

Geologic structures within the Birdseye 7.5 minute quadrangle Utah County, Utah have been related by previous workers to both the Jurassic Arapien Shale diapirism and to the mid-Cenozoic extensional collapse of the Charleston-Nebo Thrust. Whichever model proves valid, it will have implications for oil exploration and interpretation of the subsurface geologic structure in the region. A detailed map of the quadrangle was constructed to better constrain which mechanism was responsible for the deformation. Exposures of Arapien Shale near, and within the Birdseye quadrangle show no evidence of diapiric movement. Arapien involvement in the deformation of Tertiary rocks in the center of the quadrangle is therefore unlikely. Changes in the pattern of sedimentation of Eocene age rocks suggest a change in tectonics during this time. Restoration of the Eocene strata shows that the most plausible mechanism for this deformation is extension along reactivated thrusts in the Arapien Shale, Thaynes Formation, and Woodside Shale, related to Basin and Range extension. The Moroni Formation, a prominent Tertiary volcanic unit present throughout the Birdseye quadrangle, has been used to justify Eocene extension. Deformation with the formation was found to be present only along the Thistle Canyon normal fault, constraining movement along the fault to the Eocene and later. Dip and facies relationships present within the formation mainly are a result of paleotopography rather than extension. Several distinctive units were mapped within the formation, including lahar and fluvial deposits, as well as two different ash-flow tuffs. A depletion in nickel and chromium, an unusually ferroan composition, and distinctive Fe/Ti ratios suggest that the volcaniclastic rocks of the Moroni Formation are similar to volcanic rocks in the Slate Jack Canyon and Goshen quadrangles which lie about 35 km to the west. This implies that the ignimbrites and volcanic clasts in the Moroni Formation were sourced from the East Tintic volcanic center. It further implies that any mid-Tertiary extension between the East Tintic center and the Birdseye quadrangle did not create barriers to sedimentation and was limited in extent.

Cette thèse d'habilitation présente une synthèse de contributions dans le domaine du traitement numérique de la géométrie sous la forme de concepts et d'algorithmes pour la reconstruction de surfaces, l'approximation de surfaces, le remaillage quadrangle de surfaces et la génération de maillages.

Historical topographic maps are valuable resources for studying past landscapes, but they are unsuitable for geospatial analysis. Cartographic map elements must be extracted and digitized for use in GIS. This can be accomplished by sophisticated image processing and pattern recognition techniques, and more recently, artificial intelligence. While these methods are generally effective, they require high levels of technical expertise. This study presents a straightforward method to digitally extract historical topographic map elements from within popular GIS software, using new and rapidly evolving toolsets. A convolutional neural network deep learning model was used to extract elevation contour lines from a 1940 United States Geological Survey (USGS) quadrangle in Sevier County, TN, ultimately producing a Digital Elevation Model (DEM). The topographically derived DEM (TOPO-DEM) is compared to a modern LiDAR-derived DEM to analyze its quality and utility. GIS-capable historians, archaeologists, geographers, and others can use this method in research and land management.

Made available in DSpace on 2015-03-26T12:34:04Z (GMT). No. of bitstreams: 1 01 - Capa_Abstract.pdf: 55603 bytes, checksum: 3a372969ed83a2d08c9602bc879b314d (MD5) Previous issue date: 2008-03-07 / Fundação de Amparo a Pesquisa do Estado de Minas Gerais / The present work presents the results of an extensive laboratory test study for the characterization of the behavior of a dolomitic phyllite under unsaturated conditions. This rock type is commonly found at Iron Quadrangle area, Brazil and is well known for its high anisotropy and weatherability. These properties impose a distinct behavior as sound rock changes to very to highly weathered materials in several months, with severe influence on its geotechnical properties. Eight undisturbed samples were collected in two open mine pits belonging to Vale (four at Pico mine and four at Capitão do Mato mine). Both mineralogical and geotechnical characterization of these material were done. Suction curves were determined through filter paper technique. Both unsaturated strength envelope and verification of suction curves were determined through empirical method. Resulting data was used into a slope stability study of a typical geological section from Pico mine, in order to evaluate its influence over safety. Use of other models and procedures is suggested to subsidy future discussion on risk analysis of open pit mining for this particular region. / Este trabalho apresenta os estudos desenvolvidos para a caracterização do filito dolomítico presente na região do Quadrilátero Ferrífero, Minas Gerais, Brasil, com o objetivo de investigar seu comportamento em taludes de mineração para a condição não saturada. O filito dolomítico se caracteriza pela sua elevada anisotropia, em função da presença de uma foliação bem marcada e pela também elevada alterabilidade que faz com que materiais classificados como sãos, passem, em alguns meses, a materiais muito a extremamente alterados, o que piora sobremaneira suas propriedades geotécnicas. Quando muito alterado é constituído por lentes de material argiloso e lentes de areia. A amostragem constou de oito blocos indeformados, sendo que quatro foram retirados da Mina do Pico, localizada em Itabirito/MG e quatro blocos da Mina Capitão do Mato, localizada em Nova Lima/MG, ambas pertencentes à Companhia Vale do Rio Doce. Foram realizados ensaios de caracterização geotécnica e mineralógica e determinação das curvas de sucção por meio da técnica do papel filtro. Para a determinação da envoltória de resistência não saturada e verificação das curvas de sucção foram utilizados modelos empíricos. A partir dos resultados obtidos foi analisada a estabilidade dos taludes de uma seção típica, considerando a influência sobre os níveis de segurança obtidos. A utilização de outros modelos e procedimentos é sugerida com o objetivo de fornecer subsídios para futuras discussões sobre tomadas de decisão e análises de risco para os empreendimentos localizados nesta região em particular.