Master of Science / Department of Geology / Charles G. Oviatt / The Dyer Mountain quadrangle, located in Utah approximately 200 km east of Salt Lake City and 20 km north of Vernal, lies on the south flank of the east-west trending Uinta anticline. The topography of the area varies from mountain peaks to deep canyons, with rolling hills of uplands in between. The elevation in the quadrangle ranges from 3124 m (10248 ft) at the top of Dyer Mountain to 1835 m (6020 ft) at the lowest point of Big Brush Creek. Most of the northern portion of the quadrangle is vegetated by aspens and pines, whereas the southern part of the quadrangle is covered with sagebrush and grasses. Due to its location on the anticline, the quadrangle contains bedrock that dips gently to the south and southeast. The ages of the rocks within the quadrangle range from the Precambrian Uinta Mountain Group to the Quaternary and Tertiary gravels. Also present are the following formations: Cambrian Lodore; Mississippian Madison, Doughnut, and Humbug; Pennsylvanian Round Valley and Morgan; Pennsylvanian to Permian Weber; Permian Meade Peak Member of the Phosphoria and Franson Member of the Park City; and various Quaternary sediments. The Lodore Formation and the Madison Limestone rest on major unconformities, and the Quaternary and Tertiary gravels overlie the Gilbert Peak erosion surface. The Uinta anticline and southerly dip of the Proterozoic and Paleozoic rocks are a result of Late Cretaceous uplift during the Laramide orogeny; Tertiary rocks within the area show little to no deformation. Limestone and various types of ores have been mined in the quadrangle, and phosphorous is currently being mined for fertilizer production. Several landslides, common at the juncture of the Quaternary and Tertiary gravels and Permian shales, were identified within the quadrangle. An anticline and syncline, trending northwest to southeast, lie in the southeast portion of the quadrangle and transect Big Brush Gorge. Geologic hazards of the area include landslides, erosion and failure of road grades, and cliffs near trails. The karst topography of the area presents dangers of sink holes, and evidence of ceiling collapse is present within Big Brush Cave, a popular destination for tourists and cavers.

Detailed geologic mapping of the Deseret Peak East 7.5' Quadrangle yields new interpretations regarding the stratigraphy of the Oquirrh Basin, fault and fold geometry, and structural evolution of the region. The Stansbury Range consists of the north-southtrending Deseret anticline. Basal Mississippian units rest unconformably on Cambrian beds in the central part of the range. Paleozoic uplift, Mesozoic contraction, and Cenozoic extension have created a series of broad folds, large thrust faults, and several normal faults. The area is dominated by bedrock springs, with the presence of abundant and thick Quaternary deposits unrelated to Pleistocene glaciation, burying drainages, and mantling hillslopes. The influence of bedrock on groundwater flow paths and stream baseflow is suggested by local anecdotal reports that high snowfall in the Deseret Peak region generates high discharge ten miles south in Clover Creek, though they are not in the same drainage basin.

The Tugaloo terrane in the eastern Blue Ridge, located in the high-grade southern Appalachian crystalline core,contains small internal basement massifs, the Neoproterozoic Tallulah Falls Formation, and Paleozoic granitoid plutons. Detailed geologic mapping in the Lake Toxaway and eastern Big Ridge quadrangles was done to better understand the regional tectonic history. Whole-rock geochemistry was used to determine similarities between the augen phase of the 1.15 Ga Toxaway Gneiss and the 1.15 Ga Wiley Gneiss of northeastern Georgia. The study found that all eastern Blue Ridge orthogneisses are similar and probably share a source. The previously identified Whiteside, Looking Glass, and Pink Beds plutons, and the newly identified Horseshoe Rock and Round Mountain plutons were also characterized. All plutons are low-K, catazonal granodiorites and trondhjemites that plot as volcanic arc or syncollisional granites on tectonic discrimination diagrams. The Looking Glass, Pink Beds, and Round Mountain plutons were dated using U-Pb SHRIMP zircon geochronology, and their ages are 333 + 16 Ma, 371.3 + 4.2 Ma, and 342.5 + 2.4 Ma, respectively. Zircon saturation temperature estimates for these plutons, and a Whitney and Stormer two-feldspar estimate for the Round Mountain pluton, indicate that they intruded at 700-800° C. Whole-rock geochemistry was used to constrain the origin of amphibolites and hornblende gneisses around the Toxaway dome. One sample was a metabasalt with MORB composition, like other eastern Blue Ridge samples. Two other samples have a metasedimentary protolith . Migmatitic aureoles found in the amphibolite facies rocks around the Whiteside, Looking Glass, and Horseshoe Rock plutons are syn-intrusional and represent a zone of contact metasomatism. The new pluton ages constrain the regional deformation history. At least 6 deformations are recognized in the eastern Blue Ridge. Dominant regional foliation is traditionally attributed to the second event (~466 Ma). However, foliations measured within all plutons are identical to foliations measured in the surrounding rock, indicating that foliations had to form after the youngest pluton intruded (~333 Ma), and that Alleghanian deformation was dominant in this region. These observations do not explain cross-cutting relationships observed around older plutons and raise new questions about southern Appalachian tectonics.

Groundwater flow through fractured karst conduit systems can be complex and difficult to diagnose. This project explores the role of geologic structures that influence the location of recharge points, flow paths, velocities, and discharge locations within Morrell Cave and at the resurgence of Morrell Spring, both of which are located near the city of Bluff City, TN. Understanding of the groundwater sources and flow paths in the Bluff City area will allow future researchers to more readily identify sources of pollution and better resolve local agricultural well drawdown conflicts among residents. The objectives of this project are to: 1) identify the active allogenic recharge sources of Morrell Spring, the largest known spring in the Bluff City area; 2) delineate a springshed for Morrell Spring and; 3) diagnose the structural controls for groundwater flow paths to Morrell Spring. It was found that surface streams flowing across the Sevier Shale on the northern slope of Holston Mountain enter the subsurface karst system through swallets along the Sevier shale and the Jonesboro Limestone contact. Once underground the water flows to the NW following 2 dominant joint sets until it reaches the NE/SW oriented fault line along which Morrell Cave has formed. Upon entering the cave the groundwater flows to the NE to Morrell Spring and into the South Fork Holston River.

Petrologic and thermobarometric studies, coupled with geologic mapping and structural analysis, provide critical evaluation of several different models for Acadian (Late Silurian to Middle Devonian) dome evolution in southern Vermont. Previous models considered diapiric uprise and composite nappe-stage crustal thickening and subsequent diapirism as likely causes of dome formation. Both of these previous models result in symmetrical distribution of P-T values about the dome structures with corresponding coreward increases in temperature, and typically, coreward decrease in associated pressures. Thermobarometric calculations made during this study demonstrate that both P and T increase eastward across the entire region and are not symmetrically distributed about dome axes. The P-T data coupled with petrographically derived relative age relationships and available geochronology also suggest that attainment of peak metamorphic conditions and concurrent dome-stage deformation are diachronous and young from west to east. These relationships are consistent with new geologic mapping and structural analysis which show that all of the domes in southern Vermont are low-amplitude fold interference structures. A current tectonic model indicates that Acadian Barrovian metamorphism in this region was a consequence of west-directed crustal thickening of an eastward dipping tectonic wedge, presumably from the Bronson Hill Terrane; an Ordovician arc sequence. The basal surface of this allochthonous mass projects above the present land surface within this area. Accretion of lower-plate rocks (of this study) into the thrust complex and continued west-directed thrusting of the accreted package over a seismically recognizable east dipping ramp structure provided the necessary geometry and mechanism for dome-stage fabric development, calculated uplift rates (1.2 to 1.7 km/m.y. and west to east younging of Acadian structural and metamorphic evolution. Thermobarometric and geochronologic estimates of metamorphic pressure - temperature (P-T) conditions and metamorphic cooling ages were used to constrain the required thermal and tectonic input parameters for use in one-dimensional thermal modeling of an Acadian (Silurian-Devonian} tectonotherma! regime within the pre-Silurian Taconide zone of southern Vermont. This regime includes: 1) garnet-grade rocks from the eastern flank of an Acadian composite dome structure (Sadawga Dome; the western domain); 2) staurolite/kyanite-grade rocks from the western flank of a second composite structure, the Athens dome (eastern domain). Results from thermal modeling include development of P-T paths, temperature-time (T-t) and pressure-time (P-t) curves, related values of maximum temperature and pressure, pressure conditions at maximum temperature, predicted closure ages for radiogenic phases, and integrated uplift and cooling rates. Thermal modeling results are remarkably similar to independently obtained data for Acadian regional metamorphism in western New England, and provide some important constraints on regional thermal evolution: 1) pressure values contemporaneous with peak temperature on P-T paths may be substantially lower than actual maximum pressure (> 2.5 kbars); 2) differences in peak temperature for rocks initially loaded to similar crustal depths (garnetgrade vs. staurolite-grade), differences in calculated uplift rates, and differences in Ar closure ages, are consequences of variations in durations of isobaric heating events (or "residence periods"), and differences in actual tectonic uplift rates. These modeling results are internally consistent with structural model that suggests west to east younging of specific Acadian deformations and resultant diachroneity of peak metamorphic and Ar closure ages. Regional variations in timing and conditions of metamorphism may be controlled by diachronous deformational events coupled with variations in crustal levels to which rocks were initially loaded during the ca. 400 Ma onset of Acadian orogenesis in western New England. / Ph. D.

The Jackson Purchase region of western Kentucky consists of Coastal Plain sediments near the northern margin of the Mississippi Embayment. Within this region is the Paducah Gaseous Diffusion Plant (PGDP), a uranium enrichment facility operated by the US Department of Energy. At PGDP, a Superfund site, soil and groundwater studies have provided subsurface lithologic data from hundreds of monitoring wells and borings. Despite preliminary efforts by various contractors, these data have not been utilized to develop detailed stratigraphic correlations of sedimentary units across the study area. In addition, sedimentary exposures along streams in the vicinity of PGDP have not been systematically described beyond the relatively simple geologic quadrangle maps published by the US Geological Survey in 196667. This study integrates lithologic logs, other previous site-investigation data, and outcrop mapping to provide a compilation of near-surface lithologic and stratigraphic data for the PGDP area. A database of borehole data compiled during this study has been provided to PGDP for future research and archival. Developments in understanding near-surface geology include the adoption of nomenclature used by the Illinois State Geological Survey (ISGS), which separates the Continental Deposits into two distinct units, the Mounds Gravel and Metropolis Formation, based on their unique depositional histories. Additionally, faulting presented on the preliminary Joppa (IL) 7.5-minute quadrangle map, but not mapped on the Joppa (KY) 7.5-minute quadrangle map, appears to have impacted deposition of post-Eocene sediments at the site. These faults are co-linear to zones of irregularity noted in the Cretaceous McNairy Formation structure elevation map created during this study, thick zones of the Mounds Gravel noted in an isopach map from this study, and contaminant plume maps created previously by contractors.

Orientador: Ticiano Jose Saraiva dos Santos / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Geociencias / Made available in DSpace on 2018-08-09T21:14:51Z (GMT). No. of bitstreams: 1 Amaral_WagnerdaSilva_M.pdf: 44117000 bytes, checksum: fc74c3c06d9f515fb8c5571bbc187c3b (MD5) Previous issue date: 2007 / Resumo: O avanço das tecnologias de processamento de dados aerogeofísicos e integração com dados geológicos permitem recuperar informações úteis e valiosas contidas em levantamentos geofísicos com uma tecnologia mais antiga. Essas informações representam uma ferramenta essencial ao mapeamento geológico-estrutural de terrenos Pré-Cambrianos, onde as relações estratigráficas e estruturais são difíceis de serem delineadas em trabalhos de campo. Dados aerogeofísicos adquiridos nos Projetos Rio Acaraú (1975) e Itatira (1977), realizados respectivamente nas regiões noroeste e central do Ceará, foram processados e integrados com a finalidade de gerar produtos que possam ser utilizados como ferramenta indireta na identificação de feições geológicas regionais. A verificação e aplicabilidade do método foram postas em prática com a definição de uma área piloto compreendida pelas folhas topográfica 1.100.000 Umirim e Canindé. A integração dos dados aerogeofísicos e geológicos de campo, dando suporte ao mapeamento geológico em escala 1:100.000, permitiu reconhecer duas principais unidades de mapeamento: o Arco Magmático de Santa Quitéria ¿ AMSQ e as seqüências supracrustais para e ortoderivadas que o bordejam. Do arco, foram identificados quatro tipos litológicos representados por Np1: Núcleos anatéticos; Np2: Migmatitos ortoderivados; Np3: Granitos gnáissicos porfiríticos; Np4: Gnaisses granodioríticos. Da supracrustal têm-se: a seqüência paraderivada (Ccp) constituída por seis subunidades de mapeamento, onde se destacam paragnaisses, migmatitos, micaxistos, quartzitos, cálcio silicáticas e metacalcários; e a seqüência ortoderivada (Cco) formada por oito subunidades compostas por granodioritos, leucogranitóides, migmatitos (diatexitos e metatexitos), anfibolitos, dioritos e granulitos máficos. A análise dos lineamentos estruturais da área de estudo, foi realizada com o processamento e interpretação dos produtos aeromagnéticos e do modelo digital do terreno-SRTM para a extração das grandes estruturas regionais. Os maiores lineamentos da região correspondem a zonas de cisalhamentos transcorrentes destrais representadas pelo do sistema de falhas de Paramoti (ZCP) de direção NE-SW, e as zonas de cisalhamento de baixo ângulo com vergência para E-SE no setor noroeste, e para W-NW no setor sudeste. Em termos deformacionais, o principal regime atuante na área é de natureza compressiva, responsável pela geração de foliações, lineações, dobras e zonas de cisalhamento, contendo três fases deformacionais denominadas Fn, Fn+1, Fn+2. A fase Fn é representada por empurrões com vergência aproximada para E-SE no setor NW e para W-NW no setor SE. A fase Fn+1, de natureza transpressional, marca o desenvolvimento de zonas de cisalhamento de direção aproximada NE-SW. E por fim, a fase Fn+2 relaciona-se à exumação e conseqüente tectônica frágil das rochas supracrustais. As rochas do arco magmático de Santa Quitéria foram caracterizadas por apresentarem altas contagens no canal de K em quase toda região de abrangência e contagens intermediárias e baixas de Th e U. De modo geral, a seqüência supracrustal foi caracterizada por apresentar alta contribuição dos canais de U e Th e baixa de K. As subunidades Migmatitos anfibolíticos e Metaultramáficas (Cco3) e Hornblenda gnaisses migmatíticos, granulitos máficos (Cco4), compostas por rochas máficas/metaultramáficas e anfibolíticas, onde se destaca a ocorrência faixas de retro-eclogitos e granulitos máficos encaixados como lentes em gnaisses e migmatitos apresentam fortes anomalias negativas, com baixas contagens nos três canais K-Th-U. A anomalia mais proeminente com esses registros encontra-se na região central da área, a sul do município de Pentecoste. Na magnetometria essas rochas têm anomalias positivas com altos valores de susceptibilidade magnética / Abstract: Advances in airborne geophysical data processing techniques and their integration with geologic data allow recovering valuable information from both geophysical surveys and, the older technology. These information represent an essential tool for geologic-structural mapping of Pre-Cambrian terrains, where the stratigraphic and structural relations are difficult to be delineated in field works. The airborne geophysical data from Rio Acaraú (1975) and Itatira (1977) projects were carried out through respectively, in the northwest and central regions of the State of the Ceará. Their processing produced products useful to indirectly identify regional geologic features. The verification and applicability of this approach was tested in an pilot-area whose limits are within the Umirim and Canindé topographic sheets, at 1: 100,000 scale. The integration between the airborne geophysical and the geologic field data supported to the geologic mapping at the same cited scale. Two main units were recognized: the Santa Quitéria Magmatic Arc - AMSQ and the para-and-orthoderivative supracrustal sequences that surround the arc. The AMSQ has four major lithologies: Np1 with anatetic granites; Np2: orthoderivated migmatites; Np3: porfiritic gneissic granites; Np4: granodioritic gneisses. The paraderivative supracrustal sequence (Ccp) consists of six mapped subunits, the paragneisses, marbles migmatites, mica-schists, quartzites and, calk-silicated rocks. The ortoderivative sequence (Cco) is formed by eight subunits, the granodiorites, leucogranitoids, mafic migmatites (diatexites and, metatexites), amphibolites, diorites and, granulites. The structural lineaments analysis at regional scale was done after the processing and interpretation of the airborne magnetic products and, the digital elevation model derived from the Shuttle Radar Topographic Mission-SRTM. The major lineaments correspond to the dextral transcurrent Paramoti Shear Zone (ZCP) of NE-SW direction and, to low angle shear zones with E-SE thrustdirection at the Northwestern sector and, another shear zone facing to W-NW direction at the Southeastern sector. About the deformation history, the main operating regime was compressive and, responsible for foliation, lineation, folds and shear zones.This history comprises three deformational phases called Fn, Fn+1, Fn+2. The Fn phase is represented by thrust toward E-SE in the Northwestern sector and towards W-NW direction at the Southeastern sector. The Fn+1 phase, of transpressional nature, marks the development of shear zones with NE-SW direction. Finally, the Fn+2 phase is related to the exhumation and consequently ruptile tectonics of the supracrustal rocks. The rocks from Santa Quitéria magmatic arc are characterized by high counting on the K-channel in its almost entire region and intermediate and low counting of Th and U. Generally, the supracrustal sequences are characterized by high values on the U-and-Th-channels and low on K-channel. The subunit Metaultramafics (Cco3) and Hornblendgnaisses and, mafics granulites (Cco4), are remarkable by the occurrence retro-eclogites bands and mafic granulites as lenses within gneisses and migmatites. These subunits present strong negative anomalies, with low counting on the three K, Th and, U channels. The best example for this negative anomalies are in the central region of the area, at south of Pentecostes city. That area also has positive magnetic anomalies, with high values of magnetic susceptibility / Mestrado / Geologia e Recursos Naturais / Mestre em Geociências

No description available.

This research has been conducted in Vicksburg Mississippi within the Vicksburg National Military Park and surrounding areas, to produce four 7.5 minute geologic maps of the area. The park service prioritized the delineation of geologic resources within the Military Park, which was achieved throughout geologic mapping. This project provides new geologic mapping to the Park by updating and integrating existing floodplain maps with new bedrock and surficial mapping within the four 7.5 min quadrangles. The objectives were to meet the mandates of the National Park Service and provide new geologic mapping to Vicksburg National Military Park as well as verify existing maps of the floodplain, within the time line of August 2014-May 2016. The resulting maps contribute to improve the understating of the geology within the Military Park, as well as provide insight to historical understanding, and engineering purposes such mining and mitigation of slope failure.

The Lower Ordovician El Paso Group is a >400-m-thick carbonate succession exposed in the Franklin Mountains, El Paso, Texas. The El Paso Group contains multiple breccias related to collapsed-paleocave systems. These breccias have been documented as having formed during the top-Lower Ordovician Sauk depositional supersequence lowstand. Evidence presented in this study suggests that cave formation may have been as much as 350 million years younger and related to Laramide oblique right lateral compression. Regardless of the timing of formation, the breccias mapped in this study are of collapsed paleocave origin based on breccia clast organization and matrix content. Speleogenetic models are compared against observations of breccia distribution by direct field observations and mapping on sub-meter airborne light detection and ranging or lidar data. Point vectors were defined for every point within study area to highlight subtle changes in outcrop erosional profile for mapping geological features directly on the lidar point cloud. In addition, spectral data from airborne photography and hyperspectral image analysis were used assist in geological contact definition. A digital outcrop model was constructed from 3D geologic mapping results from which spatial statistic were extracted and used to reconstruct collapsed paleocave breccia bodies. The resultant breccia geometries were compared against laser-scanned modern cave dimensions, from Devil's Sinkhole, Rocksprings, Texas, and used in analysis of conceptual models for cave formation. The breccias of the southern Franklin Mountains follow linear trends that closely match Riedel shear fracture patterns predicted from right-lateral oblique compression. Stress orientations that match right-lateral oblique compression in the Phanerozoic of the El Paso region are related to the Laramide orogeny. The relationship of observed structures and the orientation of collapse breccias may indicate that southern Franklin Mountain breccia bodies are the result of a solution-enhanced tectonic karst system. / text