The Experts below are selected from a list of 81 Experts worldwide ranked by ideXlab platform
Jeffrey A Karson - One of the best experts on this subject based on the ideXlab platform.
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detachment shear zone of the atlantis massif core complex mid atlantic ridge 30 n
Geochemistry Geophysics Geosystems, 2006Co-Authors: Jeffrey A Karson, Gretchen L Fruhgreen, Deborah S Kelley, E A Williams, Dana R Yoerger, Michael V JakubaAbstract:Near-bottom investigations of the cross section of the Atlantis Massif exposed in a major tectonic escarpment provide an unprecedented view of the internal structure of the footwall domain of this oceanic core complex. Integrated direct observations, sampling, Photogeology, and imaging define a mylonitic, low-angle detachment shear zone (DSZ) along the crest of the massif. The shear zone may project beneath the nearby, corrugated upper surface of the massif. The DSZ and related structures are inferred to be responsible for the unroofing of upper mantle peridotites and lower crustal gabbroic rocks by extreme, localized tectonic extension during seafloor spreading over the past 2 m.y. The DSZ is characterized by strongly foliated to mylonitic serpentinites and talc-amphibole schists. It is about 100 m thick and can be traced continuously for at least 3 km in the tectonic transport direction. The DSZ foliation arches over the top of the massif in a convex-upward trajectory mimicking the morphology of the top of the massif. Kinematic indicators show consistent top-to-east (toward the MAR axis) tectonic transport directions. Foliated DSZ rocks grade structurally downward into more massive basement rocks that lack a pervasive outcrop-scale foliation. The DSZ and underlying basement rocks are cut by discrete, anastomosing, normal-slip, shear zones. Widely spaced, steeply dipping, normal faults cut all the older structures and localize serpentinization-driven hydrothermal outflow at the Lost City Hydrothermal Field. A thin (few meters) sequence of sedimentary breccias grading upward into pelagic limestones directly overlies the DSZ and may record a history of progressive rotation of the shear zone from a moderately dipping attitude into its present, gently dipping orientation during lateral spreading and uplift.
Michael V Jakuba - One of the best experts on this subject based on the ideXlab platform.
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detachment shear zone of the atlantis massif core complex mid atlantic ridge 30 n
Geochemistry Geophysics Geosystems, 2006Co-Authors: Jeffrey A Karson, Gretchen L Fruhgreen, Deborah S Kelley, E A Williams, Dana R Yoerger, Michael V JakubaAbstract:Near-bottom investigations of the cross section of the Atlantis Massif exposed in a major tectonic escarpment provide an unprecedented view of the internal structure of the footwall domain of this oceanic core complex. Integrated direct observations, sampling, Photogeology, and imaging define a mylonitic, low-angle detachment shear zone (DSZ) along the crest of the massif. The shear zone may project beneath the nearby, corrugated upper surface of the massif. The DSZ and related structures are inferred to be responsible for the unroofing of upper mantle peridotites and lower crustal gabbroic rocks by extreme, localized tectonic extension during seafloor spreading over the past 2 m.y. The DSZ is characterized by strongly foliated to mylonitic serpentinites and talc-amphibole schists. It is about 100 m thick and can be traced continuously for at least 3 km in the tectonic transport direction. The DSZ foliation arches over the top of the massif in a convex-upward trajectory mimicking the morphology of the top of the massif. Kinematic indicators show consistent top-to-east (toward the MAR axis) tectonic transport directions. Foliated DSZ rocks grade structurally downward into more massive basement rocks that lack a pervasive outcrop-scale foliation. The DSZ and underlying basement rocks are cut by discrete, anastomosing, normal-slip, shear zones. Widely spaced, steeply dipping, normal faults cut all the older structures and localize serpentinization-driven hydrothermal outflow at the Lost City Hydrothermal Field. A thin (few meters) sequence of sedimentary breccias grading upward into pelagic limestones directly overlies the DSZ and may record a history of progressive rotation of the shear zone from a moderately dipping attitude into its present, gently dipping orientation during lateral spreading and uplift.
Rodrigues, Flávio Henrique - One of the best experts on this subject based on the ideXlab platform.
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Análise integrada aplicada ao mapeamento geológico-geotécnico na escala de 1:20.000 da estrada de Castelhanos, Ilhabela - SP
Universidade Estadual Paulista (UNESP), 2012Co-Authors: Rodrigues, Flávio HenriqueAbstract:O mapeamento geológico-geotécnico tem se revelado um instrumento muito útil para o planejamento e gestão do meio físico, fornecendo informações importantes na prevenção de desastres naturais, e na tomada de decisões. Como observado em regiões da Serra do Mar, nos estados de São Paulo e Rio de Janeiro, vários pontos inseridos em área suscetíveis a ocorrência de deslizamentos de terra, quedas de blocos rochosos e inundações, têm sido ocupadas com diversas finalidades, levando a impactos negativos, decorrentes do processo de apropriação inadequada do terreno. Nesse sentido, o presente trabalho tem como objetivo a elaboração de um mapa geológico-geotécnico da estrada de Castelhanos, no município de Ilhabela, São Paulo. A metodologia adotada focou a análise integrada dos elementos do meio físico a partir de técnicas de fotogeologia e trabalhos de campo, buscando identificar, descrever e classificar as diferentes unidades fisiográficas do relevo na área de estudo. Baseado nas informações dos compartimentos do relevo, das litologias e perfis de alteração, o mapeamento identificou e descreveu 6 unidades geológico-geotécnicas, abrangendo as bacias hidrográficas em que a estrada de Castelhanos está localizada, o que viabilizou a elaboração do diagnóstico de situação da referida estrada com sua divisão em 8 trechos diagnósticos. Os resultados foram organizados a fim de auxiliar as atividades de manejo e conservação do Parque Estadual de Ilhabela, e são apresentados na forma de mapas, quadros descritivos, fotografias e croquis geotécnicosThe geological-geotechnical mapping has proved to be a very useful tool for physical environment planning and management, providing important information for natural disasters prevention and decision-making. As noted in Serra do Mar areas, in São Paulo and Rio de Janeiro states, several points in landslide, falling boulders and flooding susceptibility areas, have been occupied for various purposes, leading to negative impacts, arising from the misappropriation of land. In this sense, this paper aims to draw up a geological-geotechnical map of the Castelhanos Road, located in Ilhabela city, state of Sao Paulo, Brazil. The methodology focused on the integrated analysis of the physical environment elements by using Photogeology techniques and field work, seeking to identify, describe and classify the different physiographic units of the relief in the study area. Based on information from relief compartment, lithology and alteration profiles, the mapping has identified and described six geological-geotechnical units covering watersheds where the Caselhanos Road is located, which enabled the development of the road diagnostic status, divided into eight diagnostic sections. The results were organized to assist the management and conservation activities at Ilhabela State Park, and they are presented as maps, descriptive tables, photographs and geotechnical sketchesCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES
Rodrigues, Flávio Henrique [unesp] - One of the best experts on this subject based on the ideXlab platform.
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Análise integrada aplicada ao mapeamento geológico-geotécnico na escala de 1:20.000 da estrada de Castelhanos, Ilhabela - SP
Universidade Estadual Paulista (UNESP), 2012Co-Authors: Rodrigues, Flávio Henrique [unesp]Abstract:O mapeamento geológico-geotécnico tem se revelado um instrumento muito útil para o planejamento e gestão do meio físico, fornecendo informações importantes na prevenção de desastres naturais, e na tomada de decisões. Como observado em regiões da Serra do Mar, nos estados de São Paulo e Rio de Janeiro, vários pontos inseridos em área suscetíveis a ocorrência de deslizamentos de terra, quedas de blocos rochosos e inundações, têm sido ocupadas com diversas finalidades, levando a impactos negativos, decorrentes do processo de apropriação inadequada do terreno. Nesse sentido, o presente trabalho tem como objetivo a elaboração de um mapa geológico-geotécnico da estrada de Castelhanos, no município de Ilhabela, São Paulo. A metodologia adotada focou a análise integrada dos elementos do meio físico a partir de técnicas de fotogeologia e trabalhos de campo, buscando identificar, descrever e classificar as diferentes unidades fisiográficas do relevo na área de estudo. Baseado nas informações dos compartimentos do relevo, das litologias e perfis de alteração, o mapeamento identificou e descreveu 6 unidades geológico-geotécnicas, abrangendo as bacias hidrográficas em que a estrada de Castelhanos está localizada, o que viabilizou a elaboração do diagnóstico de situação da referida estrada com sua divisão em 8 trechos diagnósticos. Os resultados foram organizados a fim de auxiliar as atividades de manejo e conservação do Parque Estadual de Ilhabela, e são apresentados na forma de mapas, quadros descritivos, fotografias e croquis geotécnicosThe geological-geotechnical mapping has proved to be a very useful tool for physical environment planning and management, providing important information for natural disasters prevention and decision-making. As noted in Serra do Mar areas, in São Paulo and Rio de Janeiro states, several points in landslide, falling boulders and flooding susceptibility areas, have been occupied for various purposes, leading to negative impacts, arising from the misappropriation of land. In this sense, this paper aims to draw up a geological-geotechnical map of the Castelhanos Road, located in Ilhabela city, state of Sao Paulo, Brazil. The methodology focused on the integrated analysis of the physical environment elements by using Photogeology techniques and field work, seeking to identify, describe and classify the different physiographic units of the relief in the study area. Based on information from relief compartment, lithology and alteration profiles, the mapping has identified and described six geological-geotechnical units covering watersheds where the Caselhanos Road is located, which enabled the development of the road diagnostic status, divided into eight diagnostic sections. The results were organized to assist the management and conservation activities at Ilhabela State Park, and they are presented as maps, descriptive tables, photographs and geotechnical sketche
Dana R Yoerger - One of the best experts on this subject based on the ideXlab platform.
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detachment shear zone of the atlantis massif core complex mid atlantic ridge 30 n
Geochemistry Geophysics Geosystems, 2006Co-Authors: Jeffrey A Karson, Gretchen L Fruhgreen, Deborah S Kelley, E A Williams, Dana R Yoerger, Michael V JakubaAbstract:Near-bottom investigations of the cross section of the Atlantis Massif exposed in a major tectonic escarpment provide an unprecedented view of the internal structure of the footwall domain of this oceanic core complex. Integrated direct observations, sampling, Photogeology, and imaging define a mylonitic, low-angle detachment shear zone (DSZ) along the crest of the massif. The shear zone may project beneath the nearby, corrugated upper surface of the massif. The DSZ and related structures are inferred to be responsible for the unroofing of upper mantle peridotites and lower crustal gabbroic rocks by extreme, localized tectonic extension during seafloor spreading over the past 2 m.y. The DSZ is characterized by strongly foliated to mylonitic serpentinites and talc-amphibole schists. It is about 100 m thick and can be traced continuously for at least 3 km in the tectonic transport direction. The DSZ foliation arches over the top of the massif in a convex-upward trajectory mimicking the morphology of the top of the massif. Kinematic indicators show consistent top-to-east (toward the MAR axis) tectonic transport directions. Foliated DSZ rocks grade structurally downward into more massive basement rocks that lack a pervasive outcrop-scale foliation. The DSZ and underlying basement rocks are cut by discrete, anastomosing, normal-slip, shear zones. Widely spaced, steeply dipping, normal faults cut all the older structures and localize serpentinization-driven hydrothermal outflow at the Lost City Hydrothermal Field. A thin (few meters) sequence of sedimentary breccias grading upward into pelagic limestones directly overlies the DSZ and may record a history of progressive rotation of the shear zone from a moderately dipping attitude into its present, gently dipping orientation during lateral spreading and uplift.