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Morphology, paleogeographic setting, and origin of the Middle Wilcox Yoakum Canyon, Texas Coastal PlainDingus, William Frederick, 1959- 18 June 2013 (has links)
The Yoakum Canyon is the largest of the Gulf Coast Eocene erosional gorges and is interpreted as a buried submarine channel. It can be traced for 67 miles from the Wilcox fault zone, which defines the position of the early Eocene shelf edge, nearly to present outcrop. This paper expands on previously published descriptions of the canyon using a more extensive subsurface data base. Decompaction of the canyon shale-fill reveals that original depths of the canyon exceeded 3500 ft (1067 m). Apparent canyon wall slump scarps and a peripheral chaotic zone, interpreted as an incipient slump feature, are comparable to similar features of the late Quaternary Mississippi submarine canyon. The Yoakum canyon formed within the Garwood subembayment to the west of and adjacent to the Middle Wilcox continuation of the Rockdale delta system. Quantitative mapping of facies adjacent to the Yoakum shale indicate the following sequence of events: 1) Muddy, distal deltaic and shelf facies of the lower Middle Wilcox were deposited during a retrogradation. 2) A resurgence of progradation deposited the upper Middle Wilcox deltaic sands atop the unconsolidated, lower Middle Wilcox continental margin muds creating a density inversion which initiated slump failure of the continental margin sediments. 3) Headward erosion of the canyon across the shelf occurred contemporaneously with a subsidence-induced transgression caused by a decrease in the sediment supply. The Yoakum canyon was excavated by a combination of slumping and current scour. 4) The canyon was filled with hemipelagic and prodelta muds. 5) Progradation of the Upper Wilcox (Carrizo) deltaic sands capped the sequence. / text
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Lietuvos Respublikos vyriausybės sprendimų dėl integruotų mokslo, studijų ir verslo centrų (slėnių) kūrimo realizavimo efektyvumo tyrimas / Research on efficiency of implementation of the decisions made by the government of Lithuania due to the development of integrated science, study and business centres (valleys)Malysis, Artūras 10 February 2009 (has links)
Šiame darbe apžvelgiama Lietuvos mokslo politikos situacija ir institucijos, atsakingos už jos įgyvendinimą; problemos, kylančios ją įgyvendinant; aprašomas "slėnių" kūrimo Lietuvoje procesas nuo idėjos iki programų patvirtinimo; atliekama šiame procese dalyvavusių asmenų apklausa siekiant išsiaiškinti jų nuomonę apie "slėnių" kūrimo naudą ir efektyvumą bei apie "slėnių" kūrimo proceso eigą; lyginami pasiekti tarpiniai rezultatai (patvirtintos programos) su tikslais iškeltais proceso pradžioje. / This work reviews the situation in Lithuania's scientific policy and institutions responsible for its implementation; problems arising in the implementation; describes the process of "valleys" creation in Lithuania from idea to the programs; the interrogation of persons involved in the process to ascertain their views on the "valleys" creating value and effectiveness of the "valley" development process, was done; compared achieved the intermediate results (approved program) with the objective set in the beginning of the process.
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Predicting buried sites : analysis of the Tipton Till Plain region of IndianaSmith, Andrew M. 24 July 2010 (has links)
This thesis utilizes a combination of landform and soil data and a GIS model to analyze previous subsurface reconnaissance data within the Tipton Till Plain region of Indiana. Survey areas are analyzed according to their location within drainages as well as on their individual surface and subsurface soil characteristics. Additionally, measurements of the valley width at the investigation area and upstream are collected and considered. Soils are also analyzed as a ratio of their individual impermeability in relation to the impermeability of upstream soils. Soil taxonomy and drainage characteristics are analyzed along with the effects stream order and proximity to water have on the potential for an area to contain buried deposits. The conclusion drawn is that comparisons of the permeability of individual drainage basins in relation to the larger drainage basin is not a reliable method of predicting the potential for site burial. The relationship between the valley width at the point of investigation in relation to valley width upstream was analyzed with a weak correlation between valley width stability and the potential for buried deposits. Soil drainage and taxonomic classification analysis appear to show where buried deposits are not likely to be encountered. The analyses of stream order and proximity to water did not reveal any significant differences in the potential for encountering buried deposits. It is recommended that the current guidelines for recommending subsurface investigation should be followed more strictly. / Department of Anthropology
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A study of the segmental and suprasegmental phonology of Rhondda Valleys EnglishWalters, J. Roderick January 1999 (has links)
The research is a study of male working class pronunciation in the Rhondda, part of the 'Valleys' area of South East Wales. It encompasses both segmental and suprasegmental (prosodic) phonology. The segmental analysis is primarily auditory although it has some supporting acoustic detail. It examines the consonant and vowel systems of Rhondda Valleys English (RVE), with phonetic realizations and lexical incidence. Comparisons with British R.P. are made and similarities with neighbouring varieties of English (e.g. the West Country) and the Welsh Language are observed. The suprasegmental (prosodic) analysis is of spontaneous conversational data, and is auditory and instrumental. The phonology of RVE intonation is described mainly via a system of intonation phrases (IPs), accents, and terminal tones. IP tunes (overall contours) are observed to contain accent profiles whose pitch obtrusions to the stressed syllable are, in the majority of cases, downwards and whose initial pitch movement from the stressed syllable is rising in over 80% of final accents and final accents. A large majority of IP terminal tones in the data are ultimately rising. Aspects of length and rhythm are examined. Evidence is found of rhythmic organization, e.g. of alternation between strong and weak beats. Strongly accented syllables can be accompanied either by lengthening of the vowel, or by shortening of the vowel with lengthening of the succeeding consonant. Which of these two strategies is adopted by the speaker depends partly on the vowel and partly on how the speaker syllabifies the word. The final 'weak' syllable of an IP may be phonetically stronger (with greater duration, envelope amplitude and pitch prominence) than the accented penult. Several of the prosodic features of RVE are found to bear strong influence from the Welsh Language.
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Influência térmica das configurações urbanas ao longo do eixo do Córrego Canela na cidade de São José do Rio PretoRocha, Luciani Maria Vieira 08 February 2011 (has links)
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Previous issue date: 2011-02-08 / Financiadora de Estudos e Projetos / This research intends to investigate the influence of urban morphology in air temperature along the axis of Alberto Andaló Ave. and José Munia Ave., which border the Canela Stream in São José do Rio Preto. Initially, a review was made on the relationship between urban design and the influence of climate and vegetation on climate. Alongside, it was made a review of some existing studies on the expansion of the city, as well as on the occupation of streams margins by avenues construction. The cadastral and morphological data such as land use, topography, configuration of city blocks and lots, height of buildings and ground cover were surveyed in maps, either developed by the Municipality or obtained from satellite imagery and field observation. In order to collect temperature data, four points were chosen - two in José Munia Avenue and two in Alberto Andaló Avenue. The results of that field campaign at two measurement periods - the first in April and the second in July and August - revealed differences in the air temperature among the two avenues. The correlation of these data with the characteristics of land use and occupation showed a significant decrease of air temperature during the night due to the presence of vegetation and soil permeability, thus, minimizing the heat islands. Also, it was found that areas with high occupancy of buildings and intensely paved areas and city blocks lost less heat, leading to the formation of the highest heat islands during the night period. / Esta pesquisa procura investigar a interferência da morfologia urbana na temperatura do ar ao longo do eixo das Avenidas Alberto Andaló e José Munia que margeiam o Córrego Canela na cidade de São José do Rio Preto. Inicialmente foi feita uma revisão bibliográfica sobre a relação entre o desenho urbano e o clima e a influência da vegetação no clima. Paralelamente foi feita uma revisão de estudos existentes sobre a expansão da cidade e leitura das ocupações das margens dos córregos com a construção de avenidas. Os dados cadastrais e morfológicos: levantamento topográfico, uso e ocupação, configuração das quadras e lotes, altura das edificações, cobertura do solo, foram pesquisados em mapas desenvolvidos pela Prefeitura, obtidos através de imagem de satélite, e observados em campo. Para a medição de temperatura foram escolhidos quatro pontos, dois na Av.José Munia e dois na Av.Alberto Andaló. O resultado da coleta de dados de temperatura do ar revelou diferenças na temperatura do ar entre os pontos amostrais das duas avenidas em dois períodos de medição, o primeiro em abril e o segundo em julho e agosto. A correlação dos dados com as características de uso e ocupação do solo demonstrou uma influência significativa da presença de vegetação e permeabilidade do solo na diminuição da temperatura do ar noturna, consequentemente minimização das ilhas de calor. Também verificou-se que as áreas com maior ocupação com construções e maior pavimentação nas ruas e quadras, perderam menos calor, levando à formação de ilhas de calor noturnas mais intensas.
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Near-Surface Ground Ice Conditions In University Valley, McMurdo Dry Valleys of Antarctica.Lapalme, Caitlin January 2015 (has links)
This study aims to quantify ground ice content and describe the cryostructures and sediment in 15 ice-bearing permafrost cores collected from nine sand-wedge polygons in University Valley. The objectives were reached through laboratory measurements and computed tomodensitometric (CT) scanned image analysis of the permafrost cores. The soils in the valley were predominantly medium-sand. Four types of cryostructures were present in the cores: structureless, suspended, crustal and porphyritic. Excess ice content ranged from 0 to 93%, gravimetric water content ranged from 13 to 1881% and volumetric ice content varied from 28 to 93%. Median excess ice, volumetric ice and gravimetric water contents significantly increased in the top 20 cm of the cores taken from the polygon shoulders with increasing distance from University Glacier. Ground ice was preferentially stored in the centre of the investigated polygons where the ground surface remains cryotic throughout the year. Conversely, higher ground ice contents were measured in the shoulders of the investigated polygon where the ground surface is seasonally non-cryotic. CT-scanned images were shown to reasonably assess the distribution and presence of excess ice in permafrost cores taken from a cold and hyper-arid environment. The results of this thesis provide the first cryostratigraphic study in the McMurdo Dry Valleys of Antarctica.
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Sedimentology of the lower Carboniferous in south-western LibyaPetitpierre, Laurent January 2012 (has links)
Several hydrocarbon discoveries in the Marar Formation (Tournaisian and Viséan) were recently made in the Lower Carboniferous strata of the Ghadames and Murzuq Basins situated in SW Libya. Despite large exposures exhibiting thick sections, there is an absence of regional studies focusing on this stratigraphic interval and only rare case studies provide new sedimentary data. More generally, geological knowledge of Carboniferous in North Africa (Saharan Platform) is also understudied when compare to other regions of the world. Detail analyses of the sedimentary record on Saharan Platform may noticeably contribute to refine the current understanding of global geological episodes such as the Late Paleozoic Ice Age. The main aim of this study is to produce valuable field data for both industry and interpretations for assessing academic hypothesis. In order to develop accurate and detail correlations of sedimentary strata over long distances (over 350 km) a primary aims is to define a synchronous key marker horizon that is ideally detectable in both surface and subsurface datasets. A secondary aim is to characterise spatial variability and geometries of sedimentary bodies. Acquired during three fieldwork seasons in the area (along ca 385 km), over 4800 m of sedimentary logging, facies analyses and 800 outcrop gamma ray readings are compiled in this study. I therefore characterise the micro, meso, macro-scale geometries, regional distribution, gamma ray response and mineralogy of the Collenia stromatolites that mark the uppermost part of the Marar Formation. Mainly based on series of detailed sedimentary logging and photographic panoramas, two types of reservoirs facies are described: 1- several metres thick shorefaces sandstones that are continuous for several tens of kilometres; 2- several tens of metres thick incised valley in filled with fluvial sandstones of fewer lateral extend. A sea level curve, produced on basis of the detailed sequence stratigraphic framework of the area, reveals that eustasy almost solely explains relative changes of sea level during the Viséan. Considering the glacial record preserved on northern Gondwana during the same interval, we conclude that the onset of the Late Paleozoic Ice Age is older than uppermost Viséan and more gradual than previously thought.
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Eukaryotic diversity of miers valley hypolithsKeriuscia Gokul, Jarishma January 2012 (has links)
>Magister Scientiae - MSc / The extreme conditions of Antarctic desert soils render this environment selective towards a diverse range of psychrotrophic microbial communities. Cracks and fissures in translucent quartz rocks permit an adequate amount of penetrating light, sufficient water and nutrients to support cryptic microbial development. Hypolithons colonizing the ventral surface of these quartz rocks have been classified into three types: cyanobacterial dominated (Type I),moss dominated (Type II) and lichenized (Type III) communities. Eukaryotic microbial communities were reported to represent only a minor fraction of Antarctic communities. In this study, culture independent techniques (DGGE, T-RFLP and clone library construction) were employed to determine the profile of the dominant eukaryotes, fungi and microalgae present in the three different hypolithic communities. The 18S rRNA gene (Euk for eukaryotes), internal transcribed spacer (ITS for fungi) and microalgal specific regions of the 18S rRNA gene, were the phylogenetic markers targeted for PCR amplification from hypolith metagenomic DNA. Results suggest that the three hypolith types are characterized by different eukaryotic, fungal and microalgal communities, as implied by nMDS analysis of the DGGE and T-RFLP profiles. Sequence analysis indicates close affiliation to members of Amoebozoa, Alveolata, Rhizaria (general eukaryote), Ascomycota (fungal) and Streptophyta
(microalgal). Many of these clones may represent novel species. This study demonstrates that Dry Valley hypolithons harbour higher eukaryote diversity than previously recognised.Each hypolithon is colonized by specialized microbial communities with possible keystone species. The ecological role of the detected microorganisms in the hypolith environment is also theorized, and a trophic hierarchy postulated.
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Etude morphométrique de la cryosphère ancienne de Mars : implications paléo-climatiques / Morphometrical study of the cryosphere of early Mars : Paleo-climatic implicationsBouquety, Axel 28 November 2019 (has links)
Le climat primitif martien fascine la recherche martienne. Identifier avec le plus de précision possible les conditions primitives martiennes permettrait de contraindre les différents états de l’eau au cours de l’histoire martienne. Aujourd’hui deux hypothèses font débat, la première est celle d’un climat chaud et humide régnant à la surface de Mars à la fin du Noachien/début Héspérien. La deuxième, à l’inverse, semble indiquer que le climat aurait été froid et englacé sur les plus hautes altitudes martiennes. Néanmoins, cette deuxième hypothèse est souvent contestée, car contrairement à la présence de marqueur d’eau liquide à la surface de Mars, aucune morphologie de surface attestant d’un climat froid n’avait été identifiée. Au cours de cette thèse, nous avons étudié de manière morphométrique les structures et morphologies à la surface de Terra Sabaea, qui constitue 1% de la superficie totale de la planète. Ces structures constituent des héritages morphologiques des activités climatiques passées. Afin de caractériser au mieux l’origine érosive de ces structures, nous avons créé une nouvelle méthode d’analyse morphométrique à partir de différentes méthodes terrestres et martiennes. Cette nouvelle méthode permet d’extraire plus de 20 données exploitables par vallée. Il a donc été question de mesurer un maximum de vallée afin d’établir une base de données que nous avons comparée avec des bases de données de morphologies terrestres et martiennes. Grâce à cette analyse, il a été possible de mettre en évidence, la présence d’un paysage glaciaire dans la région de Terra Sabaea. Ce paysage est composé de (1) vallées glaciaires liées avec (2) des cirques glaciaires. La source de cette glace semble être (3) des calottes de plateaux locales à des altitudes > 3500 m. Nous avons donc démontré pour la première fois la présence de morphologies glaciaires attestant d’un climat froid il y a 3.6 Ga. Néanmoins, la présence de telles morphologies n’indique pas que l’ensemble de Terra Sabaea était englacé. L’analyse morphométrique a démontré la présence de morphologie fluviatile géographiquement proche des morphologies glaciaires et souvent à la même altitude, entre 1500 et 3500 m. Cette observation nous a permis de mettre en évidence (4) que la pente était un facteur qui influençait sur l’état de l’eau. En effet, pour une même altitude, les morphologies fluviatiles sont situées sur les pentes douces (< 3°) alors que les morphologies glaciaires sont situées sur les remparts internes des cratères d’impacts présentant une forte pente (> 10°). Cependant (5) l’altitude semble également être un facteur déterminant puisque l’on ne retrouve pas de morphologie glaciaire à des altitudes < 1500 m. L’analyse des terrains de Terra Sabaea a également mis en évidence (6) qu’il existait un lien génétique entre les morphologies glaciaires de hautes altitudes et les vallées fluviatiles plus bas. En effet, il est possible de suivre une vallée qui prend sa source sur les hauts plateaux englacés en amont, jusqu’en aval où elle rejoint des morphologies témoignant d’une activité fluviatile. Cette continuité dans les morphologies glaciaires et fluviatiles permet (7) de mieux définir l’origine des vallées ramifiées, et notamment l’origine de Naktong vallis, et il semblerait que la fonte des glaces a joué un rôle dans leurs formations. De plus, cette continuité morphologique permet de supposer qu’il existait (8) un cycle de l’eau similaire à la Terre dans la région de Terra Sabaea il y a 3.6 Ga. / The primitive Martian climate fascinates Martian research. Identifying Martian primitive conditions as accurately as possible would make it possible to constrain the different states of water during Martian history. Today two hypotheses are debated, the first is that of a hot and humid climate prevailing on the surface of Mars at the end of the Noachian / early Hesperian. The second, on the contrary, seems to indicate that the climate was cold and glacial on the highest Martian altitudes. Nevertheless, this second hypothesis is often disputed, because unlike the presence of liquid water marker on the surface of Mars, no surface morphology attesting to a cold climate had been identified. In this thesis, we studied morphometrically structures and morphologies on the surface of Terra Sabaea, which constitutes 1% of the total surface of the planet. These structures constitute morphological legacies of past climatic activities. In order to better characterize the erosive origin of these structures, we have created a new method of morphometric analysis from different terrestrial and Martian methods. This new method makes it possible to extract more than 20 exploitable data per valley. It was therefore a question of measuring a valley maximum in order to establish a database that we compared with databases of terrestrial and Martian morphologies. Thanks to this analysis, it has been possible to highlight the presence of an ice landscape in the Terra Sabaea region. This landscape is composed of (1) glacial valleys linked or not with (2) glacial cirques. The source of this ice appears to be (3) local plateau caps at altitudes> 3500 m. We thus demonstrated for the first time the presence of glacial morphologies attesting to a cold climate there are 3.6 Ga. Nevertheless, the presence of such morphologies does not indicate that the whole of Terra Sabaea was glaciated. Morphometric analysis has demonstrated the presence of fluvial morphology geographically close to glacial morphologies and often at the same altitude, between 1500 and 3500 m. This observation allowed us to highlight (4) that the slope was a factor influencing the state of the water. Indeed, for the same altitude, fluvial morphologies are located on gentle slopes (<3 °) while glacial morphologies are located on the inner walls of impact craters with a steep slope (> 10 °). However (5) altitude also seems to be a determining factor since we do not find glacial morphology at altitudes <1500 m. Terra Sabaea land analysis also revealed (6) that there is a genetic link between high altitude glacial morphologies and lower river valleys. Indeed, it is possible to follow a valley that has its source on the highlands glaciers upstream, downstream where it joins morphologies testifying to a fluviatile activity. This continuity in glacial and fluvial morphologies makes it possible (7) to better define the origin of branched valleys, and in particular the origin of Naktong vallis, and it seems that melting ice has played a role in their formations. Moreover, this morphological continuity makes it possible to suppose that there existed (8) a cycle of water similar to the Earth in the region of Terra Sabaea there is 3.6 Ga.
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Aquatic Fungi of the McMurdo Dry ValleysSheldon, Parnell Jordan 06 January 2022 (has links)
No description available.
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