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1
Russell, Andrew J. "The geomorphological and sedimentological effects of jokulhlaups." Thesis, University of Aberdeen, 1991. http://digitool.abdn.ac.uk/R?func=search-advanced-go&find_code1=WSN&request1=AAIU045907.
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The aim of this study was to test a predictive model of the geomorphological and sedimentological effects of floods resulting from the sudden drainage of ice-dammed lakes (jokulhlaups). A process-based, conceptual model for channel and sedimentary characteristics was tested within a jokulhlaup routeway near Sondre Stromfjord, west Greenland. River channel change resulting from a jokulhlaup monitored in 1987 was studied in three channel types along the flood routeway: deltaic, high gradient bedrock-controlled, and low gradient confined valley sandur. Flood powers, sediment supply and channel resistance to erosion were found to vary considerably between the channel types. Consequently, amounts of channel change and the character of the sedimentary record showed extreme variation. In addition, parts of the jokulhlaup channel which experienced backwater effects may have experienced two sediment transport peaks. Variations between the character of deposits found within each of the three channel types reflect local differences in sediment supply, stream power and channel resistance to erosion. Deposition in the delta and the sandur records sedimentation related to a number of jokulhlaups, whilst the spillway and the bedrock-confined channel provide a record of the action of the last jokulhlaup as low stage deposits, as well as that of the earliest flood events as high stage deposits. This study has shown that it is possible to predict the morphology of channel macroforms. The internal structure of these macroforms is strongly dependent upon both the amount and character of sediment supplied to the channel during a jokulhlaup. The more detailed the knowledge of the controlling variables for any one channel, the more detailed the resulting predictions are. At present, the model concerns only the products of turbulent, Newtonian, water floods. It may, however, be possible to predict thresholds marking the transition to non-Newtonian flows where sediment supply conditions and hydrograph characteristics are known. The model may also be used in reverse to reconstruct the magnitude and frequency of former jokulhlaups where sufficient geomorphological and sedimentary evidence is available.
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Dutson, Andrew S. "A Multifaceted Sedimentological Analysis on Hobble Creek." BYU ScholarsArchive, 2011. https://scholarsarchive.byu.edu/etd/2625.
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Due to the endangerment of the June sucker (Chasmistes liorus), the lower two miles of Hobble Creek, Utah has been the focus of several restoration efforts. The portion of the creek between Interstate 15 and Utah Lake has been moved into a more "natural" channel and efforts are now being made to expand restoration to the east side of the freeway. This thesis reports on three different parts of a sedimentological analysis performed on Hobble Creek. The first part is a data set that contains information about the particle size distribution on the bed of Hobble Creek between 400 W and Interstate 15 in Springville, Utah. Particle size distributions were obtained for eleven sub-reaches within the study section. Particle size parameters such as D50 were observed to decrease from an average of 72 mm to 24 mm downstream from the 1650 W crossing and Packard Dam. Streambed armoring was observed along most of the reach. This data set can be used as input for PHABSIM software to determine the location and availability of existing spawning material for June sucker during a range of flows. The second part of this thesis compares predictions from four bed-load transport models to bed-load transport data measured on Hobble Creek. In general, the Meyer-Peter, Muller and Bathurst models overpredicted sediment transport by several orders of magnitude while the Rosgen and Wilcock methods (both calibrated models) were fairly accurate. Design channel dimensions resulting from the bed-load transport predictions diverged as a function of discharge. Once validated, the models developed in this section can be used by design engineers to better understand sediment transport on Hobble Creek. The models may also be applied to other Utah Lake tributaries. The third section of the thesis introduces a detailed survey data set that covers the Hobble Creek floodplain on the shifted section between Interstate 15 and Utah Lake with an approximate 10 foot resolution grid. Water surface elevations at two flows, along with invert, fence, saddles, and other points, are labeled in the survey. A comparison with a survey completed last year did not reveal any significant lateral changes caused by the 2010 spring runoff. Due to the potential importance of the side ponds to June sucker survival, this data set can be used to monitor sedimentation in the side ponds. It may also be used in a GSSHA model to determine the magnitude of flow that is required before each side pond will be connected to the main channel.
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Nelson, Anna Elizabeth. "A sedimentological investigation of glacigenic deposits in Iceland." Thesis, University of Cambridge, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613671.
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Hutchison, Matthew P. "The sedimentological & petrophysical characterisation of dryland mudstones." Thesis, University of Aberdeen, 2014. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=210857.
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Sjunneskog, Charlotte. "Diatom and Sedimentological Investigations on West Antarctic Shelf Sediment." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2002. http://publications.uu.se/theses/91-554-5256-6/.
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Orlowski, R. J. "A sedimentological profile of the Pahau Terrane type locality." Thesis, University of Canterbury. Geology, 2001. http://hdl.handle.net/10092/7121.
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The Pahau Terrane as part of the Torlesse Superterrane extends for over 30% of the New Zealand landmass. Although an unofficial type locality around the Pahau River has been proposed, it has never been adequately described or defined. One of the main goals of this research was to describe in detail the deposits of the Pahau River area in order to define the type locality.
In total ~900m of section was logged describing four lithofacies; mudstone, interbedded mudstone - sandstone, sandstone, and conglomerate. Two formation names and a group name are proposed and intended for widespread use. The Mt Saul Formation is proposed for coarse-grained conglomeratic lithofacies whereas the Ship Spur Formation is proposed for the combined fine-grained sedimentary lithofacies. The Pahau River Group encompasses these formations.
Stratigraphic logs clearly show coarsening and thickening upward, progradational sequences, at the tops of which either highly carbonaceous beds or rootlets can be observed. The bedding in the conglomerate lithofacies are dominated by bedload transport structures including large scale cross stratification, imbrication and clast support. Micro and macrofossil collection suggest a nearshore marine sequence yet rootlets suggest subaerial indicating a range from fully marine to terrestrial depositional environments, making them the only known terrestrial deposits in the
Pahau Terrane. This suggests a fan-delta depositional setting. Very few bi-directional structures were observed, suggesting that these deposits were not influenced by wave reworking and tidal currents to any great degree but are fluvially dominated.
Thin section analysis of fine to medium sandstones suggests a transitional to mixed arc provenance. Measurable indicators suggest a palaeoflow direction towards the east to northeast. These results are similar to previous studies indicating the suitability of the Pahau River area as a type locality for the Pahau Terrane.
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Newell, Andrew John. "Sedimentological controls on vertebrate taphonomy in Triassic fluvial environments." Thesis, Queen's University Belfast, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317467.
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Smith, R. D. A. "A sedimentological analysis of the late LLandovery Welsh Basin." Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234921.
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An integrated, multidisciplinary basin analysis has been carried out for an approximately isochronous stratal interval of the Silurian fill of the Welsh Basin. The selected interval is the Upper Llandovery griestoniensis Chronozone which represents a time interval of probably less than one million years. Two mapped areas with contrasting structural styles illustrate the heterogeneous response of the basin-fill to basin inversion and shortening. One major Welsh structure, the Central Wales Synclinorium, is shown to be related to a long-lived structural discontinuity which significantly influenced early Silurian sedimentation patterns. During extension/transtension in the basin this structure, as the edge of a tilted fault block, formed a palaeohigh. Turbidite systems were confined to either side and were ponded in relatively small-scale sub-basins defined by the tilted fault block geometry. In basinal facies of griestoniensis Zone age four major lithofacies associations are recognized: the channel-lobe transition, sandstone lobe, lobe fringe, and lateral basin-slope facies associations. They represent deposits of the outer area of a moderately large (minimum length of 100 km), elongate turbidite system and its bounding slope. Large scale erosional structures, filled with conglomerates and pebbly sandstones, occur in the more proximal areas of exposure. They are either channels or huge scours excavated by large volume turbidity currents undergoing hydraulic jumps. Lateral facies variations in sandstone lobes reflect down-system and cross-system variations in competence and capacity of flows. Palaeocurrent patterns and inferred onlap relationships reflect confinement by structurally-controlled slopes. Since the system developed during a time of widespread transgression sandstone lobes probably record pulses of rapid tectonic uplift at source. Unconformities, corresponding to times of active growth of depositional sandstone lobes in the basin, were generated on the southern basin margin. Lateral gradients in palaeo-oxygenation of bottom waters and fluctuations in oxicity through time are reconstructed using trace fossil evidence and diagenetic mineral assemblages. Relic downward-migrating oxidation fronts are recorded for the first time from ancient turbidites. A diverse trace fossil assemblage associated with the turbidite system is described and interpreted. Detailed logging through the basinal sequence reveals that times of dysaerobic bottom water conditions, during which turbidites and hemipelagites were reworked by soft-bodied infauna, alternated with periods of bottom water anoxia, during which laminated hemipelagites containing a pelagic fauna of graptolites were preserved. Such alternations may be very rapid, suggesting close proximity of the anoxic-oxic interface to the sediment surface, or may have far longer periodicities, reflecting periods of stable pycnocline development above anoxic bottom waters. Phosphate cements are shown to have initiated very close to the sediment surface beneath oxygen-deficient bottom waters in the basin.
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Santos, Julio Cesar Neves dos. "Hydrological and sedimentological processes in a tropical semiarid climate." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=15010.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoThe understanding of processes such as the generation of surface runoff, sediment yield and their relations with the rainfall regime is the basis for the planning and effective management of soil and water resources in a watershed. In this context, the present study aims to identify the main processes that influence the generation of surface runoff and sediment yield in small watersheds, and determine parameters for empirical sedimentological models, as well as the Sediment Delivery Ratio (SDR) for the tropical, semi-arid region of Brazil. The study area is the Iguatu Experimental Basin (IEB), which comprises a watershed of 16.74 km2, three small nested watersheds (from 1 to 3 ha) and three erosion plots of 20 m2. One of the watersheds had been under regenerating Caatinga for 35 years, another subjected to a management, which involved thinning the Caatinga, and the last faced deforestation followed by burning and the cultivation of grass. The period of study was six years (2009 to 2014). Collections to quantify surface runoff and sediment yield were taken for each erosive rainfall event in an accumulated period of 24 hours. Surface runoff in the watersheds was quantified using Parshall flumes, and sediment yield was measured with towers and trenches to collect suspended sediment and bedload. On the watershed scale, runoff was measured by means of a spillway, and sediment yield by a turbidimeter. Cluster analysis was used to determine rainfall regimes and groups of similar rainfall-runoff events. With data from the erosion plots and watersheds, the C factors and coefficients of the Modified Universal Soil Loss Equation (MUSLE) were calibrated and validated. From data measured in the basin, sediment delivery ratios were determined. The occurrence of dry spells and the formation of cracks in the soil were important factors in controlling the generation of runoff and consequently sediment yield. The dry spells made it possible for the soil to dry out, with the formation of cracks, which acted as pathways for preferential flow, generating higher initial abstraction during the start of the rainy season. Changes in ground cover had little influence on accumulated flow, demonstrating that the soil characteristics and conditions as moisture and the presence of cracks, best explain the generation of runoff on expansive soils. The greatest runoff losses in all the watersheds under study were for Rainfall Regime II, characterized by higher depth, intensity and occurrence of the rainfall. For the ground covers under study, values for the C factors and the fit of the coefficients "a" and "b" of MUSLE, proved to be appropriate and recommended according to the statistical indices employed. Values for sediment delivery ratio for individual rainfall events ranged from 0.08 to 1.67%, with an average of 0.68%. In the basin, extreme events may cause high disaggregation of soil particles, but without sufficient transporting energy for dragging the sediment, generating low SDR.
O entendimento de processos como geraÃÃo do escoamento superficial, produÃÃo de sedimentos e suas relaÃÃes com o regime pluviomÃtrico à a base para o planejamento e a gestÃo eficaz dos recursos solo e Ãgua em uma bacia hidrogrÃfica. Nesse contexto, o presente estudo tem como objetivos identificar os principais processos que influenciam a geraÃÃo do escoamento superficial e a produÃÃo de sedimento em pequenas bacias hidrogrÃficas, e calibrar parÃmetros de modelos sedimentolÃgicos empÃricos, bem como a razÃo de aporte de sedimentos (SDR) para a regiÃo semiÃrida tropical do Brasil. A Ãrea de estudo à a Bacia Experimental de Iguatu (BEI), composta de uma bacia de 16,74 km2, trÃs pequenas microbacias aninhadas (de 1 a 3 ha) e trÃs parcelas de erosÃo de 20 m2. Uma das microbacias foi mantida com Caatinga em regeneraÃÃo hà 35 anos, outra submetida ao manejo de raleamento da Caatinga e na Ãltima foi realizado o desmatamento seguido de queimada e cultivo de capim. O perÃodo de estudo foi de seis anos (2009 a 2014). As coletas para quantificaÃÃo do escoamento superficial e da produÃÃo de sedimentos foram realizadas a cada evento de chuva erosiva, no acumulado de 24 horas. O escoamento superficial nas microbacias foi quantificado atravÃs de calhas Parshall e as produÃÃes de sedimentos foram mensuradas atravÃs de torres e fossos coletores de sedimentos em suspensÃo e arraste. Na bacia de 16,74 km2, o escoamento superficial foi mensurado por meio de um vertedor e a produÃÃo de sedimentos atravÃs de um turbidÃmetro. AnÃlises de agrupamento foram utilizadas para determinaÃÃo de regimes de chuvas e grupos de eventos similares de chuva-deflÃvio. Com dados das parcelas de erosÃo e das microbacias foram calibrados e validados os fatores C e os coeficientes da EquaÃÃo Universal de Perdas de Solo Modificada (MUSLE). A partir dos dados medidos na bacia foram determinadas as razÃes de aporte de sedimentos. A ocorrÃncia de veranicos e a formaÃÃo de fendas no solo foram determinantes no controle da geraÃÃo de escoamento e consequentemente da produÃÃo de sedimentos. A ocorrÃncia de veranicos possibilitou o secamento do solo com a formaÃÃo de fendas, que agem como caminhos preferenciais para o fluxo de Ãgua, gerando elevadas abstraÃÃes inicias durante o inÃcio da estaÃÃo chuvosa. As mudanÃas da cobertura vegetal apresentaram pouca influÃncia sobre o escoamento acumulado, indicando que as caracterÃsticas e condiÃÃes do solo, como umidade e presenÃa de fendas, explicam melhor a geraÃÃo de escoamento em solos expansivos. Maiores perdas por escoamento em todas as microbacias estudadas foram para chuvas do Regime II caracterizado por maiores alturas pluviomÃtricas, intensidades e ocorrÃncias. Quanto aos valores dos fatores C e dos coeficientes de ajuste âaâ e âbâ da MUSLE, para as coberturas estudadas, mostraram-se apropriados e recomendados de acordo com os Ãndices estatÃsticos empregados. Os valores da razÃo de aporte de sedimentos para eventos pluviomÃtricos individuais variaram de 0,08 a 1,67%, com mÃdia de 0,68%. Na bacia, eventos extremos podem causar elevada desagregaÃÃo de partÃculas de solo, mas podem nÃo dispor de energia de transporte suficiente para arrastÃ-las, gerando baixo SDR.
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Al-Washmi, Hamad Abdullah. "St Andrews Bay : a sedimentological, geophysical and morphological investigation." Thesis, University of St Andrews, 1996. http://hdl.handle.net/10023/15558.
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This thesis examines past and present day processes responsible for the morphological development of St Andrews Bay in eastern Scotland. Quaternary glacial events have contributed large volumes of sediment from the Scottish Mainland to the North Sea Basin over the last 3 million years. Since the most recent glacial event, the Late Devensian, which terminated some 14,000 years ago in Scotland, the sediments of the coastal areas have been redistributed by wave and tidal activity. Thus the bathymetry and platform of St Andrews Bay has evolved since that time, although some elements of the morphology appear to predate the last glaciation. The grain size distributions of the bed sediments of the bay show a narrow range of mean sizes between fine and very fine sand. These are indicative of a low energy tidal environment although Quartile Deviation - Median Diameter plots suggest the importance of wave activity in determining their distribution. Current measurements in the bay confirm that the hydrodynamic environment is of low energy with average current speeds rarely exceeding 15 cm s −1 one metre above the bed. Progressive vector plots show closed ellipses during calm weather but meteorological forcing and wave activity generate residual currents predominantly in the direction of wave propagation or down wind. Application of a transfer function to the current data predicts low rates of bedload transport, the residual of which generally accords with the recent pattern of sedimentation at the head of the bay. The rocky platforms of the southern margins of the bay cannot easily be sub-divided into features at different elevations. No firm evidence is presented for a pre-Late Devensian origin of the platform but it is argued that such a chronology explains the morphology of the platform. Offshore sedimentary sequences, up to 30 metres in thickness, are reported from geophysical surveys which have been laid down since the last glaciation. The units identified reflect changing environments of deposition associated with climatic and sea level changes over the last 14,000 years.
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Solangi, Sarfraz Hussain. "Geophysical/sedimentological studies of a Quaternary tidal delta system." Thesis, Bangor University, 1992. https://research.bangor.ac.uk/portal/en/theses/geophysicalsedimentological-studies-of-a-quaternary-tidal-delta-system(ae3d0f0e-f4a9-41a8-a9e1-c6f74902e331).html.
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An attempt has been made to define the Quaternary development of a tidal delta system and the surrounding area of the Menai Strait and Caernarfon Bay. The morphologies and processes of a tidal inlet and its associated flood and ebb-tidal deltas are described and a model of sediment transport pathways prevailing in the study area has been proposed. Seismic stratigraphic evidence suggests that the Quaternary deposits in Caernarfon Bay are primarily composed of three depositional sequences i. e. glacial, postglacial, and recent. The oldest sequence i. e. glacial sequence, lies unconformably on bedrock. The bedrock topography was successfully defined using a sparker seismic system and the results suggest that the bedrock surface is very uneven in nature and that there are two NE-SW trending valley features which can be linked to the Berw and Dinorwic faults. However, their typical U-shaped form may be attributed to erosion during the late Devensian ice advance. Various types of progradational reflection patterns within the postglacial sequence suggest a rapid rise in sea level after c. 9000 years B. P. It appears that the completion of the present morpho-hydrodynamic system most probably took place c. 5000 years B. P. The newly evolved morpholgy and flood and ebb tidal currents resulted in the accumulation of thick deposits of recent sediments in and outside the inlet i. e. flood and ebb-tidal deltas. A comparison of these tidal deltas with standard models suggest that whilst the flood-tidal delta shows hardly any resemblance to the standard model, the ebb-tidal delta is strikingly consistent in morphology and processes with the standard model. A model of the sediment transport pathways, proposed on the basis of comprehensive studies of bedform characteristics, grain size distribution trends, and to some extent on the basis of sediment transport calculations, suggests that there is a net sediment transport towards the southwest through the Menai Strait. The study of temporal variations in the characteristics of bedforms within the Menai Strait during a neap/spring tidal cycle suggest that the bedforms are ebb-oriented during most of the tidal states. A partial flood orientation occurs only during high spring tide. The extensive occurrence of sand ribbons with superimposed small scale megaripples (1-2m in wavelength) in the deeper parts of the Caernarfon Bay suggest a relatively lesser net sediment transport northeastwards which turns towards the north as it approaches the ebb-tidal delta body.
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Jones, Andrew. "Sedimentological record of the late palaeozoic Gondwanan glaciation in Queensland /." St. Lucia, Qld, 2003. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17532.pdf.
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Scarselli, Sonia. "Tectonic, sedimentological and palaeonvironmental history of the Marche Appenines (Italy) /." Zürich : ETH, 2007. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17382.
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Milzow, Jan Christian. "Hydrological and sedimentological modelling of the Okavango Delta Wetlands, Botswana /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=18058.
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Gatti, Emma. "Geochemical and sedimentological investigations of Youngest Toba Tuff ashfall deposits." Thesis, University of Cambridge, 2013. https://www.repository.cam.ac.uk/handle/1810/244398.
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The ~ 73 ka ‘super-eruption’ of the Toba caldera in Sumatra is the largest known eruption of the Quaternary. The products of this eruption, the Youngest Toba Tuff (YTT), have been implicated in global and regional climate deterioration with widespread ecological effects. In this thesis I study the YTT co-ignimbrite ashfall, in particular the mechanisms of transport, sedimentation and preservation of ash deposits. I use distal marine and terrestrial ash sediments: a) to estimate the volume of YTT ash fallout; b) to quantify variability in the geochemistry of YTT ash; c) to assess the reliability of YTT ash as a chronostratigraphic marker; and d) to determine local influences on the reworking of YTT ash deposits. Following the introductory chapters, I address topics a) and b) through detailed investigations of published physical and chemical evidence. Chapter three shows that particle size and sediment thickness do not decline exponentially with distance from the eruption vent, highlighting the limitations of current methods of volume estimation for co-ignimbrite super-eruptions. Chapter four analyses geochemical variation in 72 YTT samples, and reveals the signatures of magma chamber zonation and post-depositional alteration. I address topics c) and d) through fieldwork in six locations, and detailed analysis of ash samples from a wide variety of local depositional environments. Chapter five uses high-resolution stratigraphic analysis of the YTT layer in the Son Valley, India, to show that variable deposition and sediment reworking may compromise the reliability of the ash layer as an isochronous marker for interpreting archaeological sequences. Chapter six combines a new understanding of the mechanisms of reworking, using new data on microscopic characteristics of reworked ash at four sites in Malaysia to demonstrate the necessity of accounting for reworking in palaeoenvironmental reconstructions. I conclude that accurate analyses of distal ash deposits can reliably determine the chemical properties of the YTT eruption, and that a detailed understanding of deposition and reworking processes is essential to inference of the environmental impacts of super-eruptions.
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Srisuwon, Phumee. "Structural and sedimentological evolution of the Phare Basin, Northern Thailand." Thesis, Royal Holloway, University of London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.402176.
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Moore, Julian Kenneth Spencer. "Integration of the sedimentological and petrophysical properties of mudstone samples." Thesis, University of Newcastle Upon Tyne, 2005. http://hdl.handle.net/10443/227.
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Mudstones are of considerable scientific and economic importance as they are the dominant sedimentary rock type, forming the main repository of Earth history and having significance to numerous aspects of petroleum exploration and production, and many other industries. This study investigated the sedimentological characteristics of 150 diverse mudstone samples. The novel integration of grain size analysis combined with petrographic observations lead to a framework in which six mudstone grain size distribution (GSD) types are defined. The grain size types proposed are remarkably consistent in their form and characteristics and can be understood in terms of well constrained physical processes of deposition. The basis for this definition reflects largely the relative contributions of a flocculated, clay-rich component and an unflocculated silt/sand-rich grain size component. Integration of grain size data, pore size data and petrographic observations suggests a critical division between: (a) flocdominated mudrocks whose structure is supported by the clay matrix; and (b) silt-rich mudrocks whose structure is supported by a silt/fine sand framework. Floc-dominated mudrocks with clay matrix support develop low permeabilities and become very good capillary seals at relatively shallow depths. In contrast, silt-rich mudrocks with framework support only become low permeability units and very good capillary seals at much greater levels of compaction. The framework proposed here can form the basis of predictive flow and seal capacity models for mudrocks. A combined PCAcluster analysis approach to the grain size based classification of mudstones showed that of the six types defined in Chapter 2, types 1 — 4 (floc — silt mixtures) were consistently partitioned from types 5 — 6 (silt or sand rich mixtures). An attempt was made to quantify the distribution of key pore parameters, such as mean pore size, by grouping the data to reflect the matrix (grain size types 1 — 4) and framework (grain size types 5 — 6) support regimes and dividing into 5% porosity bins. The statistical distribution of pore network properties could not be verified, principally due to a combination of sparse sample numbers and highly variable nature of this data. This work illustrates that variability in mudstone pore size distributions is not constrained solely by lithology (support regime) and porosity, and thus that other factors must be taken into account if their evolution during compaction is to be understood.
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Blott, Simon James. "Morphological and sedimentological changes on artificially nourished beaches, Lincolnshire, U.K." Thesis, Royal Holloway, University of London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.396149.
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Clarke, Patrick. "Sedimentological studies in Lower Old Red Sandstone basins, northern Scotland." Thesis, Queen's University Belfast, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335340.
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Farvardini, Mandana. "The Sedimentological Distribution of Upper Brent, Oseberg field, North Sea." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-312874.
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The Oseberg hydrocarbon field is located in the northern North Sea sedimentary basin (61-62° N) on the eastern flank of the Viking Graben and is bounded to the east by the Horda Platform and the Øygarden Fault Complex (ØFC). The field is covering up most parts of block 30/6 and 30/9 on the Norwegian Continental Shelf (NOCS) but also minor parts of blocks 30/5, 30/8 and 30/12. The North Sea has developed through a very complex structural setting thus a great effect on the Oseberg hydrocarbon field where good quality sandstone reservoir rocks have been able to deposit very successively. The structural event of the Mid North Sea dome that occurred in the Middle Jurassic (Bajocian-Bathonian) is considered to be a main source of the successive sedimentary formations that the Oseberg field is buildup on. These formations are mainly a part of the Brent Group which consists of five lithological formations; Brent, Rannoch, Etive, Ness and Tarbert, where the Ness and Tarbert formation are representing great sandstone reservoir rocks. The study of structural and stratigraphic frameworks of the Oseberg field and its formations will help predict depositional environments thus evaluate reservoir systems. Fairly good results of lithology interpretation will be provided through analyzing well log-, and core-data and with seismic supplies, even stronger results. Keywords: Sedimentology, Middle Jurassic, Brent Group, paleoenvironment, petroleum geology
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Brown, Jaron Michael. "Sedimentological and Biological Analyses on Hobble Creek Prior to Restoration." Diss., CLICK HERE for online access, 2008. http://contentdm.lib.byu.edu/ETD/image/etd2268.pdf.
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Uttamo, Wutti. "Structural and sedimentological evolution of Tertiary sedimentary basins in northern Thailand." Thesis, Royal Holloway, University of London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249622.
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Crooks, Stephen. "Sedimentological controls on the geotechnical properties of saltmarsh and mudflat deposits." Thesis, University of Reading, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244710.
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Young, Melinda. "The foraminiferal and sedimentological dynamics of a Portuguese submarine canyon system." Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295866.
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Myers, K. J. "Onshore outcrop gamma ray spectrometry as a tool in sedimentological studies." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/47393.
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King, Georgina. "Fundamental and sedimentological controls on luminescence behaviour in quartz and feldspar." Thesis, University of St Andrews, 2012. http://hdl.handle.net/10023/2586.
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The optically stimulated luminescence (OSL) characteristics of a suite of quartz and feldspar samples from a range of modern glaciofluvial sediments have been explored to determine the use of OSL as a depositional pathway tracer. Paraglacial and subglacial source material and various glaciofluvial deposits have been analysed from the glacial catchments of Bergsetbreen, Fåbergstølsbreen, and Nigardsbreen as well as the Fåbergstølsgrandane sandur, Jostedalen, Norway. The OSL distribution signatures have been characterised through exploration of sample skewness, kurtosis and overdispersion, and dose distributions of the different depositional settings and source materials are distinct for both quartz and feldspar. Residual ages are greatest for feldspar, indicating significant potential age overestimation where feldspar is used to date glaciofluvial deposits. Sample dose distributions and overdispersion characteristics are driven by source sediment properties, whereas residual ages are controlled by transport and depositional processes. Those transport and depositional processes which result in significant light exposure, also influence dose distributions, and processes that sort sediments least effectively have the highest residual doses. Sample OSL characteristics, transport distance and grain size distributions have been investigated using factor analysis, as a means of predicting sediment source, facies, depositional process and deposit type. Although the depositional processes of the quartz samples can be clearly differentiated based upon OSL characteristics, factor analyses of feldspar and grain size characteristics are inconclusive. The application of quartz OSL to the Norwegian samples was limited by its very poor luminescence sensitivity. Quartz is the preferred mineral for OSL, however, despite the plethora of successful quartz OSL applications, the precise origin of the UV/blue luminescence emission, measured during OSL, remains unclear. The origins of this emission and controls on its intensity were explored using a variety of spectroscopic techniques including photoluminescence, cathodoluminescence, radioluminescence (RL), ionoluminescence (IL) and x-ray excited optical luminescence (XEOL). Exciting sample luminescence at a range of energies enables exploration of the different donor centres responsible for the luminescence emission. Cathodoluminescence and RL emission spectra are similar, comprising broad emissions at 1.5, 2.0 and 2.7 eV (detection in the UV part of the spectrum was not possible for these experiments). Ionoluminescence emission spectra were dominated by the ~ 3.3 eV emission, which is a component of the signal conventionally monitored during OSL. This emission depleted as a function of dose, to the benefit of the red emission (1.8-2.0 eV) for all samples throughout IL, and similar observations were made for the 3.4 eV emission observed from the XEOL emission spectra. The XEOL spectra are dominated by an emission at ~ 3.8 eV, not widely reported for quartz, which has tentatively been attributed to peroxy linkages. Differences between the IL and XEOL emission spectra are interpreted as evidence for the presence of multiple excited states.
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D'Arcy, Mitchall. "Constraining landscape sensitivity to climate change using geomorphological and sedimentological approaches." Thesis, Imperial College London, 2015. http://hdl.handle.net/10044/1/28651.
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Climate exerts a profound control on the processes that shape landscapes and produce the sedimentary deposits with which we can interpret the Earth's history. However, we lack a complete understanding of how sensitive tectonically-active, eroding landscapes are to climate and climate change. How does a simple sediment routing system react to a change in rainfall rate? Can mountainous landscapes respond quickly enough to preserve a record of high-frequency climate changes, e.g., glacial-interglacial cycles? What effect does headwater glaciation have on downstream sediment characteristics? Can we quantify past climate changes using the sedimentological properties of terrestrial stratigraphy? Geologists lack complete answers to these questions, among many others. Theoretical work, using physical first principles and numerical models, has produced a range of hypotheses about landscape sensitivity to climate, but we now need empirical data to test and make sense of these ideas. This thesis therefore explores empirically how geomorphological and sedimentological records have responded to climatic gradients across time and space. In the first part of this thesis, the extent to which spatial climate gradients are recorded by the longitudinal geometry of river channels is investigated. I use a simple stream power erosion law to predict an inverse relationship between channel steepness and average precipitation rate, and then test this theory using data from a variety of study areas and two complementary analytical approaches. Climate is found to be an important control on river longitudinal geometry across a range of climatic and tectonic conditions, in a way that conforms to existing theoretical knowledge and also allows the climatic signal to be discriminated from tectonics. This work therefore demonstrates that a widely-used geomorphological measurement - the channel steepness index - is quantifiably sensitive to climate in tectonically-active areas, and these findings offer a new explanation for geographic variations in channel steepness that cannot be explained by tectonics alone. The second part of this thesis focuses on the sensitivity of simple mountain catchment-alluvial fan systems to climate changes associated with the last glacial-interglacial cycle, as expressed in the south-western United States. First, eight debris flow-dominated systems located in the south-eastern Sierra Nevada, California are examined. I establish a detailed chronostratigraphic model for these fan systems by building upon and integrating existing exposure age constraints reported by others, and additionally developing a new technique for estimating the ages of these fan deposits. This technique is based on calibrating the rate of enlargement of common weathering fractures observed in exposed surface boulders, which are shown to widen at a steady and predictable rate post-deposition, and can be used as reliable age indicators for > 100 ka at this location. Using the detailed temporal record of deposition established for these fan systems, a large ( > 30,000 particle) grain size data set that spans the last full glacial-interglacial cycle is examined. I demonstrate that debris flow grain size is a highly sensitive recorder of past climate changes, capturing the glacial-interglacial cycle as a sustained and high-amplitude time series with a rapid response timescale of < 10 ka. These debris flow deposits become significantly coarser-grained with warming and overall drying of the climate, and this thesis outlines quantitative reasons why this signal can be attributed to increasing storm intensity with warming. Finally, these debris flow-dominated systems are contrasted with two carefully-selected stream flow-dominated fan systems in Death Valley, California. Using measures of down-system grain size fining and a self-similarity model of sediment calibre, sediment flux estimates during arid interglacial and wetter glacial climate conditions are derived and compared. This study shows that a decrease in average rainfall rate of ~ 30 % produced a corresponding decrease in sediment flux of ~ 20 %. However, I also demonstrate the circumstances in which signal buffering due to incision and sediment recycling destroys this climate signal. Consequently, this thesis demonstrates both the causes and results of complexity in the relationship between climate change, geomorphology, and well-dated terrestrial sedimentary records. Ultimately, this is an expression of how sediment transport processes, tectonics, the magnitude-frequency distribution of rainfall, and other factors interact to generate different climate responses in different systems. Nevertheless, for both geomorphic and sedimentological records examined here, I demonstrate that the effects of climate can be quantified clearly: channel steepness can be quantified as a function of rainfall rate; debris flow sedimentology can be quantified as a function of storm intensity; and alluvial fan sedimentology in Death Valley can be quantified as a function of glacial-interglacial climate changes. Essentially, this thesis finds that terrestrial landscapes are sensitive to known climate changes in the recent geological past, and this result is profoundly important for improving our ability to decode geomorphic and stratigraphic archives effectively. The data and ideas within this Ph.D. research provide useful opportunities for (i) testing and updating our models of how sediment routing systems respond to climate, (ii) extracting quantitative information about past climates from the sedimentary record, and (iii) predicting the effects of future climate changes on the landscape.
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Weavers, Ellen Louise. "Faunal, sedimentological and geochemical indicators of dysoxia in Cretaceous marine sediments." Thesis, University of Greenwich, 2010. http://gala.gre.ac.uk/8114/.
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This project compares palaeo-oxygenation related features of lower Cretaceous rocks from the shallow sea muds of the Gault Clay (south east England) and Niveau Pacquier and Briestroffer sequences (south east France), and the Tarfaya Basin upwelling-zone Amma Fatma sediments (Morocco). The palaeo-oxygenation indicators investigated include: sedimentological proxies, including ichnology, sedimentology, taphonomy and pyrite framboid size distribution; faunal proxies including macrofaunal properties, and biofacies models; and geochemical proxies, including trace-element abundances [Mo, V, Ni, Mn], element ratios and parameters [U/Th, authigenic U (Ua), V/Cr, Ni/Co, Ni/V, (Cu+Mo)/Zn, V/Sc and V/(V+Ni)] and Fe-S-C systematics [Total Organic Carbon (TOC), Total Sulphur/TOC ratio, Degree of Pyritisation and the Indicator of Anoxia]. The presence of lamination is a key sedimentological indicator of restricted bottom water oxygenation conditions. New descriptive categories of pyrite morphology are proposed. Interpretation of faunal proxies can be limited by poor preservation, but taphonomy-related indicators correlate well with proposed palaeo-oxygenation conditions. Molybdenum is the most reliable of the trace-metal enrichment proxies studied and altered numerical boundaries are proposed for Ua, U/Th, V/Cr and Ni/Co. Of the Fe-S-C systematics indicators, Total Organic Carbon and the Indicator of Anoxia to provide the greatest definition between palaeo-oxygenation data sets. Combinations of trace metal and Fe-S-C indicators such as [Molybdenum Enrichment Factor x Indicator of Anoxia], and plots of Ua against TOC provide the strongest palaeo-oxygenation proxies and distinguish between oxic/dysoxic, anoxic and euxinic conditions.
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Keskinler, Salih Yigit. "Sedimentological, Cyclostratigraphical And Sequence Stratigraphical Analysis Of Cretaceous Uzumlu Formation (nw Turkey)." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608355/index.pdf.
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High resolution sampling was performed along the Üzü
mlü
Formation exposed near the YeniceSihlar village of Mudurnu (Bolu). Field and thin-section analyses showed that the Ü
zü
mlü
Formation is composed of cm to m scale cycles of 4th and 5th order. The 4th order cycles are equivalencies of parasequences and have 0.4 Ma average duration. 5th order cycles are interpreted as episodic. Upper Albian (OAE1c or OAE1d) and Cenomanian/Turonian (OAE2) anoxic events are observed as black shale levels in the studied section. Position of black shale levels is interpreted using cyclostratigraphy and sequence stratigraphy. Four types of cycle are determined. A and B-type cycles are placed in transgressive and Highstand System Tract. C and D-type cycles are placed in Lowstand System Tract. Two type 3 and one type 1 sequence boundaries are recorded. The boundary between the Sogukç
am Limestone and the Ü
zü
mlü
Formation is interpreted as the first type 3 sequence boundary. The second one separates the Ü
zü
mlü
Formation and the Yenipazar Formation and is observed at the top of the section. Type 1 boundary is represented by a conglomeratic level in the middle of the succession. Provenance analysis of sandstones indicates that during the Cenomanian the source area changed from magmatic arc setting to continental setting.
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Jones, Rina. "The sedimentological and structural evolution of Tertiary basins of Vaucluse, S.E. France." Thesis, University of Liverpool, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361636.
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Kadem, Liftaa Selman. "Sedimentological, mineralogical and geochemical studies of Holocene coastal sediments, south western Scotland." Thesis, University of Glasgow, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287730.
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Jones, Hannah Amy. "Sediments in urbanised river catchments : an integrated sedimentological and magnetic mineral approach." Thesis, Manchester Metropolitan University, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412634.
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Rojas, Temistocles Simon. "Controlling realism and uncertainty in reservoir models using intelligent sedimentological prior information." Thesis, Heriot-Watt University, 2014. http://hdl.handle.net/10399/2751.
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Forecasting reservoir production has a large associated uncertainty, since this is the final part of a very complex process, this process is based on sparse and indirect data measurements. One the methodologies used in the oil industry to predict reservoir production is based on the Baye’s theorem. Baye’s theorem applied to reservoir forecasting, samples parameters from a prior understanding of the uncertainty to generate reservoir models and updates this prior information by comparing reservoir production data with model production response. In automatic history matching it is challenging to generate reservoir models that preserve geological realism (obtain reservoir models with geological features that have been seen in nature). One way to control the geological realism in reservoir models is by controlling the realism of the geological prior information. The aim of this thesis is to encapsulate sedimentological information in order to build prior information that can control the geological realism of the history-matched models. This “intelligent” prior information is introduced into the automatic history-matching framework rejecting geologically unrealistic reservoir models. Machine Learning Techniques (MLT) were used to build realistic sedimentological prior information models. Another goal of this thesis was to include geological parameters into the automatic history-match framework that have an impact on reservoir model performance: vertical variation of facies proportions, connectivity of geobodies, and the use of multiple training images as a source of realistic sedimentological prior information. The main outcome of this thesis is that the use of “intelligent” sedimentological prior information guarantees the realism of reservoir models and reduces computing time and uncertainty in reservoir production prediction.
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Mesquita, Ãquila Ferreira. "Eolianite and beachrocks in western coast of CearÃ: Meaning Sedimentological and neotectonic." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14392.
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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorOs depÃsitos holocÃnicos do litoral oeste do Cearà encontram-se em intrÃnseca relaÃÃo com a flutuaÃÃo do nÃvel relativo do mar no Holoceno Tardio, possivelmente controlada por atividade neotectÃnica. A partir do estuÃrio do rio Aracatimirim (provÃvel projeÃÃo do Lineamento Transbrasiliano), a Ãrea de estudo foi subdividida em setor Icaraà de Amontada (leste) e setor Itarema (oeste). O setor leste compreende planÃcies costeiras com grande presenÃa de eolianitos e beachrocks associados. A partir da anÃlise faciolÃgica dos depÃsitos de eolianitos, foi possÃvel identificar cinco fÃcies eÃlicas interpretadas como paleocampos de dunas frontais e cadeias de dunas barcanÃides associadas a extensÃes lineares. Esses depÃsitos foram originados em campos de dunas transgressivas em nÃvel eustÃtico alto sucedido por um recuo generalizado do nÃvel marinho local, este Ãltimo responsÃvel pela incisÃo fluvial e cimentaÃÃo de beachrocks e eolianitos. Em contrapartida, o setor oeste tambÃm registra dois momentos distintos do nÃvel relativo do mar, responsÃvel pela formaÃÃo de uma paleofalÃsia em nÃvel de mar alto e um sistema de barreiras regressivas em eventos de recuo do nÃvel do relativo do mar. Admitindo-se nenhum contraste na eustasia e suprimento sedimentar em ambos os setores, tal diferenÃa pode estar relacionada a movimentos diferenciais de blocos adjacentes à terminaÃÃo offshore do Lineamento Transbrasiliano, afetando a acomodaÃÃo sedimentar. Para os registos do nÃvel relativo do mar no Holoceno, supÃe-se que nÃvel acima do atual nÃo foi alcanÃado para a costa equatorial do Brasil, exceto na Ãrea em estudo, onde foram registrados paleonÃveis marinhos a 1,7 m e 1,0 acima do nÃvel mÃximo atual de preamares para SantarÃm e Volta do Rio, respectivamente. Essa relaÃÃo atende a hipÃtese de atividade neotectÃnica em blocos adjacentes ao Lineamento Transbrasiliano como o principal mecanismo na modificaÃÃo do espaÃo de acomodaÃÃo da bacia e recuo do nÃvel marinho. A partir dos dados morfoestruturais em tabuleiros prÃ-litorÃneos, identificou-se um leve arqueamento positivo da superfÃcie de topo dos tabuleiros no setor oeste, em contraste a uma pequena anomalia de relevo positivo (soerguimento relativo de aproximadamente 10 m) na extremidade do setor leste. Concomitante a essa movimentaÃÃo genÃrica, encontramse sÃries de movimentos transcorrentes dextrais em fraturas NE-SW com componentes transpressionais e transtracionais, promovendo movimentos verticais diferenciados de pequena amplitude. Dessa forma, postula-se que a maior componente de soerguimento, caracterÃstico do setor Icaraà de Amontada, tenha impulsionado uma maior destruiÃÃo de espaÃo para acomodaÃÃo de sedimentos no lado leste. Dessa forma, que o recuo do nÃvel marinho relativo atingiu magnitude maior nesse setor do que no setor Itarema, o que possibilitou a incisÃo fluvial no setor leste e instalaÃÃo de um sistema de barreiras regressivas no setor oeste. Esse modelo explica o contraste entre geometria e ambientes deposicionais em um compartimento relativamente pequeno do litoral noroeste do CearÃ. Entretanto, essa hipÃtese precisa ser melhor investigada e testada a fim de se obter um modelo mais robusto para a evoluÃÃo da Ãrea em questÃo, sobretudo em relaÃÃo a correlaÃÃes laterais entre os depÃsitos sedimentares, cinemÃtica e dinÃmica no contexto neotectÃnico.
The Holocene deposits of the western coast of Cearà are in close relationship with the fluctuation of the relative sea level in the Late Holocene, possibly controlled by neotectonic activity. Using the mouth of the Aracatimirim River (likely projection of Transbrasiliano Lineament) as reference, the study area was divided into Icaraà de Amontada sector (east) and Itarema (west) sector. The eastern sector comprises coastal plains with great presence of associated eolianite and beachrocks. From the facies analysis of eolianite deposits were identified five aeolian facies interpreted as frontal dunes and barcanoid dune chains associated with linear extensions. These deposits were originated in transgressive dune fields, during rising eustatic level, succeeded by a general fall of the local sea level, the latter responsible for river incision and cementation of beachrocks and eolianites. In contrast, the western sector also records two different times of relative sea level, responsible for the formation of a paleocliff in rising sea level and a system of regressive barriers in falling sea level event. Assuming no contrast in eustasy and sediment supply in both sectors, this difference may be related to differential movement of adjacent blocks offshore termination of Transbrasiliano Lineament, affecting sedimentary accommodation. For the record of relative sea level during the Holocene, it is assumed that the current level was not reached for the equatorial coast of Brazil, except in the study area, where were registered marine paleolevels from 1.7 m to 1.0 m above the current level of maximum high tides to Santarem and Rio Volta, respectively. This relationship strengths the hypothesis of neotectonic activity in locks adjacent to Transbrasiliano Lineament as the main mechanism on modification the accommodation space of the basin and retreat of sea level. From the morphostructural data in pre-coastal trays, were identified a positive smooth arching of the pre-coastal plateaus top surface in the western sector, in contrast to a small positive anomaly of relief (uplift of approximately 10 m) at the east end sector. Concomitant with this generic deformation, there was some dextral transcurrent movements in NE-SW fractures with transpressional and transtensional components,providing different vertical movements of small amplitude. Thus, it is postulated that the higher uplifting component, characteristic of Icarai de Amontada sector, has caused more destruction of accommodation space for sediment on the east side than in the west side,causing river incision in the eastern sector and installation of a regressive barriers system of in the western sector. This model explains the contrast between geometry and depositional environments in a relatively small compartment in northwestern coast of CearÃ. However, this hypothesis needs to be investigated and tested in order to obtain a more robust model for the evolution of the area, especially in relation to lateral correlations between sedimentary deposits, kinematics and dynamics in the neotectonic context.
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Simpson, Keryn. "Foraminiferal species distributions and sedimentological dynamics of the Knysna Estuary, South Africa." Master's thesis, University of Cape Town, 2003. http://hdl.handle.net/11427/10834.
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Bibliography: leaves 108-114.Although the status of the Knysna Estuary is considered to be in an acceptable environmental condition, pressures of development and tourism in the area are likely to cause substantial deterioration. Investigating the microfossil assemblages in the Knysna Estuary is imperative, since foraminifera serve as essential ecological indicators, and can be used to monitor the health of the ecosystem during development, as they are extremely sensitive to any environmental changes. The Knysna Estuary is well suited for investigating microfossil assemblages, since it has the richest fauna of the larger benthic invertebrates of any of the South African estuaries and it is open to the sea throughout the year.
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Nakanishi, Toshimichi. "Detection of multiple paleoseismic events based on high-resolution sedimentological core analysis." 京都大学 (Kyoto University), 2004. http://hdl.handle.net/2433/147821.
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Wal, Abhilasha. "Sedimentological effects of aeolian processes active in the Tentsmuir area, Fife, Scotland." Thesis, University of St Andrews, 1993. http://hdl.handle.net/10023/15197.
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Present day coastal accretion at Tentsmuir is manifest in the form of hummocky dune accumulations along the shoreline. The mode and variability of the distribution of surface sediments by the wind and the magnitude of accumulation of wind laid deposits in the Tentsmuir beach-dune complex is a measure of Aeolian activity in the area. In the Tentsmuir area fine to medium grained well sorted beach sands are entrained by high to moderate energy, seasonal, directionally unimodal to bimodal winds of low variability. During the winter season the dominant winds are from the south west (blowing towards the sea) whereas, generally during the spring the more effective winds are derived from the east (blowing towards land). The bimodal winds are composed of contrasting unimodally directional winds blowing for shorter durations. Daily sea breezes are observed during the summer. Field measurements of sand transport rates, with the aid of sand traps during anemometer determined wind speeds ranging from 4 m s-1 to 20 m s-1, in the study area show that while the onshore transport vector results in rapid foredune development, the longshore and offshore component contributes to a positive beach sediment budget. However, the net beach sediment budget is a complex interplay of Aeolian, wave and tidal processes. Shear velocities on the Tentsmuir beaches ranged from 18.5 cm s-1 to 52 cm s-1 and the focal point, u' and z' values were 1.75 m s-1 and 0.03 cm respectively. In general, the variability of the short-term Aeolian sand transport rates in the Tentsmuir beach-dune subenvironments is controlled by (i) variation in wind velocity, (ii) presence or absence of vegetation, (iii) ground surface moisture, and (iv) the sand size and source limitation. The potential sand input by the onshore winds during the last eleven years is estimated to have been approximately 28,532 m3. During the same period the potential amount of sand blown towards the sea was 109,570 m3. The amount of predicted onshore sediment input (28,532 m3) compares well with the 33,000 m3 of sand estimated to have accumulated in the lee of the beach at Tentsmuir Point The close agreement of the measured and predicted values of Aeolian transport suggests that the White (1979) expression, used in the present study to predict transport rates on the beach, provides fairly reliable estimates. Very high velocity offshore winds (>9 ms-1 produce a shelly deflation surface along the backshore, surface parallel sand sheets and sand strips on the foreshore; adhesion plane bed and adhesion structures along the moist/wet tidal margin and pyramidal dunes (offshore transport across a dune ridge >2.5m high.). Onshore high velocity winds result in the formation of surface parallel sand strips on the foreshore and a high volume of Aeolian sediment accumulation in the backshore and foredune area. Prolonged days of high velocity unidirectional winds result in the formation of barchans. Medium to high wind velocities (~6-9 ms-1) produce ballistically rippled foreshore sand lobes, lee dunes downwind of tidal debris, adhesion structures (offshore/longshore transport) and some sand accumulation in the foredune area (onshore transport). Abundant parallel laminated sand, pinchout laminae, sand lenses, precipitation deposits, trough crossbeds, plant remains at places overlying beach shell layers constitute a prograding coastal dune facies at Tentsmuir.
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Mok, Wing-yan Connie. "Integrated sedimentological, geophysical and geotechnical study of inner shelf sediments in Hong Kong." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B35675172.
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Hart, Deirdre E. Physical Environmental & Mathematical Sciences Australian Defence Force Academy UNSW. "Eco-sedimentological environments of an inter-tidal reef platform, Warraber Island, Torres Strait." Awarded by:University of New South Wales - Australian Defence Force Academy. School of Physical, Environmental and Mathematical Sciences, 2003. http://handle.unsw.edu.au/1959.4/38731.
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This thesis examines functional relationships between the morphologic, hydrodynamic, ecological and sedimentological characteristics of the Warraber reef platform, an inter-tidal reef island system, Central Torres Strait, Australia (10[degrees] 12??? S, 142 [degrees] 49??? E). Hydrodynamic and sediment-transport experiments were conducted on the reef flat using current meters, water level recorders and directional sediment traps. Results showed dominantly SE flows during the dry season and more variable NW to SE flows during the wet season. Topography and reefal water levels modulated the direction and strength of currents and the generation of wind-waves on the reef flat as well as the passage of waves over the reef rim. These hydrodynamic conditions are sufficient to induce significant transport of moderately fast to slow settling sediment (>-5.25 symbol psi) on the reef flat, though the platform as a whole is a relatively closed transport system. Carbonate production was estimated based on the key ecological variables of live assemblage distribution and cover. Overall, only 24% of the reef flat was occupied by carbonate-producing organisms. The average estimated carbonate-production rate for the reef was 1.6 kgm -2y-1 (0.07-4.37 kgm-2y-1). Production is dominated by coral (73%), with subordinate proportions contributed by coralline algae (19%). And molluscs, foraminifera and Halimeda (<4%) though actual reef-flat sediments did not reflect this potential. Instead, they were dominated by molluscs (35-55%), coralline algae (16-26%), coral (8-13%), Halimeda (7-8%) and foraminifera (5-10%). Differential rates of carbonate to sediment conversion meant the reef-platform sediments were more closely related to the cover of live organisms than to the contribution of carbonate production by each parent organism. The settling properties of the least altered particles of the five commonest constituents were measured and these provided the basis for an eco-sedimentological model of the reef-platform system. Modelled textures were compared to the actual textures, indicating the degree of textural alteration resulting from a combination of biological and physical processes, including sediment production, hydraulic sorting and mechanical breakdown. This analysis, integrated with the hydrodynamic, exposure and other data, was used to determine reef-platform surface-sediment sources, sinks and transport pathways. In using both the textual and constituent compositional properties of sediments, as well as information on local biological and physical processes, the model approach developed offers progress towards an integrative, interdisciplinary analysis of carbonate environments.
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Yeung, Chung-hang, and 楊頌恆. "Magnetic properties of seabed sediments in Hong Kong: applications to sedimentological and contaminationstudies." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31222043.
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Mok, Wing-yan Connie, and 莫穎恩. "Integrated sedimentological, geophysical and geotechnical study of inner shelf sediments in Hong Kong." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B35675172.
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Veale, Christopher J. "Geochemical and sedimentological controls on the origin of sandstone-hosted radioelement-rich bitumens." Thesis, Queen's University Belfast, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388200.
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McLean, Donald C. H. "Magnetic and sedimentological analyses of quaternary lake sediments from the English Lake District." Thesis, University of Bedfordshire, 1991. http://hdl.handle.net/10547/600845.
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Results of mineral magnetic, mobile clement, and granulometric analyses of Holocene sediments from Buttermere and Crummock Water (two closely-linked lakes in the north-west of the English Lake District) are presented. These are used to: (1) identify effects of internal (lacustrine) and external (catchment) controls on sedimentation; (2) establish catchment source-lake sediment linkages and assess the value of mineral magnetic techniques in palaeolimnological studies; (3) identify major catchment environmental changes. Analyses of lake sediment fabrics (using sediment thin sections, SEM clay flake analysis, standard granulometric analysis, and mineral magnetic indicators of grain size change) indicate that river plume sedimentation is the normal sediment dispersal mechanism in these lakes. Thin (< = 3.0 mm) chlorite-rich laminae, found at intervals in the otherwise homogeneous Holocene sediment sequence, are probably formed by trapping and concentration of fine, platy particles within lake waters. They are subsequently deposited during lake overturn. This represents an "internal" control on sedimentation. A model of sedimentation processes operating in these lakes is developed, incorporating river plume sedimentation, episodic density surges, and lake thermal structure. Mineral magnetic measurements allow the objective subdivision of the lacustrine lithostratigraphy, identifying broad changes in lake sediment characteristics. Samples from both lake catchments are clustered into six magnetically distinct groups - despite the lithological complexity of the catchment. Comparison of these with the lake sediments has enabled identification of major sources during the Holocene. Following deposition of relatively unaltered bedrock-derived material during the Late-glacial ("primary" sources), secondary sources (which may include glacial diamicts, soils and stream sediments) dominate the lake sediments. Direct input of topsoil-derived sediment from circa 1000 A.D. onwards (during and following the main period of Norse settlement of the Lake District) is identified by its distinctive mineral magnetic characteristics, (high Xfd% values, >-4%). Industrially-derived magnetic spherules contribute significantly to the mineral magnetic characteristics of the more recent sediments, (mainly those post-dating circa 1900 A.D.). These are used to construct a proxy chronology for recent sediments. Catchment environmental changes arc mainly related to stabilisation of vegetation following deglaciation and, from circa 2,000 B.P., anthropogenic effects of deforestation and land disturbance, thus increasing lake sediment accumulation rates. These findings are broadly consistent with the interpretation of the Lake District Post-glacial sediment sequence presented in studies by Mackereth, (1966a), and Pennington, (1981), demonstrating a uniformity of lake and catchment development within the Lake District. A prominent minerogenic layer present in the Buttermere and Crummock Water sediment sequence however broadly correlates with similar horizons deposited in other Lake District lakes from circa 7,400 - 5,000 B.P. These have been previously interpreted as composed of topsoil-derived material derived from human actions, (Pennington 1973, 1981). In the Buttermere and Crummock Water sediments, this layer is best interpreted as derived from glaciogenic sediment') reworked from within the lake basins, probably following lowered lake water levels during the period circa 7,300 - 5,300 B.P. Thus it is suggested that a reinterpretation of similar Lake District lacustrine sediments using the methods employed in this study would be appropriate.
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Huffer, Amanda R. "The Sedimentological and Paleontological Characteristics of the Portersville Shale, Conemaugh Group, Southeast Ohio." Ohio University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1183737592.
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MCLAUGHLIN, PATRICK IAN. "LATE ORDOVICIAN SEISMITES OF KENTUCKY AND OHIO: A SEDIMENTOLOGICAL AND SEQUENCE STRATIGRAPHIC APPROACH." University of Cincinnati / OhioLINK, 2002. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1028144697.
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Harris, Charles William. "A sedimentological and structural analysis of the Proterozoic Uncompahgre Group, Needle Mountains, Colorado." Diss., Virginia Polytechnic Institute and State University, 1987. http://hdl.handle.net/10919/79644.
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Siliciclastic sediments of the Proterozoic Uncompahgre Group can be subdivided into stratigraphic units of quartzite (Q) and pelite (P); these units include a basal, fining- and thinning-upward retrogradational sequence (Q1-P1) that records the transition from an alluvial to a shallow-marine setting. Overlying the basal sequence are three thickening- and coarsening-upward progradational sequences (P2-Q2, P3-Q3 and P4-Q4) that were influenced by tide-, storm- and wave-processes. The progradational units are subdivided into the following facies associations in a vertical sequence. Outer-to inner-shelf mudstones, Bouma sequence beds and storm beds of association A are succeeded by inner-shelf to shoreface cross-stratified sandstones of association B. Conglomerates and cross-bedded sandstones of upper association B represent alluvial braid-delta deposits. Tidal cross-bedded facies of the inner shelf/shoreface (association C) gradationally overlie association B. Interbedded within the tidal facies in upper association C are single pebble layers or <1 m-thick conglomerate beds and trough cross-bedded pebbly sandstones. Single pebble layers could be due to storm winnowing whereas conglomerates and pebbly sandstones may record shoaling to an alluvial/ shoreface setting.
A temporally separated storm/alluvial and tidal shelf model best explains the origin and lateral distribution of facies in the progradational sequences. The presence of smaller progradational increments in the mudstone dominated units (P3) and the recurrence of facies associations in the thick quartzite/conglomerate units (Q2, Q3, Q4) suggests that external cyclic factors controlled sedimentation. A composite relative sea level curve integrating glacio-eustatic oscillations and long-term subsidence may account for the evolution of the thick progradational sequences of the Uncompahgre Group.
Sedimentary rocks of the Uncompahgre Group have been subjected to polyphase deformation and greenschist facies metamorphism. Phase 1 structures (localized to the West Needle Mountains) include bedding-parallel deformation zones, F₁ folds and an S₁ cleavage. Phase 2 coaxial deformation resulted in the development of upright, macroscopic F₂ folds and an axial-planar crenulation cleavage, S₂. In addition basement-cover contacts were folded. Phase 3 conjugate shearing generated strike-parallel offset in stratigraphic units, a macroscopic F₃ fold, and an S₃ crenulation cleavage. In addition, oblique-slip, reverse faults were activated along basement-cover contacts.
The Uncompahgre Group unconformably overlies and is inferred to be parautochthonous upon ca. 1750 Ma gneissic basement that was subjected to polyphase deformation (DB) and amphibolite facies metamorphism. Basement was intruded by ca. 1690 Ma granitoids. Deformation of gneissic and plutonic basement together with cover (DBC) postdates deposition of the Uncompahgre Group. The structural evolution of the Uncompahgre Group records the transition from a ductile, north-directed, fold-thrust belt to the formation of a basement involved “megamullion" structure which was subjected to conjugate strike-slip faulting to accommodate further shortening. DBC deformation may be analogous to the deep foreland suprastructure of an orogenic belt that developed from ca. 1690 to 1600 Ma in the southwestern U.S.A ..Ph. D.
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Knight, Alan Paul. "Ecological and sedimentological studies on china clay waste deposits in Mevagissey Bay, Cornwall." Thesis, Royal Holloway, University of London, 1988. http://repository.royalholloway.ac.uk/items/e77fc85a-3f3b-4542-add0-a49aa83df617/1/.
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Prior to 1973, the St Austell china clay industry discharged fine grade waste into local rivers which carried the waste into Mevagissey Bay, Cornwall. The clay waste, a mica and quartz rich silt buried a marine shell gravel substrate by up to 2 metres. The china clay waste and natural sediments on the surface and subsurface of Mevagissey Bay have been studied and the distribution of live and dead benthic faunas analysed. The benthic faunas presently living in the china clay waste and surrounding shell gravel have been compared to faunas from a similar survey taken during the period of peak discharge (1968) and during the reduction of discharges (1970-1973). Within the bay are four different benthic communities whose distribution reflects the amount and nature of china clay waste present. The only notable changes since the the cessation of dumping being the colonisation by a Tellina tenuis community of a previously azoic muddy substrate near the point of waste discharge into the bay. This research suggests that benthic communities in areas subjected toinert solid pollution will change to communities typical of the grain size of the waste. Each community can be recognised by a distinctive death assemblage although these show little resemblance to the composition of the original living community. Different taphonomic processes control the preservation within each community. Radiographs and microscopic examination of impregnated box core samples reveal the important effect of bioturbation on the orientation and position of shells and shell fragments within the substrate. Since the cessation of china clay waste dumping in 1973, shell debris formed by local benthos has began to transform the soft, fine grade substrate into a shell gravel. It is predicted that it will take within the order of 10,000 years for the substrate to resemble the original shell gravel now lying below the china clay waste.
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Wood, Jonathan Derek. "Sedimentological characterization and regional palaeo-environmental implications of the Messak Fm, SW Libya." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/sedimentological-characterization-and-regional-palaeoenvironmental-implications-of-the-messak-fm-sw-libya(e5da88e0-fa5a-463a-a16d-be60247de5dd).html.
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During the Early Cretaceous a regionally extensive cover of dominantly siliciclastic sediments was deposited across the North African continental margin. Historically, these siliciclastic sediments have been considered to be a relatively homogeneous lithofacies known as the ‘Nubian sandstone’. This lithofacies is generally described as coarse grained, cross-bedded sandstone and is ascribed to a braided fluvial depositional environment. However, there have been few detailed sedimentological studies carried out on these sediments. Furthermore, the stratigraphic relationships between regional Early Cretaceous continental strata in different North African countries has only briefly been described and has only locally been related to equivalent marine deposits. In order to address these problems, this study focuses upon two main approaches. Firstly, outcrop analysis of the Messak Fm (SW Libya) and the Sidi Aïch Fm (C Tunisia) details and contrasts the lithofacies variability of Early Cretaceous siliciclastic sediments in North Africa. Secondly, a unified stratigraphic framework is erected for the Early Cretaceous of Algeria, Tunisia, Libya and Egypt and the palaeogeographic evolution is reconstructed. Detailed sedimentological investigation of the Messak Fm has identified greater variation in lithofacies and depositional processes than was previously recognised. By lithostratigraphic correlation with outcrops in northwest Libya, we show a fluvial system transported sediment northward into a wide fluvio-paralic basin covering western Libya. Several episodes of marine influence culminating in a distinct and regionally correlatable transgressive episode are identified. This is the first time that marine influence has been identified in the Murzuq Basin and increases the maximum known extent of marine transgression in the Early Cretaceous of Libya by 600km. The sedimentology of the Messak Fm is contrasted with the sandstone dominated Sidi Aïch Fm which, although showing similar lithofacies, was deposited in a marginal-shallow marine environment.Building upon previous reviews and new insights from the Messak Fm and Sidi Aïch Fm, a synthesis and reinterpretation of the spatial and temporal heterogeneity of sediments and depositional environments in this region throughout the Early Cretaceous is presented. During the Berriasian-Barremian, the North African platform coastline was dominated by a dry subtropical climate with moderate vegetation. The interior of the platform experienced a Savannah-like semi-arid climate with limited vegetation and palaeosol development but was crossed by extensive fluvial networks draining the equatorial tropics. During the Late Barremian-Early Aptian, simultaneous aridification and marine transgression led to a decreased detrital flux to the marginal basins and widespread deposition of marine carbonates and mudstones. During the Late Aptian-Albian the platform returned to a humid tropical climate. Widespread coarse grained fluvial sediments mark the base of this sequence and palaeosols occur locally. The results of this work have implications for the development and controls of large-scale fluvio-paralic systems and illustrate the fact that, in a limited accommodation epicontinental setting, relative sea-level may be the key control on sedimentation and depositional processes for many hundreds of kilometres inland of the lowstand coastline.
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McLaughlin, Patrick I. "Late Ordovician seismites of Kentucky and Ohio a sedimentological and sequence stratigraphic approach /." Cincinnati, Ohio : University of Cincinnati, 2002. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=ucin1028144697.
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Nelson, Craig V. "Sedimentological and Foraminiferal Characterization of a Holocene Island Slope (130-240m), North Jamaica." DigitalCommons@USU, 1986. https://digitalcommons.usu.edu/etd/6687.
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Recent carbonate sediments from (133-236m) on the northern Jamaican island slope are significantly different from shallower reef zones (l-70m) in grain constituents, textural parameters, and foraminiferal assemblages. The island slope sediment is dominated by coral fragments, calcareous algae, Halimeda plates, and foraminiferal tests. The sediment is characteristically poorly-sorted, nearly-symmetrically skewed, and mesokurtic, with a mean grain size in the fine sand range. Mineralogically, the sediment is predominantly aragonite (66%) and high-Mg calcite (22%), with some calcite (8%), and minor amounts of clays and other insoluble minerals (4%). Q-mode cluster analyses of sediment constituents, textural parameters, and foraminiferal species and larger group abundances were utilized in the delineation of shelf and island slope depositional environments. ineffective for such use. Mineralogy proves No significant differences are observed in sedimentological parameters (textures, constituents, and sedimentation rates) between an island slope traverse located below an area with prominant sill reefs and a traverse below an area lacking well-developed sill reefs. It is suggested that the sill reefs have less effect on off-reef transport than was previously believed. Based on the abundance trends of certain sediment grains and the similarity of sediment grains in island slope and deep fore reef/fore reef slope sediment, it is suggested that the deeper reef zones (>30m) are the source of most sediment transported seaward. Foraminiferal abundances show lateral differences between traverses related to input of shallow water (