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1
Woronko, Barbara, Paweł Zieliński und Robert Jan Sokołowski. „Climate evolution during the Pleniglacial and Late Glacial as recorded in quartz grain morphoscopy of fluvial to aeolian successions of the European Sand Belt“. Geologos 21, Nr. 2 (01.06.2015): 89–103. http://dx.doi.org/10.1515/logos-2015-0005.
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Abstract We present results of research into fluvial to aeolian successions at four sites in the foreland of the Last Glacial Maximum, i.e., the central part of the “European Sand Belt”. These sites include dune fields on higher-lying river terraces and alluvial fans. Sediments were subjected to detailed lithofacies analyses and sampling for morphoscopic assessment of quartz grains. Based on these results, three units were identified in the sedimentary succession: fluvial, fluvio-aeolian and aeolian. Material with traces of aeolian origin predominate in these sediments and this enabled conclusions on the activity of aeolian processes during the Pleniglacial and Late Glacial, and the source of sediment supply to be drawn. Aeolian processes played a major role in the deposition of the lower portions of the fluvial and fluvio-aeolian units. Aeolian material in the fluvial unit stems from aeolian accumulation of fluvial sediments within the valley as well as particles transported by wind from beyond the valley. The fluvio-aeolian unit is composed mainly of fluvial sediments that were subject to multiple redeposition, and long-term, intensive processing in an aeolian environment. In spite of the asynchronous onset of deposition of the fluvio-aeolian unit, it is characterised by the greatest homogeneity of structural and textural characteristics. Although the aeolian unit was laid down simultaneously, it is typified by the widest range of variation in quartz morphoscopic traits. It reflects local factors, mainly the origin of the source material, rather than climate. The duration of dune-formation processes was too short to be reflected in the morphoscopy of quartz grains.
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Lin, Zhipeng, Le Chen, Jingfu Shan, Tan Zhang, Qianjun Sun und Yiwu Wang. „A New Sequence Stratigraphic Framework of Terrestrial Fluvial“. Studies in Engineering and Technology 4, Nr. 1 (30.07.2017): 85. http://dx.doi.org/10.11114/set.v4i1.2521.
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Currently, the recognition and research on the classification of fluvial types mainly focus on the description and results of a series of indicators, such as the plane shape and sediment characteristics. However, there is limited literacy about how to demonstrate the fluvial types from the depositional process, especially less on sequence model of inland fluvial. Thus, this paper aims o propose a new kind of sequence stratigraphic framework, which is able to reflect the fluvial processes under the perspective of sequence stratigraphy. Accordingly, we use the principle of concrete analysis for concrete problems by comprehensively summing up the previous classification schemes of river types. With the research method of sedimentation process, new fluvial systems tracts for fluvial are presented here, including four parts: low fluvial system tract (LFST), advancing fluvial system tract (AFST), flooding fluvial system tract (FFST), receding fluvial system tract (RFST). Moreover, these could be applied to tackle the problem of the traditional division of fluvial. Various rivers have the different characteristics of systems tracts, then this may play a vital role in the discrimination of meandering river, braided river, anastomosing river and branched river. This study embodies the philosophical thought of Process Sedimentology and may contribute to revealing the deposition process of the fluvial system more profoundly from the aspect of genetic mechanism and evolution course. Most importantly, the fluvial classification system is definitely improved from the description stage to a complete rational stage.
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Hassan, Marwan A., Hal Voepel, Rina Schumer, Gary Parker und Luigi Fraccarollo. „Displacement characteristics of coarse fluvial bed sediment“. Journal of Geophysical Research: Earth Surface 118, Nr. 1 (25.02.2013): 155–65. http://dx.doi.org/10.1029/2012jf002374.
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Payenberg, T. H. D., und S. C. Lang. „RESERVOIR GEOMETRY OF FLUVIAL DISTRIBUTARY CHANNELS—IMPLICATIONS FOR NORTHWEST SHELF, AUSTRALIA, DELTAIC SUCCESSIONS“. APPEA Journal 43, Nr. 1 (2003): 325. http://dx.doi.org/10.1071/aj02017.
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The exploration and development of stratigraphically trapped hydrocarbons requires detailed knowledge of the morphologies and reservoir characteristics of the stratigraphic body. Fluvial distributary channels are important exploration targets because they are typically isolated reservoirs, laterally and vertically sealed by delta plain and abandoned channel mudstone, and thus form excellent stratigraphic traps. The morphology and reservoir characteristics of fluvial distributary channels have been confused with fluvial channels in the past. Knowing the characteristics of fluvial distributary channels and their difference from fluvial channels is the key to the successful exploration and development of distributary channel reservoirs.Fluvial distributary channels, formed by mixed-load systems, are commonly rectilinear channel segments found only on the delta plain between the head of passes and the depositional mouthbars. While fluvial channel reservoirs are mainly sandstone deposits of meander pointbars or braided sheets, fluvial distributary channel reservoirs are typically elongated sandy channel sidebars attached to morphologically rectilinear channel walls. The sidebars form by both lateral and downstream accretion resulting from flow in a confined, but lowsinuosity thalweg, which may be filled with organic mud following channel abandonment. On 3D seismic data the morphology of a fluvial distributary channel is often slightly sinuous and can easily be mistaken for part of a meander channel belt.Fluvial distributary channels are usually thinner and shallower compared to their updip fluvial channel belts. Width-thickness ratios for fluvial distributary channel reservoirs are on average 50:1 (range 15:1 to 100:1), while meandering fluvial channel reservoirs have widththickness ratios typically >100:1, and braided river reservoirs show ratios of 500:1 or higher. Examples from the Mahakam Delta are used to illustrate these issues. Implications for exploration and development of deltaic deposits on the North West Shelf of Australia are discussed.
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Huang, Kai, Chunsheng Shen, Kai Kang, Libing Wang, Zhongbo Xu und Lin Li. „Characteristics of Mudstone in Complex Fluvial Sedimentary System in Bohai L Oilfield“. Earth Science Research 7, Nr. 2 (08.07.2018): 79. http://dx.doi.org/10.5539/esr.v7n2p79.
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Bohai L oilfield develops a complex fluvial sedimentary system, which includes many types of fluvial sedimentary facies. Based on the coring well of oil field, the distribution characteristics of mudstone are analyzed, it is shown that the mudstone has similar internal structure and can be classified into four types according to its color: gray to grayish, variegated, brown to gray-brown and khaki, the assemblage has a large gray to grayish mudstone section, large gray to grayish mudstone intercalated thin layer sandstone, gray to grayish mudstone associated with variegated (brown) mudstone, grayish mudstone associated with lacustrine sand grain bedding sandstone, concomitant generation of large staggered bedding sandstone and grayish mudstone, mixed (gray-brown) mudstone associated with large staggered bedding sandstone, interaction between different colors of mudstone and sandstone and large interlaced sandstone intercalated with thin layer mudstone. The mudstone color is mainly gray and grayish, and very few oxidized mudstone is developed alone, which indicates that fluvial mudstone may be formed in the reductive environment in humid climate, and the fluvial mudstone in this area may be formed in the oxidizing environment, which is different from the general understanding of fluvial facies, the oxidation color is the result of the later transformation.
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ZHANG, Yuanfu, Xin DAI, Min WANG und Xinxin LI. „The concept, characteristics and significance of fluvial fans“. Petroleum Exploration and Development 47, Nr. 5 (Oktober 2020): 1014–26. http://dx.doi.org/10.1016/s1876-3804(20)60113-6.
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Ferreira, Cesar Cardoso, Paulo César Rocha, Arnaldo Yoso Sakamoto und Heloissa Gabriela Silva Sokolowski. „Análise Temporal da Dinâmica de Aspectos Físicos Fluviais no Rio Abobral-Pantanal-MS-BR“. Revista Brasileira de Geografia Física 12, Nr. 7 (29.02.2020): 2672. http://dx.doi.org/10.26848/rbgf.v12.7.p2672-2684.
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O conhecimento de características geomorfológicas fluviais é de suma relevância para estudos voltados aos recursos hídricos, tanto do ponto de vista da hidráulica, da sedimentologia, como também do ponto de vista do planejamento regional. Nesse sentido, este artigo tem como objetivo individualizar e analisar sazonalmente a dinâmica fluvial do rio Abobral no Pantanal-MS situado na bacia do Alto Paraguai, compreendendo uma área composta por extensa superfície de acumulação sujeita a inundações periódicas. Para alcançar o objetivo supracitado, foram executados procedimentos divididos em quatro etapas: coleta de amostras; individualização morfológica, sedimentológica e hidráulica; processamento dos dados cartográficos e estabelecer correlações entre as variáveis físico-fluviais. Deste modo, observou-se que tipicamente o trecho do rio estudado, é caracterizado como meandrante em planície de inundação, com aspectos de sazonalidades de cheias e secas, além disso, no período de inverno, começa a cessar a vazão e o rio Abobral, no qual, configura-se seccionado, com presença de bancos de areias e aspectos de lagos encaixados e alongados na planície. Temporal analysis of the fluvial physical aspects dynamics in the Aboral river-Pantanal-MS-BR A B S T R A C TThe knowledge of fluvial geomorphological characteristics is of great relevance for studies on water resources, both from the point of view of hydraulics and sedimentology, as well as from the point of view of regional planning. In this sense, this article aims to individualize and analyse seasonally the fluvial physical aspects of the Abobral river in the Pantanal-MS located in the Upper Paraguay watershed, an area composed by extensive accumulation surface subject to periodic flooding. In order to achieve the aforementioned objective, the executed procedures divided into four steps: sample collection; morphological, sedimentological and hydraulic individualization; cartographic data processing and the establishment of correlations between the physical-fluvial variables. In this way, it was observed that typically the river section studied typically characterized as meandering in floodplain, with aspects of seasonality of floods and droughts, in addition, in the winter period, the flow and the Abobral river cease, which, it is sectioned, with the presence of sand banks and aspects of lakes embedded and elongated in the plain.Keywords: Pantanal, Abobral river, fluvial geomorphology.
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Guo, Shao Lei, und Xuan Ying Guo. „The Fluvial Process of Wandering Reach in the Lower Yellow River“. Applied Mechanics and Materials 438-439 (Oktober 2013): 1309–13. http://dx.doi.org/10.4028/www.scientific.net/amm.438-439.1309.
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There are three characteristics of river channel which are wandering, transitional, bending in the Lower Yellow River. The fluvial process is complicated and variable. The channel characteristics of wandering reach was analyzed, and then based on the measured data and model test data, the formation conditions, basic characteristics and influencing factor of the fluvial process law in wandering river were analyzed. All of this can provide technical guidance and theoretical support for river regulation of the Lower Yellow River.
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Zheng, Dong-Yu, und Si-Xuan Wu. „Principal component analysis of textural characteristics of fluvio-lacustrine sandstones and controlling factors of sandstone textures“. Geological Magazine 158, Nr. 10 (21.05.2021): 1847–61. http://dx.doi.org/10.1017/s0016756821000418.
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AbstractTextures are important features of sandstones; however, their controlling factors are not fully understood. We present a detailed textural analysis of fluvio-lacustrine sandstones and discuss the influences of provenance and depositional environments on sandstone textures. The upper Permian – lowermost Triassic Wutonggou sandstones in the Bogda Mountains, NW China, are the focus of this study. Sandstone thin-sections were studied by point counting and their textures were analysed using statistical and principal component analysis. Fluvial lithic, fluvial feldspathic, deltaic lithic, deltaic feldspathic, littoral lithic and littoral feldspathic sandstone were classified and compared. These comparisons indicate that lithic and feldspathic sandstones from the same depositional settings have significant differences in graphic mean, graphic standard deviation and roundness; in contrast, sandstones from different depositional settings but with similar compositions have limited differences in textures. Moreover, three principal components (PCs) are recognized to explain 75% of the total variance, of which the first principal component (PC1) can explain 44%. In bivariate plots of the PCs, sandstones can be distinguished by composition where lithic and feldspathic sandstones are placed in different fields of the plots along the axis of PC1. However, sandstones from different depositional settings overlap and show no clear division. These results indicate that provenance, mainly the source lithology, is the most significant controlling factor on sandstone texture, whereas the depositional environment has limited influence. This study improves our understanding of textural characteristics of fluvio-lacustrine sandstones and their controlling factors, and shows the potentiality of principal component analysis in sandstone studies.
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Alexouli - Livaditi, A., K. Vouvalidis, G. Livaditis und S. Pechlivanidou. „Drainage network characteristics of Athens plain at the end of the 19th century“. Bulletin of the Geological Society of Greece 40, Nr. 4 (01.01.2007): 1513. http://dx.doi.org/10.12681/bgsg.17054.
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Kephissos River is the main fluvial system of the hydrological basin of Athens. It drains the central part of Attica and almost the entire urban area of the city of Athens. In this paper, we present the results of both the qualitative and quantitative analysis of the initial drainage network of the plain before the urbanization through the processing of digitised data with GIS software. The initial drainage network of the. basin, plotted with the use of a very detailed mosaic of maps, was constructed by German cartographers (Curtius E. and Kaupert J.) at the end of the 19' century. For the analysis of the drainage network the Laws of drainage composition were used and values for the D and F indices were calculated. One of the major aspects of this article is \o reveal information about the fluvial and environmental conditions in the plain of Athens before the urbanization of the area. This kind of information is very critical because until that time (end of the 19th century) the fluvial system of Kephissos\ was natural, without any human intervention.
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解, 超. „Research on Composite Sandbody Structure Characteristics of Fluvial Reservoirs“. Advances in Geosciences 08, Nr. 03 (2018): 608–17. http://dx.doi.org/10.12677/ag.2018.83065.
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12
Yeh, Keh-Chia, Shian-Jang Li und Wen-Lin Chen. „Modeling Non-Uniform-Sediment Fluvial Process by Characteristics Method“. Journal of Hydraulic Engineering 121, Nr. 2 (Februar 1995): 159–70. http://dx.doi.org/10.1061/(asce)0733-9429(1995)121:2(159).
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13
Wang, Sui-ji, Jin-song Li und Shou-peng Yin. „Basic characteristics and controlling factors of anastomsing fluvial systems“. Chinese Geographical Science 10, Nr. 1 (März 2000): 30–37. http://dx.doi.org/10.1007/s11769-000-0033-6.
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Wang, Yuanjian, Xudong Fu und Guangqian Wang. „Conceptual Model for Simulating the Adjustments of Bankfull Characteristics in the Lower Yellow River, China“. Journal of Applied Mathematics 2014 (2014): 1–12. http://dx.doi.org/10.1155/2014/852174.
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We present a conceptual model for simulating the temporal adjustments in the banks of the Lower Yellow River (LYR). Basic conservation equations for mass, friction, and sediment transport capacity and the Exner equation were adopted to simulate the hydrodynamics underlying fluvial processes. The relationship between changing rates in bankfull width and depth, derived from quasiuniversal hydraulic geometries, was used as a closure for the hydrodynamic equations. On inputting the daily flow discharge and sediment load, the conceptual model successfully simulated the 30-year adjustments in the bankfull geometries of typical reaches of the LYR. The square of the correlating coefficient reached 0.74 for Huayuankou Station in the multiple-thread reach and exceeded 0.90 for Lijin Station in the meandering reach. This proposed model allows multiple dependent variables and the input of daily hydrological data for long-term simulations. This links the hydrodynamic and geomorphic processes in a fluvial river and has potential applicability to fluvial rivers undergoing significant adjustments.
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Lu, Zhiyuan, Zhiliang He, Shizhong Ma und Yu He. „Sedimentary characteristics and sand-body distributions in the Lower Permian He 8 Member, Ordos Basin, China“. Interpretation 10, Nr. 2 (22.02.2022): T223—T236. http://dx.doi.org/10.1190/int-2021-0101.1.
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The Lower Permian He 8 Member (P1h8) in the Ordos Basin is a typical producing zone of tight lithologic gas reservoirs. Analyses of sedimentary characteristics, electrofacies, and sand-body distributions of P1h8, conducted on modern fluvial deposits, outcrops, cores, and well logs, revealed that braided rivers that developed in the Lower P1h8 and Upper P1h8 are characterized by meandering river. Within these fluvial deposits, the procedure consists of analyzing high-resolution sequence stratigraphy and sedimentary dynamics defined from calibrated logging curve signatures and depositional studies. According to modern and ancient fluvial deposits, we have developed a process-based sedimentary conceptual model for interpreting and predicting the distribution and geometries of sand bodies in braided and meandering deposits. The main sand body of the braided river system was bars and channel fill deposits. The braided river sand bodies are distributed over multiple vertical superimpositions and overlapping horizontal connections. The meandering river sand bodies are mainly point-bar deposits, which are bead-shaped and exhibit scattered development in the vertical direction. This comparison indicates that there were significant differences between braided and meandering deposystems. The sand bodies in the Lower P1h8 were multidirectionally connected and primarily distributed in a stacked pattern. In contrast, the sand bodies in the Upper P1h8 were distributed in an isolated manner, and fine grains (mud and silt) were deposited between the sand bodies with poor connectivity. We interpreted the fluvial deposits that control the distributions of the sand body of the He8 Member in the eastern Sulige gas field and constructed a corresponding prediction model of a braided-meandering reservoir. This model will promote understanding of the extent of fluvial deposits and sand-body distribution of P1h8, thus elucidating hydrocarbon-bearing sand units of the Ordos Basin for future exploration.
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Gouw, Marc J. P., und Marc P. Hijma. „From apex to shoreline: fluvio-deltaic architecture for the Holocene Rhine–Meuse delta, the Netherlands“. Earth Surface Dynamics 10, Nr. 1 (12.01.2022): 43–64. http://dx.doi.org/10.5194/esurf-10-43-2022.
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Abstract. Despite extensive research on alluvial architecture, there is still a pressing need for data from modern fluvio-deltaic environments. Previous research in the fluvial-dominated proximal and central Rhine–Meuse delta (the Netherlands) has yielded clear spatial trends in alluvial architecture. In this paper, we include the backwater length to establish architectural trends from apex to shoreline. Channel-belt sand body width / thickness ratios and interconnectedness were determined, and the proportions of fluvial channel-belt deposits, fluvial overbank deposits, organics and intertidal deposits were calculated for the complete fluvio-deltaic wedge based on high-resolution geological cross sections. It was found that the average width / thickness ratio of channel-belt sand bodies in the proximal delta is 5 times higher than in the distal delta. Other down-valley trends include an 80 % decrease in the channel deposit proportion (CDP) and a near-constant proportion of overbank deposits. Additionally, interconnectedness in the proximal delta is 3 times higher than in the distal delta. Based on the Rhine–Meuse dataset, we propose a linear empirical function to model the spatial variability of CDP. It is argued that this relationship is driven by four key factors: channel lateral-migration rate, channel-belt longevity, creation of accommodation space and inherited floodplain width. Additionally, it is established that the sensitivity of CDP to changes in the ratio between channel-belt sand body width and floodplain width (normalized channel-belt sand body width) varies spatially and is greatest in the central and distal delta. Furthermore, the proportion of fluvial channel-belt sands is generally an appropriate proxy for the total sand content of fluvio-deltaic successions, although its suitability as a total sand indicator rapidly fades in the distal delta. Characteristics of the backwater zone of the Rhine–Meuse delta are (1) sand body width / thickness ratios that are lower as a consequence of channel narrowing (not deepening), (2) a rapid increase and then a drop in the organic proportion, (3) an increase in the total sand proportion towards the shoreline, and (4) a drop in the connectedness ratio. For this paper, unique high-resolution quantitative data and spatial trends of the alluvial architecture are presented for an entire delta, providing data that can be used to further improve existing fluvial stratigraphy models.
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van den Berg, J. H., J. R. Boersma und A. van Gelder. „Diagnostic sedimentary structures of the fluvial-tidal transition zone – Evidence from deposits of the Rhine and Meuse“. Netherlands Journal of Geosciences 86, Nr. 3 (September 2007): 287–306. http://dx.doi.org/10.1017/s0016774600077866.
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AbstractIn mesotidal settings the transition of a coastal plain estuary to the river is marked by the change of a multiple ebb and flood channel configuration to a single channel system. At high river discharge fluvial processes operate, whereas in periods of low discharge the flow is complicated by a tidal component and a landward intrusion of the salt wedge. These hydraulic and morphological characteristics make the transitional zone different from the ‘pure’ fluvial and estuarine environment. Inspection of published and unpublished data from a number of outcrops of Recent and Tertiary deposits of the Rhine reveals that also in a sedimentary sense a transitional zone can be recognized. In order to separate this zone from the upstream fluvial and downstream estuarine environment a sedimentological definition of the fluvial-tidal zone is proposed being the part of river that lies between the landward limit of observable effects of tidal-induced flow deceleration on fluvial cross-bedding at low river discharge and the most seaward occurrence of a textural or structural fluvial signature related to the high river stage.
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Kiss, Tímea, György Sipos und Róbert Vass. „Alluvial ridge development and structure: Case study on the Upper Tisza, Hungary“. Geographica Pannonica 26, Nr. 3 (2022): 230–40. http://dx.doi.org/10.5937/gp26-38365.
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The juxtaposition of natural levees results in alluvial ridges with a unique fluvial record. Our aims were to (1) identify the alluvial ridges of the Upper Tisza (Hungary); (2) determine their morphological characteristics; and (3) reconstruct the Late Quaternary fluvial history of the region. The oldest paleo-meander was abandoned ca. 29 ka ago; referring to early avulsion of the Tisza. Five alluvial ridges were identified with intensive fluvial activity at ca. 12-13 ka, 7.7-8.6 ka, 6.1-6.6 ka, 4.8 and 2.9 ka ago. Moderate fluvial activity was indicated by early Atlantic and Subboreal paleosols. The sedimentation rate in the paleo-channels (0.3-0.5 mm/y) and on the alluvial ridges (0.3-0.5 mm/y) was slow, influenced by the reactivation of a paleo-channel.
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Zhang, Qian, Mingming Tang, Shuangfang Lu, Xueping Liu und Sichen Xiong. „Effects of Mud Supply and Hydrodynamic Conditions on the Sedimentary Distribution of Estuaries: Insights from Sediment Dynamic Numerical Simulation“. Journal of Marine Science and Engineering 11, Nr. 1 (10.01.2023): 174. http://dx.doi.org/10.3390/jmse11010174.
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Estuaries are important sediment facies in the fluvial-to-marine transition zone, are strongly controlled by dynamic interactions of tides, waves, and fluvial flows, and show various changes in depositional processes and sediment distribution. Deep investigations on the sediment dynamic processes of the sand component of estuaries have been conducted; however, the understanding of how mud supply affects estuaries’ sedimentary characteristics and morphology is still in vague. Herein, the effects of mud concentration, mud transport properties, fluvial discharge, and tidal amplitude on the sedimentary characteristics of an estuary were systematically analyzed using sedimentary dynamic numerical simulation. The results show that the mud concentration has significant effects on the morphology of tidal channels in estuaries, which become more braided with a lower mud concentration, and straighter, with reduced channel migration, with a higher mud concentration. The mud transport properties, namely, setting velocity, critical bed shear stress for sedimentation, and erosion, mostly affect the ratio between the length and width (RLW) of the sand bar; a sheet-like sand bar with a lower RLW value develops in the lower settling velocity, while there are obvious strip shaped bars with a high RLW value in the higher settling velocity case. Moreover, the effects of hydrodynamic conditions on sedimentary distribution were analyzed by changing the tidal amplitudes and fluvial discharges. The results show that a higher tidal amplitude is often accompanied by a stronger tidal energy, which induces a more obvious seaward progradation, while a higher fluvial discharge usually yields a higher deposition rate and yields a greater deposition thickness. From the above numerical simulations, the statistical characteristics of tidal bars and mud interlayers were further obtained, which show good agreement with modern sedimentary characteristics. This study suggests that sedimentary dynamic numerical simulation can provide insights into an efficient quantitative method for analyzing the effects of mud components on the sediment processes of estuaries.
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Cong, Lin, Shi Zhong Ma, Yu Sun und Ru Bin Li. „A Preliminary Study on Sedimentary Mode of Putaohua Oil Layer in the East of Sanzhao Depression“. Advanced Materials Research 524-527 (Mai 2012): 3–9. http://dx.doi.org/10.4028/www.scientific.net/amr.524-527.3.
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Based on ten well cores, seventeen hundred logging data and initial potential data, sedimentary characteristics and mode of shallow lacustrine fluvial-dominated delta of Putaohua oil layer in the east of Sanzhao depression were analyzed. It is realized that distributary channel sandbodies as sand body framework of this delta system, which is abundant, closely and narrow, and the framework of sand body is in a large number of narrow banded shape (mostly 200 ~ 300m), and can extend hundreds of kilometers of continuous, dense, overall was SW, and combines well with other types sand surface to become a better distributary channel sand body. Based on understanding of sedimentary background, developmental process, sedimentary characteristics and sedimentary facies type of Putaohua oil layer in Sanzhao depression, sedimentary mode of shallow lacustrine fluvial-dominated delta is established in the study area, and sedimentary mode of five subfacies is further divided: Delta distributary plain subfacies is mode of fluvial-dominated belt body; Transition region of front-distributary plain is mode of inshore; Inner front is mode of fluvial-dominated belt body; Transition region of inner front-outer front is mode of fluvial-dominated sheet sand; Shallow lacustrine fluvial-dominated delta outer front is mode of tide-dominated sheet sand; Also pointed out that overall shows NE –SW trending submerged distributary channel sandbodies which is abundant, closely and narrow is the main reservoir of the study area. It provides the solid geological basis for the establishment of spatial distribution pattern of reservoir; identify the causes of mainly monosandbody and further tapping the potential of oil field.
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Sepulveda, Adam J., Warren T. Colyer, Winsor H. Lowe und Mark R. Vinson. „Using nitrogen stable isotopes to detect long-distance movement in a threatened cutthroat trout (Oncorhynchus clarkii utah)“. Canadian Journal of Fisheries and Aquatic Sciences 66, Nr. 4 (April 2009): 672–82. http://dx.doi.org/10.1139/f09-020.
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Interior cutthroat trout occupy small fractions of their historic ranges and existing populations often are relegated to headwater habitats. Conservation requires balancing protection for isolated genetically pure populations with restoration of migratory life histories by reconnecting corridors between headwater and mainstem habitats. Identification of alternative life history strategies within a population is critical to these efforts. We tested the application of nitrogen stable isotopes to discern fluvial from resident Bonneville cutthroat trout (BCT; Oncorhynchus clarkii utah ) in a headwater stream. Fluvial BCT migrate from headwater streams with good water quality to mainstem habitats with impaired water quality. Resident BCT remain in headwater streams. We tested two predictions: (i) fluvial BCT have a higher δ15N than residents, and (ii) fluvial BCT δ15N reflects diet and δ15N enrichment characteristics of mainstem habitats. We found that fluvial δ15N was greater than resident δ15N and that δ15N was a better predictor of life history than fish size. Our data also showed that fluvial and resident BCT had high diet overlap in headwater sites and that δ15N of lower trophic levels was greater in mainstem sites than in headwater sites. We conclude that the high δ15N values of fluvial BCT were acquired in mainstem sites.
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Erkinaro, Jaakko, Eero Niemelä, Aila Saari, Yuri Shustov und Lisbeth Jørgensen. „Timing of habitat shift by Atlantic salmon parr from fluvial to lacustrine habitat: analysis of age distribution, growth, and scale characteristics“. Canadian Journal of Fisheries and Aquatic Sciences 55, Nr. 10 (01.10.1998): 2266–73. http://dx.doi.org/10.1139/f98-107.
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This study investigated the timing of a habitat shift from fluvial to lacustrine habitat of Atlantic salmon, Salmo salar, parr in a subarctic river in northern Finland and whether the individuals that shifted already had the best growth rate prior to the shift or, alternatively, whether the shift was triggered by competition-induced growth depression. The age distribution of parr indicated that most of the fish that shifted belonged to the age group 2+ and the proportion of 1+ fish was less than 3%. However, the analyses of somatic growth and scale characteristics reflected an earlier shift, at the age of 1+, for the greater part of the lacustrine fish. The growth of lacustrine fish exceeded that of their fluvial counterparts after the first year of life. Based on the growth of the first year, no indications that the lacustrine parr were recruited from the fastest growing part of the population were found. However, the growth patterns during the second year may indicate that fluvial parr with the fastest growth at age 1+ may be those that shift at age 2+. Some evidence of growth depression in fluvial fish was found.
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GUEDES, CARLOS C. F., ANDRE O. SAWAKUCHI, PAULO C. F. GIANNINI, REGINA DEWITT und VITOR A. P. AGUIAR. „Luminescence characteristics of quartz from Brazilian sediments and constraints for OSL dating“. Anais da Academia Brasileira de Ciências 85, Nr. 4 (27.09.2013): 1303–16. http://dx.doi.org/10.1590/0001-37652013104912.
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This study analyzes the optically stimulated luminescence (OSL) characteristics of quartz grains from fluvial, eolian and shallow marine sands of northeastern and southeastern Brazil, with especial focus on the applicability of the single-aliquot regenerative dose (SAR) dating protocol. All analyzed Brazilian sediments presented relatively high OSL sensitivity and good behavior regarding their luminescence characteristics relevant for radiation dose estimation. However, some samples from the Lençóis Maranhenses region in northeastern Brazil showed inadequate OSL sensitivity correction, hampering the implementation of the SAR protocol and their ability to behave as a natural dosimeter. While the shallow marine and eolian samples showed a narrow and reliable dose distribution, the fluvial sample had a wide dose distribution, suggesting incomplete bleaching and natural doses estimates dependent on age models.
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Li, Jian-ping, Zi-ying Qiu und Hong-yi Li. „Lithology and Lithofacies Characteristics of Deeply Buried Clastic Reservoirs in Alternating Wet-arid Climate and its Hydrocarbon Significance“. Journal of Physics: Conference Series 2594, Nr. 1 (01.10.2023): 012039. http://dx.doi.org/10.1088/1742-6596/2594/1/012039.
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Abstract There have been series of HPHT (high temperature and high pressure) reservoirs with good quality and high productivity discovered in the Triassic Skagerrak Formation in the Central Graben of the UK North Sea. The bottlenecks for further E&P activity are the complicated depositional facies and high reservoir heterogeneity. The main reservoir space is a mixed porosity network composed of primary pores, micro-pores, secondary pores, secondary micro-pores and micro-fractures. Reservoirs of the Skagerrak Formation have greatly varied lateral connectivity as well as poor vertical connectivity. In the case of sufficiently high pressure differentials, hydrocarbon can be fed from high-potential area to low-potential area. There is no simple linear relationship between depth and reservoir quality. The primary depositional texture (grain size/sorting/clay content, etc.) linked to facies has a fundamental control on reservoir quality. Clean and well sorted cross laminated sandstone has the best reservoir quality, while the reservoir quality of planar laminated sandstone decreased due to increased degree of compaction caused by mica drapes. The reservoir quality of the fine-grained ripple cross laminated sandstone is even poorer than that of the planar laminated sandstone, due to abundant mica and clay drapes. Mottled bioturbated sandstone is fine grained with high clay content, which is more muddy because of containing burrows and insect larva. Pedoturbated sandstone has the poorest reservoir quality due to severe dolomite cementation. The dominant detrital material of the Skagerrak Formation is feldspar that provides abundant secondary porosity by alteration and dissolution. Chlorite coats are commonly developed and stained with residual oil or bitumen, which clearly inhibits quartz cementation and feldspar overgrowth. The presence of these clay coats contributes to the preservation of anomalously high porosity at depth in the cleaner and coarser grained fluvial channel facies. The Skagerrak formation facies is a dryland fluvial-lacustrine depositional system which is controlled by fluctuations of depositional base level due to salt mobilisation. The Skagerrak formation consists of several cycles that are vertically separated by lacustrine mudstone. The reservoir permeability system is composed of active fluvial channel sandstones, terminal splay sandstones, abandoned fluvial channel sandstones, minor channel sandstones connecting fluvial channel and terminal splay, as well as low-permeability faults, while the active fluvial channel sandstone is the “sweet spot”. The analysis of controls on deeply buried reservoir quality is significant to precisely predict “sweet spot” in the Skagerrak Formation.
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Abdulkarim, Mubarak, Stoil Chapkanski, Damien Ertlen, Haider Mahmood, Edward Obioha, Frank Preusser, Claire Rambeau, Ferréol Salomon, Marco Schiemann und Laurent Schmitt. „Morpho-sedimentary characteristics of Holocene paleochannels in the Upper Rhine alluvial plain, France“. E&G Quaternary Science Journal 71, Nr. 2 (08.09.2022): 191–212. http://dx.doi.org/10.5194/egqsj-71-191-2022.
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Abstract. The French Upper Rhine alluvial plain is characterized by a complex system of paleochannels inherited from Late Glacial to Holocene fluvial dynamics of the Rhine and Ill river systems, among other smaller rivers. These paleochannels represent valuable archives for understanding and reconstructing the fluvial and landscape evolution of the area. However, the Holocene temporal trajectories of the paleochannels, in response to a range of environmental changes, remain poorly understood. This study presents a detailed and systematic mapping and characterization of an extensive network of paleochannels spanning the entire width (19 km) of a reach of the central French Rhine plain. Based on qualitative and quantitative lidar analysis, field investigations, and provenance investigations of paleochannel infill sequences, five distinct paleochannel groups (PG 1 to PG 5) were identified in the study area. These paleochannel groups differ considerably regarding their channel patterns, morphological characteristics, and sedimentary sources of the infilling sediments. The interpretation of the different datasets indicates that the development of these different paleomorphologies is attributed to significant changes in hydro-geomorphodynamic processes in the area during the Holocene, especially lateral migrations of the Rhine and Ill rivers. The findings reported here are promising and will have significant implications for reconstructing the long-term (Late Glacial to Holocene) evolution of the Upper Rhine fluvial hydrosystem in response to various controlling factors.
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Hartley, A. J., G. S. Weissmann, G. J. Nichols und G. L. Warwick. „Large Distributive Fluvial Systems: Characteristics, Distribution, and Controls on Development“. Journal of Sedimentary Research 80, Nr. 2 (01.02.2010): 167–83. http://dx.doi.org/10.2110/jsr.2010.016.
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Lamouroux, Nicolas, Jean-Michel Olivier, Henri Persat, MarC PouilLy, YveS Souchon und Bernhard Statzner. „Predicting community characteristics from habitat conditions: fluvial fish and hydraulics“. Freshwater Biology 42, Nr. 2 (September 1999): 275–99. http://dx.doi.org/10.1046/j.1365-2427.1999.444498.x.
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Fongngern, Rattanaporn, Cornel Olariu, Ron Steel, David Mohrig, Csaba Krézsek und Thomas Hess. „Subsurface and outcrop characteristics of fluvial‐dominated deep‐lacustrine clinoforms“. Sedimentology 65, Nr. 5 (02.03.2018): 1447–81. http://dx.doi.org/10.1111/sed.12430.
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Li, Guofa, Jinliang Xiong, Hui Zhou und Tongli Zhai. „Seismic reflection characteristics of fluvial sand and shale interbedded layers“. Applied Geophysics 5, Nr. 3 (September 2008): 219–29. http://dx.doi.org/10.1007/s11770-008-0025-3.
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Walling, D. E., und P. W. Moorehead. „The particle size characteristics of fluvial suspended sediment: an overview“. Hydrobiologia 176-177, Nr. 1 (Juli 1989): 125–49. http://dx.doi.org/10.1007/bf00026549.
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Cui, Kunning. „Characteristics of sedimentary system evolution and sequence stratigraphy boundary of Denglouku group in Xujiaweizi fault depression, Songliao Basin“. IOP Conference Series: Earth and Environmental Science 1087, Nr. 1 (01.10.2022): 012073. http://dx.doi.org/10.1088/1755-1315/1087/1/012073.
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Abstract In the previous studies on this area, the sequence division is relatively rough. This study has improved the precision, and the Denglouku formation is divided into 10 fourth-order sequences, with the thickness of each small layer of about 70-80m. The characteristics of each small sequence boundary are described, and three third-order, four fourth-order sequence flooding surfaces are found. The stratigraphic framework is established. From bottom to top, the base level of all strata shows decline-rise-decline, which means regression-transformation-regression. The Denglouku 1st mainly includes lacustrine and fan delta, the sources of sediments from northeast, northwest, southwest and Southeast directions. In Denglouku 2nd and Denglouku 3rd, braided fluvial delta and intermittent lacustrine are dominant, which were controlled by the sedimentary systems from east, south, north, northeast, southwest, and the northwest. In Denglouku 4th, there is mainly braided fluvial, rarely are lacustrine and braided fluvial delta plain, the main source was from the northeast, and a small amount of source is from the west.
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Santana, Camila Ignez, und Mônica Dos Santos Marçal. „Identificação de Estilos Fluviais na Bacia do Rio Macabu (RJ) a Serem Aplicados na Gestão dos Recursos Hídricos“. Revista Brasileira de Geografia Física 13, Nr. 4 (11.06.2020): 1886. http://dx.doi.org/10.26848/rbgf.v13.4.p1886-1903.
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A pesquisa foi desenvolvida na Bacia do Rio Macabu que integra a Região Hidrográfica IX do Baixo Paraíba do Sul e Itabapoana e, assim como várias regiões hidrográficas fluminenses, apresenta longo histórico de intervenções antrópicas dentro e fora dos canais fluviais. O objetivo do trabalho é apresentar mapeamento dos Estilos Fluviais identificados na Bacia do rio Macabu, considerando-se a dinâmica atual dos processos geomorfológicos e hidrogeomorfológico a serem aplicados na gestão dos recursos hídricos. O mapeamento e classificação dos segmentos dos rios e suas tipologias foram realizados com base na aplicação de parâmetros morfométricos, para a avaliação dos controles regionais e locais sobre a forma e o comportamento do rio, no confinamento do vale, na forma em planta de toda a extensão do canal e nas unidades geomorfológicas do fundo de vale. Os resultados mostram que a compartimentação do relevo possibilita a ocorrência de diferentes feições fluviais, exerce controle regional no sistema fluvial e tem influência sobre característica do vale. Dessa forma, a configuração espacial dos compartimentos determina os padrões de comportamento em cada setor. Foram identificados oito Estilos Fluviais cuja diferenciação entre os segmentos permite compreender como os processos e formas se caracterizam, integram e se distribuem dentro do sistema fluvial. De um modo geral, a bacia do rio Macabu se expressa como um ambiente múltiplo e complexo, com muitas problemáticas relacionadas aos seus usos e modificações. Os resultados representam parte dos subsídios necessários para uma gestão eficiente e eficaz e para a tomada de decisão. Identification of River Styles in the Macabu Basin (RJ) to be Applied in Water Resource Management A B S T R A C TThe research was developed in the Macabu Basin that integrates the Lower Paraíba do Sul and Itabapoana Hydrographic Region and, as well as several basin of fluminense hydrographic regions, presents a long history of anthropogenic interventions inside and outside channels. The objective of this present work is bringing forward mapping of the River Styles in the Macabu Basin to be applied in the management of water resources, considering the current dynamics of geomorphological and hydrogeomorphological processes. The mapping and the classification of river segments and their typologies were performed based on the application of morphometric parameters for the evaluation of regional and local controls on the river shape and behavior, valley confinement, river planform, channel length and valley bottom geomorphological units. The results show that the relief compartments allows the occurrence of different fluvial features, exerts regional control in the fluvial system and influences the valley characteristics. Thus, the spatial configuration of the compartments determines the patterns of behavior in each sector. Eight River Styles have been identified whose differentiation allows understanding how processes and forms are characterized, integrated and distributed within the river system. In general, Macabu Basin is a multiple and complex environment with many issues related to its uses and modifications. The results represent part of the inputs needed for efficient and effective management and decision-making.Keywords: Fluvial Geomorphoplogy; River Classification; Morphometric Index; Valley Setting.
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Vandenberghe, Jef, Cornelis Kasse, Dragan Popov, Slobodan Markovic, Dimitri Vandenberghe, Sjoerd Bohncke und Gyula Gabris. „Specifying the External Impact on Fluvial Lowland Evolution: The Last Glacial Tisza (Tisa) Catchment in Hungary and Serbia“. Quaternary 1, Nr. 2 (16.08.2018): 14. http://dx.doi.org/10.3390/quat1020014.
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External impact on the development of fluvial systems is generally exerted by changes in sea level, climate and tectonic movements. In this study, it is shown that a regional to local differentiation of fluvial response may be caused by semi-direct effects of climate change and tectonic movement; for example, vegetation cover, frozen soil, snow cover and longitudinal gradient. Such semi-direct effects may be responsible for specific fluvial activity resulting in specific drainage patterns, sedimentation series and erosion–accumulation rates. These conclusions are exemplified by the study of the fluvial archives of the Tis(z)a catchment in the Pannonian Basin in Hungary and Serbia from the middle of the last glacial to the Pleistocene–Holocene transition. Previous investigations in that catchment are supplemented here by new geomorphological–sedimentological data and OSL-dating. Specific characteristics of this catchment in comparison with other regions are the preponderance of meandering systems during the last glacial and the presence of very large meanders in given time intervals.
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Alege, T. S., J. I. Omada und K. Uchendu. „Field and Sedimentological Studies of Nataco-Banda Sediments of Lokoja Formation, Southern Bida Basin, Nigeria: Implication for Depositional Environment“. Journal of Applied Sciences and Environmental Management 26, Nr. 11 (30.11.2022): 1835–42. http://dx.doi.org/10.4314/jasem.v26i11.15.
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The study area falls within the Lokoja Formation of the Southern Bida Basin. The objective of this study was to evaluate the field characteristics and sedimentological parameters of depositional environment of the Nataco-Banda Sediments of Lokoja Formation, Southern Bida Basin, Nigeria using appropriate techniques such as granulometric and pebble morphometric analysis. Field studies revealed a repeated alternating sequence of conglomeratic and pebbly to coarse-grained sandstone and overbank fine sediment that is indicative of a braided fluvial source while the presence of crossbedding is suggestive of tidal influence. The morphometric analysis shows a fluvial setting where pebbles plot in the river area than the beach area. Environmental discrimination formulae for Y1, Y2 and Y3 indicated the dominance of Beach and Shallow agitated marine in both Y1 and Y2, respectively, while the almost equal percentage values of Y3 in both fluvial and shallow marine settings are highly suggestive of a shallow marine environment that is largely influenced by fluvial deposition.
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Schwartz, Theresa M., Marieke Dechesne und Kristine L. Zellman. „Evidence for variable precipitation and discharge from Upper Cretaceous–Paleogene fluvial deposits of the Raton Basin, Colorado–New Mexico, U.S.A.“ Journal of Sedimentary Research 91, Nr. 6 (10.06.2021): 571–94. http://dx.doi.org/10.2110/jsr.2020.081.
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ABSTRACT The Raton Basin of Colorado–New Mexico, USA, is the southeasternmost basin of the Laramide intraforeland province of North America. It hosts a thick succession (4.5 km or 15,000 ft) of Upper Cretaceous to Paleogene marine and continental strata that were deposited in response to the final regression of the Western Interior Seaway and the onset of Laramide intraforeland deformation. The Upper Cretaceous–Paleogene Raton and Poison Canyon formations were previously described as meandering river and braided river deposits that represented distal and proximal members of rivers that drained the basin-bounding Sangre de Cristo–Culebra uplift. We present new observations of fluvial-channel architecture that show that both formations contain the deposits of sinuous fluvial channels. However, fluvial channels of the Raton Formation formed in ever-wet environments and were affected by steady discharge, whereas channels of the overlying Poison Canyon Formation formed in drier environments and were affected by variable discharge. The apparent transition in fluvial discharge characteristics was coeval with the progradation of fluvial fans across the Raton Basin during the Paleocene, emanating from the ancestral Sangre de Cristo–Culebra uplift. The construction of fluvial fans, coupled with the sedimentary features observed within, highlights the dual control of Laramide deformation and early Cenozoic climatic patterns on the sedimentary evolution of the Raton Basin.
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Vestena, Leandro Redin, und Alessandro Kominecki. „Hidrogeomorfologia em confluência fluvial obtusa, Guarapuava, Paraná“. Revista Brasileira de Geografia Física 14, Nr. 4 (2021): 2131–48. http://dx.doi.org/10.26848/rbgf.v14.4.p2131-2148.
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Solid and liquid mixtures in river courses intensify in areas of river confluence, conditioned mainly by the angular opening of the junction. Knowledge of hydrosedimentological dynamics in bedrock junctions with different angular openings is essential for understanding morphological adjustment at confluences and for supporting actions for the preservation and conservation of river ecosystems. For this reason, this article presents the results of a hydrogeomorphologic study on a river confluence with an obtuse junction angle (>100º), in a plateau bedrock river, in the Serra Geral Formation. The research evaluated a fluvial segment upstream and downstream of the Pedras River and in the Pombas River tributary, in Guarapuava, Paraná, through observations and measurements of morphological and hydraulic characteristics, width, talweg depth, bed declivity and bankfull flow. Morphological adjustment in obtuse confluences is peculiar in that the fluvial junction angle conditions specific flow, erosion, sediment transport and deposition dynamics, mainly resulting from its association with the geological nature of the river bed and types of land use and management upstream of the confluence.
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Liu, Yuming, Luxing Dou, Xiaoxu Ren und Jiagen Hou. „Sedimentary characteristics of muddy deposits in sandy braided fluvial system: A case study from outcrops of the Jurassic Yungang Formation in the Datong Basin, Central China“. Interpretation 8, Nr. 3 (01.07.2020): SM139—SM149. http://dx.doi.org/10.1190/int-2019-0174.1.
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The sandbodies within braided fluvial deposits are important reservoirs for the oil fields in China, and they usually have complex sedimentary architecture. A lot of research has been concentrated on characterizing the architecture of the sandbodies. Based on the observation that muddy deposits are commonly well preserved in fluvial deposits, we find that understanding the contact relationship between the muddy deposits and surrounding sand bodies can help characterize the depositional process of sandy braided fluvial systems. We have determined the effectiveness of this idea by characterizing a well-exposed outcrop of sandy braided fluvial system in the Datong Basin, Shanxi Province of China. We first define six muddy lithofacies by integrating the thickness of the muddy deposits, the morphology of the muddy deposit, and the lithofacies of surrounding sand deposits. The six muddy lithofacies include floodplain muddy deposits between intermittent channel complex, lateral covering muddy deposits and fall-silt seam muddy deposits between migrated bar complex, muddy gravel deposits in erosional bar complex, and channel-fill muddy deposits and gully-fill muddy deposits in abandoned bar complex. We then analyze the depositional environments according to the defined muddy lithofacies. We finally build the architecture of the outcrops by integrating the lithofacies of sand deposits and evolution of the depositional environments deduced from the muddy lithofacies.
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Meyer, Patricia A., und Carolyn H. Eyles. „Nature and origin of sediments infilling poorly defined buried bedrock valleys adjacent to the Niagara Escarpment, southern Ontario, Canada“. Canadian Journal of Earth Sciences 44, Nr. 1 (01.01.2007): 89–105. http://dx.doi.org/10.1139/e06-085.
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The buried Paleozoic bedrock surface of southern Ontario is dissected by an interconnected system of valleys. These buried valleys are infilled with thick successions of glacial, interglacial, and fluvial sediments that contain a lengthy record of changing environmental conditions during the late Quaternary. Detailed logging of over 500 m of sediment recovered from 11 continuously cored boreholes provides the basis for this study. The boreholes were drilled within two poorly defined bedrock valleys located east of the Niagara Escarpment in southern Ontario as part of a groundwater exploration program. Six distinct facies types were identified within the cores: sand, gravel, fine-grained sediment, and sand-rich, mud-rich, and clast-rich diamict. Textural characteristics of the cored sediments and vertical changes in facies types were used to identify six stratigraphic units (SU I through SU VI) within the valley-infill deposits. These units are interpreted to record fluvial or colluvial (SU I), lacustrine (SU II), fluvial, glaciofluvial or deltaic (SU III), subglacial (SU IV), glaciofluvial (SU V) and subglacial or ice marginal (SU VI) conditions. Sediment characteristics and stratigraphic relationships allow tentative correlation with known surficial deposits. Analysis of the subsurface characteristics and geometries of this stacked succession of coarse- and fine-grained stratigraphic units also allows identification of the geometry of potential aquifers.
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Sun, Yu, Xiu Li Zhang, Jin Yan Zhang und Chen Chen. „Analysis on Grain-Size Characteristics and Sedimentary Environment of Conglomerate Reservoirs in Ying-4 Section of Xingcheng Gas Field of Songliao Basin“. Advanced Materials Research 734-737 (August 2013): 286–89. http://dx.doi.org/10.4028/www.scientific.net/amr.734-737.286.
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Aimed at difficulty of conglomerate in Ying-4 Section of Xingcheng Gas Field, Songliao Basin, which it is impossible to be carried out, using routine granularity analysis methods, and the iconic grain-size analysis is carried out. According to iconic two-dimension grain-size analysis, and contacting to fundamental sedimentary characteristics of conglomerate, sedimentary environment analysis is carried out. It is thought that this area is Shallow gravel-bed braided fluvial fan deltas, to braided fluvial delta transition, which supported an important geological foundation for the next disposition of exploration in Xingcheng Gas Field.
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Birchler, Justin, Courtney Harris, Christopher Sherwood und Tara Kniskern. „Sediment Transport Model Including Short-Lived Radioisotopes: Model Description and Idealized Test Cases“. Journal of Marine Science and Engineering 6, Nr. 4 (27.11.2018): 144. http://dx.doi.org/10.3390/jmse6040144.
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Geochronologies derived from sediment cores in coastal locations are often used to infer event bed characteristics such as deposit thicknesses and accumulation rates. Such studies commonly use naturally occurring, short-lived radioisotopes, such as Beryllium-7 (7Be) and Thorium-234 (234Th), to study depositional and post-depositional processes. These radioisotope activities, however, are not generally represented in sediment transport models that characterize coastal flood and storm deposition with grain size patterns and deposit thicknesses. We modified the Community Sediment Transport Modeling System (CSTMS) to account for reactive tracers and used this capability to represent the behavior of these short-lived radioisotopes on the sediment bed. This paper describes the model and presents results from a set of idealized, one-dimensional (vertical) test cases. The model configuration represented fluvial deposition followed by periods of episodic storm resuspension. Sensitivity tests explored the influence on seabed radioisotope profiles by the intensities of bioturbation and wave resuspension and the thickness of fluvial deposits. The intensity of biodiffusion affected the persistence of fluvial event beds as evidenced by 7Be. Both resuspension and biodiffusion increased the modeled seabed inventory of 234Th. A thick fluvial deposit increased the seabed inventory of 7Be and 234Th but mixing over time greatly reduced the difference in inventory of 234Th in fluvial deposits of different thicknesses.
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Wei, Jie, und Shaohua Li. „Application of Convolutional Neural Network in Quantifying Reservoir Channel Characteristics“. Applied Sciences 14, Nr. 6 (07.03.2024): 2241. http://dx.doi.org/10.3390/app14062241.
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After many years of exploitation in the petroleum field, most of the oil fields are in advanced stages of development, with a strong non-homogeneity of the reservoir, more residual oil, and low recovery efficiency. Therefore, research on various methods has been carried out by scholars to improve the rate of recovery and to understand the distribution pattern of residual oil in reservoirs. Among the whole clastic reservoirs, fluvial reservoirs occupy a large proportion, so fluvial reservoirs will be the priority for future reservoir research in China. The key to the fine characterization of fluvial-phase reservoirs is to able to reproduce the continuous curvature of the channel, and one important parameter is the width of the channel. The width of the channel sand body is one of the key factors in designing well programs, and accurately identifying the channel boundary is the key to identifying a single channel. Traditional research methods cannot accurately characterize the continuous bending and oscillating morphology of underwater diversion channels, and it is not easy to quantitatively characterize the spatial structure. Therefore, in this paper, a deep learning method is applied to quantitatively identify the width of a single channel within an underwater diversion channel at the delta front edge. Based on the sedimentary background of the block and modern depositional studies, we established candidate models for underwater diversion channels with channel widths of 100, 130, 160, 190, 220, and 250 m based on target simulation and human–computer interactions. The results show that when the width of the underwater diversion channel is 160 m, it has the highest matching rate with the conditional data and corresponds to the actual situation. Therefore, it can be determined that it is the common width of underwater diversion channel in the study area. And it is shown that the method can accurately identify the width of underwater diversion channels, and the results provide a basis for reservoir fine characterization studies.
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Wang, Yang Jun, Tai Ju Yin und Zhi Hao Deng. „A Study on the Evolution of Distributary Channels in River-Dominated Deltas Using Numerical Simulations of Hydrodynamic Behaviors“. Applied Mechanics and Materials 744-746 (März 2015): 1050–55. http://dx.doi.org/10.4028/www.scientific.net/amm.744-746.1050.
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The Fluvial-dominated delta is one of the extremely important deposition systems in oil and gas exploration. In this paper, the three-dimensional numerical simulation of hydrodynamics has been applied to the precise analysis of the formation of fluvial-dominated deltas and the evolution of their distributary channels. The model has been created using the Delft3D program, and the conditions of the numerical model have been set according to the hydrodynamic characteristics of modern rivers and deltas. The calculation field was 20.5 km in length by 10 km in width. With the Mor-Factor set to 60, the simulation time was 45 days. The formation and the avulsion of the mouth bar, as well as the extension, migration and bifurcation of distributary channels, have been observed and studied through analysis of the simulation results. The vertical cross-section shows that the distributary channel was filled multiple times. According to distributary channel evolution characteristics combined with quantitative methods, the terminal distributary channels can be extremely developed under ideal conditions. Due to the cross-cutting and reform effort of distributary channels, sediments were spread widely and continuously. The results show that the numerical model works well in explaining the process of evolution in fluvial-dominated delta distributary channels. This study not only enables us to quantitatively understand the dynamic processes of terminal distributary channels in fluvial-dominated delta systems, but also provides a reference model for numerical simulation of hydrodynamics in sedimentology study.
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TSUJIMOTO, Tetsuro, Toshiharu OKADA und Takashi MURASE. „Vegetation and River-Morphological Characteristics in a River in Fluvial Fan“. PROCEEDINGS OF HYDRAULIC ENGINEERING 37 (1993): 207–14. http://dx.doi.org/10.2208/prohe.37.207.
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Nagy-László, Zsolt, Judit Padisák, Gábor Borics, András Abonyi, Viktória B-Béres und Gábor Várbíró. „Analysis of niche characteristics of phytoplankton functional groups in fluvial ecosystems“. Journal of Plankton Research 42, Nr. 3 (Mai 2020): 355–67. http://dx.doi.org/10.1093/plankt/fbaa020.
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Abstract Assigning species to functional response groups in phytoplankton ecology reduces the number of functional units, which helps understand the processes that shape diversity and functioning of planktonic assemblages. Although the concept has become widespread in recent years, numerical characterization of the groups’ positions in the niche space remained a challenging task. Using a large river phytoplankton dataset, we characterized the functional groups (FGs) of phytoplankton by their niche position and niche breadth in the niche space defined by the relevant environmental variables using the Outlying Main Index approach. The niche space has been defined primarily by trophic-related (nutrients) and river size-related variables (water residence time, discharge). Although we hypothesized that FGs with central niche position would have wide, while those with marginal niche position have narrow niche breadth, these have not been corroborated by the results. Rather, FGs occurred both with central niche position and intermediate breadth, as well as with marginal niche position and wide breadth. Niche position of several FGs was different from that suggested by their known habitat templates in lakes. Furthermore, we found no significant relationship between niche position and niche breadth, suggesting that the occurrence of FGs in rivers is simultaneously influenced by both niche characteristics.
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Lv, Yingbo, Yifei Liang und HongXue Wang. „Research on variogram analysis method for 3D modeling of sandstone reservoir“. E3S Web of Conferences 416 (2023): 01018. http://dx.doi.org/10.1051/e3sconf/202341601018.
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Analysis of variogram is a necessary step in 3D stochastic modeling, and different settings of variograms can directly affect the final distribution of model attribute. How to optimize the setting of variogram parameters by unit and facies type has become a key step in geological modeling. This article focuses on the reservoir within sedimentary background of fluvial-deltas in the layer SII7+8 which develops multiple sedimentary microfacies, such as fluvial channels, abandoned fluvial channels, flood plains, and natural levee with strong heterogeneity, so as to study the impact of changes of the variogram parameters on the simulation results of reservoir properties, in order to explore the analysis method of the variogram. On this basis, the reservoir is divided into 3 types of sand bodies and 11 types of sedimentary microfacies based on net pay thickness, sedimentary environment, and main sand scale and morphology. The distribution characteristics and extension scale of different facies types on the plane are classified and studied, in order to determine the characteristic parameters of the variogram of different types of sand bodies, accurately simulate the distribution characteristics of reservoir physical property, and further improve the accuracy of the 3D attribute model.
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Wei, Xing, Jinlong Zhou, Yinzhu Zhou, Yanyan Zeng und Yunfei Chen. „Hydrochemistry and Environmental Isotope Characteristics of Groundwater in the Kashgar Delta Area, Xinjiang, China“. E3S Web of Conferences 98 (2019): 09032. http://dx.doi.org/10.1051/e3sconf/20199809032.
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The hydrochemistry and isotope characteristics of groundwater of different geomorphological types in the Kashgar Delta in Xinjiang, China were studied using isotopic analyses. Results showed that groundwater in the study area was mainly recharged by precipitation, and that groundwater ions were mainly affected by weathering-leaching of rock salt and evaporite as well as cation exchange and adsorption. The hydrochemical type of phreatic water in the alluvial-proluvial gravel plain on the piedmont slope was mainly SO4·Cl-Na·Ca type, with an average age of 28a. The phreatic water in the fluvial plain had shallow buried depth and intense evaporation. The hydrochemical type of phreatic water varied from SO4·Cl-Na·Mg type to Cl-Na type, with an average age of 99a. Along the groundwater flow path eastward, confined water in the fluvial plain experienced gradually more intense cation exchange and stronger adsorption. The major hydrochemical type of which was the SO4·Cl-Na type, with an average age of 30405a.
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Kale, Vishwas S. „Fluvial geomorphology of Indian rivers: an overview“. Progress in Physical Geography: Earth and Environment 26, Nr. 3 (September 2002): 400–433. http://dx.doi.org/10.1191/0309133302pp343ra.
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The rivers of India reveal certain special characteristics because they undergo large seasonal fluctuations in flow and sediment load. The rivers are adjusted to an array of discharges, and most rivers exhibit morphologies that are related to high-magnitude floods. In the last 100 years primarily hydraulic engineers have contributed to the understanding of the fluvial forms and processes. Though this trend has continued even today, in recent decades some interesting fluvial research has also been carried out by earth scientists. Four large rivers, namely Brahmaputra, Kosi, Indus and Narmada, have received greater attention from fluvial geomorphologists. The major themes in Indian fluvial geomorphology include the hydrology of monsoonal rivers; forms and processes in alluvial channels; causes of avulsion, channel migration; and anomalous variations in channel patterns; dynamics of suspended sediment; and the geomorphic impacts of floods. Studies of bedrock channels are far less than similar studies in alluvial channels. Only a few rivers have been investigated in this respect. Studies indicate that the Himalayan rivers are different in many respects from those of the Indian Peninsula. The former occupy a highly dynamic environment with extreme variability in discharge and sediment load. Earthquakes and landslides also have a great impact on these rivers from time to time. Consequently, the rivers are characterized by frequent changes in shape, size, position and planform. In comparison, the adjustments in Peninsular rivers are less frequent and of a much smaller magnitude. An inescapable conclusion is that in the tropical monsoonal environment, large floods are important geomorphic agents that temporarily affect the forms and behavioural characteristics of some rivers, but leave a lasting effect on others. In magnitude-frequency terms, large floods are major formative events in many rivers of the Indian region in general and the Indian Peninsula in particular.
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Carranza-Edwards, Arturo, Leticia Rosales-Hoz und Susana Santiago-Pérez. „Provenance memories and maturity of holocene sands in northwest Mexico“. Canadian Journal of Earth Sciences 31, Nr. 10 (01.10.1994): 1550–56. http://dx.doi.org/10.1139/e94-137.
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Beach and fluvial sediments from the region around Todos Santos Bay, Baja California, have been studied to determine their maturity, provenance, chemical alteration, and tectonic relationships. Analysis of the CaO–Na2O–K2O content of several samples demonstrated a difference between those from a beach environment and those from a fluvial environment. Transport affects the characteristics of the sediment, producing an enrichment of material resistant to chemical and physical attack on the beach area. The beach sand samples are mineralogically and chemically more mature than those from the fluvial sands. The provenance index (feldspar/rock fragments) gives relatively low average values for fluvial sands, provided that they are richer in rock fragments. The chemical index of alteration has low average values for beach sands because the minerals are more resistant to energy from waves and currents. Tectonic settings, defined through the binary diagram from Roser and Korsch, suggest that the samples belong to active continental margin and arc domains. When tectonic fields are assigned, based on a Q–F–L triangular diagram analysis, the sediments from the study area fall in an active magmatic arc field, even though this region is not presently subject to subduction.
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Fambrini, Gelson Luís, Diego da Cunha Silvestre, José Acioli Bezerra de Menezes-Filho, Ian Cavalcanti da Costa und Virgínio Henrique de Miranda Lopes Neumann. „Architectural and facies characterization of the Aptian fluvial Barbalha Formation, Araripe Basin, NE Brazil“. Geological Society, London, Special Publications 488, Nr. 1 (2019): 119–50. http://dx.doi.org/10.1144/sp488-2017-275.
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AbstractThe Aptian Barbalha Formation records the beginning of the post-rift stage of the Araripe Basin. It consists predominantly of sandstones and mudstones interbedded with thin layers of bituminous black shales and conglomerates. The depositional and architectural features of the alluvial succession of the Barbalha Formation were characterized by detailed study and descriptions of the selected outcrops and analysis of well core data. In this study, two main depositional sequences were identified. The lower depositional sequence is more than 100 m thick and comprises a vertical facies succession composed of amalgamated, multistorey, braided fluvial channel sandstone bodies overlain by a widespread lacustrine black shale up to 10 m thick. The lacustrine black shales–carbonate mixed interval is known as the Batateira Beds and constitutes a regionally important stratigraphic correlation marker in the basin. This interval records the establishment of a large lake that experienced severe water-level fluctuations and anoxic events. The upper depositional sequence is 60–95 m thick, and mainly consists of thin, yellowish, medium- to fine-grained sandstones and variegated shales. The upper sequence rests unconformably on the lacustrine black shales of the Batateira Beds. Thin and discontinuous conglomerate beds at the base of the upper sequence laterally grade into coarse-grained sandstones. These coarse-grained sandstones are overlain by interbedded sandstones and mudstones organized in fluvial cycles. The upper and lower sequences of the Barbalha Formation are separated by an erosive unconformity, traceable throughout the study area, formed during a period of stratigraphic base-level lowering. This surface marks a change in the lower sequence from a dominantly fluvial depositional style, with amalgamated multistorey braided fluvial channel sand bodies, to a lacustrine system in the top to an eminently fluvial sedimentation, which in the basal section comprises amalgamated, multistorey, braided fluvial channel sand bodies, and in the superior section the amalgamated fluvial channels are overlain by floodplain and overbank sandstone bodies with fixed fluvial channel deposits, interpreted as a suspended-load-dominated fluvial system in the upper sequence. This change in the depositional style is accompanied by a reduction in grain size and a change in the fluvial regime, suggesting that the drainage system was restructured due to tectonic movements in the basin and climatic variations. In addition to the restructuring of the drainage basin, the characteristics of the discharge of the river system have changed, probably because of the more humid climatic conditions that dominated during the deposition of the upper sequence. The fluvial deposition in the lower sequence is associated with more ephemeral river systems, while the facies architecture of the upper sequence is associated with perennial systems and is suggestive of a suspended-load-dominated fluvial system. This fluvial system is capped by lacustrine deposits of the Crato Formation. The upper sequence grades upwards into the Crato Formation. The boundary between these two units is delineated by the presence of greenish calciferous shales that are covered by lacustrine laminated limestones and shales of Neoaptian age. Palaeocurrent readings from the fluvial deposits of both sequences display a consistent palaeoflow to the SE. Sedimentological and palaeontological evidence indicates a tectonic control on sedimentation and humid to subhumid climate conditions.
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Zhang, Yong Qing, Shi Zhong Ma, Yu Sun und Jin Yan Zhang. „Sedimentary Characteristics of Fuyu Oil Layer in the Southern Fuxin Uplift of Songliao Basin“. Advanced Materials Research 868 (Dezember 2013): 164–67. http://dx.doi.org/10.4028/www.scientific.net/amr.868.164.
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Based on 22 well cores and logging data of nearly 800 well, sedimentary characteristics of Fuyu oil layer in the southern Fuxin uplift was analyzed. It is shown that types of sandstone in the Fuyu oil layer are main feldspathic litharenite, debris arkose and minor litharenite. Granularity probability curve is displayed as a typical of two-stage or three-stage. A large number of parallel bedding, one-way oblique bedding, small-scale cross bedding, the bottom scour structure and syngenetic deformation structure can be seen in the Fuyu oil layer. Mudstone color is main fuchsia, grey purple massive mudstone and gray-green, gray, dark gray massive mudstone. Combined with the analysis of the sedimentary facies sign, Fuyu oil layer in the southern Fuxin uplift is large fluvial-dominated shallow water delta deposition. The skeletal sand bodies in the delta system are distributary channelsand bodies that are large, dense, narrow strip, continuous distribution. The overall is south-southwest trending. Sand body is continuous and far underwater extension until it disappears into thin sandsheet. multi-branch fluvial-dominated ribbon-like bodies are formed.