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| Registros recuperados: 13 | |
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| Chen, Guocheng; Zheng, Hongbo; Li, Jianru; Xie, Xin; Me, Xi. |
| High-resolution oxygen isotope stratigraphy of Core MD05-2901, which is located off eastern Vietnam in the western South China Sea (SCS), was established and indicated that the core spans a time period of the past 450 ka. Based on the bulk density, fractional porosity and lithogenic content of the sediments, terrigenous mass accumulation rate (TMAR) was obtained, which is 4.9-6.0 g cm(-2) ka(-1) on average during interglacial stages, higher than that during glacial stages, i.e. 1.9-5.0 g cm(-2) ka(-1), which is different from northern and southern SCS which show higher TMAR in glacial stages. By principle component analysis of grain size distribution of all the samples, two main control factors (F1 and F2) were obtained, which are responsible for about 80%... |
| Tipo: Text |
Palavras-chave: South China Sea; Late Quaternary; Terrigenous sediments; Grain size; East Asian monsoon. |
| Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00207/31846/30290.pdf |
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| Boswell, Steven; Toucanne, Samuel; Creyts, Timothy T.; Hemming, Sidney R.. |
| We introduce a methodology for determining the transport distance of subglacially comminuted and entrained sediments. We pilot this method on sediments from the terminal margin of the Baltic Ice Stream, the largest ice stream of the Fennoscandian Ice Sheet during the Last Glacial Maximum. A strong correlation (R2 = 0.83) between the εNd and latitudes of circum-Baltic river sediments enables us to use εNd as a calibrated measure of distance. The proportion of subglacially transported sediments in a sample is estimated from grain size ratios in the silt fraction (<63 μm). Coupled εNd and grain size analyses reveal a common erosion source for the Baltic Ice Stream sediments located near the Åland sill, more than 850 km upstream from the terminal moraines.... |
| Tipo: Text |
Palavras-chave: Fennoscandian Ice Sheet; Baltic Ice Stream; Provenance; Epsilon Nd; Grain size; EMMA. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00434/54567/57539.pdf |
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| Bouchez, Julien; Gaillardet, Jerome; France-lanord, Christian; Maurice, Laurence; Dutra-maia, Poliana. |
| Residual solid products of erosion display a wide range of size, density, shape, mineralogy, and chemical composition and are hydrodynamically sorted in large river channels during their transport. We characterize the chemical and isotopic variability of river sediments of the Amazon Basin, collected at different water depths, as a function of grain size. Absolute chemical concentrations and Sr and Nd isotopic ratios greatly varies along channel depth. The Al/Si ratio, tightly linked to grain size distribution, systematically decreases with depth, mostly reflecting dilution by quartz minerals. A double-normalization diagram is proposed to correct from dilution effects. Elements define fan-shaped patterns and can be classified in three different groups with... |
| Tipo: Text |
Palavras-chave: Amazon River; Suspended sediments; Hydrodynamic sorting; Depth profiles; Grain size. |
| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00214/32562/31016.pdf |
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| Dennielou, Bernard; Huchon, Agnès; Beaudouin, Célia; Berne, Serge. |
| The fining upward trend commonly described on levees of turbidite systems can be either attributed to changes in the sediment supply (external forcing = allocyclic) or changes in the spillover processes related to the growth of the levee (internal forcing = autocyclic). However the real causes remain speculative and difficult to demonstrate. Knowledge of vertical change in flow velocity (or grain size) in turbidity currents, of the turbidity current's height, as well as the growth rate of a levee are theoretically sufficient to describe the evolution of the grain size of a leveed turbidite sequence deposited by spillover processes. A piston core (MD99-2344) retrieved on the right levee of the Petit-Rhone neofan, sampled an 8.50 m long turbidite sequence... |
| Tipo: Text |
Palavras-chave: Allocyclicity; Amocyclicity; Grain size; Channel levee; Turbidite. |
| Ano: 2006 |
URL: http://archimer.ifremer.fr/doc/2006/publication-2311.pdf |
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| Mccave, I. N.; Hall, I. R.. |
| The basis for, and use of, fine grain size parameters for inference of paleoflow speeds is reviewed here. The basis resides in data on deposited sediment taken in conjunction with flow speed measurements in the field, experimental data on suspended sediment transport and deposition, and theoretical treatments of the generation of size distributions of deposits from suspension controlled by particle settling velocity and flow speed. In the deep sea, sorting events occur under resuspension/deposition events in benthic storms. At flow speeds below 10 - 15 cm s(-1), size in the noncohesive "sortable silt'' ( 10 - 63 mm) range is controlled by selective deposition, whereas above that range, removal of finer material by winnowing also plays a role. The best... |
| Tipo: Text |
Palavras-chave: Sortable silt; Grain size; Paleocurrent; Flow speed; Ocean circulation; Contourite; Sediment drift. |
| Ano: 2006 |
URL: https://archimer.ifremer.fr/doc/00234/34515/33417.pdf |
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| Andrieux-loyer, Françoise; Aminot, Alain. |
| Phosphorus forms with respect to sediment characteristics, such as grain-size, and major chemical elements, were studied in French coastal marine areas (the Bay of Seine and the Loire and Gironde Estuaries).In the three areas, Fe/Al-bound phosphate (Fe/Al-P) and exchangeable phosphate (exch-P) were significantly related to the proportion of fine fraction (< 63 mum). The special association of these forms with fine particles, as well as the relationships between exch-P, Fe/Al-P and Fe showed that adsorption processes on Fe oxides had taken place. However, for similar Fe concentrations, Bay of Seine sediments showed Fe/Al-P concentrations which were four to five times higher than those found in the Loire and Gironde Estuaries. This was attributed to... |
| Tipo: Text |
Palavras-chave: Coastal areas; Major elements; Phosphorus forms; Grain size; Sediments. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-469.pdf |
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| Kissel, Catherine; Laj, Carlo; Kienast, Markus; Bolliet, Timothe; Holbourn, Ann; Hill, Paul; Kuhnt, Wolfgang; Braconnot, Pascale. |
| Magnetic and grain size properties of a sediment core located in the western equatorial Pacific, off the southeastern tip of the Philippine island of Mindanao, are presented in an effort to reconstruct past changes in the East Asian Monsoon and deep ocean circulation during the last 160 kyrs. The sedimentary concentration of magnetic particles, interpreted to reflect past changes in runoff from Mindanao, varies almost in antiphase with Northern Hemisphere insolation. This suggests that precipitation was lower in the western equatorial Pacific region during boreal insolation maxima and thus corroborates model results showing opposing trends in precipitation between land and the marine realm there. Variations in the grain size distribution of the inorganic... |
| Tipo: Text |
Palavras-chave: North atlantic; Grain size; Water; Core; Mindanao; Paleoceanography; Susceptibility; Anisotropy; Remanence; Iceland. |
| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00207/31854/30262.pdf |
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| Cao, Linglong; Wang, Ping; Wang, Jianhua; Wang, Xiaojing; Yang, Jie. |
| Through the Pearl River Estuary Wan Qing-sha W2 core AMS 14C dating of sediments, combining with paleomagnetic test, pollen analysis, and comprehensive comparison with other relevant records, the regional framework of Holocene age was established. Using the combined feature grain size and magnetic susceptibility proxies for the environment, climate change information in the area since about 6 000 cal yr BP was obtained. The result showed the area since the middle Holocene had experienced three stages climate changes of warm and dry - cool and wet temperature and humidity. South area of China in the late Holocene climate (especially rainfall) had important changes, corresponding to the Northern Hemisphere solar radiation reducing, air temperature... |
| Tipo: Journal Contribution |
Palavras-chave: Grain size; Magnetic susceptibility; Holocene; Palaeoclimate. |
| Ano: 2012 |
URL: http://hdl.handle.net/1834/5851 |
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| Chkioua, A.; BRAHIM, M.. |
| Les résultats des analyses granulométriques et minéralogiques des sédiments de surface du golfe de Tunis, prélevés à différentes profondeurs entre Sidi El Mekki et le Cap Bon, ont permis d’identifier l’origine de ces sédiments et de préciser les modes de transport et de dépôt. L’étude granulométrique a montré que les matériaux détritiques dans le golfe de Tunis sont d’origine continentale. L’étude minéralogique a permit de mettre en évidence une nette relation entre le stock sédimentaire récent du golfe de Tunis et les formations géologiques bordières. La répartition des sédiments grossiers et fins dans le golfe de Tunis est contrôlée par les courants généraux de la méditerranée. Le passage des courants généraux dans le golfe conditionne la présence... |
| Tipo: Journal Contribution |
Palavras-chave: Dynamics; Grain size; Granulometry; Mineralogy; Sediment analysis; Sediment distribution. |
| Ano: 2007 |
URL: http://hdl.handle.net/1834/4254 |
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| Brahim., M.; Abdelfattah., A.. |
| Les analyses granulométriques des sédiments superficiels de la zone côtière située entre Ras Taguermess et Ras Marmours montrent que les petits fonds (-2 à -10 m) sont couverts par des sables fins aux sables grossiers (la moyenne est entre 0,39 et 3,34 ), généralement mal à très mal classés. Cependant, le haut de plage situé entre Ras Taguermess et Ras Marmour est couvert essentiellement par des sables fins et des sables moyens (la moyenne est entre 1,082 et 2,823 ). La répartition spatiale des sables ne montre pas un grano-classement décroissant ou croissant des sédiments de la côte vers le large. Cette distribution est due à l‘existence d’une énergie importante où la houle joue le rôle essentiel sur leur répartition. L’étude granulométrique montre aussi... |
| Tipo: Journal Contribution |
Palavras-chave: Beaches; Coastal zone; Grading; Grain size; Longshore sediment transport; Sand; Sediment analysis; Sediment texture; Sediments; Swell. |
| Ano: 2009 |
URL: http://hdl.handle.net/1834/4456 |
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| Huangh, Yuanhui; Lan, Dongzhao. |
| Core D（21°23′02″N，116°47′13″E, water depth 405 m）was sampled from the upper slope from the northeastern South China Sea (SCS) and applied to analyze the sedimentary environmental change in this sea area since the last glacial stage. The results of grain size analysis, diatom analysis and detrital mineral analysis were well matched. We divided the core D into two layers. The surface sand layer (0 - 2 cm) consisted of residual sediments, which might be originally the sediment in the late Pleistocene and later suffered from being transformed in the post glacial transgression. The lower layer (2 - 130 cm) was quite different from the surface one, which might mainly result from a neritic sedimentary environment in the last glacial stage. Two sedimentary cycles... |
| Tipo: Journal Contribution |
Palavras-chave: Grain size; Diatoms; Sedimentary environments. |
| Ano: 2007 |
URL: http://hdl.handle.net/1834/5836 |
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| Brahim, M.; Ben Amor, R.; Gueddari, M.. |
| The results of the grain size and mineralogical analysis of the surface sediments of the Gulf of Gabes, taken with Various depths between the coast Sfax-Zarzis and the isobaths -100 m, allow to identify the origin of these sediments and to specify the factors and the phenomena, which are involved in their transport and their deposit. The mineralogical study resulted in high lighting a clear relation between the recent sedimentary stock of the gulf of Gabès and the bordering geological formations. The sediments study showed that the detritus materials are of continental origin and the sediments coming from the coastal erosion are subjected to a dynamics, which is controlled, primarily by the action of the currents (current coastal and currents tide and by... |
| Tipo: Journal Contribution |
Palavras-chave: Grain size; Sediment analysis; Sediment chemistry; Sediments; Mineralogy. |
| Ano: 2003 |
URL: http://hdl.handle.net/1834/1118 |
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| Lanckneus, J.; De Moor, G.; Berné, S.; Chamley, H.; De Batist, M.; Henriet, J.-P.; Terwindt, J.; Trentesaux, A.. |
| The paper analyses the first results obtained in the framework of the RESECUSED project (MAST) whose objectives are the detailed analysis of the behaviour of sediments and bedforms of and on the Middelkerke Bank (Belgian Continental Shelf) and the study of the interaction between water movement, sediment transport and bedform mobility. The results include a preliminary analysis of the residual bottom load transport paths deduced from side scan sonar registrations, a map of the sandwaves on the bank, the first grain-size results of the superficial sediment and a study on the internal structure of the bank. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bed forms; Continental shelves; Grain size; Granulometry; Sand waves; Sediment dynamics; Sediment transport; Shelf facies; Side scan sonar. |
| Ano: 1991 |
URL: http://www.vliz.be/imisdocs/publications/262327.pdf |
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| Registros recuperados: 13 | |
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