Eléments radiochronologiques et palynologiques sur les alluvions du lit majeur de la Loire (Val d'Avaray, Loir-et-Cher, France) / Radiocarbon dating and palynology of alluvial deposits in the Loire flood plain (Val d'Avaray, Loir-et-Cher, France).

Quaternaire ◽  
2001 ◽  
Vol 12 (1) ◽  
pp. 69-88 ◽  
Author(s):  
Manuel Garcin ◽  
Geneviève Farjanel ◽  
Denis Giot
Keyword(s):  
Radiocarbon Dating ◽  
Flood Plain ◽  
Alluvial Deposits

scholarly journals Innovative strategies for high resolution site characterization: application to a flood plain

2014 ◽  
Vol 3 (4) ◽  
Author(s):  
Thomas Vienken ◽  
Manuel Kreck ◽  
Jörg Hausmann ◽  
Ulrike Werban ◽  
Peter Dietrich
Keyword(s):  
Hydraulic Properties ◽  
Test Site ◽  
Flood Plain ◽  
Site Characterization ◽  
Geological Structure ◽  
Small Scale ◽  
Alluvial Deposits ◽  
Innovative Strategies ◽  
Sedimentary Deposits

Solving complex hydrogeological problems often requires a thorough understanding of (hydro-) geological subsurface conditions. This is especially true for sedimentary deposits with complex architecture, where lithology and/or hydraulic properties can significantly vary over short horizontal and vertical distances. At these sites, a traditional, solely sample-based investigation approach is often not applicable due to limited data accuracy, resolution, and efficiency. Instead, an adapted investigation approach is required that combines exploration technologies of different resolution and investigation scales. This paper aims to demonstrate the feasibility of such a multi-scale approach for the characterization of a test site near the city of Löbnitz, Germany, that is comprised of heterogeneous alluvial deposits. Our focus is on site characterization in terms of lithology and hydraulic properties, as well as on the delineation and characterization of an aggradated oxbow as a typical example of a small scale geological structure.

scholarly journals Paleotsunami deposits along the coast of Egypt correlate with historical earthquake records of eastern Mediterranean

2018 ◽  
Vol 18 (8) ◽  
pp. 2203-2219 ◽  
Author(s):  
Asem Salama ◽  
Mustapha Meghraoui ◽  
Mohamed El Gabry ◽  
Said Maouche ◽  
Moussa Hesham Hussein ◽  
...  
Keyword(s):  
Radiocarbon Dating ◽  
Eastern Mediterranean ◽  
Coastal Lagoons ◽  
Historical Earthquakes ◽  
High Energy ◽  
Coarse Sand ◽  
X Rays ◽  
Alluvial Deposits ◽  
Inorganic Matter ◽  
Mediterranean Regions

Abstract. We study the sedimentary record of past tsunamis along the coastal area west of Alexandria (NW Egypt) taking into account the occurrence of major historical earthquakes in the eastern Mediterranean. The two selected sites at Kefr Saber (∼32 km west of Marsa-Matrouh city) and ∼ 10 km northwest of El Alamein village are coastal lagoons protected by 2–20 m-high dunes parallel to the shoreline. Field data were collected by (1) coastal geomorphology along estuaries, wedge-protected and dune-protected lagoons; and (2) identification and spatial distribution of paleotsunamis deposits using five trenches (1.5 m-depth) at Kefr Saber and twelve cores (1 to 2.5 m-depth) at El Alamein. Detailed logging of sedimentary sections was conducted using X-rays, grain size and sorting, total organic and inorganic matter, bulk mineralogy, magnetic susceptibility, and radiocarbon dating to identify past tsunamis records. Generally of low energy, the stratigraphic succession made of coastal lagoon and alluvial deposits includes intercalated high-energy deposits made of mixed fine and coarse sand with broken shells, interpreted as catastrophic layers correlated with tsunami deposits. Radiocarbon dating of 46 samples consist in mixed old (>13 000 BP) and young (<5500 BP), dated charcoal and shells in sedimentary units correlate with the 24 June AD 1870 (Mw 7.5), 8 August AD 1303 (Mw ∼ 8) and 21 July AD 365 (Mw 8–8.5) large tsunamigenic earthquakes that caused inundation along the Alexandria and northern Egyptian shoreline. Our results point out the size and recurrence of past tsunamis and the potential for future tsunami hazards on the Egyptian coastline and the eastern Mediterranean regions.

scholarly journals A 2600-yr-long paleoseismic record for the Himalayan Main Frontal Thrust (Western Bhutan)

2020 ◽  
Author(s):  
Romain Le Roux-Mallouf ◽  
Matthieu Ferry ◽  
Rodolphe Cattin ◽  
Jean-François Ritz ◽  
Dowchu Drukpa ◽  
...  
Keyword(s):  
Radiocarbon Dating ◽  
Late Holocene ◽  
Slip Rate ◽  
Historical Earthquakes ◽  
Large River ◽  
Fault Propagation ◽  
Alluvial Deposits ◽  
Seismic Slip ◽  
Fault Propagation Fold ◽  
Cumulative Deformation

Abstract. In spite of an increasing number of paleoseismic studies carried out over the last decade along the Himalayan arc, the chronology of historical and pre-historical earthquakes is still poorly constrained. In this paper, we present geomorphologic and paleoseismic studies conducted over a large river-cut exposure along the Main Fontal Thrust in southwestern Bhutan. The Piping site reveals a 30-m-high fault-propagation fold deforming late Holocene alluvial deposits. There, we carried out detailed paleoseismic investigations and built a chronological framework on the basis of 22 detrital charcoal samples submitted to radiocarbon dating. Our analysis reveals the occurrence of at least five large and great earthquakes between 485 ± 125 BC and AD 1714 with an average recurrence interval of 550 ± 211 yr. Co-seismic slip values for most events reach at least 13 m and suggest associated magnitudes are in the range of Mw 8.5–9. The cumulative deformation yields an average slip rate of 25.3 ± 4 mm/yr along the Main Frontal Thrust, over the last 2600 yr in agreement with geodetic and geomorphological results obtained nearby.

High Resolution Radiocarbon Dating at the Gerstle River Site, Central Alaska

2012 ◽  
Vol 77 (1) ◽  
pp. 71-98 ◽  
Author(s):  
Ben A. Potter ◽  
Joshua D. Reuther ◽  
Bradley A. Newbold ◽  
David T. Yoder
Keyword(s):  
High Resolution ◽  
Radiocarbon Dating ◽  
Bone Collagen ◽  
Considerable Variability ◽  
Alluvial Deposits ◽  
Vertical Thickness ◽  
Loess Deposits ◽  
Lithic Artifacts ◽  
High Level ◽  
River Site

AbstractEarly Holocene cultural material at Gerstle River, central Alaska, provides excellent contextual controls for examining variability in radiocarbon dating. Over 4,000 bone and teeth fragments are directly associated with over 7,000 lithic artifacts and 10 discrete charcoal-rich hearths in a thin occupation layer (∼10 cm vertical thickness) within well-stratified loess deposits. Radiocarbon dating of the hearth features indicates overlapping ages at 2σ, suggesting contemporaneity. This study uses the high level of resolution at Gerstle River to evaluate systematic radiocarbon variation due to different materials (collagen and charcoal), different pretreatments of collagen (regular and ultrafiltered), and interlaboratory variation through paired bone and hearth charcoal dates, split samples, and cross-checks. Accurately dating bone collagen is important given the closer association of dated samples with human activities (e.g., butchering) compared with charcoal fragments in certain contexts (e.g., driftwood, paleosols, or alluvial deposits). This study demonstrates the efficacy of bone collagen dating with ultrafiltration to counter potential site-specific contamination. These results also indicate that even in high-resolution situations with little evidence for old-wood effect and contamination, considerable variability can exist among cross-check and even split samples from single pieces of charcoal from short-lived species.

scholarly journals Concerning the Microdiamonds and Cosmic Spherules from Middle Pleistocene Selenge River Basin in North Mongolia

2017 ◽  
Vol 1 (1) ◽  
Keyword(s):  
River Basin ◽  
Practical Interest ◽  
Flood Plain ◽  
Middle Pleistocene ◽  
Alluvial Deposits ◽  
The North ◽  
River Terraces ◽  
Cosmic Spherules ◽  
Alluvial Terraces ◽  
North And South

This paper concerns deals with new discovery of microdiamonds and cosmic spherules from Middle Pleistocene Selenge river basin by the example of the Teel and Khukh Ereg terrace alluvial terraces. The Teel and Khukh Ereg alluvial terraces are located at the north and south edges of the Selenge river (Fig.1), at the base of mountain Namnan uul (Fig.2). These terraces are those whose cusp and bench entirely composed of alluvial sediments of Middle Pleistocene age [1]. This indicates that the Selenge river has a long history of development, had time to develop a flood plain and to deposit alluvium, through which it cut subsequently and north and south behind as a Teel and Khukh Ereg terraces [2]. Alluvium studies may be of great practical interest because in some areas, river terraces are veritable treasure-troves of economic minerals. With river terraces are associated most placer deposits of such important economic minerals as gold, platinum, diamond, etc. Numerous engineering projects, an example, bridges (Kherlen, Tuul, Selenge, Orkhon, Baidrag, Tui, Zavkhan, Delger Muren, etc.), dams and hydropower plants (Durgun Nuur, Ulaan Boom) are built on alluvial deposits. Hence the need to know all the essential features of the geostructure of river terraces. Just our investigation of the Selenge river terraces in 2006-2010 and 2014 gave possibility to discover the placer diamonds within the Teel and Khukh Ereg alluvial terraces for the first time in Mongolia [3,4].

scholarly journals STUDY OF THE HOLOCENE STAGE OF FORMATION OF THE DNIESTER VALLEY IN THE EASTERN CARPATHIAN FORELAND

2020 ◽  
pp. 118-139
Author(s):  
Andriy Yatsyshyn ◽  
Piotr Gębica
Keyword(s):  
Cross Sections ◽  
Radiocarbon Dating ◽  
Large Scale ◽  
Alluvial Deposits ◽  
The Holocene ◽  
Meandering Channel ◽  
Pollen Diagrams ◽  
Human Economic Activity ◽  
History Of ◽  
Two Stages

The article describes the main stages of studying of the floodplain and the first floodplain terrace of the Dniester river within the Eastern Carpathian Foreland fragment of the valley, and evaluates the results of existing studies. It is discovered that during all the stages of the research morphological and morphometric parameters of the floodplain and the first floodplain terrace of the Dniester river, morphology and facie structures of the alluvial accumulations, as well as palynological analyses of biogenic accumulations buried in an alluvial series are performed. The results obtained during the palynological analyzes are used to date the erosion-accumulation cycles and to reconstruct the physical-geographical conditions of the time of the floodplain and the first floodplain formation of the Dniester terrace. The radiocarbon dating of biogenic sediments buried in alluvial series is also actively conducted at the last stage of the research. The array of geological and geomorphological information collected at the first two stages of research made it possible to establish that, first, the first floodplain terrace and floodplain were formed during the Holocene in the Dniester Valley. The first floodplain terrace (the height of which reaches 4–6 m above the Dniester riverbed) can be considered as a high floodplain which is often covered by high floods. The terrace is accumulative, but unlike all other terraces of the Dniester it is devoid of the loess cover. In the cross-sections of its accumulations the deposits of the alluvium of the channel facies builted of pebbles are exposed and covered with the alluvium of the floodplain facies composed of sands, sandy loams and loams. The total thickness of alluvium reaches 9–10 m and it doesn’t varysignificantly downstream of the Dniester. Except the Upper Dniester basin, where the thickness of the alluvium increases to 10–18 m, and the layers of peat are found. The floodplain is 4–5 m above the Dniester riverbed and is built of alluvium of the channel facies, dominated by sand and pebble series. In someplaces floodplain is covered with sandy or loamy deposits of floodplain facies. Secondly, in the Eastern Carpathian Foreland part of the Dniester valley the course of fluvial morpholitogenetic processes was regulated not only by climatic changes and neotectonic movements, but also by human economic activity. During the XIX–XX centuries especially large-scale human influence was on the Dniester riverbeds by construction of flood ramparts, reclamation canals, etc. The results of recent geomorphological research conducted within the studied fragment of the river valley particularly palynological and radiocarbon dating have significantly improved the idea of morphology, structure and history of floodplain formation and the first floodplain terrace of the Dniester. The research revealed that the accumulation of alluvium of the first floodplain terrace which is above the Dniester riverbed reaches 5,5–6,5 (7) m and started to develop in the late Pleistocene (Bølling–Allerød interstadial) (13 000–11 000 years ago (GI–1)). Presumably in the early Dryas (11 000–10 000 years ago (GS–1)), the first floodplain terrace was dissected by the meandering channel of the Dniester. The alluvial deposits that fill these large paleomeanders are still well preserved and are often exposed in the ledges of the first terrace. The further development of the floodplain and first floodplain terrace of the Dniester river was taking place in several stages such as the end of the boreal, the beginning of the atlantic, the end of the atlantic, subboreal, the beginning of the subatlantic, as well as during V–VI, X–XII and XIV–XVI centuries. These stages are identified in correlation with the cycles of humidification of the climate and the growth of fluvial activity of riverbeds (flood phases). As a result of the intensification of erosion-accumulation activity of the Dniester the two – three levels of Holocene floodplain were formed up to 4–5 m and 3–4 m high. The first traces of human activity within the studied fragment of the Dniester valley were dated by subboreal and recorded by the presence of grain pollen in the spore-pollen diagrams of Mainych (Upper Dniester Basin) and Tsvitova (Galician-Bukachiv Basin) sections. Key words: Dniester valley; floodplain; the first floodplain terrace; alluvium; phases of floods; Allerød; early Dryas; Holocene.

scholarly journals The geochronology of a palaeolake at the Pleistocene/Holocene transition in the Muya-Kuanda Basin (Eastern Siberia, Russia)

2021 ◽  
pp. 1115-1125
Author(s):  
E.M. Ineshin ◽  
◽  
V.L. Ruposov ◽  
Buyantuev ◽  
V.I. Voronin ◽  
...  
Keyword(s):  
Decision Making ◽  
Radiocarbon Dating ◽  
Archaeological Sites ◽  
Eastern Siberia ◽  
Alluvial Deposits ◽  
Flooded Forests ◽  
Stratigraphic Position ◽  
Modern Economic ◽  
Bodies Of Water ◽  
Tree Stump

Abstract. This article presents new data on the study of preserved wood from flooded forests in the Muya-Kuanda Basin, Eastern Siberia. On the basis of the stratigraphic position of a buried tree stump horizon, the analysis of the associated alluvial deposits and a new programme of radiocarbon dating, the chronology of formation and collapse for a Late Pleistocene pal eolake in the Muya-Kuanda Basin can be precisely determined. The accuracy of dating of geological events with the radiocarbon method and the possibility of linking them to calendrical dates is discussed. As a result of this research it is possible to connect the geochronology of the lake with archaeological sites in the Vitim Basin, both upstream and downstream along the river. The reasons for the periodic formation of substantial bodies of water in the Muya-Kuanda Basin are also discussed, with implications for decision making with regard to the modern economic development of the region.

scholarly journals Paleotsunami deposits along the coast of Egypt correlate with historical earthquake records of eastern Mediterranean

2018 ◽  
Author(s):  
Asem Salama ◽  
Mustapha Meghraoui ◽  
Mohamed El Gabry ◽  
Said Maouche ◽  
Hesham Moussa Hussein ◽  
...  
Keyword(s):  
Radiocarbon Dating ◽  
Eastern Mediterranean ◽  
Coastal Lagoons ◽  
Historical Earthquakes ◽  
High Energy ◽  
Coarse Sand ◽  
X Rays ◽  
Alluvial Deposits ◽  
Inorganic Matter ◽  
Stratigraphic Succession

Abstract. We study the sedimentary record of past tsunamis along the coastal area west of Alexandria (NW Egypt) taking into account the occurrence of major historical earthquakes in the eastern Mediterranean. The two selected sites at Kefr Saber (~ 32-km west of Marsa-Matrouh city) and ~ 10 km northwest of El Alamein village are coastal lagoons protected by 2 to 20-m-high dunes parallel to the shoreline. Field data were collected by: (1) Coastal geomorphology along estuaries, wedge-protected and dune-protected lagoons, and (2) identification of paleotsunamis deposits and their spatial distribution using five trenches (1.5-m-depth) at Kefr Saber and twelve cores (1 to 2.5-m-depth) at El Alamein. Detailed logging of sedimentary sections were analysed using X rays, grain size and sorting, total organic and inorganic matter, bulk mineralogy, magnetic susceptibility and radiocarbon dating necessary for the identification of past tsunamis records. Generally of low energy, the stratigraphic succession made of marine and alluvial deposits includes intercalated high-energy deposits made of mixed fine and coarse sand with broken shells, interpreted as catastrophic layers correlated with tsunami deposits. Although the radiocarbon dating of 46 samples consist in mixed old (> 13 000 year BP) and young (

Potassium Status of Four Rice Growing Soils of Bangladesh

2012 ◽  
Vol 36 (4) ◽  
pp. 633-646
Author(s):  
M S Uddin ◽  
M J Abedin Mian ◽  
M R Islam ◽  
M A Saleque ◽  
MS Islam
Keyword(s):  
Laboratory Experiments ◽  
Field Experiments ◽  
Flood Plain ◽  
Silt Loam ◽  
Clayey Soils ◽  
Rice Soils ◽  
Alluvial Deposits ◽  
Release Capacity ◽  
Farm Soils ◽  
Exchangeable Form

Soils of varying K status were selected at the BAU farm, Mymensingh and   BADC farm, Madhupur for conducting laboratory, pot, and field experiments to see the dynamics of potassium in wet land rice soils. The soils were BAU-1(0.087 cmol/kg soil), BAU-2 (0.146 cmol/kg soil), Maddhupur-1 soil (0.097cmol/kg soil), and Madhupur-2 soil (0.706 cmol/kg soil). Almost neutral silt loam soils (Sonatola series) of BAU firm developed on the recent alluvial deposits of Old Brahmaputra Flood Plain and the acidic clayey soils (Noadda and Kalma series) of BADC farm developed on Madhupur clay. The laboratory experiments were potassium release capacity of soils, Q/I relationships of potassium. Results of the experiments showed that BADC farm soils released more K than BAU farm soils. The Q/I relationship showed that the equilibrium exchangeable K (EK0) and labile K (KL) of Madhupur-2 soil were higher than other soils. The potential buffering capacity (PBCK) was higher in BAU-2(5.19±0.12 cmol/kg (mol/L)1/2 soil followed by BAU-1 (4.07±0.09 cmol/kg (mol/L)1/2) and then Madhupur-2 soil (2.23±0.04 cmol/kg (mol/L)1/2). BAU farm soils adsorbed 55 to 60% of added K in non-exchangeable form, while it was 33 to 39% in BADC farm soils.   DOI: http://dx.doi.org/10.3329/bjar.v36i4.11750   Bangladesh J. Agril. Res. 36(4): 633-646, December 2011    

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