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Alluvial Plain (alluvial + plain)
Selected AbstractsBronze Age paleohydrography of the southern Venetian PlainGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 1 2010Silvia Piovan The Bronze Age paleohydrography of the distal Adige and Po alluvial plain (northeastern Italy) is notable for its relations with protohistoric human activities in this area. This paper regards the stratigraphy and petrography of the Saline,Cona alluvial ridge, upon which the Saline, Sarzano, and Cantarana Bronze Age sites lie, and the petrography of Fratta alluvial ridge, upon which the Frattesina complex (Bronze,Iron Age) lies. Sand analyses indicate the Po River as the source for sediments underlying the alluvial ridge that runs through Fratta Polesine, Rovigo, Sarzano, and Cona. Radiometric ages indicate that the branch of the Saline,Cona ridge was formed by the Po River between the second half of the 3rd millennium B.C. and the end of 2nd millennium B.C. This ridge represents the maximum northward expansion of the Po alluvial system, through the same area of coastal plain crossed by the Adige and Brenta paleochannels. This paleohydrographic setting implies that fluvial connections between the Central Po Plain settlements, the Venetian Plain and Alps were relatively less complex in the Early and Middle Bronze Age than in the Late Bronze Age, when the terminal reach of the Po River was separated by the Adige River by hundreds of km2 of swampy terrain. © 2009 Wiley Periodicals, Inc. [source] Palynological evidence for Pennsylvanian (Late Carboniferous) vegetation change in the Sydney Coalfield, eastern CanadaGEOLOGICAL JOURNAL, Issue 4 2010Tatyana K. Dimitrova Abstract The palynology of clastic samples from seven stratigraphical levels in the late Moscovian Sydney Mines Formation, exposed along the shore at Bras d'Or, Nova Scotia, has been investigated. Most of the samples were from roof shales of major coals; the one sample that was not yielded a much higher proportion of pollen derived from extra-basinal vegetation. The four stratigraphically lower roof shale samples yielded essentially similar palynological spectra, with 39,±,4% lycophytes, 9,±,4% sphenophylls, 23,±,4% tree-ferns, 12,±,4% other ferns and 5,±,3% cordaites. The palynology of the upper part of the investigated succession suggests a shift in vegetation towards one favouring more marattialean tree-ferns, cordaites and conifers, and fewer lycophytes. This correlates with changes in drainage patterns as the alluvial plain migrated seawards and thus changed water tables. No evidence was found to suggest significant climate change at this time. Copyright © 2009 John Wiley & Sons, Ltd. [source] Ancient Boats, Boat Timbers, and Locked Mortise-and-Tenon Joints from Bronze/Iron-Age Northern VietnamINTERNATIONAL JOURNAL OF NAUTICAL ARCHAEOLOGY, Issue 1 2007Peter Bellwood This paper describes two nautical discoveries buried c.2000 years ago in the Red River alluvial plain, northern Vietnam. One is part of a logboat with a series of empty mortise and locking-peg holes for plank attachment using loose rectangular tenons. The other, from an infant mortuary house, is a series of re-used 4-m-long timbers with exactly the same locked mortise-and-tenon technology. Both finds are interpreted as having belonged to river-boats like those shown on the sides of Heger 1 (Dong Son) bronze drums. Potentially-related technologies from the Mediterranean and China are also discussed. © 2006 The Authors [source] CONTRASTING SUBSISTENCE STRATEGIES IN THE EARLY IRON AGE?OXFORD JOURNAL OF ARCHAEOLOGY, Issue 2 2009AND THE THRACIAN PLAIN, BULGARIA, HUNGARY, NEW RESULTS FROM THE ALFÖLD PLAIN Summary. What can students of the past do to establish the predominant land-use and settlement practices of populations who leave little or no artefactual discard as a testament to their lifeways? The traditional answer, especially in Eastern Europe, is to invoke often exogenous nomadic pastoralists whose dwelling in perpetuo mobile was based on yurts, minimal local ceramic production and high curation levels of wooden and metal containers. Such a lacuna of understanding settlement structure and environmental impacts typifies Early Iron Age (henceforth ,EIA') settlements in both Bulgaria and eastern Hungary , a period when the inception of the use of iron in Central and South-East Europe has a profound effect on the flourishing regional bronze industries of the Late Bronze Age (henceforth ,LBA'). The methodological proposal in this paper is the high value of palynological research for subsistence strategies and human impacts in any area with a poor settlement record. This proposal is illustrated by two new lowland pollen diagrams , Ezero, south-east Bulgaria, and Sarló-hát, north-east Hungary , which provide new insights into this research question. In the Thracian valley, there is a disjunction between an area of high arable potential, the small size and short-lived nature of most LBA and EIA settlements and the strong human impact from the LBA and EIA periods in the Ezero diagram. In the Hungarian Plain, the pollen record suggests that, during the LBA,EIA, extensive grazing meadows were established in the alluvial plain, with the inception of woodland clearance on a massive scale from c.800 cal BC, that contradicts the apparent decline in human population in this area. An attempted explanation of these results comprises the exploration of three general positions , the indigenist thesis, the exogenous thesis and the interactionist thesis. Neither of these results fits well with the traditional view of EIA populations as incoming steppe nomadic pastoralists. Instead, this study seeks to explore the tensions between local productivity and the wider exchange networks in which they are entangled. [source] Simulating the spatial distribution of clay layer occurrence depth in alluvial soils with a Markov chain geostatistical approachENVIRONMETRICS, Issue 1 2010Weidong Li Abstract The spatial distribution information of clay layer occurrence depth (CLOD), particularly the spatial distribution maps of occurrence of clay layers at depths less than a certain threshold, in alluvial soils is crucial to designing appropriate plans and measures for precision agriculture and environmental management in alluvial plains. Markov chain geostatistics (MCG), which was proposed recently for simulating categorical spatial variables, can objectively decrease spatial uncertainty and consequently increase prediction accuracy in simulated results by using nonlinear estimators and incorporating various interclass relationships. In this paper, a MCG method was suggested to simulate the CLOD in a meso-scale alluvial soil area by encoding the continuous variable with several threshold values into binary variables (for single thresholds) or a multi-class variable (for all thresholds being considered together). Related optimal prediction maps, realization maps, and occurrence probability maps for all of these indicator-coded variables were generated. The simulated results displayed the spatial distribution characteristics of CLOD within different soil depths in the study area, which are not only helpful to understanding the spatial heterogeneity of clay layers in alluvial soils but also providing valuable quantitative information for precision agricultural management and environmental study. The study indicated that MCG could be a powerful method for simulating discretized continuous spatial variables. Copyright © 2009 John Wiley & Sons, Ltd. [source] Similarities and differences in the historical development of flood management in the alluvial stretches of the Lower Mississippi Basin and the Rhine Basin,§IRRIGATION AND DRAINAGE, Issue S1 2006Dick de Bruin ingénierie hydraulique fluviale; développement historique des bassins du Rhin et du Mississippi inférieur; plaines alluviales Abstract Although the rivers Rhine and Mississippi cannot be compared as features of nature,the Mississippi River as a feature of nature is much bigger and more impressive than the Rhine,one can still observe striking similarities on flood management in both river basins, in particular in the alluvial flat reaches. But there are also some fundamental differences, not only technically but also institutionally. Since industrialization (around 1800), inland navigation became a major user on both river systems and later flood control started developing more fundamentally. Large intervention works were needed, mainly developed and based on trial and error. In both cases it has led to irreversible effects, which demand continuous attention. For the alluvial stretches in both river basins, a review is given on the most important developments in river engineering over the last two centuries. For both rivers, nautical management and flood control were held in one institutional hand at national/federal level, because both uses/sectors need the creation and regular maintenance of one similar issue: a stable and deep main channel. But the way in which in particular flood management gradually developed institutionally, as an essential part of integrated water management in the alluvial flat lower reaches of both river systems, has diverged. Discussions on financing, priorities, public disclosure, multifunctional aspects, etc. have led in both basins to lengthy procedures and complicated policy making. This paper elaborates on the historic development of fundamentals in river engineering and river management in the alluvial plains of the Rhine Basin and the Lower Mississippi Basin, more in particular focusing on the development of flood protection dikes, and on the stabilization of major channels. Copyright © 2006 John Wiley & Sons, Ltd. Bien que le Rhin et le Mississippi ne puissent pas être comparés en termes physiques,le Mississippi est beaucoup plus grand et impressionnant que le Rhin,on peut pourtant observer des similitudes saisissantes dans la protection contre les inondations des deux bassins, en particulier dans les plaines alluviales. Mais il existe également quelques différences fondamentales, non seulement techniques mais institutionnelles. Depuis les débuts de l'industrialisation (vers 1800), la navigation est devenue un usage très important sur les deux fleuves et la protection contre les inondations à commencer à se mettre en place de façon plus systématique. De grands travaux d'intervention ont été nécessaires, principalement basés sur la règle empirique de l'essai/erreur. Dans les deux cas, ceci a entraîné des effets irréversibles, qui nécessitent une surveillance permanente. Pour les plaines alluviales des deux bassins, l'article passe en revue la plupart des développements de l'ingénierie hydraulique fluviale des deux cent dernières années. Pour les deux fleuves, la gestion de la navigation et la protection contre les inondations ont été regroupées dans une même institution au niveau national/fédéral, parce que les deux usages/secteurs demandaient la création et l'entretien régulier d'une même infrastructure: un canal principal stable et profond. Mais la manière dont la protection contre les inondations s'est progressivement développée sur le plan institutionnel, comme élément essentiel de la gestion intégrée de l'eau dans les plaines alluviales des deux fleuves, s'est différenciée. Des débats sur le financement, les priorités, l'information du public, les aspects multi fonctionnels, etc., ont conduit les deux bassins à mettre en place des procédures lourdes et des prises de décision complexes. Cet article présente le développement historique des principes fondamentaux de l'hydraulique fluviale et de la gestion de fleuve dans les plaines alluviales du bassin du Rhin et du bassin inférieur du Mississippi, en mettant l'accent sur le développement des digues de protection et la stabilisation des canaux principaux. Copyright © 2006 John Wiley & Sons, Ltd. [source] Evidence of genetic distinction and long-term population decline in wolves (Canis lupus) in the Italian ApenninesMOLECULAR ECOLOGY, Issue 3 2004V. Lucchini Abstract Historical information suggests the occurrence of an extensive human-caused contraction in the distribution range of wolves (Canis lupus) during the last few centuries in Europe. Wolves disappeared from the Alps in the 1920s, and thereafter continued to decline in peninsular Italy until the 1970s, when approximately 100 individuals survived, isolated in the central Apennines. In this study we performed a coalescent analysis of multilocus DNA markers to infer patterns and timing of historical population changes in wolves surviving in the Apennines. This population showed a unique mitochondrial DNA control-region haplotype, the absence of private alleles and lower heterozygosity at microsatellite loci, as compared to other wolf populations. Multivariate, clustering and Bayesian assignment procedures consistently assigned all the wolf genotypes sampled in Italy to a single group, supporting their genetic distinction. Bottleneck tests showed evidences of population decline in the Italian wolves, but not in other populations. Results of a Bayesian coalescent model indicate that wolves in Italy underwent a 100- to 1000-fold population contraction over the past 2000,10 000 years. The population decline was stronger and longer in peninsular Italy than elsewhere in Europe, suggesting that wolves have apparently been genetically isolated for thousands of generations south of the Alps. Ice caps covering the Alps at the Last Glacial Maximum (c. 18 000 years before present), and the wide expansion of the Po River, which cut the alluvial plains throughout the Holocene, might have provided effective geographical barriers to wolf dispersal. More recently, the admixture of Alpine and Apennine wolf populations could have been prevented by deforestation, which was already widespread in the fifteenth century in northern Italy. This study suggests that, despite the high potential rates of dispersal and gene flow, local wolf populations may not have mixed for long periods of time. [source] Age and Provenance of Loess deposits on the Northern Flank of Tianshan MountainACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 3 2009Qingdong YUAN Abstract: The distribution, optically stimulated luminescence dating and granulometric properties suggest that the loess on the northern flank of Tian Shan should be divided into two types. One which is like mantle and is named type A, is located on the windward slopes and dated to about 54.5±5.73 Ka. The other, called type B, lies flatly on the terraces of the rivers or low hills and penetrated 30.8±2.05 Ka ago. Here we study the origin and the age of two types of loess, and a model of loess formation is proposed. The dust was entrained from the Gobi Desert located to the north of Tian Shan by the monsoon from Mongolia, obstructed by the high mountains and deposited on the windward slopes of the mountains. The rivers and flows then transported the aeolian loess to low terraces and piedmont alluvial plains. [source] | |||||||||||||