Géoarchéologie alluviale du site antique de Molesme en plaine alluviale de Laigne (Bourgogne). Réunion des Sciences de la Terre (RST), Dijon.

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Inverse modeling of past lead atmospheric deposition in South Greenland

The aim of this study is to model atmospheric lead fluxes in two different paleoenvironmental records located in southern Greenland. Fifty five sediment samples collected from the Lake Igaliku sedimentary sequence were analyzed for lead and aluminum concentrations, and lead isotopic compositions. The second archive consists in a previously published dataset, obtained from a minerogenic peat deposit, located at Tasiusaq, 16 km northwest from Lake Igaliku. A flux model fitted to both dataset produces similar results, allowing past anthropogenic atmospheric deposition to be reconstructed. This original method can be easily adapted for other studies where natural inputs dominate over discrete a…

Les sites ecclésiaux et monastiques de l’archipel du Kvarner (Croatie) : campagne 2016

La campagne 2016 du programme de recherche sur les sites ecclesiaux et monastiques de l’archipel du Kvarner a essentiellement porte sur la fouille du petit complexe antique et medieval septentrional du site de Mirine-Fulfinum – secteur dit de « l’eglise a trois absides » – (ile de Krk), du 11 au 23 avril 2016, et sur la poursuite de la fouille de la grande eglise paleochretienne du complexe de Martinscica (ile de Cres) du 27 juin au 14 juillet (fig. 1). Fig. 1 – Carte de l’archipel du Kvarner...

Approche géoarchéologique de la vallée de la Laigne

The conclusions from the research project in the Laigne Valley show the relevance of the geoarchaeological approach conducted on two scales of investigation. The first, over the entire alluvial plain, allows general data to be collected which characterise the specific functions of each catchment basin during the Holocene period : determination of sedimentary sequences, evolution of specific functions of each catchment basin during the Holocene period : determination of sedimentary sequences, evolution of vegetation and phases of human occupation. The second is a geoarchaeological approach on the scale of a test site: it demonstrates and dates as precisely as possible, interactions between n…

Sanctuaire de source, sanctuaire des eaux ou simple sanctuaire en milieu humide? Découverte d'un complexe cultuel antique à Magny-Cours (Nièvre)

In advance of the future extension of the "technopole" and the construction of a service station in the district of Magny-Cours, the undertaking of two evaluations covering 15 hectares and 4 hectares, respectively, has revealed dense occupation of the site from the Neolithic period to the Middle Ages. The most important remains are associated with the Roman period and belong to a complex endowed with public buildings including several temples in an organised arrangement. This paper, preliminary to a larger study that will report on the whole of the site, is concerned specifically with the results obtained in a waterlogged area comprised within a zone that was excluded from the rescue excava…

Les sites ecclésiaux et monastiques de l’archipel du Kvarner (Croatie)

La campagne 2016 du programme de recherche sur les sites ecclésiaux et monastiques de l’archipel du Kvarner a essentiellement porté sur la fouille du petit complexe antique et médiéval septentrional du site de Mirine-Fulfinum – secteur dit de « l’église à trois absides » – (île de Krk), du 11 au 23 avril 2016, et sur la poursuite de la fouille de la grande église paléochrétienne du complexe de Martinšćica (île de Cres) du 27 juin au 14 juillet (fig. 1). Fig. 1 – Carte de l’archipel du Kvarner...

Sur les traces d'Erik le Rouge (film et conférence)

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Première datation par chronologie radiocarbone du dernier maximum glaciaire dans le Jura

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An Inverse Modeling Approach to Investigate Past Lead Atmospheric Deposition in Southern Greenland

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Salt springs exploitation without pottery during Prehistory. From New Guinea to the French Jura

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Landscape and Settlement Evolution during the Sixteenth Century: A multidisciplinary study of two mountain areas (Eastern France)

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Vers l'Amérique : l'implantation médiévale scandinave de la côte sud-ouest du Groenland. Approches historiques et premiers résultats des études paléoenvironnementales

International audience; During the Viking Age (ca AD 800-1100) Scandinavian explorers settled the islands of the western North Atlantic, making the northernmost agricultural area of the medieval period. Expansion to south-west coast of Greenland at the end of the tenth century brought Norse settlers closer to the limits of their European-style agricultural systems. In response to the harsh low arctic climate, the Greenland Norse have adapted their farming strategies and changed their subsistence pattern, giving a more important place to hunting and fishing. This evolution had probably been accelerated by climatic changes of the Little Ice Age. A good knowledge of the Greenland Norse economy…

The history and impacts of farming activities in south Greenland: an insight from lake deposits.

International audience; Agriculture in southern Greenland has a two-phase history: with the Norse, who first settled and farmed the region between 985ad and circa 1450ad, and with the recent reintroduction of sheep farming (1920ad to the present). The agricultural sector in Greenland is expected to grow over the next century as anticipated climate warming extends the length of the growing season and increases productivity. This article presents a synthesis of results from a well-dated 1500-year lake sediment record from Lake Igaliku, south Greenland (61°00′N, 45°26′W, 15m asl) that demonstrates the relative impacts of modern and Norse agricultural activities. Pollen, non-pollen palynomorphs…

APPROCHE GÉOARCHÉOLOGIQUE ET PALÉOENVIRONNEMENTALE D'UNE ZONE HUMIDE EN CONTEXTE CULTUEL LE CAS DE MAGNY-COURS (NIÈVRE)

Im Rahmen einer Präventivgrabung wurde auf dem Gebiet der Gemeinde Magny-Cours (Departement Nièvre) ein großes antikes Heiligtum freigelegt. Die Bedeutung des Fundplatzes beruht eher auf der Entdeckung mehrerer Torfzonen mit organischen Funden (Exvotos und Holzabfälle) als auf dem Heiligtum selbst. Ein interdisziplinärer Ansatz ermöglichte es, die Natur dieser Funde und ihre Verbindung mit den benachbarten Kultstrukturen zu verstehen. Die archäologische Studie wurde durch geomorphologische und paläoumweltliche Studien ergänzt, insbesondere dendrologische, karpologische, palynologische und sedimentäre Analysen.

Towards America: environmental consequences of the Viking occupation in Greenland.

A 2500 year record of natural and anthropogenic soil erosion in South Greenland

International audience; The environmental impact of the Norse landnám in Greenland has been studied extensively. But to date, no study has quantified the soil erosion that Norse agricultural practices are believed to have caused. To resolve this problem, a high resolution sedimentary record from Lake Igaliku in South Greenland is used to quantitatively reconstruct 2500 years of soil erosion driven by climate and historical land use. An accurate chronology allows for the estimation of detritic fluxes and their uncertainties. Land clearance and the introduction of grazing livestock by the Norse around 1010 AD caused an acceleration of soil erosion up to 8 mm/century in 1180 AD which is two-fo…

The impact of Norse occupation in south Greenland: pollen, NPP's and sedimentological analyses from lakes and peat deposits.

Environmental responses of past and recent agropastoral activities on south Greenlandic ecosystems through molecular biomarkers

Paleoenvironmental studies previously performed on Lake Igaliku revealed two agropastoral phases in south Greenland: the Norse settlement from AD 986 to ca. AD 1450 and the recent installation of sheep farmers, since the 1920s. To improve the knowledge of the timing and magnitude of the Greenlandic agropastoral activities, a lipid inventory was realized and compared with biological and geochemical data. During the 12th century, a major increase in deoxycholic acid (DOC) and coprophilous fungal spores revealed a maximum of herbivores. Synchronously, a minimum of the n-C29/ n-C31 alkane ratio and tree and shrub pollen and a maximum of triterpenyl acetates showed a reduction in the tree and s…

Environmental consequences of the Norse occupation in south Greenland: first results of pollen and NPP's data from a peat bog (Qassiarsuk).

Pollen and non-pollen palynomorph evidence of medieval farming activities in southwestern Greenland

International audience; Radiocarbon dating, pollen and non-pollen palynomorph analyses from a lake core were used to establish the timing and effects of farming activities around Lake Igaliku, Eastern Settlement, Greenland. The absence of agro-pastoral impact before the medieval colonization by Europeans provides an opportunity to understand the development of farming activity in a pristine landscape. The results show that the first phase of clearance and grazing pressure, without the expansion of the Norse apophyte (native plant, in habitats created by humans) Rumex acetosa type, could have occurred in the 9–10th century A.D. The presence of Norse settlers and livestock is clearly recorded…

Analyses polliniques du marais de l’Abîme à Molesme (Côte-d’Or, France)

The pollen analysis of a borehole from the Laigne Valley, in Molesme (21), gives the first complete Holocene reference for the southeast of the Paris Basin. This low altitude sequence differs from those obtained in mid-mountainous regions: the pine forest is not replaced by oak and beech woods until the end of the Atlantic chronozone. Certain fluctuations which reveal changes in humidity in the alluvial plain, also shown by malacological analyses on a nearby outcrop, could be the result of more global climatic changes. The first palynological clues to anthropisation do not appear until the Iron Age, and fit perfectly with local archaeological data.

Identification des indices environnementaux d'anthropisation dans la séquence sédimentaire historique du lac d'Igaliko (Groenland)

Palaeoecological response to Greenlandian (Early Holocene) climatic changes: Insight from an abandoned-channel sequence of the Meuse River at Autrecourt-et-Pourron (Ardennes, France)

Abstract A Greenlandian (Early Holocene) palaeochannel of the Meuse River is described from Autrecourt-et-Pourron in the Ardennes region of northern France. During the Younger Dryas, fluvial deposits represent a high-energy, sinuous palaeochannel, but at the onset of the Holocene, progressive channel abandonment resulted in the establishment of a low-energy meandering river system. Well-dated studies using palynology, carpology, malacology and geomorphology reveal a Greenlandian succession of changes in fluvial dynamics and vegetation. Between 11,700 and 11,400 cal yr BP, warmer temperatures led to the development of a birch community (Betula sp.) within an open grassland, dominated by herb…

Long-term dynamics in microbial eukaryotes communities: a palaeolimnological view based on sedimentary DNA

International audience; Assessing the extent to which changes in lacustrine biodiversity are affected by anthropogenic or climatic forces requires extensive palaeolimnological data. We used high-throughput sequencing to generate time-series data encompassing over 2200 years of microbial eukaryotes (protists and Fungi) diversity changes from the sedimentary DNA record of two lakes (Lake Bourget in French Alps and Lake Igaliku in Greenland). From 176 samples, we sequenced a large diversity of microbial eukaryotes, with a total 16 386 operational taxonomic units distributed within 50 phylogenetic groups. Thus, microbial groups, such as Chlorophyta, Dinophyceae, Haptophyceae and Ciliophora, tha…

Detecting human impacts: non-pollen palynomorphs as proxies for human impact on the environment

International audience; Abstract Non-pollen palynomorphs (NPPs) are widely used to detect human activities, in addition to the anthropogenic indicators used in palynology. This paper first tries to determine the best way to approach most probable number (MPN) counting for young scientists. It then looks at the anthropogenic indicators and the different types of human activity that can reveal the studied taxa. Among the different fungal spores, coprophilous fungi are very useful to evidence pastoral activities and grazing pressure. Numerous taxa related to dung are also indicators of decaying organic matter and deserve our attention. Erosion processes due to human activities increase the rep…

Land use change, soil erosion and alluvial dynamic in the lower Doubs Valley over the 1st millenium AD (Neublans, Jura, France)

International audience; Geochemical and particle size analyses, surface scanning magnetic susceptibility, microscopic charcoal counting and pollen analysis, have been carried out on two cores from the lower Doubs valley in order to reconstruct the land use history. The interpretation of anthropogenic pollen indicators and micro-charcoal deposits is discussed in relation to the lithological variation of sedimentary accumulation and evolution of the settlement. The environmental changes which occurred during the 1st and the 6th century AD reflect the impact of human activities on the landscape in the immediate surroundings of the site. Multiproxy indicators indicate that soil erosion as a con…

Chapter 4 : The search for a common methodology for studying the spatial dynamics of material and product circulation in ancient times

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Vers l'Amérique : l'implantation médiévale scandinave de la côte sud-ouest du Groenland

During the Viking Age (ca AD 800-1100) Scandinavian explorers settled the islands of the western North Atlantic, making the northernmost agricultural area of the medieval period. Expansion to south-west coast of Greenland at the end of the tenth century brought Norse settlers closer to the limits of their European-style agricultural systems. In response to the harsh low arctic climate, the Greenland Norse have adapted their farming strategies and changed their subsistence pattern, giving a more important place to hunting and fishing. This evolution had probably been accelerated by climatic changes of the Little Ice Age. A good knowledge of the Greenland Norse economy by means of historical …

Data from: Long-term dynamics in microbial eukaryotes communities: a paleolimnological view based on sedimentary DNA

Assessing the extent to which changes in lacustrine biodiversity are affected by anthropogenic or climatic forces requires extensive palaeolimnological data. We used high-throughput sequencing to generate time-series data encompassing over 2200 years of microbial eukaryotes (protists and Fungi) diversity changes from the sedimentary DNA record of two lakes (Lake Bourget in French Alps and Lake Igaliku in Greenland). From 176 samples, we sequenced a large diversity of microbial eukaryotes, with a total 16 386 operational taxonomic units distributed within 50 phylogenetic groups. Thus, microbial groups, such as Chlorophyta, Dinophyceae, Haptophyceae and Ciliophora, that were not previously co…