Drancy (Seine-Saint-Denis). Rue Charles Gide – Rue Marcelin Berthelot

Un diagnostic archéologique a permis de repérer quatorze structures de types et de périodes différents (trous de poteau, silos, fosses et fossés), dont l’état de conservation est suffisant pour les dater entre le xiiie et le xive s., mais dont l’interprétation reste délicate : habitat rural ? Zone d’artisanat ? L’aperçu des aménagements (restreint en raison des méthodes de diagnostic) ne permet pas de trancher entre les différentes hypothèses

Nouvelle approche de la céramique post-Campaniforme et du Bronze ancien en Ile-de-France

This paper is a synthesis of Early Bronze Age pottery in theMarne valley, part of an ongoing research programme entitled“From the Recent Neolithic to the Early Bronze Age: definitionand interaction of cultural groups”. It centres on establishing atypochronology of pottery production from the post Campaniforme period to the Middle Bronze Age. After the integration ofdata from new sites, the pottery corpus is presented using asequence comparing different variables, method which is subsequently discussed. Post-Campaniforme pottery is seen to begrouped at the beginning of the sequence with radiocarbondates around the turn of the second millennium BC. The nextsection of the sequence is divided into three categories: engravedmotifs, horseshoe cordons and cord impressions, dating to thebeginning of the second millennium BC. At this stage of ourresearch is has not been able to establish if these three groupsrepresent the Early Bronze Age pottery corpus or if they marksuccessive chronological stagesn vallée de Marne, dans le cadre du Programme collectif derecherche «Du Néolithique récent à l’âge du Bronze ancien :définitions et interactions des groupes culturels», montrait lapossibilité d’établir une typochronologie des céramiques entreles productions post-campaniformes et celles du Bronze moyen.Après intégration de nouveaux sites, le corpus est présenté dansun tableau croisé par association de caractère qui fait l’objetd’une discussion et d’une critique. On constate que les productionspost-campaniformes sont regroupées en début de séquence et secalent par 14c avant l’aube du deuxième millénaire. Le reste dutableau est scindé en trois catégories, décor incisé, cordon arciforme, et décor à la cordelette, rattachables aux premiers sièclesdu IIe millénaire. Dans l’état actuel des recherches, il n’est pasencore possible de distinguer si ces trois groupes reflètent le corpusdu Bronze ancien ou marquent des étapes chronologiques

Nouvelle approche de la céramique post-Campaniforme et du Bronze ancien en Ile-de-France

This paper is a synthesis of Early Bronze Age pottery in theMarne valley, part of an ongoing research programme entitled“From the Recent Neolithic to the Early Bronze Age: definitionand interaction of cultural groups”. It centres on establishing atypochronology of pottery production from the post Campaniforme period to the Middle Bronze Age. After the integration ofdata from new sites, the pottery corpus is presented using asequence comparing different variables, method which is subsequently discussed. Post-Campaniforme pottery is seen to begrouped at the beginning of the sequence with radiocarbondates around the turn of the second millennium BC. The nextsection of the sequence is divided into three categories: engravedmotifs, horseshoe cordons and cord impressions, dating to thebeginning of the second millennium BC. At this stage of ourresearch is has not been able to establish if these three groupsrepresent the Early Bronze Age pottery corpus or if they marksuccessive chronological stagesn vallée de Marne, dans le cadre du Programme collectif derecherche «Du Néolithique récent à l’âge du Bronze ancien :définitions et interactions des groupes culturels», montrait lapossibilité d’établir une typochronologie des céramiques entreles productions post-campaniformes et celles du Bronze moyen.Après intégration de nouveaux sites, le corpus est présenté dansun tableau croisé par association de caractère qui fait l’objetd’une discussion et d’une critique. On constate que les productionspost-campaniformes sont regroupées en début de séquence et secalent par 14c avant l’aube du deuxième millénaire. Le reste dutableau est scindé en trois catégories, décor incisé, cordon arciforme, et décor à la cordelette, rattachables aux premiers sièclesdu IIe millénaire. Dans l’état actuel des recherches, il n’est pasencore possible de distinguer si ces trois groupes reflètent le corpusdu Bronze ancien ou marquent des étapes chronologiques

Anse, l’établissement de la Citadelle

National audienc

Nutritional Composition and Rearing Potential of the Meadow Grasshopper (Chorthippus parallelus Zetterstedt)

Insects, particularly those belonging to the family Acrididae (grasshoppers), are commonly consumed as human food in many parts of the world. Grasshoppers of the species Chorthippus parallelus are abundantly found throughout Europe. However, these insects were not consumed by Europeans till now, but could possibly be used as human food, which is why we investigated their chemical composition. We found that they contain high level of proteins (69%), with an excellent amino acid profile and protein digestibility (97%). Furthermore, specimens of C. parallelus have an interesting fatty acids profile and minerals composition. Preliminary toxicity assessment indicates that these insects do not exhibit toxicity towards neutrophil cells (white blood cells). These data suggest that C. parallelus could be considered for human consumption. Rearing trials done during the study show that commercial rearing could be developed to produce sufficient biomass for sustaining human consumption

Bi-decadal variability in physico-biogeochemical characteristics of temperate coastal ecosystems: from large-scale to local drivers

International audienceCoastal marine ecosystems, which play a crucial role in the biogeochemical and ecological functioning of the Earth, are highly sensitive to the combined effects of climate and human activities. Because of their location, coastal ecosystems are directly influenced by human activities, but it remains challenging to assess the spatial and temporal scales at which climate influences coastal ecosystems. We monitored 12 sampling stations, distributed in 8 ecosystems in France, over 2 decades for physico-biogeochemical parameters (temperature, salinity, concentrations of dissolved oxygen, nutrients and particulate material). The study encompasses a large diversity of temperate coastal ecosystems with respect to e.g. geomorphology, trophic status, tidal regime, river influence and turbidity. Time-series analysis coupled with standardised 3-mode principal component analyses, partial triadic analyses and correlations were used to assess bi-decadal variability and ecosystem trajectories, and to identify large-scale, regional and local drivers. Our results highlighted 2 abrupt changes in 2001 and 2005. The bi-decadal changes were related to changes in large-scale and regional climate, detected through proxies of temperature and atmospheric circulation, as well as through river discharge. Ecosystem trajectories tended to move towards an increase in temperature and salinity, and/or a decrease in chlorophyll a , nutrients and particulate matter. However, the magnitude of change, the year-to-year variability and the sensitivity to the 2001 and 2005 changes varied among the ecosystems. This study highlights the need for establishing long-term time series and combining data sets as well as undertaking multi-ecosystem and local studies to better understand the long-term variability of coastal ecosystems and its associated drivers

Dynamics of particulate organic matter composition in coastal systems: Forcing of spatio-temporal variability at multi-systems scale

International audienceIn costal systems, particulate organic matter (POM) results from a multiplicity of sources having their respective dynamics in terms of production, decomposition, transport and burial. The POM pool experiences thus considerable spatial and temporal variability. In order to better understand this variability, the present study employs statistical multivariate analyses to investigate links between POM composition and environmental forcings for a panel of twelve coastal systems distributed along the three maritime regions of France and monitored weekly to monthly for 1 to 8 years.At multi-system scale, two main gradients of POC composition have been identified: a 'Continent-Ocean' gradient associated with hydrodynamics, sedimentary dynamics and depth of the water column, and a gradient of trophic status related to nutrient availability. At local scale, seasonality of POC composition appears to be station-specific but still related to part of the above-mentioned forcings. A typology of systems was established by coupling spatial and temporal variability of POC composition. Four groups were highlighted: (1) the estuarine stations where POC composition is dominated by terrestrial POM and driven by hydrodynamics and sedimentary processes, (2) the oligotrophic systems, characterized by the contribution of diazotrophs due to low nutrient availability, and the marine meso/eutroph systems whose POC composition is (3) either deeply dominated by phytoplankton or (4) dominated by phytoplankton but where the contribution of continental and benthic POC is not negligible and is driven by hydrodynamics, sedimentary processes and the height of the water column.Finally, the present study provides several insights into the different forcings to POM composition and dynamics in temperate coastal systems at local and multi-system scales. This work also presents a methodological approach that establishes statistical links between forcings and POM composition, helping to gain more objectively insight of forcings

Dynamics of particulate organic matter composition in coastal systems: a spatio-temporal study at multi-systems scale

International audienceIn coastal systems, the multiplicity of sources fueling the pool of particulate organic matter (POM) leads to divergent estimations of POM composition. Eleven systems (two littoral systems, eight embayments and semi-enclosed systems and one estuary) distributed along the three maritime façades of France were studied for two to eight years in order to quantify the relative contribution of organic matter sources to the surface-water POM pool in coastal systems. This study was based on carbon and nitrogen elemental and isotopic ratios, used for running mixing models. The POM of the estuary is dominated by terrestrial material (93% on average), whereas the POM of the other systems is dominated by phytoplankton (84% on average). Nevertheless, for the latter systems, the POM composition varies in space, with 1) systems where POM is highly composed of phytoplankton (≥ 93%), 2) systems characterized by a non-negligible contribution of benthic (8 to 19%) and/or riverine (7 to 19%) sources, and 3) the Mediterranean systems characterized by the contribution of diazotroph organisms (ca. 14%). A continent-to-ocean gradient of riverine and/or benthic POM contribution is observed. Finally, time series reveal 1) seasonal variations of POM composition, 2) differences in seasonality between systems, and 3) an inshore-offshore gradient of seasonality within each system that were sampled at several stations. Spatial and seasonal patterns of POM composition are mainly due to local to regional processes such as hydrodynamics and sedimentary hydrodynamic (e.g. resuspension processes, changes in river flows, wind patterns influencing along-shore currents) but also due to the geomorphology of the systems (depth of the water column, distance to the shore). Future studies investigating the link between these forcings and POM composition would help to better understand the dynamics of POM composition in coastal systems