The RESET project: constructing a European tephra lattice for refined synchronisation of environmental and archaeological events during the last c. 100 ka

This paper introduces the aims and scope of the RESET project (. RESponse of humans to abrupt Environmental Transitions), a programme of research funded by the Natural Environment Research Council (UK) between 2008 and 2013; it also provides the context and rationale for papers included in a special volume of Quaternary Science Reviews that report some of the project's findings. RESET examined the chronological and correlation methods employed to establish causal links between the timing of abrupt environmental transitions (AETs) on the one hand, and of human dispersal and development on the other, with a focus on the Middle and Upper Palaeolithic periods. The period of interest is the Last Glacial cycle and the early Holocene (c. 100-8 ka), during which time a number of pronounced AETs occurred. A long-running topic of debate is the degree to which human history in Europe and the Mediterranean region during the Palaeolithic was shaped by these AETs, but this has proved difficult to assess because of poor dating control. In an attempt to move the science forward, RESET examined the potential that tephra isochrons, and in particular non-visible ash layers (cryptotephras), might offer for synchronising palaeo-records with a greater degree of finesse. New tephrostratigraphical data generated by the project augment previously-established tephra frameworks for the region, and underpin a more evolved tephra 'lattice' that links palaeo-records between Greenland, the European mainland, sub-marine sequences in the Mediterranean and North Africa. The paper also outlines the significance of other contributions to this special volume: collectively, these illustrate how the lattice was constructed, how it links with cognate tephra research in Europe and elsewhere, and how the evidence of tephra isochrons is beginning to challenge long-held views about the impacts of environmental change on humans during the Palaeolithic. © 2015 Elsevier Ltd.RESET was funded through Consortium Grants awarded by the Natural Environment Research Council, UK, to a collaborating team drawn from four institutions: Royal Holloway University of London (grant reference NE/E015905/1), the Natural History Museum, London (NE/E015913/1), Oxford University (NE/E015670/1) and the University of Southampton, including the National Oceanography Centre (NE/01531X/1). The authors also wish to record their deep gratitude to four members of the scientific community who formed a consultative advisory panel during the lifetime of the RESET project: Professor Barbara Wohlfarth (Stockholm University), Professor Jørgen Peder Steffensen (Niels Bohr Institute, Copenhagen), Dr. Martin Street (Romisch-Germanisches Zentralmuseum, Neuwied) and Professor Clive Oppenheimer (Cambridge University). They provided excellent advice at key stages of the work, which we greatly valued. We also thank Jenny Kynaston (Geography Department, Royal Holloway) for construction of several of the figures in this paper, and Debbie Barrett (Elsevier) and Colin Murray Wallace (Editor-in-Chief, QSR) for their considerable assistance in the production of this special volume.Peer Reviewe

Lateral Fold Identification in Northern Tunisia Thrust Belt Front

International audienc

Water quality and sediment transport issues in surface water

Recent sedimentary and morphological changes at the new mouth of Medjerda-River (Gulf of Tunis) are investigated using a multiproxy approach of sediment cores complited by 210Pbex and 137Cs method dating. The subject of the study is to focus on surveying the sedimentary evolution of Medjerda-Raoued Delta caused by the human intervention in the management of the main tributaries of the Medjerda-River (artificial channel of Henchir Tobias). Sediment cores (CEM-1 and CEM-3) were subjected to both multiproxy approaches (Grain size, geochemical analysis and dating radiometric 210Pbex and 137Cs). The sedimentological analysis of the new deltaic deposits shows a progradation sequence with the silt and clay deposits on the historic sandy substratum. The mean grain size evolution on the old beach profile shows a decreasing trend from backshore (CEM-3) to nearshore (CEM-1). The geochemical results show varying concentrations of chemical elements such as Fe, K, Rb, Nb, Cr, Ti, Ba, Ca, Sr, Zr, V, and potentially toxic metal trace elements such as Pb, Zn and the As. The Principal component Analysis (PCA) applied in the geochemical elements evolution confirms the marine origin of the sand deposits in the basic layers of the two cores. The chronological method (210Pbex and 137Cs) affirms that the first fluvial deposits were set up only after 1950. The sedimentological and geochemical result confirm the actual unless of coarser fluvial supplies under the human activities leading the negative coastal sediment balance and the shoreline retreat as well

Lateral ramp-related folding evidences in the Tellian domain of Tunisia: Tectonic implications

National audienc

Paleobiodiversity and tectono-sedimentary records in the Mediterranean tethys and related eastern areas

The geochemical and grain size analysis were carried out on surface and down core sediments from the present-day alluvial-coastal plain of the Medjerda River, Gulf of Tunis, Tunisia. The aim of this paper is to characterize the geochemical and grain size distribution of sediments and its relationship with the hydrodynamics extreme events occurring during the last century. Using a multi proxy approach, six turbidities layers have been identified in down core sediment (i.e. TL-1, TL-2, TL-3, TL-4, TL-5, TL-6, TL-7 and TL-8) characterized by multimodal grain size distribution. The terrestrial sediment which feeds the northern coastal of the Gulf of Tunis is characterized by very fine-grained sediment (clay and silt). The geochemical signature shows a highly concentration of Rb, Ti, Zn and Pb. The Medjerda River is the mainly source of silts and clay sediment. Besides, the mining pollution (Zn and Pb) is relatively strong in the coastal area, especially during the great floods events of Medjerda watershed recorded in the 1953; 1957; 1969 and 1973. Even during high frequency events, the sediments are devoid of any coarse fraction

Sensitivity assessment of the deltaic coast of Medjerda based on fine-grained sediment dynamics, Gulf of Tunis, Western Mediterranean

International audienceAs coastal areas become increasingly vulnerable to climate change, the study of nearshore sediment textures along the littoral cell of the Medjerda delta in the Gulf of Tunis, southern Mediterranean coast can provide valuable information (i) on the origin (continental or marine) of the sediment, (ii) its transport direction, and (iii) constitutes an important tool in the assessment of coastal sensitivity. A total of 120 sediments samples underwent grain size analysis and statistic parameters have been calculated. These allowed the identification of five different Sedimentary Types (ST). Accordingly, using grain size indexes (i.e. Mz, SKI and Ku), Sediment Trend Analysis (STA) modeling tools were applied to define the seasonal sediment transport pathways throughout the nearshore of the Medjerda sedimentary cell. Results show that grain size distribution (GSD) and STA model pathways are determined by cross-shore geomorphology, location of the sediment-cell, seasonal incident wave and local terrestrial supply. The appearance in an atypical seabed location of the finer (Mo = 0.1 mm) and the coarser STs (Mo = 0.8 mm) can be indicative of human influence since the coarser particles are usually retained by dam structures. Moreover, the bimodality and the increased distribution of mud are also related to the seasonal incident wave winnowing of the historic deltaic plain submerged by the relative rise in sea level. The evolution of the sediment pattern towards a greater proportion of very fine grains indicates a deficit of sediment supply, particularly of the coarser grains, and demonstrates the coastal vulnerability of the Gulf of Tunis due to anthropic effects

Installation épipaléolithique à Hergla, Tunisie littorale: SHM-1, note préliminaire (stratigraphie, culture matérielle, subsistance)

Un projet d’études multidisciplinaires portant sur le peuplement holocène côtier de la Tunisie orientale a été mis en place à partir de 2002, désignant Hergla et son environnement lagunaire et côtier comme épicentre de nos études. Des prospections extensives ont permis de cartographier de nouveaux sites et stations. En raison de son fort potentiel stratigraphique nous avons choisi de fouiller la rammadiya de SHM-1 (VIIe-VIe millénaire cal B.C.). La lecture comparative de plusieurs coupes et celle des surfaces exposées en planimétrie, ont permis de reconnaître une série d’au moins sept niveaux majeurs d’occupation. Chacun apparait comme ayant été intentionnellement structuré par des aménagements de l’espace depuis la première phase d’occupation, qui s’installa directement sur le sol dunaire vierge bordant la sebkha-lagune de Halk el Menjel. L’analyse préliminaire des complexes structurels mis au jour permet d’envisager de considérer le site comme un véritable village. Il s’agit d’empierrements, interrompus par des trous de poteaux, associés à des restes de murets en pierres sèches, à des foyers, à des structures en creux de différentes dimensions et à des zones destinées à des activités spécifiques. L’étude de l’ensemble archéologique nous permet d’avancer les premières interprétations sur le comportement des groupes humains qui s’installèrent dans ce contexte littoral, et sur leurs interactions avec d’autres communautés contemporaines. Ces résultats, acquis grâce à une lecture attentive de la stratigraphie, ainsi qu’à une méthodologie adaptée à ce type de terrain permettent, enfin, de proposer plusieurs hypothèses sur la gestion des espaces de vie des communautés épipaléolithiques finales ayant fréquenté SHM-1