Aix-Marseille University, LAMPEA UMR 7269 CNRS, Research Engineer (CNRS), Member of the Luberon Natural Park Scientific Council and member of the Advisory Committee of the geological reserve of Luberon (Vaucluse-Alpes de Haute Provence)
Highlights
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In the Lesser Caucasus, some evidences of Early Neolithic river management... more Highlights
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In the Lesser Caucasus, some evidences of Early Neolithic river management have been discovered.
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We report a preliminary data set indicating that the river management was made 5900 cal. BC ago and led to Neolithic village flooding, destruction and local abandonment of the hydraulic infrastructures between 5750 and 5430 cal. BC.
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We carried out isotopic analyzes on the seeds in order to characterize or not the occurrence of irrigation.
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We highlight the possibility of a development in the Caucasus of the oldest known water management practices.
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We also present an original focus on the potential effects of torrential palaeo-floods in Neolithic water management structures and riparian habitats.
River management is generally thought to have started at 5500 cal. BC within the development of eastern Neolithic societies. In the Lesser Caucasus, evidence of early river management has been discovered around the famous Neolithic sites of Shulaveri, Gadachrili Gora, and Imiris Gora in Georgia. Here we report a preliminary data set indicating that river management was set up at 5900 cal. BC leading to the flooding, destruction, and local abandonment of the hydraulic infrastructures of the Gadachrili village between 5750 and 5430 cal. BC. The hydraulic infrastructures were developed during a more humid period encompassing the 8200 cal. BP (6200 cal. BC) climatic event, probably to optimize agricultural yield. It potentially led to the first prehistoric engineering accident for which there is evidence, which may have been followed by the reorganisation of the occupation and/or to architectural modifications.
AbstrAct. Discovered in 2006, a collective burial, located at 200 m,
north of the site Collet-Red... more AbstrAct. Discovered in 2006, a collective burial, located at 200 m, north of the site Collet-Redon, in la Couronne, was excavated during two campaigns in 2014 and 2015. Located in the small valley called “the Chappats”, the tomb is installed in a pit with architectural features. Two sepulchral levels were identified. The first, probably composed of primary deposits, was partially removed. The second is consisted of an articulated individual and many commingled remains close to one of the wall. At least, 11 subjects (adults and immatures) are necessary to explain the composition of the osteological series. Only 7 beads made in limestone were associated with the human remains. Four radiocarbon dates are situated in the Recent Neolithic or at the very beginning of the Late Neolithic, before the widespread of collective burials in Provence. The chronological situation of the tomb, its location, the originality of its architectural feature and the use pattern are discussed taking into account the actual knowledge on funerary practices in the south of France at the end of Neolithic.
Highlights
-Carbonate denudation rates in Provence are comparable to those in other settings.
-Pr... more Highlights -Carbonate denudation rates in Provence are comparable to those in other settings. -Precipitation distribution has little influence on carbonate denudation. -Denudation variability is linked to Holocene hillslope destabilization events. -For similar climate denudation of carbonates is higher than for other lithologies.
Abstract The dynamics of carbonate-dominated landscapes is still debated, and first-order questions pertaining to the respective importance of chemical and mechanical weathering processes or the influence of climatic variability on denudation rates are largely open. To address these issues, we investigate the denudation pattern across a climatic gradient in Provence, SE France. We focused on a series of major carbonate mountain ranges with elevation spanning 200 to 2000 m and associated with >2-fold variations in mean annual temperature and precipitation. We collected 25 samples from 10 different mountain ranges and quantified denudation rates through the measurement of their 36Cl concentrations in order to explore tectonic and climatic controls on these carbonate landscapes evolution. We observe that most of our samples experience denudation rates in the 30–60 mm/ka range (averaged over 5 to 40 ka), with no evident dependence on variations of mean annual temperature or precipitation. One range (Lure mountain) stands out as a significant outlier, with much higher denudation rates (>100 mm/ka) than adjacent sites (Ventoux mountain) at the same elevation and experiencing similar present-day environmental conditions. We explore in details the climatic, tectonic and geomorphological contexts of these two ranges in order to understand the reasons for this apparent 3-fold difference in denudation rates. A regionally-documented major Holocene hillslope destabilization event appears to be a likely candidate to explain the observed lower 36Cl concentrations at the top of the Lure mountain. At longer wavelengths, our regional dataset shows no clear control of modern precipitation gradients on denudation rates, consistent with previous observations in landscapes underlain by other lithologies.
A sedimentological and geochemical study was carried out on the travertines from Bongongo and Ngo... more A sedimentological and geochemical study was carried out on the travertines from Bongongo and Ngol locations along the Cameroon Volcanic Line. This work seeks to ascertain: (1) the origin and typology of the studied travertine deposits, (2) the palaeo-environmental depositional model and (3) the typical characteristic of the hydrothermal system. The distribution and typology of travertine deposits were performed from natural outcrops. Oxygen and carbon stable isotope methods have been employed in the detail study of representative travertine samples from Bongongo and Ngol. The different travertine deposits along Ngol stream valley occur around waterfall/cascade, slopes and pools. At Bongongo the travertine precipitation can be linked to temporal fluctuation of carbonate mineral saturation level in rising thermal fluids and the depth of the boiling zone. The hydrothermal system of Ngol and Bongongo has been clarified using results of geochemical analyses of stable isotope, which can be applied regionally. The studied travertines are characterized by δ 18 O values from −8.4 to −6.4‰ V-PDB for Ngol and −5.8 to −5.9‰ V-PDB for Bongongo and δ 13 C values from 0.4 to 0.5‰ V-PDB for Ngol and from 1.1 to 2‰ V-PDB for Bongongo, in accordance with global travertine deposit environments. The values of stable carbon isotopes analyses of Bongongo and Ngol travertines are very far from the isotopic composition of magmatic carbon. Based on the geothermal environment, the high temperature parent solution (31 °C and 49 °C) and stable isotope study, it can be considered that the studied travertine from Bongongo and Ngol are charasteristic of the thermogenic type.
Géoarchéologie de l'aqueduc, panneau 2 de l'exposition "Alle origini del Galermi. Un acquedotto a... more Géoarchéologie de l'aqueduc, panneau 2 de l'exposition "Alle origini del Galermi. Un acquedotto attraverso la storia", Museo Paolo Orsi Siracusa, 2017
Le Grand Abri aux Puces (GAP), located on the right bank of the Ouvèze River of southern France, ... more Le Grand Abri aux Puces (GAP), located on the right bank of the Ouvèze River of southern France, has been known to contain well-preserved stone tools and faunal remains, but our work in 2008 was the first professional, controlled excavation at the site and has exposed at least 1 archaeological layer with a very rich and diverse faunal assemblage (23 macrofaunal species, as many for the microfauna, 27 land snail species), abundant charcoals (fragments are large and preserve small twigs with their pith and bark still intact), and stone tools with immaculate surface preservation (retaining their original freshness and preserving microscopic use wear). The information issuing from paleontology, micropaleontology, malacology, and anthracology all place the principle GAP human occupation unambiguously in a temperate climatic phase. Different biometric and biochronological characters of the fauna converge to place the layers found thus far from before the last glacial, and most likely in MIS 5e (127e117 kya). The lithic elements, mainly composed of tools of superior quality, demonstrating particular technical investment, and made from widely distributed raw material sources, lead us to hypothesize brief passages of hunting groups in the cave focused around an anticipated activity. This hypothesis will be refined and tested during further excavations.
Résumé :
Dans le cadre du programme HYDRΩMED (A*MIDEX Aix Marseille Université), de nouvelles re... more Résumé :
Dans le cadre du programme HYDRΩMED (A*MIDEX Aix Marseille Université), de nouvelles recherches concernant la gestion de l’eau en Méditerranée au cours du premier millénaire avant J.C. ont été développées. Nous présentons ici nos premiers résultats obtenus dans le cadre d’une approche pluridisciplinaire sur la cité de Solonte (nord-ouest de la Sicile) mêlant archéologie, hydrogéologie et géoarchéologie. Auparavant considérée comme exclusivement issue de la collecte des eaux de pluies par l’intermédiaire de systèmes de citernes, l’alimentation en eau du site apparaît en fait beaucoup plus riche et complexe. Cette dernière proviendrait plutôt de l’exploitation de systèmes de fractures tectoniques guidant des remontées hydrothermales, et fournissant des eaux thermominérales additionnelles et pérennes dans une grande partie des infrastructures hydrauliques identifiées à Solonte (notamment des thermes). Ces nouveaux résultats mettent en évidence un des paramètres fondamentaux ayant pu influencer le choix du Monte Catalfano comme site privilégié d’implantation de la cité durant l’antiquité. Une analyse descriptive de la grande citerne maçonnée fournit également des informations améliorant les connaissances sur la gestion de l’eau dans la cité antique de Solonte.
Abstract :
New research about water management in the Mediterranean during the first millennia BC are developed in the frame of the HYDRΩMED (A*MIDEX Aix Marseille University) program. We present here our first results obtained within the framework of a multidisciplinary approach on the city of Solonte (northwest of Sicily) combining archeology, hydrogeology and geoarchaeology. Previously considered exclusively from the collection of rainwater through cistern systems, the water supply to the site actually appears much richer and more complex. The latter would come rather from the exploitation of tectonic faulting guiding hydrothermal flow providing additional and perennial thermomineral waters in a large part of the hydraulic infrastructures identified at Solonte (including thermal baths). These new results highlight one of the fundamental parameters that may have influenced the choice of Monte Catalfano as a privileged site for the settlement of the city during antiquity. A descriptive analysis of the large built cistern also provides information to improve the knowledge of water management in the ancient city of Solonte.
Abstract :
Nell’ambito del programma HYDRΩMED (A*MIDEX Aix Marseille Université), si sono condotte nuove ricerche sulla gestione idrica nel Mediterraneo durante il primo millennio a. C. Si presentano in questo contributo i primi risultati ottenuti nel quadro di un approccio pluridisciplinare alla città di Solunto (nord ovest della Sicilia), il quale unisce archeologia, idrogeologia e geoarcheologia. Inizialmente considerata come esclusivo esito della raccolta dell’acqua piovana attraverso i sistemi delle cisterne, l’alimentazione idrica del sito sembrerebbe in realtà molto più ricca e complessa. Quest’ultima deriverebbe, piuttosto, dallo sfruttamento delle fratture tettoniche del sito, caratterizzate da fenomeni idrotermali che fornivano acque termominerali in gran parte delle infrastrutture idrauliche identificate a Solunto (in particolare le terme). Questi nuovi risultati mettono in evidenza uno dei parametri fondamentali che hanno potuto influenzare la scelta di Monte Catalfano come sito privilegiato per l’impianto della città nell’antichità. Un’analisi descrittiva della grande cisterna in muratura, inoltre, fornisce informazioni che contribuiscono alla conoscenza della gestione idrica nell’antica città di Solunto.
The influence of the morphological setting on the denudation of carbonate landscapes and the resp... more The influence of the morphological setting on the denudation of carbonate landscapes and the respective contributions of mechanical and chemical weathering processes are still debated. We have addressed these questions by measuring 36Cl concentrations in 40 samples from the Luberon mountain, SE France, in order to constrain the denudation of various landscape elements. We observe a clear contrast between the local denudation rates from the flat summit surface, clustered around 30 mm/ka, and the basin average denudation rates across the flanks, ranging from 100 to 200 mm/ka. This difference highlights the transient evolution of the range, whose topography is still adjusting to previous uplift events. Such a pattern also suggests that carbonate dissolution is not the only driver of denudation in this setting, which appears to be significantly controlled by slope-dependent processes.
The nature and timing of environmental changes throughout the last glacial-interglacial transitio... more The nature and timing of environmental changes throughout the last glacial-interglacial transition in the South Caucasus, and more widely in eastern Europe, are still not fully understood. According to certain pollen records, forest expansion occurred in many areas several millennia after what is considered worldwide as the onset of the Holocene. The current problem we face is that the time lag in forest expansion varies from one sequence to another, sometimes with no delay at all. Moreover, the potential forcing/controlling factors behind this complex pattern, contrary to the almost synchronous global Holocene warming, are still a matter for debate. Accordingly, we revisit the issue of forest expansion through vegetation history obtained in the South Caucasus using a new pollen record, retrieved from the Nariani paleolake (South Georgia). These data attest to a steppic phase, initially dominated by Amaranthaceae-Chenopodiaceae (12,700–10,500 cal yr BP), then by Poaceae (10,500–9000 cal yr BP), culminating with a more forested phase (9000–5000 calyrBP). Although some palaeoclimatic regional reconstructions show a wet early Holocene, we interpret the delay in forest expansion recorded in Nariani (2500 years) as the result of reduced spring precipitation, which would have limited forest development at that time.
Keywords: landscape evolution carbonates denudation cosmogenic nuclides hillslope processes Under... more Keywords: landscape evolution carbonates denudation cosmogenic nuclides hillslope processes Understanding topographic evolution requires integrating elementary processes acting at the hillslope scale into the long-wavelength framework of landscape dynamics. Recent progress has been made in the quantification of denudation of eroding landscapes and its links with topography. Despite these advances, data is still sparse in carbonate terrain, which covers a significant part of the Earth's surface. In this study, we measured both long-term denudation rates using in situ-produced 36 Cl concentrations in bedrock and regolith clasts and surface convexity at 12 sites along ridges of the Luberon carbonate range in Provence, Southeastern France. Starting from ∼30 mm/ka for the lowering of the summit plateau surface, denudation linearly increases with increasing hilltop convexity up to ∼70 mm/ka, as predicted by diffusive mass transport theory. Beyond this point denudation rates appear to be insensitive to the increase in hilltop convexity. We interpret this constant denudation as indicating a transition from a regime where hillslope evolution is primarily controlled by diffusive downslope regolith transport, toward a situation in which denudation is limited by the rate at which physical and chemical weathering processes can produce clasts and lower the hilltop. Such an abrupt transition into a weathering-limited dynamics may prevent hillslope denudation from balancing the rate of base level fall imposed by the river network and could potentially explain the development of high local relief in many Mediterranean carbonate landscapes.
Keywords: landscape evolution carbonates denudation cosmogenic nuclides hillslope processes Under... more Keywords: landscape evolution carbonates denudation cosmogenic nuclides hillslope processes Understanding topographic evolution requires integrating elementary processes acting at the hillslope scale into the long-wavelength framework of landscape dynamics. Recent progress has been made in the quantification of denudation of eroding landscapes and its links with topography. Despite these advances, data is still sparse in carbonate terrain, which covers a significant part of the Earth's surface. In this study, we measured both long-term denudation rates using in situ-produced 36 Cl concentrations in bedrock and regolith clasts and surface convexity at 12 sites along ridges of the Luberon carbonate range in Provence, Southeastern France. Starting from ∼30 mm/ka for the lowering of the summit plateau surface, denudation linearly increases with increasing hilltop convexity up to ∼70 mm/ka, as predicted by diffusive mass transport theory. Beyond this point denudation rates appear to be insensitive to the increase in hilltop convexity. We interpret this constant denudation as indicating a transition from a regime where hillslope evolution is primarily controlled by diffusive downslope regolith transport, toward a situation in which denudation is limited by the rate at which physical and chemical weathering processes can produce clasts and lower the hilltop. Such an abrupt transition into a weathering-limited dynamics may prevent hillslope denudation from balancing the rate of base level fall imposed by the river network and could potentially explain the development of high local relief in many Mediterranean carbonate landscapes.
À Bédoin dans le Vaucluse, la fouille de sauvetage urgent du Limon-Raspail dirigée par J. Cauliez... more À Bédoin dans le Vaucluse, la fouille de sauvetage urgent du Limon-Raspail dirigée par J. Cauliez en 2005 a livré, sur une surface de 250 m 2 , une trentaine d'aménagements creusés révélant l'existence d'un habitat relativement bien préservé et implanté en position privilégiée à près de 350 m d'altitude. Le site est daté du Néolithique final, entre 2880 et 2580 av. J.-C. Cette trentaine de structures en creux offre la vision d'une zone d'activités, là où se concentrent des foyers et des aménagements liés à la conservation, tous réutilisés comme dépotoirs. Voisin de sites éponymes à l'origine de l'identification de trois des quatre principales cultures du Néolithique final du sud-est de la France – les groupes Rhône-Ouvèze, de Fraischamp et du Nord-Vaucluse –, le gisement du Limon-Raspail ne s'ac-corde pas, sur le plan chronoculturel, avec l'un ou l'autre de ces ensembles. L'originalité du site peut s'expliquer par sa localisation dans une zone tampon. Il est à la limite nord des aires d'extension reconnues pour les groupes provençaux. Il s'inscrit également dans des flux de circulations alimentés par le Piémont italien ; il pourrait être enfin en liaison avec des groupes de régions plus septentrionales, tels que ceux de l'axe Saône-Rhône, dont les influences seraient perceptibles, au Néolithique final, jusque dans la moyenne vallée du Rhône. Mots-clés Néolithique final, Sud-Est de la France, habitat de plein-air, interactions culturelles, groupe multipolaire. Abstract The open-air settlement of Limon-Raspail has been discovered in March 2005. It has been subject to a rescue excavation during spring 2005. This excavation was conducted under the direction of Jessie Cauliez and was headed by the Service Régional de l'Archéologie de Provence-Alpes-Côte-d'Azur. The site of Limon-Raspail is localized on a small hill at 350 m height and covers a surface of almost 15 000 square meters. The site dominates the Mormoiron depression in the south and the one of Bédoin in the north. The excavation carried out on a surface of 250 square meters has allowed discovery of a settlement organized around thirty-five pits. It is assigned to the Final Neolithic and dated to a time span of between 2880 and 2580 cal BC at most. This interval is based on six radiocarbon AMS dates made from faunal remains and charcoal all stemming from distinct features. Multiple occupations are possible as some of the pits overlap. As a matter of fact, with this in mind, the homogeneity of the pottery and lithic
The Provence region located in SouthEastern France has registered significant earthquakes in the ... more The Provence region located in SouthEastern France has registered significant earthquakes in the last 1000 years, some reaching intensities up to IX. It is currently undergoing a very slow tectonic deformation with little seismicity and long recurrence intervals for major earthquakes (such as the 1909 magnitude 6 Lambesc earthquake). Several West-trending ranges are an important part of the landscape, and the influence of tectonic uplift compared to denudation during the Pliocene-Quaternary is not yet fully understood in the region. The geology of SouthEastern France is dominated by a thick Mesozoic series primarily consisting of carbonate rocks. The iconic ranges of Provence resulting from the Pyrenean orogeny (late Eocene) are mostly made up of uplifted lower Cretaceous. A minor reactivation occurred during the more recent Alpine late Cenozoic tectonic phase and contributed to the rejuvenation of the relief. Carbonate rocks are prone to complete chemical dissolution and are thus highly sensitive to climatic forcings such as precipitation. Moreover, the elevation and the frequency of freezing and thawing are parameters strongly influencing the geomorphic evolution in such environments. To investigate on this matter, 42 carbonate rock samples were collected for 36Cl denudation measurements on the Petit Luberon range. Denudation rates have been determined for both bedrock samples from the crest and sediments from rivers draining the southern and northern flanks of the range, allowing insights into long-term relief evolution. We observe a strong denudation contrast between the flanks lowering at 100-200 mm/ka and the summit surface, at around 30 mm/ka. These results suggest a transient evolution and a probable narrowing of the range. In addition, we collected 23 carbonate bedrock samples from other Mesozoic ranges in Provence with a wide altitude range (from 150 up to 1800 meters high asl), for similar 36Cl analysis. Our objective in this study (CEA-Cashima) is to have a regional overview of the distribution of denudation rates in an area dominated by carbonate rocks and to evaluate the influence of altitude, climate and associated processes on erosion and eventually link it to a slow regional uplift. Thus this study will allow a better understanding of the denudation processes in a carbonate dominated area characterized by slow tectonic deformations and moderate precipitations.
Le tuf calcaire de la Thomassine : paysages et climats du Néolithique ancien dans les collines de... more Le tuf calcaire de la Thomassine : paysages et climats du Néolithique ancien dans les collines de Manosque
Vincent OLLIVIER , Frédéric MAGNIN , Adam ALI , Christine BALME & Pierre FRAPA
Le tuf calcaire de la Thomassine, localisé sur le site même de la Maison de la Biodiversité à Manosque (Alpes-de-Haute-Provence), fait actuellement l’objet d’une étude pluridisciplinaire afin de reconstituer les rythmes de l’évolution du paysage dans le secteur de Manosque. Les analyses géomorphologiques, les datations radiocarbone et l’étude des assemblages de gastéropodes contenus dans les sédiments, permettent de caractériser différentes composantes de l’environnement du Luberon au début du Néolithique, il y a plus de 6500 ans.
The calcareous tufa of La Thomassine: Early Neolithic landscapes and climates in the Manosque countryside
The Thomassine calcareous tufa, located near the “Biodiversity House” (Manosque, Alpes-de-Haute-Provence), is currently the subject of a multidisciplinary study to reconstruct the rhythms of the landscape changes in the Manosque area. Geomorphological analysis, radiocarbon dating and land snail assemblage studies are used to characterize the various components of the Luberon environment in the early Neolithic, more than 6,500 years ago.
The Caspian Sea relative level variation evolution is based on high frequency and wide amplitude ... more The Caspian Sea relative level variation evolution is based on high frequency and wide amplitude rhythmicity, well defined for the Pleistocene-Lateglacial period and with high resolution for the Holocene. These variations are not strictly correlated with the global and/or rapid climate changes components, and the inland effects of such marine oscillations are nowadays poorly known. Our researches are focused on the retroactive impact of these “climato-eustatic” Caspian variations on the main fluvial system (Kura and Arax) and their tributaries as well as on the Holocene societies in the Lesser Caucasus. The geomorphological analysis (stratigraphy, sedimentology, morphosedimentary changes), and the geochronological and geoarchaeological studies (14C dating and studies on Neolithic to Bronze Age sites) gave us some precious data correlating the sea movement to the sedimentation rhythmicity and human occupation phases in a regional scale. Since the Upper Pleistocene, the upstream hydrosystem have reacted to marine regressions by powerful riverbed incisions (>37 000; 37 000-27 000; 13 000-11 000; 3 200-2 900; 2 100-1 600; 1 000-400; 150-0 cal. BP) and to transgression phases by thick valley infilling (eg. 27 000-13 000; 11 000-3 200; 2 900-2 100; 1 600-1 000; 400-150 cal. BP). The retroactive morphogenic effects were also perceived to intramontainous area far away from the Caspian shoreline. These different sedimentary balance sheets, and the changes in the fluvial geomorphology, led to landscape changes affecting the land use availability for agriculture and herding in the vicinity of the riparian zone. This is also spatially and diachronically traduced in the settlement location (depending on the sedimentological/ pedological amenities and water accessibility) but also on their abandonment and their destruction and/or burying by the erosive processes. Climatic oscillations and base level changes data are now discretized and integrated in the geoarchaeological analyses concerning the land use in the Caspian Sea hydrographic basin in the frame of the ANR ORIMIL research program.
Article du Courrier d'Erevan sur la Conférence "Paysages et climats du passé... un regard vers l'... more Article du Courrier d'Erevan sur la Conférence "Paysages et climats du passé... un regard vers l'avenir" à l'ambassade de France en Arménie.
Le climat de notre planète a beaucoup varié au cours des temps géologiques. Depuis 2.6 millions d... more Le climat de notre planète a beaucoup varié au cours des temps géologiques. Depuis 2.6 millions d’années, au cours du Quaternaire, des périodes de glaciations et de réchauffements se succèdent de manière cyclique à l’échelle globale. Les sociétés humaines ont traversé ces périodes de fluctuations climatiques. Dans les paysages, de nombreux indices nous permettent de caractériser et de comprendre l’origine, la nature et l’ampleur de ces changements. Au travers des recherches menées dans le cadre de missions scientifiques internationales soutenues par le Ministère des Affaires Etrangères, le CNRS (Laboratoires Internationaux Associés) et l’Agence Nationale de la Recherche, nous aborderons les différentes étapes de ces changements climatiques et de leurs impacts millénaires sur les paysages et les sociétés de l’Arménie, et plus généralement du Petit Caucase.
Leroyer, C., Joannin, S., Aoustin, D., Ali, A.A., Peyron, O., Ollivier V., Tozalakyan, P., Karakh... more Leroyer, C., Joannin, S., Aoustin, D., Ali, A.A., Peyron, O., Ollivier V., Tozalakyan, P., Karakhanyan, A., Jude F.
Quaternary International 2015
A sediment core has been retrieved from Vanevan peat (south-eastern shore of Lake Sevan, Armenia), which is today disconnected from Lake Sevan thanks to an artificial shallowing of the lake. Based on 5 radiocarbon dates, Vanevan record covers the Mid Holocene (from ca. 7800 to ca. 5100 cal. BP). The Late Holocene is today absent in the peat stratigraphy due to modern peat exploitation by surface mining. This study focuses on a multi-proxy approach including pollen, charcoals, and pollen-inferred climate reconstruction.
An open-land, steppic vegetation is recorded up to ca. 7700 cal. BP, followed by a more forested landscape during the Mid Holocene (up to ca. 5700 cal. BP), and ending again with an open-land vegetation (to the end of record, 5100 cal. BP). This vegetation dynamics responds to general climate changes documented in the Near East. Whether human activities are documented since ca. 7500 cal. BP (Late Neolithic) in Vanevan, they remain marginal and probably did not affect the area. Early Holocene dry climate, which caused the steppic environment to be widespread through the Near East, is strongly related to low late spring precipitation (PMay–Jun = 180 mm). Mid Holocene forested landscape and increasing lake-level seem related to late spring precipitation (+28%), which is the main change in estimated climate parameters. This has to be linked with reinforcement of the Westerlies and less active Siberian High, which are inversely involved in the following, dry phase starting at ca. 5700 cal. BP.
Highlights
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In the Lesser Caucasus, some evidences of Early Neolithic river management... more Highlights
•
In the Lesser Caucasus, some evidences of Early Neolithic river management have been discovered.
•
We report a preliminary data set indicating that the river management was made 5900 cal. BC ago and led to Neolithic village flooding, destruction and local abandonment of the hydraulic infrastructures between 5750 and 5430 cal. BC.
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We carried out isotopic analyzes on the seeds in order to characterize or not the occurrence of irrigation.
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We highlight the possibility of a development in the Caucasus of the oldest known water management practices.
•
We also present an original focus on the potential effects of torrential palaeo-floods in Neolithic water management structures and riparian habitats.
River management is generally thought to have started at 5500 cal. BC within the development of eastern Neolithic societies. In the Lesser Caucasus, evidence of early river management has been discovered around the famous Neolithic sites of Shulaveri, Gadachrili Gora, and Imiris Gora in Georgia. Here we report a preliminary data set indicating that river management was set up at 5900 cal. BC leading to the flooding, destruction, and local abandonment of the hydraulic infrastructures of the Gadachrili village between 5750 and 5430 cal. BC. The hydraulic infrastructures were developed during a more humid period encompassing the 8200 cal. BP (6200 cal. BC) climatic event, probably to optimize agricultural yield. It potentially led to the first prehistoric engineering accident for which there is evidence, which may have been followed by the reorganisation of the occupation and/or to architectural modifications.
AbstrAct. Discovered in 2006, a collective burial, located at 200 m,
north of the site Collet-Red... more AbstrAct. Discovered in 2006, a collective burial, located at 200 m, north of the site Collet-Redon, in la Couronne, was excavated during two campaigns in 2014 and 2015. Located in the small valley called “the Chappats”, the tomb is installed in a pit with architectural features. Two sepulchral levels were identified. The first, probably composed of primary deposits, was partially removed. The second is consisted of an articulated individual and many commingled remains close to one of the wall. At least, 11 subjects (adults and immatures) are necessary to explain the composition of the osteological series. Only 7 beads made in limestone were associated with the human remains. Four radiocarbon dates are situated in the Recent Neolithic or at the very beginning of the Late Neolithic, before the widespread of collective burials in Provence. The chronological situation of the tomb, its location, the originality of its architectural feature and the use pattern are discussed taking into account the actual knowledge on funerary practices in the south of France at the end of Neolithic.
Highlights
-Carbonate denudation rates in Provence are comparable to those in other settings.
-Pr... more Highlights -Carbonate denudation rates in Provence are comparable to those in other settings. -Precipitation distribution has little influence on carbonate denudation. -Denudation variability is linked to Holocene hillslope destabilization events. -For similar climate denudation of carbonates is higher than for other lithologies.
Abstract The dynamics of carbonate-dominated landscapes is still debated, and first-order questions pertaining to the respective importance of chemical and mechanical weathering processes or the influence of climatic variability on denudation rates are largely open. To address these issues, we investigate the denudation pattern across a climatic gradient in Provence, SE France. We focused on a series of major carbonate mountain ranges with elevation spanning 200 to 2000 m and associated with >2-fold variations in mean annual temperature and precipitation. We collected 25 samples from 10 different mountain ranges and quantified denudation rates through the measurement of their 36Cl concentrations in order to explore tectonic and climatic controls on these carbonate landscapes evolution. We observe that most of our samples experience denudation rates in the 30–60 mm/ka range (averaged over 5 to 40 ka), with no evident dependence on variations of mean annual temperature or precipitation. One range (Lure mountain) stands out as a significant outlier, with much higher denudation rates (>100 mm/ka) than adjacent sites (Ventoux mountain) at the same elevation and experiencing similar present-day environmental conditions. We explore in details the climatic, tectonic and geomorphological contexts of these two ranges in order to understand the reasons for this apparent 3-fold difference in denudation rates. A regionally-documented major Holocene hillslope destabilization event appears to be a likely candidate to explain the observed lower 36Cl concentrations at the top of the Lure mountain. At longer wavelengths, our regional dataset shows no clear control of modern precipitation gradients on denudation rates, consistent with previous observations in landscapes underlain by other lithologies.
A sedimentological and geochemical study was carried out on the travertines from Bongongo and Ngo... more A sedimentological and geochemical study was carried out on the travertines from Bongongo and Ngol locations along the Cameroon Volcanic Line. This work seeks to ascertain: (1) the origin and typology of the studied travertine deposits, (2) the palaeo-environmental depositional model and (3) the typical characteristic of the hydrothermal system. The distribution and typology of travertine deposits were performed from natural outcrops. Oxygen and carbon stable isotope methods have been employed in the detail study of representative travertine samples from Bongongo and Ngol. The different travertine deposits along Ngol stream valley occur around waterfall/cascade, slopes and pools. At Bongongo the travertine precipitation can be linked to temporal fluctuation of carbonate mineral saturation level in rising thermal fluids and the depth of the boiling zone. The hydrothermal system of Ngol and Bongongo has been clarified using results of geochemical analyses of stable isotope, which can be applied regionally. The studied travertines are characterized by δ 18 O values from −8.4 to −6.4‰ V-PDB for Ngol and −5.8 to −5.9‰ V-PDB for Bongongo and δ 13 C values from 0.4 to 0.5‰ V-PDB for Ngol and from 1.1 to 2‰ V-PDB for Bongongo, in accordance with global travertine deposit environments. The values of stable carbon isotopes analyses of Bongongo and Ngol travertines are very far from the isotopic composition of magmatic carbon. Based on the geothermal environment, the high temperature parent solution (31 °C and 49 °C) and stable isotope study, it can be considered that the studied travertine from Bongongo and Ngol are charasteristic of the thermogenic type.
Géoarchéologie de l'aqueduc, panneau 2 de l'exposition "Alle origini del Galermi. Un acquedotto a... more Géoarchéologie de l'aqueduc, panneau 2 de l'exposition "Alle origini del Galermi. Un acquedotto attraverso la storia", Museo Paolo Orsi Siracusa, 2017
Le Grand Abri aux Puces (GAP), located on the right bank of the Ouvèze River of southern France, ... more Le Grand Abri aux Puces (GAP), located on the right bank of the Ouvèze River of southern France, has been known to contain well-preserved stone tools and faunal remains, but our work in 2008 was the first professional, controlled excavation at the site and has exposed at least 1 archaeological layer with a very rich and diverse faunal assemblage (23 macrofaunal species, as many for the microfauna, 27 land snail species), abundant charcoals (fragments are large and preserve small twigs with their pith and bark still intact), and stone tools with immaculate surface preservation (retaining their original freshness and preserving microscopic use wear). The information issuing from paleontology, micropaleontology, malacology, and anthracology all place the principle GAP human occupation unambiguously in a temperate climatic phase. Different biometric and biochronological characters of the fauna converge to place the layers found thus far from before the last glacial, and most likely in MIS 5e (127e117 kya). The lithic elements, mainly composed of tools of superior quality, demonstrating particular technical investment, and made from widely distributed raw material sources, lead us to hypothesize brief passages of hunting groups in the cave focused around an anticipated activity. This hypothesis will be refined and tested during further excavations.
Résumé :
Dans le cadre du programme HYDRΩMED (A*MIDEX Aix Marseille Université), de nouvelles re... more Résumé :
Dans le cadre du programme HYDRΩMED (A*MIDEX Aix Marseille Université), de nouvelles recherches concernant la gestion de l’eau en Méditerranée au cours du premier millénaire avant J.C. ont été développées. Nous présentons ici nos premiers résultats obtenus dans le cadre d’une approche pluridisciplinaire sur la cité de Solonte (nord-ouest de la Sicile) mêlant archéologie, hydrogéologie et géoarchéologie. Auparavant considérée comme exclusivement issue de la collecte des eaux de pluies par l’intermédiaire de systèmes de citernes, l’alimentation en eau du site apparaît en fait beaucoup plus riche et complexe. Cette dernière proviendrait plutôt de l’exploitation de systèmes de fractures tectoniques guidant des remontées hydrothermales, et fournissant des eaux thermominérales additionnelles et pérennes dans une grande partie des infrastructures hydrauliques identifiées à Solonte (notamment des thermes). Ces nouveaux résultats mettent en évidence un des paramètres fondamentaux ayant pu influencer le choix du Monte Catalfano comme site privilégié d’implantation de la cité durant l’antiquité. Une analyse descriptive de la grande citerne maçonnée fournit également des informations améliorant les connaissances sur la gestion de l’eau dans la cité antique de Solonte.
Abstract :
New research about water management in the Mediterranean during the first millennia BC are developed in the frame of the HYDRΩMED (A*MIDEX Aix Marseille University) program. We present here our first results obtained within the framework of a multidisciplinary approach on the city of Solonte (northwest of Sicily) combining archeology, hydrogeology and geoarchaeology. Previously considered exclusively from the collection of rainwater through cistern systems, the water supply to the site actually appears much richer and more complex. The latter would come rather from the exploitation of tectonic faulting guiding hydrothermal flow providing additional and perennial thermomineral waters in a large part of the hydraulic infrastructures identified at Solonte (including thermal baths). These new results highlight one of the fundamental parameters that may have influenced the choice of Monte Catalfano as a privileged site for the settlement of the city during antiquity. A descriptive analysis of the large built cistern also provides information to improve the knowledge of water management in the ancient city of Solonte.
Abstract :
Nell’ambito del programma HYDRΩMED (A*MIDEX Aix Marseille Université), si sono condotte nuove ricerche sulla gestione idrica nel Mediterraneo durante il primo millennio a. C. Si presentano in questo contributo i primi risultati ottenuti nel quadro di un approccio pluridisciplinare alla città di Solunto (nord ovest della Sicilia), il quale unisce archeologia, idrogeologia e geoarcheologia. Inizialmente considerata come esclusivo esito della raccolta dell’acqua piovana attraverso i sistemi delle cisterne, l’alimentazione idrica del sito sembrerebbe in realtà molto più ricca e complessa. Quest’ultima deriverebbe, piuttosto, dallo sfruttamento delle fratture tettoniche del sito, caratterizzate da fenomeni idrotermali che fornivano acque termominerali in gran parte delle infrastrutture idrauliche identificate a Solunto (in particolare le terme). Questi nuovi risultati mettono in evidenza uno dei parametri fondamentali che hanno potuto influenzare la scelta di Monte Catalfano come sito privilegiato per l’impianto della città nell’antichità. Un’analisi descrittiva della grande cisterna in muratura, inoltre, fornisce informazioni che contribuiscono alla conoscenza della gestione idrica nell’antica città di Solunto.
The influence of the morphological setting on the denudation of carbonate landscapes and the resp... more The influence of the morphological setting on the denudation of carbonate landscapes and the respective contributions of mechanical and chemical weathering processes are still debated. We have addressed these questions by measuring 36Cl concentrations in 40 samples from the Luberon mountain, SE France, in order to constrain the denudation of various landscape elements. We observe a clear contrast between the local denudation rates from the flat summit surface, clustered around 30 mm/ka, and the basin average denudation rates across the flanks, ranging from 100 to 200 mm/ka. This difference highlights the transient evolution of the range, whose topography is still adjusting to previous uplift events. Such a pattern also suggests that carbonate dissolution is not the only driver of denudation in this setting, which appears to be significantly controlled by slope-dependent processes.
The nature and timing of environmental changes throughout the last glacial-interglacial transitio... more The nature and timing of environmental changes throughout the last glacial-interglacial transition in the South Caucasus, and more widely in eastern Europe, are still not fully understood. According to certain pollen records, forest expansion occurred in many areas several millennia after what is considered worldwide as the onset of the Holocene. The current problem we face is that the time lag in forest expansion varies from one sequence to another, sometimes with no delay at all. Moreover, the potential forcing/controlling factors behind this complex pattern, contrary to the almost synchronous global Holocene warming, are still a matter for debate. Accordingly, we revisit the issue of forest expansion through vegetation history obtained in the South Caucasus using a new pollen record, retrieved from the Nariani paleolake (South Georgia). These data attest to a steppic phase, initially dominated by Amaranthaceae-Chenopodiaceae (12,700–10,500 cal yr BP), then by Poaceae (10,500–9000 cal yr BP), culminating with a more forested phase (9000–5000 calyrBP). Although some palaeoclimatic regional reconstructions show a wet early Holocene, we interpret the delay in forest expansion recorded in Nariani (2500 years) as the result of reduced spring precipitation, which would have limited forest development at that time.
Keywords: landscape evolution carbonates denudation cosmogenic nuclides hillslope processes Under... more Keywords: landscape evolution carbonates denudation cosmogenic nuclides hillslope processes Understanding topographic evolution requires integrating elementary processes acting at the hillslope scale into the long-wavelength framework of landscape dynamics. Recent progress has been made in the quantification of denudation of eroding landscapes and its links with topography. Despite these advances, data is still sparse in carbonate terrain, which covers a significant part of the Earth's surface. In this study, we measured both long-term denudation rates using in situ-produced 36 Cl concentrations in bedrock and regolith clasts and surface convexity at 12 sites along ridges of the Luberon carbonate range in Provence, Southeastern France. Starting from ∼30 mm/ka for the lowering of the summit plateau surface, denudation linearly increases with increasing hilltop convexity up to ∼70 mm/ka, as predicted by diffusive mass transport theory. Beyond this point denudation rates appear to be insensitive to the increase in hilltop convexity. We interpret this constant denudation as indicating a transition from a regime where hillslope evolution is primarily controlled by diffusive downslope regolith transport, toward a situation in which denudation is limited by the rate at which physical and chemical weathering processes can produce clasts and lower the hilltop. Such an abrupt transition into a weathering-limited dynamics may prevent hillslope denudation from balancing the rate of base level fall imposed by the river network and could potentially explain the development of high local relief in many Mediterranean carbonate landscapes.
Keywords: landscape evolution carbonates denudation cosmogenic nuclides hillslope processes Under... more Keywords: landscape evolution carbonates denudation cosmogenic nuclides hillslope processes Understanding topographic evolution requires integrating elementary processes acting at the hillslope scale into the long-wavelength framework of landscape dynamics. Recent progress has been made in the quantification of denudation of eroding landscapes and its links with topography. Despite these advances, data is still sparse in carbonate terrain, which covers a significant part of the Earth's surface. In this study, we measured both long-term denudation rates using in situ-produced 36 Cl concentrations in bedrock and regolith clasts and surface convexity at 12 sites along ridges of the Luberon carbonate range in Provence, Southeastern France. Starting from ∼30 mm/ka for the lowering of the summit plateau surface, denudation linearly increases with increasing hilltop convexity up to ∼70 mm/ka, as predicted by diffusive mass transport theory. Beyond this point denudation rates appear to be insensitive to the increase in hilltop convexity. We interpret this constant denudation as indicating a transition from a regime where hillslope evolution is primarily controlled by diffusive downslope regolith transport, toward a situation in which denudation is limited by the rate at which physical and chemical weathering processes can produce clasts and lower the hilltop. Such an abrupt transition into a weathering-limited dynamics may prevent hillslope denudation from balancing the rate of base level fall imposed by the river network and could potentially explain the development of high local relief in many Mediterranean carbonate landscapes.
À Bédoin dans le Vaucluse, la fouille de sauvetage urgent du Limon-Raspail dirigée par J. Cauliez... more À Bédoin dans le Vaucluse, la fouille de sauvetage urgent du Limon-Raspail dirigée par J. Cauliez en 2005 a livré, sur une surface de 250 m 2 , une trentaine d'aménagements creusés révélant l'existence d'un habitat relativement bien préservé et implanté en position privilégiée à près de 350 m d'altitude. Le site est daté du Néolithique final, entre 2880 et 2580 av. J.-C. Cette trentaine de structures en creux offre la vision d'une zone d'activités, là où se concentrent des foyers et des aménagements liés à la conservation, tous réutilisés comme dépotoirs. Voisin de sites éponymes à l'origine de l'identification de trois des quatre principales cultures du Néolithique final du sud-est de la France – les groupes Rhône-Ouvèze, de Fraischamp et du Nord-Vaucluse –, le gisement du Limon-Raspail ne s'ac-corde pas, sur le plan chronoculturel, avec l'un ou l'autre de ces ensembles. L'originalité du site peut s'expliquer par sa localisation dans une zone tampon. Il est à la limite nord des aires d'extension reconnues pour les groupes provençaux. Il s'inscrit également dans des flux de circulations alimentés par le Piémont italien ; il pourrait être enfin en liaison avec des groupes de régions plus septentrionales, tels que ceux de l'axe Saône-Rhône, dont les influences seraient perceptibles, au Néolithique final, jusque dans la moyenne vallée du Rhône. Mots-clés Néolithique final, Sud-Est de la France, habitat de plein-air, interactions culturelles, groupe multipolaire. Abstract The open-air settlement of Limon-Raspail has been discovered in March 2005. It has been subject to a rescue excavation during spring 2005. This excavation was conducted under the direction of Jessie Cauliez and was headed by the Service Régional de l'Archéologie de Provence-Alpes-Côte-d'Azur. The site of Limon-Raspail is localized on a small hill at 350 m height and covers a surface of almost 15 000 square meters. The site dominates the Mormoiron depression in the south and the one of Bédoin in the north. The excavation carried out on a surface of 250 square meters has allowed discovery of a settlement organized around thirty-five pits. It is assigned to the Final Neolithic and dated to a time span of between 2880 and 2580 cal BC at most. This interval is based on six radiocarbon AMS dates made from faunal remains and charcoal all stemming from distinct features. Multiple occupations are possible as some of the pits overlap. As a matter of fact, with this in mind, the homogeneity of the pottery and lithic
The Provence region located in SouthEastern France has registered significant earthquakes in the ... more The Provence region located in SouthEastern France has registered significant earthquakes in the last 1000 years, some reaching intensities up to IX. It is currently undergoing a very slow tectonic deformation with little seismicity and long recurrence intervals for major earthquakes (such as the 1909 magnitude 6 Lambesc earthquake). Several West-trending ranges are an important part of the landscape, and the influence of tectonic uplift compared to denudation during the Pliocene-Quaternary is not yet fully understood in the region. The geology of SouthEastern France is dominated by a thick Mesozoic series primarily consisting of carbonate rocks. The iconic ranges of Provence resulting from the Pyrenean orogeny (late Eocene) are mostly made up of uplifted lower Cretaceous. A minor reactivation occurred during the more recent Alpine late Cenozoic tectonic phase and contributed to the rejuvenation of the relief. Carbonate rocks are prone to complete chemical dissolution and are thus highly sensitive to climatic forcings such as precipitation. Moreover, the elevation and the frequency of freezing and thawing are parameters strongly influencing the geomorphic evolution in such environments. To investigate on this matter, 42 carbonate rock samples were collected for 36Cl denudation measurements on the Petit Luberon range. Denudation rates have been determined for both bedrock samples from the crest and sediments from rivers draining the southern and northern flanks of the range, allowing insights into long-term relief evolution. We observe a strong denudation contrast between the flanks lowering at 100-200 mm/ka and the summit surface, at around 30 mm/ka. These results suggest a transient evolution and a probable narrowing of the range. In addition, we collected 23 carbonate bedrock samples from other Mesozoic ranges in Provence with a wide altitude range (from 150 up to 1800 meters high asl), for similar 36Cl analysis. Our objective in this study (CEA-Cashima) is to have a regional overview of the distribution of denudation rates in an area dominated by carbonate rocks and to evaluate the influence of altitude, climate and associated processes on erosion and eventually link it to a slow regional uplift. Thus this study will allow a better understanding of the denudation processes in a carbonate dominated area characterized by slow tectonic deformations and moderate precipitations.
Le tuf calcaire de la Thomassine : paysages et climats du Néolithique ancien dans les collines de... more Le tuf calcaire de la Thomassine : paysages et climats du Néolithique ancien dans les collines de Manosque
Vincent OLLIVIER , Frédéric MAGNIN , Adam ALI , Christine BALME & Pierre FRAPA
Le tuf calcaire de la Thomassine, localisé sur le site même de la Maison de la Biodiversité à Manosque (Alpes-de-Haute-Provence), fait actuellement l’objet d’une étude pluridisciplinaire afin de reconstituer les rythmes de l’évolution du paysage dans le secteur de Manosque. Les analyses géomorphologiques, les datations radiocarbone et l’étude des assemblages de gastéropodes contenus dans les sédiments, permettent de caractériser différentes composantes de l’environnement du Luberon au début du Néolithique, il y a plus de 6500 ans.
The calcareous tufa of La Thomassine: Early Neolithic landscapes and climates in the Manosque countryside
The Thomassine calcareous tufa, located near the “Biodiversity House” (Manosque, Alpes-de-Haute-Provence), is currently the subject of a multidisciplinary study to reconstruct the rhythms of the landscape changes in the Manosque area. Geomorphological analysis, radiocarbon dating and land snail assemblage studies are used to characterize the various components of the Luberon environment in the early Neolithic, more than 6,500 years ago.
The Caspian Sea relative level variation evolution is based on high frequency and wide amplitude ... more The Caspian Sea relative level variation evolution is based on high frequency and wide amplitude rhythmicity, well defined for the Pleistocene-Lateglacial period and with high resolution for the Holocene. These variations are not strictly correlated with the global and/or rapid climate changes components, and the inland effects of such marine oscillations are nowadays poorly known. Our researches are focused on the retroactive impact of these “climato-eustatic” Caspian variations on the main fluvial system (Kura and Arax) and their tributaries as well as on the Holocene societies in the Lesser Caucasus. The geomorphological analysis (stratigraphy, sedimentology, morphosedimentary changes), and the geochronological and geoarchaeological studies (14C dating and studies on Neolithic to Bronze Age sites) gave us some precious data correlating the sea movement to the sedimentation rhythmicity and human occupation phases in a regional scale. Since the Upper Pleistocene, the upstream hydrosystem have reacted to marine regressions by powerful riverbed incisions (>37 000; 37 000-27 000; 13 000-11 000; 3 200-2 900; 2 100-1 600; 1 000-400; 150-0 cal. BP) and to transgression phases by thick valley infilling (eg. 27 000-13 000; 11 000-3 200; 2 900-2 100; 1 600-1 000; 400-150 cal. BP). The retroactive morphogenic effects were also perceived to intramontainous area far away from the Caspian shoreline. These different sedimentary balance sheets, and the changes in the fluvial geomorphology, led to landscape changes affecting the land use availability for agriculture and herding in the vicinity of the riparian zone. This is also spatially and diachronically traduced in the settlement location (depending on the sedimentological/ pedological amenities and water accessibility) but also on their abandonment and their destruction and/or burying by the erosive processes. Climatic oscillations and base level changes data are now discretized and integrated in the geoarchaeological analyses concerning the land use in the Caspian Sea hydrographic basin in the frame of the ANR ORIMIL research program.
Article du Courrier d'Erevan sur la Conférence "Paysages et climats du passé... un regard vers l'... more Article du Courrier d'Erevan sur la Conférence "Paysages et climats du passé... un regard vers l'avenir" à l'ambassade de France en Arménie.
Le climat de notre planète a beaucoup varié au cours des temps géologiques. Depuis 2.6 millions d... more Le climat de notre planète a beaucoup varié au cours des temps géologiques. Depuis 2.6 millions d’années, au cours du Quaternaire, des périodes de glaciations et de réchauffements se succèdent de manière cyclique à l’échelle globale. Les sociétés humaines ont traversé ces périodes de fluctuations climatiques. Dans les paysages, de nombreux indices nous permettent de caractériser et de comprendre l’origine, la nature et l’ampleur de ces changements. Au travers des recherches menées dans le cadre de missions scientifiques internationales soutenues par le Ministère des Affaires Etrangères, le CNRS (Laboratoires Internationaux Associés) et l’Agence Nationale de la Recherche, nous aborderons les différentes étapes de ces changements climatiques et de leurs impacts millénaires sur les paysages et les sociétés de l’Arménie, et plus généralement du Petit Caucase.
Leroyer, C., Joannin, S., Aoustin, D., Ali, A.A., Peyron, O., Ollivier V., Tozalakyan, P., Karakh... more Leroyer, C., Joannin, S., Aoustin, D., Ali, A.A., Peyron, O., Ollivier V., Tozalakyan, P., Karakhanyan, A., Jude F.
Quaternary International 2015
A sediment core has been retrieved from Vanevan peat (south-eastern shore of Lake Sevan, Armenia), which is today disconnected from Lake Sevan thanks to an artificial shallowing of the lake. Based on 5 radiocarbon dates, Vanevan record covers the Mid Holocene (from ca. 7800 to ca. 5100 cal. BP). The Late Holocene is today absent in the peat stratigraphy due to modern peat exploitation by surface mining. This study focuses on a multi-proxy approach including pollen, charcoals, and pollen-inferred climate reconstruction.
An open-land, steppic vegetation is recorded up to ca. 7700 cal. BP, followed by a more forested landscape during the Mid Holocene (up to ca. 5700 cal. BP), and ending again with an open-land vegetation (to the end of record, 5100 cal. BP). This vegetation dynamics responds to general climate changes documented in the Near East. Whether human activities are documented since ca. 7500 cal. BP (Late Neolithic) in Vanevan, they remain marginal and probably did not affect the area. Early Holocene dry climate, which caused the steppic environment to be widespread through the Near East, is strongly related to low late spring precipitation (PMay–Jun = 180 mm). Mid Holocene forested landscape and increasing lake-level seem related to late spring precipitation (+28%), which is the main change in estimated climate parameters. This has to be linked with reinforcement of the Westerlies and less active Siberian High, which are inversely involved in the following, dry phase starting at ca. 5700 cal. BP.
Hydrogeomorphology and water management, an open Mediterranean perspective
Vincent Ollivier
Aix... more Hydrogeomorphology and water management, an open Mediterranean perspective
Vincent Ollivier
Aix-Marseille Université, CNRS, MCC, LAMPEA UMR 7269, Aix-en-Provence, France.
Water management is often linked through time to local and/or regional hydrogeomorphic conditions. Water supply, flooding protection, river diversion, settlement location also evolved following the hydrogeologic and climatic changes. In addition, due to the sensitivity of some environmental conditions, the use of water resources by ancient populations have sometimes destabilized the morphosedimentary balance of the exploited systems (river, karst, calcareous tufa, etc.). Using hydrogeomorphologic and geoarcheological approach, diachronic and various examples in and around the Mediterranean will be presented to illustrate and expand the enriching debate about the relationship between water management and environmental constraints evolution.
La séquence extraite à Vanevan (sud est du lac Sevan, Arménie) a fait l’objet d’une étude
pluridi... more La séquence extraite à Vanevan (sud est du lac Sevan, Arménie) a fait l’objet d’une étude pluridisciplinaire (pollen, micro-charbons, modélisation paléoclimatologique), renforcée par les recherches géomorphologiques et archéologiques menées aux alentours du lac. Selon le modèle d’âge, l’Holocène moyen est documenté avec une résolution de 79 ans entre les échantillons. L’Holocène récent a disparu avec l’exploitation actuelle de la tourbière. Entre 7.8 et 5.1 ka cal. BP, trois types d’environnements se succèdent ; dynamique à commande principalement climatique puisque les occupations humaines recensées autour du lac Sevan ne paraissent pas affecter l’environnement. Jusqu’à 7.7 ka cal. BP, un environnement steppique perdure sous un climat sec avec de très basses précipitations de fin de printemps (PMay–Jun = 180 mm). Une nette fermeture du milieu se marque entre 7.7 et 5.7 ka cal. BP. Une hausse des précipitations de fin de printemps (+28%) accompagne cette phase plus boisée, également contemporaine d’une élévation du niveau du lac. Après 5.7 ka cal. BP, le milieu est plus ouvert alors que se développent les incendies. Le climat est à nouveau plus sec et le niveau du lac Sevan baisse.
The Caspian Sea relative level variation evolution is based on high frequency and wide amplitude ... more The Caspian Sea relative level variation evolution is based on high frequency and wide amplitude rhythmicity, well defined for the Pleistocene-Lateglacial period and with high resolution for the Holocene. These variations are not strictly correlated with the global climate changes components and the inland effects of such marine oscillations are nowadays unknown. Our researches are focused on the retroactive impact of these “climato-eustatic” Caspian variations on the main fluvial system (Kura and Arax) and their tributaries as well as on the Holocene societies in Lesser Caucasus. The geomorphological analysis (stratigraphy, sedimentology, morphosedimentary evolution), and the geochronological and geoarchaeological studies (14C dating and Neolithic to Bronze age sites) gave us some precious data correlating the sea movement to the sedimentation rhythmicity and human occupation phases in a regional scale. Since at least the Upper Pleistocene, the upstream hydrosystem have reacted to marine regressions by powerful riverbed incisions (>37 000; 37 000-27 000; 13 000-11 000; 3 200-2 900; 2 100-1 600; 1 000-400; 150-0 cal. BP) and to transgression phases by thick valley infilling (eg. 27 000-13 000; 11 000-3 200; 2 900-2 100; 1 600-1 000; 400-150 cal. BP). The retroactive morphogenic effects were also perceived to intramontainous area far away from the Caspian shoreline. These different sedimentary balance sheets and the changes in the fluvial geomorphology were weakly influenced by the evolution of the tectonic settings. The human societies, who lived in the valleys and terraces of the Kura hydrosystem, have seen their modes of occupations affected by these landscape mutations from the Neolithic period to the Age of metals. This is spatially and diachronically traduced in the settlement location (depending on the sedimentological/ pedological amenities and water accessibility) but also on their abandonment and their destruction and/or burying by the erosive processes. These new data must be considered in the further geoarchaeological analyses concerning the Lesser Caucasus area. The question of the direct link between Rapid Climate Changes (RCC) and/or the predominance of the retroactive sea level impact on the landscape mutations and societies in the Circumcaspian regions should also be cleared.
The Caspian Sea relative level variation evolution is based on high frequency and wide amplitude ... more The Caspian Sea relative level variation evolution is based on high frequency and wide amplitude rhythmicity, well defined for the Pleistocene-Lateglacial period and with high resolution for the Holocene. These variations are not strictly correlated with the global climate changes components and the inland effects of such marine oscillations are nowadays unknown. Our researches are focused on the retroactive impact of these climato-eustatic Caspian variations on the main fluvial system (Kura and Arax) and their tributaries as well as on the Holocene societies in Lesser Caucasus. The geomorphological analysis (stratigraphy, sedimentology, morphosedimentary evolution), and the geochronological and geoarchaeological studies (14C dating and Neolithic to Bronze age sites) gave us some precious data correlating the eustatic movement to the sedimentation rhythmicity and human occupation phases in a regional scale. Since at least the Upper Pleistocene, the upstream hydrosystem have reacted to marine regressions by powerful riverbed incisions and to transgression phases by thick valley infilling. The retroactive morphogenic effects were also perceived to intramontainous area far away from the Caspian shoreline. These different sedimentary balance sheets and the changes in the fluvial geomorphology were weakly influenced by the evolution of the climatic and tectonic settings. The human societies, who lived in the valleys and terraces of the Kura hydrosystem, have seen their modes of occupations affected by these landscape mutations from the Neolithic period to the Age of metals. This is spatially and diachronically traduced in the settlement location (depending on the sedimentological/ pedological amenities and water accessibility) but also on their abandonment and their destruction and/or burying by the erosive processes. These new data must be considered in the further geoarchaeological analyses concerning the Circumcaspian regions.
In the Javakheti highlands, two lakes were cored respectively in 2009 and 2011: the Lake Paravani... more In the Javakheti highlands, two lakes were cored respectively in 2009 and 2011: the Lake Paravani (2073 m a.s.l, 41°27’N 43°48’E) and the palaeolake Nariani (2058 m a.s.l., 41°40' N 43°40'E). The sequences cover the end of Late-Glacial and the Holocene. They were investigated for a multi-proxy analysis. We will present the palynological and sedimentological data from these two lakes aiming to document palaeoecological changes in the central South Caucasus driven by climate and/or human impact. The investigations performed on the sediments has allowed us to characterize a unique vegetation history in relation to the post-glacial climatic variations and the dynamic of the Samsari-Javakheti glaciers.
Three palaeoecological phases have been identified (Messager et al., 2013):
- The first phase spanning the Younger Dryas and the Early Holocene, corresponds to a steppic environment with a limited lake productivity driven by a cold and particularly dry climate.
- A second phase starts with an important expansion of trees at 8 300 cal years BP. As soon as the climatic and edaphic conditions were favourable, the main deciduous and coniferous trees expanded concurrently due to the proximity of glacial forest refugia located in western Caucasus.
- A third phase starts at 3000-2000 cal BP and corresponds to the decline of forests on the plateau and the expansion of herbaceous formations, leading to the present-day steppic environment. This deforestation phase is driven by the deterioration of the climate conditions and human impact.
References
Messager, E., Belmecheri, S., von Grafenstein, U., Nomade, S., Ollivier, V., Voinchet, P., Puaud, S., Courtin-Nomade, A., Guillou, H., Mgeladze, A., Dumoulin, J.P., Mazuy, A., Lordkipanidze, D., 2013. Late Quaternary record of the vegetation and catchment-related changes from Lake Paravani (Javakheti, South Caucasus). Quaternary Science Reviews 77, 125-140.
Vincent OLLIVIER 1 & 2, Michel FONTUGNE 3,
Bertille LYONNET 1 Christine CHATAIGNER 4
1 PrO... more Vincent OLLIVIER 1 & 2, Michel FONTUGNE 3,
Bertille LYONNET 1 Christine CHATAIGNER 4
1 PrOCauLAC - Collège de France, CNRS (UMR 7192), Paris, France, Vincent.ollivier@college-de-france.fr 2 LAMPEA – Université de Provence, CNRS, MCC, IRD (UMR 7269), Maison Méditerranéenne des Sciences de l'Homme, Aix-en-Provence, France.
3 LSCE – UVSQ, CNRS (UMR 1572), Gif sur Yvette, France.
4Université de Lyon 2, Archéorient, UMR 5133, Maison de l’Orient, Lyon, France, christine. chataigner@mom.fr
L’évolution de la mobilité relative du niveau de la mer Caspienne au cours du Quaternaire récent s’exprime selon des rythmes de haute fréquence et de moyenne à forte amplitude. Cette rythmicité est bien définie sur la période Pléistocène supérieur - Postglaciaire et de manière détaillée pour l’Holocène. Les variations eustatiques enregistrées ne sont pas systématiquement en phase avec les rétroactions habituellement connues sous contrôle climatique au niveau global. Les niveaux de terrasses marines et les deltas constituent jusqu’à présent les supports essentiels sur lesquels reposent de telles reconstructions. De nouveaux travaux, réalisés dans le cadre de l’ANR franco-allemande Ancient Kura (CNRS-DFG, sous la direction de Bertille Lyonnet de l’UMR 7192 PrOCauLAC et de Barbara Helwing du Deutsches Archäologisches Institut) de la mission Caucase (CNRS, ministère des Affaires Etrangères) et du Laboratoire international associé HEMHA (Humans and Environment in Mountainous Habitats : the case of Armenia) dirigés par Christine Chataigner, se concentrent actuellement sur les impacts des oscillations climato-eustatiques sur les dynamiques érosives et de transfert au niveau des hydrosystèmes de piémont du Petit Caucase. Les analyses géomorphologiques (stratigraphies, sédimentologie, évolution morphosédimentaire), géochronologiques (datations 14C) et géoarchéologiques (sites néolithiques, chalcolithiques et du Bronze) sont conduites sur le fleuve Kura et ses affluents, principalement dans les régions de Tovuz et d’Agjabedi au nord-ouest et au sud de l’Azerbaïdjan mais aussi dans d’autres secteurs du Petit Caucase. Ces recherches ont permis d’élaborer une première trame des rythmes de sédimentation à l’échelle régionale et de déterminer en partie l’origine, les moteurs et les impacts possibles des mutations paysagères holocènes sur les sociétés des espaces riverains de la mer Caspienne. Nos premiers résultats indiquent une forte réponse des variations de tendances morphogéniques aux oscillations eustatiques de l’extrême fin du dernier cycle climatique. Les hydrosystèmes amont réagissent aux régressions marines par de puissantes incisions régressives et aux transgressions par d’imposantes phases de remblaiements. Les rétroactions s’expriment jusqu’aux zones intramontagnardes largement distantes de la ligne de rivage. Ces différents bilans sédimentaires et les changements engendrés dans la morphologie fluviale sont faiblement influencés par l’évolution des paramètres exclusivement climatiques et tectoniques. Les sociétés occupant les vallées et systèmes de terrasses de l’hydrosystème Kura, ont vu leurs modes d’occupations concernés par ces mutations paysagères au cours du Néolithique et jusqu’à l’Age des métaux. Ce qui se traduit spatialement et de manière diachronique dans la localisation des sites (fonction des aménités sédimentaires, pédologiques et d’accessibilité à l’eau), dans les modalités de leur abandon et de leur disparition par érosion ou enfouissement. Ces nouvelles données doivent désormais être prises en compte dans les analyses géoarchéologiques concernant les régions Circumcaspiennes.
Vincent Ollivier, Marc Boréani, Chérine Gebara
ASSOCIATION FRANÇAISE POUR L'ETUDE DU SOL Secti... more Vincent Ollivier, Marc Boréani, Chérine Gebara
ASSOCIATION FRANÇAISE POUR L'ETUDE DU SOL Section Méditerranée JOURNEE THEMATIQUE : « APPORTS DES ETUDES PEDOLOGIQUES, ARCHEOLOGIQUES au préalable d’un projet d’aménagement d’une liaison hydraulique sur un linéaire de 75 kms dans le Var » , vendredi 18 juin 2010 organisée par la SCP et le Service Départemental d’archéologie du Var .
Gaëlle Delaunay, Vincent Ollivier
&
André Müller, Sophie Martin,
Jean-Louis Guendon, Emilie B... more Gaëlle Delaunay, Vincent Ollivier
&
André Müller, Sophie Martin,
Jean-Louis Guendon, Emilie Blaise,
Stephane Bourne, Christophe Gilabert,
Muriel Pellisier
Vincent Ollivier1, Adam Ali2, Paul Roiron2, Frédéric Magnin3, Jean Louis Guendon1, Sophie Martin4... more Vincent Ollivier1, Adam Ali2, Paul Roiron2, Frédéric Magnin3, Jean Louis Guendon1, Sophie Martin4
Les travertins sont les témoins privilégiés des fluctuations bioclimatiques et morphogéniques postglaciaires entre Provence et zone subalpine. La sensibilité du développement des formations travertineuses aux modifications du biotope permet, selon l’organisation séquentielle des pôles morphosédimentaires, d’établir une trame relativement détaillée des niveaux d’instabilités, de ruptures ou d’équilibres de la morphogenèse sous contrainte climatique ou climato-anthropique. La préservation de marqueurs paléoécologiques (charbons, malacofaunes et empreintes foliaires) et la présence régulière de vestiges archéologiques (artéfacts, niveaux d’occupation) au sein des dépôts constituant la séquence travertineuse, renforce les possibilités d’analyses spatiales et temporelles des dynamiques paysagères sur le long terme.
Dans la zone subalpine, l’étude croisée des faciès carbonatés, empreintes foliaires et charbons nous délivre une image diachronique de la végétation, des fréquences d’incendies des instabilités de versant et de la position de la limite supérieure des arbres au cours de l’Holocène.
En Provence, les fluctuations morphosédimentaires observées (érosions, incisions intraformationnelles et variations des faciès) dans les séquences travertineuses, et les analyses paléoécologiques réalisées, nous renseignent sur la rythmicité de la morphogenèse (stabilités, instabilités, ruptures) dès le Tardiglaciaire et sur l’impact des modes d’occupations Néolithiques dans les dynamiques paysagères.
Ainsi, dès 15500 cal. BP une puissante phase d’accumulation sédimentaire s’amorce dans les vallons inscrits sur les piémonts du Luberon. Aux débouchés des exsurgences karstiques, le développement des formations travertineuses signe le réchauffement climatique engagé. Par la suite, et dans l’ensemble des formations détritiques et carbonatées, deux incisions principales se produisent vers 9000 et 6000 cal. BP en alternance avec des phases de remblaiements.
Dès le Néolithique Final et jusqu’au Haut Moyen Age, les séquences enregistrent une série de ruptures (incisions) de haute fréquence et de faible amplitude. Ces perturbations sont accompagnées de changements de faciès dans les systèmes carbonatés (fig. 1) et d’ouvertures fortes du milieu végétal.
Entre le XIIIème et le XVIIème siècle après Jésus Christ, les formations L.S. sont démantelées dans une dynamique majeure d’incision linéaire des talwegs.
L’action conjuguée des oscillations climatiques et des modes d’occupation humaines apparaît comme le principal moteur d’une morphogenèse mouvementée au cours de la deuxième partie du Postglaciaire.
Paul Roiron1, Vincent Ollivier2, Samvel Nahapetyan3, Ivan Gabrielyan4, Jean-Jacques Cornée5, Séba... more Paul Roiron1, Vincent Ollivier2, Samvel Nahapetyan3, Ivan Gabrielyan4, Jean-Jacques Cornée5, Sébastien Joannin6, Christine Chataigner7, Jacques Jaubert8, Boris Gasparyan9
1 CBAE, UMR 5059, Institut de Botanique, 163 rue A. Broussonet, 34090 Montpellier paul.roiron@univ-montp2.fr 2 UMR 6636, Maison Médit. des Sciences de l'Homme, BP 647, 5 rue du Château de l'Horloge, 13545 Aix-en-Provence vincent.ollivier@univ-cezanne.fr 3 Faculty of Geography, Department of Geomorphology and Cartography, Yerevan State University, Armenia nahapetyan@ysu.am 4 Institute of Botany of National Academy of Sciences, Department of Higher Plants taxonomy and geography, 375063 Yerevan, Armenia gabrielyanivan@yahoo.com 5 UMR 5243, Université Montpellier2, place E. Bataillon, 34095 Montpellier cedex 5 cornee@gm.univ-montp2.fr 6 Maison des Sciences de l'Homme et de l'Environnement, USR 312 Laboratoire de Chrono-Environnement 16 route de Gray, 25030 Besançon sebastien.joannin@mshe.univ-fcomte.fr 7 UMR 5133, Maison de L'Orient et de la Méditerranée, Université Lumière Lyon2, 7 rue Raulin, 69007 Lyon christine.chataigner@mom.fr 8 PACEA, UMR 5199, Université Bordeaux1, B8, avenue des facultés, 33405 Talence j.jaubert@ipgq.u-bordeaux1.fr 9 Archeological Institute, Azatutian st. 7B, apt.64, Yerevan, Armenia borisg@virtualarmenia.am
L’Arménie est une zone volcanique du Petit Caucase qui subit à la fois des influences climatiques méditerranéennes et asiatiques. C’est aussi le lieu de développement et d’échanges des cultures préhistoriques qui se sont développées depuis le Paléolithique dans la région et qui ne sont connues que de manière ponctuelle. Nos travaux ont pour but d’apporter des données nouvelles permettant de reconstituer l’évolution de l’environnement au cours du Quaternaire et d’étudier les conséquences de ces changements sur l’occupation humaine.
Du Pleistocène inférieur au Postglaciaire, la chaîne du Caucase a été marquée par une intense activité volcanique. Au nord du pays (région du Lori), une séquence fluvio-lacustre contenant des empreintes foliaires de ripisylve est encadrée par deux coulées volcaniques datées de 2,01 et 1,96 Ma. Cette région est en lien avec le plateau de Dmanissi qui a livré des restes de Homo georgicus datés de 1,8 Ma (de Lumley & al., 2002).
Dans le sud de l’Arménie (Syunik) les coulées de laves et les mouvements tectoniques ont fermé plusieurs vallées, provoquant la formation de lacs et le développement de diatomites qui ont fossilisé des macrorestes et des pollens permettant des reconstructions environnementales et paléoclimatiques.
Une carte géomorphologique et des transects géologiques ont été dessinés. La chronologie est précisée par magnétostratigraphie et par des datations radiométriques sur les laves (K/Ar) ou les ponces volcaniques (Ar/Ar). L’étude palynologique et des restes foliaires de la section de Shamb a permis de mettre en évidence une alternance de phases forestières et steppiques en lien avec la périodicité de l’obliquité (41 ka). Pendant le Pleistocène inférieur, ce secteur a subi des fluctuations climatiques allant d’un climat tempéré-chaud à un climat plus sec puis plus froid pendant les périodes glaciaires.
Au Pleistocène moyen, plusieurs paléolacs de la zone centrale de l’Arménie (région d’Aparan) sont entourés par de nombreux sites du Paléolithique moyen.
Au nord du lac Sevan, la localité de Kalavan a livré un site du Paléolithique moyen (stade isotopique 3) et une occupation holocène.
Les traces de plusieurs glaciations pleistocènes (du stade isotopique 11 au stade 2) sont observées dans la vallée du Vorotan (Syunik), soulignant le rôle important des phases glaciaires dans la morphogénèse quaternaire du sud de l’Arménie.
L’Holocène est documenté par plusieurs coupes alluviales (Tsilkar, Geghakot) indiquant la présence de zones humides attractives pour les populations humaines.
Le territoire arménien contient aussi de nombreuses formations travertineuses pléistocènes et holocènes dont certaines contiennent des empreintes de feuilles. Des datations U/Th ou 14C indiquent que ces travertins se sont développés au cours de phases interglaciaires ou interstadiaires.
L’étude conjointe des formations lacustres, alluviales, glaciaires et travertineuses du Pléistocène et de l’Holocène en lien avec les changements climatiques et les occupations humaines permet d’appréhender le rythme et l’ampleur des mutations paysagères et leur relation avec le développement des sociétés caucasiennes.
Vincent OLLIVIER,
Paul ROIRON, Adam ALI, Jean-Louis GUENDON
Les formations travertineuses du s... more Vincent OLLIVIER,
Paul ROIRON, Adam ALI, Jean-Louis GUENDON
Les formations travertineuses du sud de la France sont de précieux indicateurs sur l'évolution des hydrosystèmes et des paléoenvironnements quaternaires. Milieux attractifs pour les sociétés humaines en raison de leurs importantes potentialités (eaux abondantes et de qualité notamment), ces systèmes carbonatés fournissent des archives sédimentaires riches en vestiges archéologiques mais aussi en données paléoécologiques (malacofaunes, charbons, pollens, empreintes foliaires, entomofaunes). La diversité des contextes géomorphologiques, topographiques, micro-climatiques et des occupations humaines (cultures et densités), souligne la remarquable représentativité des informations disponibles dans cet espace géographique mosaïque où hautes montagnes internes, vallées, massifs côtiers et plaines littorales se côtoient.
Les séquences travertineuses du Luberon, de St Antonin, de Roquevaire, du Queyras, du Serre de Montdenier et de St Guilhem, pour ne citer que quelques sites emblématiques en cours d’étude, y occupent une place privilégiée au regard de leur qualité stricte d’archives sédimentaires haute résolution, mais aussi et surtout, car il s’agit de systèmes dynamiques et évolutifs aux temps de réponse rapides, particulièrement sensibles aux moindres variations de leur biotope (forçages locaux ou globaux). Dans le cadre d’analyses séquentielles, la variabilité des faciès travertineux devient un précieux indicateur des dynamiques paléohydrologiques et morphologiques dans un espace paysager en perpétuelle mutation. Cet aspect renforce la qualité des enregistrements liée aux capacités de bonne conservation de ces milieux ainsi que les bénéfices que l’on peut habituellement envisager par l’exploitation de leurs données. Les raisons des arrêts, ruptures et reprises multiples de l’accumulation carbonatée ainsi que du démantèlement de ces formations, restent mal connues (variations des composantes bioclimatiques ? poids des facteurs d’origine climato-anthropique ?) soulevant de nombreuses questions sur la rythmicité et l’amplitude des évolutions paysagères au cours du dernier cycle climatique en fonction des différents contextes environnementaux (montagnards, de piémonts ou de vallées). Le croisement des données géomorphologiques, géoécologiques et archéologiques issues de ces séquences représentatives de la frange méditerranéenne permet en définitive d’appréhender l’évolution des ce type de milieux sous l’angle des relations entre fluctuations climatiques et biologiques, occupations humaines et dynamiques morphosédimentaires.
OLLIVIER Vincent 1, NAHAPETYAN Samvel 2, ROIRON Paul 3, GABRIELYAN Ivan 4, CORNÉE Jean-Jacques 5... more OLLIVIER Vincent 1, NAHAPETYAN Samvel 2, ROIRON Paul 3, GABRIELYAN Ivan 4, CORNÉE Jean-Jacques 5, JOANNIN Sébastien 5, CHATAIGNER Christine 6, JAUBERT Jacques 7, GASPARYAN Boris 8.
1 Laboratoire Méditerranéen de Préhistoire Europe Afrique, UMR 6636, Aix-en-Provence, France
2 Department of Cartography and Geomorphology , Yerevan State University, Armenia.
3 Centre de Bio-Archéologie et d’Ecologie, UMR 5059, Montpellier, France.
4 Institute of Botany, National Academy of Sciences of the Republic of Armenia
5 UMR 5125 PEPS, Université Lyon 1, Bt Géode, 11-45 bd du 11 novenbre, 69622 Lyon Cedex, France..
6 Maison de l’Orient, UMR 5133 Archéorient, Lyon, France.
7UMR 5808, Institut de Préhistoire et de Géologie du Quaternaire, Bordeaux, France.
8 Institute of Archaeology and Ethnography, National Academy of Sciences of the Republic of Armenia.
Abstract:
The main goal of our study is to evaluate the respective influence of Quaternary climate oscillations (glacial and interglacial alternations) and paroxysmal events (seism and volcanism) on the morphogenic / palaeoenvironmental dynamics (landscape evolution rhythms) and human occupations in Eurasia.
During the Quaternary period, the Lesser Caucasus range was marked by an intense volcanic activity. From northern to southern Armenia (Aragatsotn and Syunik region notably), bulky lava flows and tectorogenic movements closed the main valleys during the Pleistocene and allowed the establishment of several lacustrine areas with volcanogenic and/or diatomaceous deposits between 1.6 My and 700 Ky. Some of these deposits contain leaf impressions and pollens enabling local palaeoclimatic reconstructions, others are surrounded by Palaeolithic human occupations.
Several field-trips in Armenia highlight the variability of the Quaternary morphogenesis in relation with volcanism, fluvio-lacustrine deposits, glacial inheritance and travertine formations. Geomorphological maps and geological transects were performed. Preliminary events chronology is determined by K/Ar, Ar/Ar, U/Th radiometric dating (on basalt, volcanic pumice and travertine samples) and magnetostratigraphy.
Magnetostratigraphic analyses were carried out on the major fluvio-lacustral section of the Syunik area (Shamb locality, southern Armenia) from which most of the palaeoecological data were extracted. According to the paleomagnetic results, the K/Ar age of the basalt flow in the upper part of the main section studied (993 ± 22 ka), and the Ar/Ar age of a pumice in a lower level (1,21 Ma ± 40 kyr), the whole stratigraphy must have been deposited during the Matuyama period of reversed polarity, between Olduvai and Jaramillo events.
The combined palynological and macroremains analysis of the same section highlights the alternation of relatively forested and steppic phases related to climatic variations moved from the obliquity periodicity (41 kyr). During the Lower Pleistocene, this area underwent major climatic fluctuations, going from a warm-temperate climate to a drier and temperate climate, and then to a cold climate during the glacial periods.
Evidence for several glaciations from Marine Isotopic Stage 11 to MIS 2 described at relatively modest altitudes (bottom of the Vorotan valley) underline the important role of the quaternary cold episodes in the Pleistocene morphogenic dynamic of southern Armenia. From northern to southern Armenia, major travertine formations with leaf imprints were developed on the slopes at 340 Kyr, 250 kyr, 160 kyr and 53 kyr, confirming the establishment of the interglacial or interstadial warming and there potential influences on the human occupations during the second part of the Pleistocene.
This multi-proxy study reveal the major and rapid morphogenetic changes of the studied regions from the predominance of lacustrine environments at the beginning of the Pleistocene to the present river and canyon landscapes, in relation to tecto-volcanic events and climate variability. Then from the recent archeological discovery of the French ECLIPSE and Caucase Mission program team, the effect of the evolution of the Quaternary landscapes on the settlement of the Caucasian societies will be approached in the light of the numerous chronological data and palaeoenvironmental reconstructions.
1 Ollivier V., 2 Roiron P., 3 Nahapetyan S., 4 Joannin S., 5 Chataigner C.
1 Collège de France, ... more 1 Ollivier V., 2 Roiron P., 3 Nahapetyan S., 4 Joannin S., 5 Chataigner C.
1 Collège de France, PrOCauLAC-UMR 7192 du CNRS, Proche-Orient, Caucase: Langues, Archéologie, Cultures, Paris, France & Maison Méditerranéenne des Sciences de l’Homme, LAMPEA-UMR 7269 du CNRS, Laboratoire Méditerranéen de Préhistoire Europe-Afrique, Aix en Provence, France, vincent.ollivier@college-de-france.fr.
2 Université de Montpellier 2, CBAE-UMR 5059 du CNRS, Centre de Bio-Archéologie et d’Ecologie, Montpellier, France, roiron@univ-montp2.fr.
3 Department of Cartography and Geomorphology, Yerevan State University, Armenia, nahapetyan@ysu.am 4 Université Lyon 1, UMR 5276 LGLTPE, Laboratoire de Géologie de Lyon, Terre, Planètes, Environnement, Lyon, France, sebastien.joannin@univ-lyon1.fr 5Université de Lyon 2, Archéorient, UMR 5133, Maison de l’Orient, Lyon, France, christine.chataigner@mom.fr
In the course of the International Associated Laboratory HEMHA (Humans and Environment in Mountainous Habitats : the case of Armenia), the French Foreign Affair Ministry Caucasus Mission (CNRS-UMR 5133 Archéorient, Lyon University) and the French-German research program Ancient Kura (CNRS-UMR 7192 PrOCauLAC, Paris, France, Deutsches Archäologisches Institut, Eurasien-Abteilung, Berlin, Germany with ANR-CNRS and DFG funding) numerous sites of the Lesser Caucasus territory are under geomorphological, palaeoenvironmental and archaeological investigations. Through comparisons between the tufa/travertine system and the detrital formation morphosedimentary evolution, one of our research interests is to define the Late Quaternary landscape mutations as well as the origin and rhythmicity of the major morphogenic trends reversals. The impacts of the environmental changes highlighted on the human occupation modes are also debated. A total of 14 travertine and tufa formations were studied (8 Pleistocene and 6 Postglacial formations) on a Northwest-Southeast transect of more than 300 km across the Lesser Caucasus. Each of these carbonated system development are correlated with high global relative sea levels and interstadial climates on a range between the Marine Isotopic Stage 11 and 1 (ca. 335 to 1.5 Ky BP). The absolute chronology is constrained by a series of U/Th and 14C dating. A total of 24 dating was performed (6 radiocarbon and 18 U/Th datings), allowing a high quality overview of the travertinization process over the time at a regional scale. Jointly with the measurement of the late Quaternary interglacial series impact on the tufas development in the Caucasus, the geomorphological position of some travertinous formations and their absolute dating gives some clues about the neotectonic evolution of the studied valleys. In some area, the uplift rate has been determined (ca. 8 mm/year) and discretized from the alluvial incision signal. The analysis of the carbonated deposits (faciological determinations, palaeobotanical and palynological identifications of leave imprints and pollens), which are the expression of specific climatic conditions, and the comparative approach with the general morphosedimentary evolution, give a complete reading grid of the regional landscape mutation expressions and origins (Caspian Sea eustatism or exclusive climatic impact), necessary to understand the magnitude of the changes and their influence on the Circumcaspian societies.
Erwan Messager (1), Soumaya Belmecheri (2), Ulrich Von Grafenstein (3), Sébastien Nomade (3), Pie... more Erwan Messager (1), Soumaya Belmecheri (2), Ulrich Von Grafenstein (3), Sébastien Nomade (3), Pierre
Voinchet (1), Vincent Ollivier (4), Ana Mgeladze (5), and David Lordkipanidze (5)
(1) UMR 7194 CNRS Département de Préhistoire Muséum national d’Histoire naturelle. 1, rue René Panhard, 75013 Paris,
France (erwan.m@mnhn.fr), (2) Earth and Environmental Systems Institute,The Pennsylvania State University. 416 Walker
Building University Park, PA 16802, (3) LSCE/IPSL, Laboratoire CEA-CNRS-UVSQ. Domaine du CNRS, Bât. 12, Avenue
de la Terrasse, 91198 Gif sur Yvette, France, (4) UMR 7192 CNRS Proche-Orient, Caucase: Langues, Archéologie, Cultures,
52 rue du Cardinal Lemoine 75005 Paris, France, (5) Georgian National Museum. 3, Rustaveli Avenue 0105 Tbilisi, Georgia.
Located in the steppic grasslands of South-Transcaucasia in the Samsari-Djavakheti volcanic plateau, the Paravani
Lake (2073 m a.s.l, 4127’N 4348’E) is the largest lake of Georgia (37.5 km2, 2-3 m depth). The lake has a high
potential to reconstruct palaeoclimatic and palaeoenvironmental conditions in Caucasus that currently lack of long
continuous records.
The volcanic range (up to 3000 m, 400 to 10 ka in age) located in the western part of the lake was covered
by an ice cap (50-100 m) during the last two glacial periods as attested by the presence of numerous and well
preserved glacial morphology and associated deposits. For example, moraines are found all around the Paravani
Lake thus suggesting that the ice cap reached the lake level during the coldest events.
In 2009, a first sediment core was extracted from Paravani Lake. Ten radiocarbon dates show that the core
covers the last 13 ka period. The multi-proxy analysis performed on the sediments has allowed us to characterize
an original evolution of the vegetation in relation to the post-glacial climatic variations and the dynamic of the
Samsari-Djavakheti glaciers.
Based on this ongoing work, new sedimentological (image sizing, and classical analysis) palaeocol... more Based on this ongoing work, new sedimentological (image sizing, and classical analysis) palaeocological (malacology, anthracology, palaeontology) and geochemical (XRF, spectrocolorimetry, C14, C13, oxygen isotopes, etc..) analysis will be done (new technical platform PlaSéDo of the CNRS LAMPEA Laboratory) to improve the event resolution and their precise modality.
Mediterranean landscape evolution (southern Luberon, Vaucluse, France) from the last glacial period to the Holocene period is analysed through alluvial deposits and travertine system development linked to climate changes and human occupations. Results of geomorphological, sedimento-stratigraphical and physico-chemical analysis increased by archaeological and palaeoecological (malacology and anthracology) studies and about fifty 14C dating are the basement of a pluridisciplinary research on the links between Man and environment in Mediterranean France.
Around 50 Ky BP, numerous glacis formation, made up of torrential pebbles and reworked cryoclasts, covered the southern Luberon piedmont with frequently more than thirty meters thickness. At their bases several “red-soils” and their palaeontological content show the more temperate climate conditions of isotopic stage 3 interstadials in Mediterranean region.
Between the Last Glacial Maximum and the Lateglacial period (18-17 Ky cal. BP. ?), a major scale incision occurred with fastness. Since 15500 cal. BP, travertine and detrital deposits were developed. Inside this new morphogenetic tendency, travertine formations located downstream karstic re-emergence are indicative of the Postglacial warming. These carbonated deposits are the oldest testimony of the restarting of the southern France Postglacial travertine accumulation. Then, around 9000 cal. BP and 6000 cal. BP, two main incisions occurred in alternation with embankment phases. The morphogenic dynamic of the first part of postglacial period seems to be linked to the bioclimatic changes.
Since the Final Neolithic, in the context of growing human occupation, ruptures (incisions) in the travertine sequences have been recorded. These ruptures, of high frequency but low amplitude, were accompanied by facies changing and strong vegetation opening determined upon palaeoecological analysis. Travertine sensitivity in accordance with climato-anthropic biotope changes is underlined.
Between the XIth and the XIIIth century A.D., the decline and the dismantlement of the travertine formations became noticeable. In the same way, the major linear talweg incision (well known in southern France but poorly chronologically discerned until now) was introduced in a morphogenic dynamic only partly interrupted after the XVIIth century A.D., during the Little Ice Age, by a detrital deposit phases. Then a final incision has occurred and it’s still happening today. Combined effect of climatic oscillations and human society occupation modes above the “natural environment” seem to be the main driving force of a bustling morphogenesis during the second part of the Postglacial period.
Keywords: Luberon, Provence, morphogenesis, last Pleniglacial, Postglacial, travertine deposits, incisions, sedimentation rhythms, palaeoclimate, palaeoenvironment, human occupations.
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In the Lesser Caucasus, some evidences of Early Neolithic river management have been discovered.
•
We report a preliminary data set indicating that the river management was made 5900 cal. BC ago and led to Neolithic village flooding, destruction and local abandonment of the hydraulic infrastructures between 5750 and 5430 cal. BC.
•
We carried out isotopic analyzes on the seeds in order to characterize or not the occurrence of irrigation.
•
We highlight the possibility of a development in the Caucasus of the oldest known water management practices.
•
We also present an original focus on the potential effects of torrential palaeo-floods in Neolithic water management structures and riparian habitats.
River management is generally thought to have started at 5500 cal. BC within the development of eastern Neolithic societies. In the Lesser Caucasus, evidence of early river management has been discovered around the famous Neolithic sites of Shulaveri, Gadachrili Gora, and Imiris Gora in Georgia. Here we report a preliminary data set indicating that river management was set up at 5900 cal. BC leading to the flooding, destruction, and local abandonment of the hydraulic infrastructures of the Gadachrili village between 5750 and 5430 cal. BC. The hydraulic infrastructures were developed during a more humid period encompassing the 8200 cal. BP (6200 cal. BC) climatic event, probably to optimize agricultural yield. It potentially led to the first prehistoric engineering accident for which there is evidence, which may have been followed by the reorganisation of the occupation and/or to architectural modifications.
north of the site Collet-Redon, in la Couronne, was excavated during
two campaigns in 2014 and 2015. Located in the small valley called
“the Chappats”, the tomb is installed in a pit with architectural
features. Two sepulchral levels were identified. The first, probably
composed of primary deposits, was partially removed. The second
is consisted of an articulated individual and many commingled
remains close to one of the wall. At least, 11 subjects (adults
and immatures) are necessary to explain the composition of
the osteological series. Only 7 beads made in limestone were
associated with the human remains. Four radiocarbon dates are
situated in the Recent Neolithic or at the very beginning of the Late
Neolithic, before the widespread of collective burials in Provence.
The chronological situation of the tomb, its location, the originality
of its architectural feature and the use pattern are discussed taking
into account the actual knowledge on funerary practices in the
south of France at the end of Neolithic.
-Carbonate denudation rates in Provence are comparable to those in other settings.
-Precipitation distribution has little influence on carbonate denudation.
-Denudation variability is linked to Holocene hillslope destabilization events.
-For similar climate denudation of carbonates is higher than for other lithologies.
Abstract
The dynamics of carbonate-dominated landscapes is still debated, and first-order questions pertaining to the respective importance of chemical and mechanical weathering processes or the influence of climatic variability on denudation rates are largely open. To address these issues, we investigate the denudation pattern across a climatic gradient in Provence, SE France. We focused on a series of major carbonate mountain ranges with elevation spanning 200 to 2000 m and associated with >2-fold variations in mean annual temperature and precipitation. We collected 25 samples from 10 different mountain ranges and quantified denudation rates through the measurement of their 36Cl concentrations in order to explore tectonic and climatic controls on these carbonate landscapes evolution. We observe that most of our samples experience denudation rates in the 30–60 mm/ka range (averaged over 5 to 40 ka), with no evident dependence on variations of mean annual temperature or precipitation. One range (Lure mountain) stands out as a significant outlier, with much higher denudation rates (>100 mm/ka) than adjacent sites (Ventoux mountain) at the same elevation and experiencing similar present-day environmental conditions. We explore in details the climatic, tectonic and geomorphological contexts of these two ranges in order to understand the reasons for this apparent 3-fold difference in denudation rates. A regionally-documented major Holocene hillslope destabilization event appears to be a likely candidate to explain the observed lower 36Cl concentrations at the top of the Lure mountain. At longer wavelengths, our regional dataset shows no clear control of modern precipitation gradients on denudation rates, consistent with previous observations in landscapes underlain by other lithologies.
Dans le cadre du programme HYDRΩMED (A*MIDEX Aix Marseille Université), de nouvelles recherches concernant la gestion de l’eau en Méditerranée au cours du premier millénaire avant J.C. ont été développées. Nous présentons ici nos premiers résultats obtenus dans le cadre d’une approche pluridisciplinaire sur la cité de Solonte (nord-ouest de la Sicile) mêlant archéologie, hydrogéologie et géoarchéologie. Auparavant considérée comme exclusivement issue de la collecte des eaux de pluies par l’intermédiaire de systèmes de citernes, l’alimentation en eau du site apparaît en fait beaucoup plus riche et complexe. Cette dernière proviendrait plutôt de l’exploitation de systèmes de fractures tectoniques guidant des remontées hydrothermales, et fournissant des eaux thermominérales additionnelles et pérennes dans une grande partie des infrastructures hydrauliques identifiées à Solonte (notamment des thermes). Ces nouveaux résultats mettent en évidence un des paramètres fondamentaux ayant pu influencer le choix du Monte Catalfano comme site privilégié d’implantation de la cité durant l’antiquité. Une analyse descriptive de la grande citerne maçonnée fournit également des informations améliorant les connaissances sur la gestion de l’eau dans la cité antique de Solonte.
Abstract :
New research about water management in the Mediterranean during the first millennia BC are developed in the frame of the HYDRΩMED (A*MIDEX Aix Marseille University) program. We present here our first results obtained within the framework of a multidisciplinary approach on the city of Solonte (northwest of Sicily) combining archeology, hydrogeology and geoarchaeology. Previously considered exclusively from the collection of rainwater through cistern systems, the water supply to the site actually appears much richer and more complex. The latter would come rather from the exploitation of tectonic faulting guiding hydrothermal flow providing additional and perennial thermomineral waters in a large part of the hydraulic infrastructures identified at Solonte (including thermal baths). These new results highlight one of the fundamental parameters that may have influenced the choice of Monte Catalfano as a privileged site for the settlement of the city during antiquity. A descriptive analysis of the large built cistern also provides information to improve the knowledge of water management in the ancient city of Solonte.
Abstract :
Nell’ambito del programma HYDRΩMED (A*MIDEX Aix Marseille Université), si sono condotte nuove ricerche sulla gestione idrica nel Mediterraneo durante il primo millennio a. C. Si presentano in questo contributo i primi risultati ottenuti nel quadro di un approccio pluridisciplinare alla città di Solunto (nord ovest della Sicilia), il quale unisce archeologia, idrogeologia e geoarcheologia. Inizialmente considerata come esclusivo esito della raccolta dell’acqua piovana attraverso i sistemi delle cisterne, l’alimentazione idrica del sito sembrerebbe in realtà molto più ricca e complessa. Quest’ultima deriverebbe, piuttosto, dallo sfruttamento delle fratture tettoniche del sito, caratterizzate da fenomeni idrotermali che fornivano acque termominerali in gran parte delle infrastrutture idrauliche identificate a Solunto (in particolare le terme). Questi nuovi risultati mettono in evidenza uno dei parametri fondamentali che hanno potuto influenzare la scelta di Monte Catalfano come sito privilegiato per l’impianto della città nell’antichità. Un’analisi descrittiva della grande cisterna in muratura, inoltre, fornisce informazioni che contribuiscono alla conoscenza della gestione idrica nell’antica città di Solunto.
Vincent OLLIVIER , Frédéric MAGNIN , Adam ALI , Christine BALME & Pierre FRAPA
Le tuf calcaire de la Thomassine, localisé sur le site même de la Maison de la Biodiversité à Manosque (Alpes-de-Haute-Provence), fait actuellement l’objet d’une étude pluridisciplinaire afin de reconstituer les rythmes de l’évolution du paysage dans le secteur de Manosque. Les analyses géomorphologiques, les datations radiocarbone et l’étude des assemblages de gastéropodes contenus dans les sédiments, permettent de caractériser différentes composantes de l’environnement du Luberon au début du Néolithique, il y a plus de 6500 ans.
The calcareous tufa of La Thomassine: Early Neolithic landscapes and climates in the Manosque countryside
The Thomassine calcareous tufa, located near the “Biodiversity House” (Manosque, Alpes-de-Haute-Provence), is currently the subject of a multidisciplinary study to reconstruct the rhythms of the landscape changes in the Manosque area. Geomorphological analysis, radiocarbon dating and land snail assemblage studies are used to characterize the various components of the Luberon environment in the early Neolithic, more than 6,500 years ago.
Quaternary International 2015
A sediment core has been retrieved from Vanevan peat (south-eastern shore of Lake Sevan, Armenia), which is today disconnected from Lake Sevan thanks to an artificial shallowing of the lake. Based on 5 radiocarbon dates, Vanevan record covers the Mid Holocene (from ca. 7800 to ca. 5100 cal. BP). The Late Holocene is today absent in the peat stratigraphy due to modern peat exploitation by surface mining. This study focuses on a multi-proxy approach including pollen, charcoals, and pollen-inferred climate reconstruction.
An open-land, steppic vegetation is recorded up to ca. 7700 cal. BP, followed by a more forested landscape during the Mid Holocene (up to ca. 5700 cal. BP), and ending again with an open-land vegetation (to the end of record, 5100 cal. BP). This vegetation dynamics responds to general climate changes documented in the Near East. Whether human activities are documented since ca. 7500 cal. BP (Late Neolithic) in Vanevan, they remain marginal and probably did not affect the area. Early Holocene dry climate, which caused the steppic environment to be widespread through the Near East, is strongly related to low late spring precipitation (PMay–Jun = 180 mm). Mid Holocene forested landscape and increasing lake-level seem related to late spring precipitation (+28%), which is the main change in estimated climate parameters. This has to be linked with reinforcement of the Westerlies and less active Siberian High, which are inversely involved in the following, dry phase starting at ca. 5700 cal. BP.
•
In the Lesser Caucasus, some evidences of Early Neolithic river management have been discovered.
•
We report a preliminary data set indicating that the river management was made 5900 cal. BC ago and led to Neolithic village flooding, destruction and local abandonment of the hydraulic infrastructures between 5750 and 5430 cal. BC.
•
We carried out isotopic analyzes on the seeds in order to characterize or not the occurrence of irrigation.
•
We highlight the possibility of a development in the Caucasus of the oldest known water management practices.
•
We also present an original focus on the potential effects of torrential palaeo-floods in Neolithic water management structures and riparian habitats.
River management is generally thought to have started at 5500 cal. BC within the development of eastern Neolithic societies. In the Lesser Caucasus, evidence of early river management has been discovered around the famous Neolithic sites of Shulaveri, Gadachrili Gora, and Imiris Gora in Georgia. Here we report a preliminary data set indicating that river management was set up at 5900 cal. BC leading to the flooding, destruction, and local abandonment of the hydraulic infrastructures of the Gadachrili village between 5750 and 5430 cal. BC. The hydraulic infrastructures were developed during a more humid period encompassing the 8200 cal. BP (6200 cal. BC) climatic event, probably to optimize agricultural yield. It potentially led to the first prehistoric engineering accident for which there is evidence, which may have been followed by the reorganisation of the occupation and/or to architectural modifications.
north of the site Collet-Redon, in la Couronne, was excavated during
two campaigns in 2014 and 2015. Located in the small valley called
“the Chappats”, the tomb is installed in a pit with architectural
features. Two sepulchral levels were identified. The first, probably
composed of primary deposits, was partially removed. The second
is consisted of an articulated individual and many commingled
remains close to one of the wall. At least, 11 subjects (adults
and immatures) are necessary to explain the composition of
the osteological series. Only 7 beads made in limestone were
associated with the human remains. Four radiocarbon dates are
situated in the Recent Neolithic or at the very beginning of the Late
Neolithic, before the widespread of collective burials in Provence.
The chronological situation of the tomb, its location, the originality
of its architectural feature and the use pattern are discussed taking
into account the actual knowledge on funerary practices in the
south of France at the end of Neolithic.
-Carbonate denudation rates in Provence are comparable to those in other settings.
-Precipitation distribution has little influence on carbonate denudation.
-Denudation variability is linked to Holocene hillslope destabilization events.
-For similar climate denudation of carbonates is higher than for other lithologies.
Abstract
The dynamics of carbonate-dominated landscapes is still debated, and first-order questions pertaining to the respective importance of chemical and mechanical weathering processes or the influence of climatic variability on denudation rates are largely open. To address these issues, we investigate the denudation pattern across a climatic gradient in Provence, SE France. We focused on a series of major carbonate mountain ranges with elevation spanning 200 to 2000 m and associated with >2-fold variations in mean annual temperature and precipitation. We collected 25 samples from 10 different mountain ranges and quantified denudation rates through the measurement of their 36Cl concentrations in order to explore tectonic and climatic controls on these carbonate landscapes evolution. We observe that most of our samples experience denudation rates in the 30–60 mm/ka range (averaged over 5 to 40 ka), with no evident dependence on variations of mean annual temperature or precipitation. One range (Lure mountain) stands out as a significant outlier, with much higher denudation rates (>100 mm/ka) than adjacent sites (Ventoux mountain) at the same elevation and experiencing similar present-day environmental conditions. We explore in details the climatic, tectonic and geomorphological contexts of these two ranges in order to understand the reasons for this apparent 3-fold difference in denudation rates. A regionally-documented major Holocene hillslope destabilization event appears to be a likely candidate to explain the observed lower 36Cl concentrations at the top of the Lure mountain. At longer wavelengths, our regional dataset shows no clear control of modern precipitation gradients on denudation rates, consistent with previous observations in landscapes underlain by other lithologies.
Dans le cadre du programme HYDRΩMED (A*MIDEX Aix Marseille Université), de nouvelles recherches concernant la gestion de l’eau en Méditerranée au cours du premier millénaire avant J.C. ont été développées. Nous présentons ici nos premiers résultats obtenus dans le cadre d’une approche pluridisciplinaire sur la cité de Solonte (nord-ouest de la Sicile) mêlant archéologie, hydrogéologie et géoarchéologie. Auparavant considérée comme exclusivement issue de la collecte des eaux de pluies par l’intermédiaire de systèmes de citernes, l’alimentation en eau du site apparaît en fait beaucoup plus riche et complexe. Cette dernière proviendrait plutôt de l’exploitation de systèmes de fractures tectoniques guidant des remontées hydrothermales, et fournissant des eaux thermominérales additionnelles et pérennes dans une grande partie des infrastructures hydrauliques identifiées à Solonte (notamment des thermes). Ces nouveaux résultats mettent en évidence un des paramètres fondamentaux ayant pu influencer le choix du Monte Catalfano comme site privilégié d’implantation de la cité durant l’antiquité. Une analyse descriptive de la grande citerne maçonnée fournit également des informations améliorant les connaissances sur la gestion de l’eau dans la cité antique de Solonte.
Abstract :
New research about water management in the Mediterranean during the first millennia BC are developed in the frame of the HYDRΩMED (A*MIDEX Aix Marseille University) program. We present here our first results obtained within the framework of a multidisciplinary approach on the city of Solonte (northwest of Sicily) combining archeology, hydrogeology and geoarchaeology. Previously considered exclusively from the collection of rainwater through cistern systems, the water supply to the site actually appears much richer and more complex. The latter would come rather from the exploitation of tectonic faulting guiding hydrothermal flow providing additional and perennial thermomineral waters in a large part of the hydraulic infrastructures identified at Solonte (including thermal baths). These new results highlight one of the fundamental parameters that may have influenced the choice of Monte Catalfano as a privileged site for the settlement of the city during antiquity. A descriptive analysis of the large built cistern also provides information to improve the knowledge of water management in the ancient city of Solonte.
Abstract :
Nell’ambito del programma HYDRΩMED (A*MIDEX Aix Marseille Université), si sono condotte nuove ricerche sulla gestione idrica nel Mediterraneo durante il primo millennio a. C. Si presentano in questo contributo i primi risultati ottenuti nel quadro di un approccio pluridisciplinare alla città di Solunto (nord ovest della Sicilia), il quale unisce archeologia, idrogeologia e geoarcheologia. Inizialmente considerata come esclusivo esito della raccolta dell’acqua piovana attraverso i sistemi delle cisterne, l’alimentazione idrica del sito sembrerebbe in realtà molto più ricca e complessa. Quest’ultima deriverebbe, piuttosto, dallo sfruttamento delle fratture tettoniche del sito, caratterizzate da fenomeni idrotermali che fornivano acque termominerali in gran parte delle infrastrutture idrauliche identificate a Solunto (in particolare le terme). Questi nuovi risultati mettono in evidenza uno dei parametri fondamentali che hanno potuto influenzare la scelta di Monte Catalfano come sito privilegiato per l’impianto della città nell’antichità. Un’analisi descrittiva della grande cisterna in muratura, inoltre, fornisce informazioni che contribuiscono alla conoscenza della gestione idrica nell’antica città di Solunto.
Vincent OLLIVIER , Frédéric MAGNIN , Adam ALI , Christine BALME & Pierre FRAPA
Le tuf calcaire de la Thomassine, localisé sur le site même de la Maison de la Biodiversité à Manosque (Alpes-de-Haute-Provence), fait actuellement l’objet d’une étude pluridisciplinaire afin de reconstituer les rythmes de l’évolution du paysage dans le secteur de Manosque. Les analyses géomorphologiques, les datations radiocarbone et l’étude des assemblages de gastéropodes contenus dans les sédiments, permettent de caractériser différentes composantes de l’environnement du Luberon au début du Néolithique, il y a plus de 6500 ans.
The calcareous tufa of La Thomassine: Early Neolithic landscapes and climates in the Manosque countryside
The Thomassine calcareous tufa, located near the “Biodiversity House” (Manosque, Alpes-de-Haute-Provence), is currently the subject of a multidisciplinary study to reconstruct the rhythms of the landscape changes in the Manosque area. Geomorphological analysis, radiocarbon dating and land snail assemblage studies are used to characterize the various components of the Luberon environment in the early Neolithic, more than 6,500 years ago.
Quaternary International 2015
A sediment core has been retrieved from Vanevan peat (south-eastern shore of Lake Sevan, Armenia), which is today disconnected from Lake Sevan thanks to an artificial shallowing of the lake. Based on 5 radiocarbon dates, Vanevan record covers the Mid Holocene (from ca. 7800 to ca. 5100 cal. BP). The Late Holocene is today absent in the peat stratigraphy due to modern peat exploitation by surface mining. This study focuses on a multi-proxy approach including pollen, charcoals, and pollen-inferred climate reconstruction.
An open-land, steppic vegetation is recorded up to ca. 7700 cal. BP, followed by a more forested landscape during the Mid Holocene (up to ca. 5700 cal. BP), and ending again with an open-land vegetation (to the end of record, 5100 cal. BP). This vegetation dynamics responds to general climate changes documented in the Near East. Whether human activities are documented since ca. 7500 cal. BP (Late Neolithic) in Vanevan, they remain marginal and probably did not affect the area. Early Holocene dry climate, which caused the steppic environment to be widespread through the Near East, is strongly related to low late spring precipitation (PMay–Jun = 180 mm). Mid Holocene forested landscape and increasing lake-level seem related to late spring precipitation (+28%), which is the main change in estimated climate parameters. This has to be linked with reinforcement of the Westerlies and less active Siberian High, which are inversely involved in the following, dry phase starting at ca. 5700 cal. BP.
Vincent Ollivier
Aix-Marseille Université, CNRS, MCC, LAMPEA UMR 7269, Aix-en-Provence, France.
Water management is often linked through time to local and/or regional hydrogeomorphic conditions. Water supply, flooding protection, river diversion, settlement location also evolved following the hydrogeologic and climatic changes. In addition, due to the sensitivity of some environmental conditions, the use of water resources by ancient populations have sometimes destabilized the morphosedimentary balance of the exploited systems (river, karst, calcareous tufa, etc.). Using hydrogeomorphologic and geoarcheological approach, diachronic and various examples in and around the Mediterranean will be presented to illustrate and expand the enriching debate about the relationship between water management and environmental constraints evolution.
pluridisciplinaire (pollen, micro-charbons, modélisation paléoclimatologique), renforcée par les
recherches géomorphologiques et archéologiques menées aux alentours du lac. Selon le modèle
d’âge, l’Holocène moyen est documenté avec une résolution de 79 ans entre les échantillons.
L’Holocène récent a disparu avec l’exploitation actuelle de la tourbière. Entre 7.8 et 5.1 ka cal. BP,
trois types d’environnements se succèdent ; dynamique à commande principalement climatique
puisque les occupations humaines recensées autour du lac Sevan ne paraissent pas affecter
l’environnement. Jusqu’à 7.7 ka cal. BP, un environnement steppique perdure sous un climat sec
avec de très basses précipitations de fin de printemps (PMay–Jun = 180 mm). Une nette fermeture du
milieu se marque entre 7.7 et 5.7 ka cal. BP. Une hausse des précipitations de fin de printemps
(+28%) accompagne cette phase plus boisée, également contemporaine d’une élévation du niveau
du lac. Après 5.7 ka cal. BP, le milieu est plus ouvert alors que se développent les incendies. Le
climat est à nouveau plus sec et le niveau du lac Sevan baisse.
Three palaeoecological phases have been identified (Messager et al., 2013):
- The first phase spanning the Younger Dryas and the Early Holocene, corresponds to a steppic environment with a limited lake productivity driven by a cold and particularly dry climate.
- A second phase starts with an important expansion of trees at 8 300 cal years BP. As soon as the climatic and edaphic conditions were favourable, the main deciduous and coniferous trees expanded concurrently due to the proximity of glacial forest refugia located in western Caucasus.
- A third phase starts at 3000-2000 cal BP and corresponds to the decline of forests on the plateau and the expansion of herbaceous formations, leading to the present-day steppic environment. This deforestation phase is driven by the deterioration of the climate conditions and human impact.
References
Messager, E., Belmecheri, S., von Grafenstein, U., Nomade, S., Ollivier, V., Voinchet, P., Puaud, S., Courtin-Nomade, A., Guillou, H., Mgeladze, A., Dumoulin, J.P., Mazuy, A., Lordkipanidze, D., 2013. Late Quaternary record of the vegetation and catchment-related changes from Lake Paravani (Javakheti, South Caucasus). Quaternary Science Reviews 77, 125-140.
Bertille LYONNET 1 Christine CHATAIGNER 4
1 PrOCauLAC - Collège de France, CNRS (UMR 7192), Paris, France, Vincent.ollivier@college-de-france.fr
2 LAMPEA – Université de Provence, CNRS, MCC, IRD (UMR 7269), Maison Méditerranéenne des Sciences de l'Homme, Aix-en-Provence, France.
3 LSCE – UVSQ, CNRS (UMR 1572), Gif sur Yvette, France.
4Université de Lyon 2, Archéorient, UMR 5133, Maison de l’Orient, Lyon, France, christine. chataigner@mom.fr
L’évolution de la mobilité relative du niveau de la mer Caspienne au cours du Quaternaire récent s’exprime selon des rythmes de haute fréquence et de moyenne à forte amplitude. Cette rythmicité est bien définie sur la période Pléistocène supérieur - Postglaciaire et de manière détaillée pour l’Holocène. Les variations eustatiques enregistrées ne sont pas systématiquement en phase avec les rétroactions habituellement connues sous contrôle climatique au niveau global. Les niveaux de terrasses marines et les deltas constituent jusqu’à présent les supports essentiels sur lesquels reposent de telles reconstructions. De nouveaux travaux, réalisés dans le cadre de l’ANR franco-allemande Ancient Kura (CNRS-DFG, sous la direction de Bertille Lyonnet de l’UMR 7192 PrOCauLAC et de Barbara Helwing du Deutsches Archäologisches Institut) de la mission Caucase (CNRS, ministère des Affaires Etrangères) et du Laboratoire international associé HEMHA (Humans and Environment in Mountainous Habitats : the case of Armenia) dirigés par Christine Chataigner, se concentrent actuellement sur les impacts des oscillations climato-eustatiques sur les dynamiques érosives et de transfert au niveau des hydrosystèmes de piémont du Petit Caucase. Les analyses géomorphologiques (stratigraphies, sédimentologie, évolution morphosédimentaire), géochronologiques (datations 14C) et géoarchéologiques (sites néolithiques, chalcolithiques et du Bronze) sont conduites sur le fleuve Kura et ses affluents, principalement dans les régions de Tovuz et d’Agjabedi au nord-ouest et au sud de l’Azerbaïdjan mais aussi dans d’autres secteurs du Petit Caucase. Ces recherches ont permis d’élaborer une première trame des rythmes de sédimentation à l’échelle régionale et de déterminer en partie l’origine, les moteurs et les impacts possibles des mutations paysagères holocènes sur les sociétés des espaces riverains de la mer Caspienne. Nos premiers résultats indiquent une forte réponse des variations de tendances morphogéniques aux oscillations eustatiques de l’extrême fin du dernier cycle climatique. Les hydrosystèmes amont réagissent aux régressions marines par de puissantes incisions régressives et aux transgressions par d’imposantes phases de remblaiements. Les rétroactions s’expriment jusqu’aux zones intramontagnardes largement distantes de la ligne de rivage. Ces différents bilans sédimentaires et les changements engendrés dans la morphologie fluviale sont faiblement influencés par l’évolution des paramètres exclusivement climatiques et tectoniques. Les sociétés occupant les vallées et systèmes de terrasses de l’hydrosystème Kura, ont vu leurs modes d’occupations concernés par ces mutations paysagères au cours du Néolithique et jusqu’à l’Age des métaux. Ce qui se traduit spatialement et de manière diachronique dans la localisation des sites (fonction des aménités sédimentaires, pédologiques et d’accessibilité à l’eau), dans les modalités de leur abandon et de leur disparition par érosion ou enfouissement. Ces nouvelles données doivent désormais être prises en compte dans les analyses géoarchéologiques concernant les régions Circumcaspiennes.
ASSOCIATION FRANÇAISE POUR L'ETUDE DU SOL Section Méditerranée JOURNEE THEMATIQUE : « APPORTS DES ETUDES PEDOLOGIQUES, ARCHEOLOGIQUES au préalable d’un projet d’aménagement d’une liaison hydraulique sur un linéaire de 75 kms dans le Var » , vendredi 18 juin 2010 organisée par la SCP et le Service Départemental d’archéologie du Var .
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André Müller, Sophie Martin,
Jean-Louis Guendon, Emilie Blaise,
Stephane Bourne, Christophe Gilabert,
Muriel Pellisier
1 Laboratoire Méditerranéen de Préhistoire Europe-Afrique, UMR 6636 du CNRS, Aix en Provence, France, ollivier@mmsh.univ-aix.fr et guendon@mmsh.univ-aix.fr.
2 Centre de Bio-Archéologie et d’Ecologie, UMR 5059 du CNRS, Montpellier, France, roiron@univ-montp2.fr et ali@univ-montp2.fr.
3 Institut Méditerranéen d’Ecologie et de Paléoécologie, UMR 6116 du CNRS, Aix en Provence, France, frederic.magnin@univ-cezanne.fr.
4 INRAP Nîmes et UMR 5140 CNRS Montpellier-Lattes, France, sophie.martin@inrap.fr
Les travertins sont les témoins privilégiés des fluctuations bioclimatiques et morphogéniques postglaciaires entre Provence et zone subalpine. La sensibilité du développement des formations travertineuses aux modifications du biotope permet, selon l’organisation séquentielle des pôles morphosédimentaires, d’établir une trame relativement détaillée des niveaux d’instabilités, de ruptures ou d’équilibres de la morphogenèse sous contrainte climatique ou climato-anthropique. La préservation de marqueurs paléoécologiques (charbons, malacofaunes et empreintes foliaires) et la présence régulière de vestiges archéologiques (artéfacts, niveaux d’occupation) au sein des dépôts constituant la séquence travertineuse, renforce les possibilités d’analyses spatiales et temporelles des dynamiques paysagères sur le long terme.
Dans la zone subalpine, l’étude croisée des faciès carbonatés, empreintes foliaires et charbons nous délivre une image diachronique de la végétation, des fréquences d’incendies des instabilités de versant et de la position de la limite supérieure des arbres au cours de l’Holocène.
En Provence, les fluctuations morphosédimentaires observées (érosions, incisions intraformationnelles et variations des faciès) dans les séquences travertineuses, et les analyses paléoécologiques réalisées, nous renseignent sur la rythmicité de la morphogenèse (stabilités, instabilités, ruptures) dès le Tardiglaciaire et sur l’impact des modes d’occupations Néolithiques dans les dynamiques paysagères.
Ainsi, dès 15500 cal. BP une puissante phase d’accumulation sédimentaire s’amorce dans les vallons inscrits sur les piémonts du Luberon. Aux débouchés des exsurgences karstiques, le développement des formations travertineuses signe le réchauffement climatique engagé. Par la suite, et dans l’ensemble des formations détritiques et carbonatées, deux incisions principales se produisent vers 9000 et 6000 cal. BP en alternance avec des phases de remblaiements.
Dès le Néolithique Final et jusqu’au Haut Moyen Age, les séquences enregistrent une série de ruptures (incisions) de haute fréquence et de faible amplitude. Ces perturbations sont accompagnées de changements de faciès dans les systèmes carbonatés (fig. 1) et d’ouvertures fortes du milieu végétal.
Entre le XIIIème et le XVIIème siècle après Jésus Christ, les formations L.S. sont démantelées dans une dynamique majeure d’incision linéaire des talwegs.
L’action conjuguée des oscillations climatiques et des modes d’occupation humaines apparaît comme le principal moteur d’une morphogenèse mouvementée au cours de la deuxième partie du Postglaciaire.
1 CBAE, UMR 5059, Institut de Botanique, 163 rue A. Broussonet, 34090 Montpellier paul.roiron@univ-montp2.fr
2 UMR 6636, Maison Médit. des Sciences de l'Homme, BP 647, 5 rue du Château de l'Horloge, 13545 Aix-en-Provence vincent.ollivier@univ-cezanne.fr
3 Faculty of Geography, Department of Geomorphology and Cartography, Yerevan State University, Armenia nahapetyan@ysu.am
4 Institute of Botany of National Academy of Sciences, Department of Higher Plants taxonomy and geography, 375063 Yerevan, Armenia gabrielyanivan@yahoo.com
5 UMR 5243, Université Montpellier2, place E. Bataillon, 34095 Montpellier cedex 5 cornee@gm.univ-montp2.fr
6 Maison des Sciences de l'Homme et de l'Environnement, USR 312 Laboratoire de Chrono-Environnement 16 route de Gray, 25030 Besançon sebastien.joannin@mshe.univ-fcomte.fr
7 UMR 5133, Maison de L'Orient et de la Méditerranée, Université Lumière Lyon2, 7 rue Raulin, 69007 Lyon christine.chataigner@mom.fr
8 PACEA, UMR 5199, Université Bordeaux1, B8, avenue des facultés, 33405 Talence j.jaubert@ipgq.u-bordeaux1.fr
9 Archeological Institute, Azatutian st. 7B, apt.64, Yerevan, Armenia borisg@virtualarmenia.am
L’Arménie est une zone volcanique du Petit Caucase qui subit à la fois des influences climatiques méditerranéennes et asiatiques. C’est aussi le lieu de développement et d’échanges des cultures préhistoriques qui se sont développées depuis le Paléolithique dans la région et qui ne sont connues que de manière ponctuelle. Nos travaux ont pour but d’apporter des données nouvelles permettant de reconstituer l’évolution de l’environnement au cours du Quaternaire et d’étudier les conséquences de ces changements sur l’occupation humaine.
Du Pleistocène inférieur au Postglaciaire, la chaîne du Caucase a été marquée par une intense activité volcanique. Au nord du pays (région du Lori), une séquence fluvio-lacustre contenant des empreintes foliaires de ripisylve est encadrée par deux coulées volcaniques datées de 2,01 et 1,96 Ma. Cette région est en lien avec le plateau de Dmanissi qui a livré des restes de Homo georgicus datés de 1,8 Ma (de Lumley & al., 2002).
Dans le sud de l’Arménie (Syunik) les coulées de laves et les mouvements tectoniques ont fermé plusieurs vallées, provoquant la formation de lacs et le développement de diatomites qui ont fossilisé des macrorestes et des pollens permettant des reconstructions environnementales et paléoclimatiques.
Une carte géomorphologique et des transects géologiques ont été dessinés. La chronologie est précisée par magnétostratigraphie et par des datations radiométriques sur les laves (K/Ar) ou les ponces volcaniques (Ar/Ar). L’étude palynologique et des restes foliaires de la section de Shamb a permis de mettre en évidence une alternance de phases forestières et steppiques en lien avec la périodicité de l’obliquité (41 ka). Pendant le Pleistocène inférieur, ce secteur a subi des fluctuations climatiques allant d’un climat tempéré-chaud à un climat plus sec puis plus froid pendant les périodes glaciaires.
Au Pleistocène moyen, plusieurs paléolacs de la zone centrale de l’Arménie (région d’Aparan) sont entourés par de nombreux sites du Paléolithique moyen.
Au nord du lac Sevan, la localité de Kalavan a livré un site du Paléolithique moyen (stade isotopique 3) et une occupation holocène.
Les traces de plusieurs glaciations pleistocènes (du stade isotopique 11 au stade 2) sont observées dans la vallée du Vorotan (Syunik), soulignant le rôle important des phases glaciaires dans la morphogénèse quaternaire du sud de l’Arménie.
L’Holocène est documenté par plusieurs coupes alluviales (Tsilkar, Geghakot) indiquant la présence de zones humides attractives pour les populations humaines.
Le territoire arménien contient aussi de nombreuses formations travertineuses pléistocènes et holocènes dont certaines contiennent des empreintes de feuilles. Des datations U/Th ou 14C indiquent que ces travertins se sont développés au cours de phases interglaciaires ou interstadiaires.
L’étude conjointe des formations lacustres, alluviales, glaciaires et travertineuses du Pléistocène et de l’Holocène en lien avec les changements climatiques et les occupations humaines permet d’appréhender le rythme et l’ampleur des mutations paysagères et leur relation avec le développement des sociétés caucasiennes.
Paul ROIRON, Adam ALI, Jean-Louis GUENDON
Les formations travertineuses du sud de la France sont de précieux indicateurs sur l'évolution des hydrosystèmes et des paléoenvironnements quaternaires. Milieux attractifs pour les sociétés humaines en raison de leurs importantes potentialités (eaux abondantes et de qualité notamment), ces systèmes carbonatés fournissent des archives sédimentaires riches en vestiges archéologiques mais aussi en données paléoécologiques (malacofaunes, charbons, pollens, empreintes foliaires, entomofaunes). La diversité des contextes géomorphologiques, topographiques, micro-climatiques et des occupations humaines (cultures et densités), souligne la remarquable représentativité des informations disponibles dans cet espace géographique mosaïque où hautes montagnes internes, vallées, massifs côtiers et plaines littorales se côtoient.
Les séquences travertineuses du Luberon, de St Antonin, de Roquevaire, du Queyras, du Serre de Montdenier et de St Guilhem, pour ne citer que quelques sites emblématiques en cours d’étude, y occupent une place privilégiée au regard de leur qualité stricte d’archives sédimentaires haute résolution, mais aussi et surtout, car il s’agit de systèmes dynamiques et évolutifs aux temps de réponse rapides, particulièrement sensibles aux moindres variations de leur biotope (forçages locaux ou globaux). Dans le cadre d’analyses séquentielles, la variabilité des faciès travertineux devient un précieux indicateur des dynamiques paléohydrologiques et morphologiques dans un espace paysager en perpétuelle mutation. Cet aspect renforce la qualité des enregistrements liée aux capacités de bonne conservation de ces milieux ainsi que les bénéfices que l’on peut habituellement envisager par l’exploitation de leurs données. Les raisons des arrêts, ruptures et reprises multiples de l’accumulation carbonatée ainsi que du démantèlement de ces formations, restent mal connues (variations des composantes bioclimatiques ? poids des facteurs d’origine climato-anthropique ?) soulevant de nombreuses questions sur la rythmicité et l’amplitude des évolutions paysagères au cours du dernier cycle climatique en fonction des différents contextes environnementaux (montagnards, de piémonts ou de vallées). Le croisement des données géomorphologiques, géoécologiques et archéologiques issues de ces séquences représentatives de la frange méditerranéenne permet en définitive d’appréhender l’évolution des ce type de milieux sous l’angle des relations entre fluctuations climatiques et biologiques, occupations humaines et dynamiques morphosédimentaires.
1 Laboratoire Méditerranéen de Préhistoire Europe Afrique, UMR 6636, Aix-en-Provence, France
2 Department of Cartography and Geomorphology , Yerevan State University, Armenia.
3 Centre de Bio-Archéologie et d’Ecologie, UMR 5059, Montpellier, France.
4 Institute of Botany, National Academy of Sciences of the Republic of Armenia
5 UMR 5125 PEPS, Université Lyon 1, Bt Géode, 11-45 bd du 11 novenbre, 69622 Lyon Cedex, France..
6 Maison de l’Orient, UMR 5133 Archéorient, Lyon, France.
7UMR 5808, Institut de Préhistoire et de Géologie du Quaternaire, Bordeaux, France.
8 Institute of Archaeology and Ethnography, National Academy of Sciences of the Republic of Armenia.
Abstract:
The main goal of our study is to evaluate the respective influence of Quaternary climate oscillations (glacial and interglacial alternations) and paroxysmal events (seism and volcanism) on the morphogenic / palaeoenvironmental dynamics (landscape evolution rhythms) and human occupations in Eurasia.
During the Quaternary period, the Lesser Caucasus range was marked by an intense volcanic activity. From northern to southern Armenia (Aragatsotn and Syunik region notably), bulky lava flows and tectorogenic movements closed the main valleys during the Pleistocene and allowed the establishment of several lacustrine areas with volcanogenic and/or diatomaceous deposits between 1.6 My and 700 Ky. Some of these deposits contain leaf impressions and pollens enabling local palaeoclimatic reconstructions, others are surrounded by Palaeolithic human occupations.
Several field-trips in Armenia highlight the variability of the Quaternary morphogenesis in relation with volcanism, fluvio-lacustrine deposits, glacial inheritance and travertine formations. Geomorphological maps and geological transects were performed. Preliminary events chronology is determined by K/Ar, Ar/Ar, U/Th radiometric dating (on basalt, volcanic pumice and travertine samples) and magnetostratigraphy.
Magnetostratigraphic analyses were carried out on the major fluvio-lacustral section of the Syunik area (Shamb locality, southern Armenia) from which most of the palaeoecological data were extracted. According to the paleomagnetic results, the K/Ar age of the basalt flow in the upper part of the main section studied (993 ± 22 ka), and the Ar/Ar age of a pumice in a lower level (1,21 Ma ± 40 kyr), the whole stratigraphy must have been deposited during the Matuyama period of reversed polarity, between Olduvai and Jaramillo events.
The combined palynological and macroremains analysis of the same section highlights the alternation of relatively forested and steppic phases related to climatic variations moved from the obliquity periodicity (41 kyr). During the Lower Pleistocene, this area underwent major climatic fluctuations, going from a warm-temperate climate to a drier and temperate climate, and then to a cold climate during the glacial periods.
Evidence for several glaciations from Marine Isotopic Stage 11 to MIS 2 described at relatively modest altitudes (bottom of the Vorotan valley) underline the important role of the quaternary cold episodes in the Pleistocene morphogenic dynamic of southern Armenia. From northern to southern Armenia, major travertine formations with leaf imprints were developed on the slopes at 340 Kyr, 250 kyr, 160 kyr and 53 kyr, confirming the establishment of the interglacial or interstadial warming and there potential influences on the human occupations during the second part of the Pleistocene.
This multi-proxy study reveal the major and rapid morphogenetic changes of the studied regions from the predominance of lacustrine environments at the beginning of the Pleistocene to the present river and canyon landscapes, in relation to tecto-volcanic events and climate variability. Then from the recent archeological discovery of the French ECLIPSE and Caucase Mission program team, the effect of the evolution of the Quaternary landscapes on the settlement of the Caucasian societies will be approached in the light of the numerous chronological data and palaeoenvironmental reconstructions.
1 Collège de France, PrOCauLAC-UMR 7192 du CNRS, Proche-Orient, Caucase: Langues, Archéologie, Cultures, Paris, France & Maison Méditerranéenne des Sciences de l’Homme, LAMPEA-UMR 7269 du CNRS, Laboratoire Méditerranéen de Préhistoire Europe-Afrique, Aix en Provence, France, vincent.ollivier@college-de-france.fr.
2 Université de Montpellier 2, CBAE-UMR 5059 du CNRS, Centre de Bio-Archéologie et d’Ecologie, Montpellier, France, roiron@univ-montp2.fr.
3 Department of Cartography and Geomorphology, Yerevan State University, Armenia, nahapetyan@ysu.am
4 Université Lyon 1, UMR 5276 LGLTPE, Laboratoire de Géologie de Lyon, Terre, Planètes, Environnement, Lyon, France, sebastien.joannin@univ-lyon1.fr
5Université de Lyon 2, Archéorient, UMR 5133, Maison de l’Orient, Lyon, France, christine.chataigner@mom.fr
In the course of the International Associated Laboratory HEMHA (Humans and Environment in Mountainous Habitats : the case of Armenia), the French Foreign Affair Ministry Caucasus Mission (CNRS-UMR 5133 Archéorient, Lyon University) and the French-German research program Ancient Kura (CNRS-UMR 7192 PrOCauLAC, Paris, France, Deutsches Archäologisches Institut, Eurasien-Abteilung, Berlin, Germany with ANR-CNRS and DFG funding) numerous sites of the Lesser Caucasus territory are under geomorphological, palaeoenvironmental and archaeological investigations. Through comparisons between the tufa/travertine system and the detrital formation morphosedimentary evolution, one of our research interests is to define the Late Quaternary landscape mutations as well as the origin and rhythmicity of the major morphogenic trends reversals. The impacts of the environmental changes highlighted on the human occupation modes are also debated. A total of 14 travertine and tufa formations were studied (8 Pleistocene and 6 Postglacial formations) on a Northwest-Southeast transect of more than 300 km across the Lesser Caucasus. Each of these carbonated system development are correlated with high global relative sea levels and interstadial climates on a range between the Marine Isotopic Stage 11 and 1 (ca. 335 to 1.5 Ky BP). The absolute chronology is constrained by a series of U/Th and 14C dating. A total of 24 dating was performed (6 radiocarbon and 18 U/Th datings), allowing a high quality overview of the travertinization process over the time at a regional scale. Jointly with the measurement of the late Quaternary interglacial series impact on the tufas development in the Caucasus, the geomorphological position of some travertinous formations and their absolute dating gives some clues about the neotectonic evolution of the studied valleys. In some area, the uplift rate has been determined (ca. 8 mm/year) and discretized from the alluvial incision signal. The analysis of the carbonated deposits (faciological determinations, palaeobotanical and palynological identifications of leave imprints and pollens), which are the expression of specific climatic conditions, and the comparative approach with the general morphosedimentary evolution, give a complete reading grid of the regional landscape mutation expressions and origins (Caspian Sea eustatism or exclusive climatic impact), necessary to understand the magnitude of the changes and their influence on the Circumcaspian societies.
Voinchet (1), Vincent Ollivier (4), Ana Mgeladze (5), and David Lordkipanidze (5)
(1) UMR 7194 CNRS Département de Préhistoire Muséum national d’Histoire naturelle. 1, rue René Panhard, 75013 Paris,
France (erwan.m@mnhn.fr), (2) Earth and Environmental Systems Institute,The Pennsylvania State University. 416 Walker
Building University Park, PA 16802, (3) LSCE/IPSL, Laboratoire CEA-CNRS-UVSQ. Domaine du CNRS, Bât. 12, Avenue
de la Terrasse, 91198 Gif sur Yvette, France, (4) UMR 7192 CNRS Proche-Orient, Caucase: Langues, Archéologie, Cultures,
52 rue du Cardinal Lemoine 75005 Paris, France, (5) Georgian National Museum. 3, Rustaveli Avenue 0105 Tbilisi, Georgia.
Located in the steppic grasslands of South-Transcaucasia in the Samsari-Djavakheti volcanic plateau, the Paravani
Lake (2073 m a.s.l, 4127’N 4348’E) is the largest lake of Georgia (37.5 km2, 2-3 m depth). The lake has a high
potential to reconstruct palaeoclimatic and palaeoenvironmental conditions in Caucasus that currently lack of long
continuous records.
The volcanic range (up to 3000 m, 400 to 10 ka in age) located in the western part of the lake was covered
by an ice cap (50-100 m) during the last two glacial periods as attested by the presence of numerous and well
preserved glacial morphology and associated deposits. For example, moraines are found all around the Paravani
Lake thus suggesting that the ice cap reached the lake level during the coldest events.
In 2009, a first sediment core was extracted from Paravani Lake. Ten radiocarbon dates show that the core
covers the last 13 ka period. The multi-proxy analysis performed on the sediments has allowed us to characterize
an original evolution of the vegetation in relation to the post-glacial climatic variations and the dynamic of the
Samsari-Djavakheti glaciers.
Mediterranean landscape evolution (southern Luberon, Vaucluse, France) from the last glacial period to the Holocene period is analysed through alluvial deposits and travertine system development linked to climate changes and human occupations. Results of geomorphological, sedimento-stratigraphical and physico-chemical analysis increased by archaeological and palaeoecological (malacology and anthracology) studies and about fifty 14C dating are the basement of a pluridisciplinary research on the links between Man and environment in Mediterranean France.
Around 50 Ky BP, numerous glacis formation, made up of torrential pebbles and reworked cryoclasts, covered the southern Luberon piedmont with frequently more than thirty meters thickness. At their bases several “red-soils” and their palaeontological content show the more temperate climate conditions of isotopic stage 3 interstadials in Mediterranean region.
Between the Last Glacial Maximum and the Lateglacial period (18-17 Ky cal. BP. ?), a major scale incision occurred with fastness. Since 15500 cal. BP, travertine and detrital deposits were developed. Inside this new morphogenetic tendency, travertine formations located downstream karstic re-emergence are indicative of the Postglacial warming. These carbonated deposits are the oldest testimony of the restarting of the southern France Postglacial travertine accumulation. Then, around 9000 cal. BP and 6000 cal. BP, two main incisions occurred in alternation with embankment phases. The morphogenic dynamic of the first part of postglacial period seems to be linked to the bioclimatic changes.
Since the Final Neolithic, in the context of growing human occupation, ruptures (incisions) in the travertine sequences have been recorded. These ruptures, of high frequency but low amplitude, were accompanied by facies changing and strong vegetation opening determined upon palaeoecological analysis. Travertine sensitivity in accordance with climato-anthropic biotope changes is underlined.
Between the XIth and the XIIIth century A.D., the decline and the dismantlement of the travertine formations became noticeable. In the same way, the major linear talweg incision (well known in southern France but poorly chronologically discerned until now) was introduced in a morphogenic dynamic only partly interrupted after the XVIIth century A.D., during the Little Ice Age, by a detrital deposit phases. Then a final incision has occurred and it’s still happening today. Combined effect of climatic oscillations and human society occupation modes above the “natural environment” seem to be the main driving force of a bustling morphogenesis during the second part of the Postglacial period.
Keywords: Luberon, Provence, morphogenesis, last Pleniglacial, Postglacial, travertine deposits, incisions, sedimentation rhythms, palaeoclimate, palaeoenvironment, human occupations.