c2fa54213c58c9e8fef27e960eb38a75
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The Marmara region (Western Turkey) is expected to have included one of the principal pathways in the transcontinental dispersal of modern humans from the Near East to the Balkans. Lake Íznik is located in the east of the Marmara Sea, adjacent to the North Anatolian Fault and holds a continuous sediment record. We recovered continuous sediment cores (max 14m) from Lake Íznik in 2005 and 2009. We are now able to reconstruct the environmental history and climate pattern on local and regional scale during the reestablishment of human habitats at the end of the MIS 3 and the dispersal of Neolithic economy (15,000-7,000 a BP). First results of our sedimentological and geochemical analyses suggest a cyclic ( 700 years) precipitation pattern with increased terrigenous input in contrary to in-lake carbonate production. Despite these results, records of biological indicators (Cladocera and Ostracoda) show little or no response to environmental changes during the last 35,000 years. But intensive changes of land use in the northern farmlands of Lake Íznik, starting around 1950 are synchronously detected by sedimentological, geochem- ical and biological proxies in the sediment record. From 1950 to 1990, woodland was converted to farmland and a more intense farming began. Together with high sedimentation rates more weathered materials were eroded and transported into the lake bassin (K/Na Ratios and Mn concentration). The fossil monospecific ostracod fauna (Limnocythere- association) was replaced by a Candona- association during this short period. Our project is integrated in the Collaborative Research Center (CRC) 806: “Our Way to Europe - Culture-Environment Interaction and Human Mobility in the Late Quaternary” ESTABLISHING A HOLOCENE SEDIMENT BUDGET FOR A SMALL RIVER CATCHMENT IN WESTERN FRANCE Vincent Viel. Caen Basse-Normandie, France E-mail address: [email protected] Geomorphological and paleoenvironmental research on Holocene sedi- mentation in Western France provide evidence for long term fluvial system changes. In order to precise the rate of erosion and subsequent sedimen- tation in the valley bottom and the processes of sediment transfer, we have developed a quantitative approach. An Holocene sediment budget based on field data was constructed for the Seulles catchment (430 Km 2 , Nor- mandy) located at the junction between 2 morphological contexts (Armorican massif, sedimentary Paris Basin). Data from 39 cores and hand auger cross-sections, regularly placed along the valley bottom, were used to quantify alluvial storage. In total, 38 AMS radiocarbon dating on organic samples from core drillings were used to define the chronostratigraphy of the alluvial filling. Slope erosion and deposition was determined using 230 soil profiles descriptions from auger coring transects within two small catchments and extrapolated to the entire river basin according to a soil erosion model. Soil profile description stresses the importance of slope erosion and colluvial and alluvial deposits testify the migration of eroded sediments into the valley bottom. Comparison between the Seulles floodplain and its main tributary highlight the role of the geological context in the variation of the sedimentation rate. Nevertheless, valley bottoms are finally filled by silty deposits (overbank and colluvial material). Available radiocarbon datings on the last organic deposit date the onset of silty deposits and the increase of sedimentation rate in between 800 BC and 500 AD. The causes of this widespread change are discussed with the available archaeological and palaeonvironmental data. It stresses the main role of the land use and subsequent connectivity changes within the river basin but the role of a wet oscillation registered by numerous fluvial systems in the Paris basin is also evocated. A COMBINED NUMERICAL MODELLING AND MAPPING APPROACH TO THE RECONSTRUCTING OF YOUNGER DRYAS STADIAL GLACIERS IN THE SOUTH-WEST ENGLISH LAKE DISTRICT Andreas Vieli. University of Durham, United Kingdom E-mail address: [email protected] Glacial geomorphological records have been widely used to reconstruct the palaeo-climatic conditions during the Younger Dryas Stadial in the British Isles. However, all such studies are based on a non-dynamic approach using a static glacier surface and extent along with some simple rules on glacier flow and mass balance. We use a dynamic 2-dimensional numerical glacier model forced by changes in ELA and we apply it to the South-West English Lake District area. The modelling is compared with extensive glacial geomorphological mapping of the area and shows good agreement with mapped glacier extents. Unlike previous reconstructions, the modelling suggests that the majority of the mapped moraines may have been produced during the Younger Dryas Stadial as a result of climatic fluctuations. Furthermore, modelled maximum positions in glacier extent are not synchronous in time as a result of different geometric settings and consequently response times. Our modelling therefore puts an alternative perspective into the interpretation of glacial geomorphology in the South- West English Lake District and questions the traditional approach of assuming static glaciers at steady state conditions. NEW DATA FOR THE CHARACTERIZATION OF MEDITERRANEAN UPPER MAGDALENIAN: THE CENDRES CAVE (TEULADA-MORAIRA, VALENCIAN COUNTRY) Valentin Villaverde. Universitat de València, Spain E-mail address: [email protected] The excavations carried out in Cendres cave since 1995 have documented a long sequence of Upper Palaeolithic. These levels end with an important occupation during the Upper Magdalenian (levels IX and XI). Several radiocarbon dates obtained in the last years, have allowed us to limit the main occupation during the Upper Magdalenian between ca. 13400-13100 BP (16000-15400 cal. BP). In this level, we have recovered a large amount of materials, both industrial as economic and ornamental. The recovered remains provide some new data for the Mediterranean Upper Magdalenian, as the high presence of hipermicrolithic backed points (some of 6-7 mm). We have also recovered a large number of bone and antler industries, with an special abundance of harpoons and needles. Among the faunal remains, there is a significant amount of processed rabbit remains, while the deer is dominant in the good-sized mammals. Thus, the data from Cendres cave will serve us to expose the latest data about the Mediterranean Upper Magdalenian in Valencian Country. VEGETATION, CLIMATE, AND FIRE HISTORY OF THE PÁRAMO OF JIMBURA, SOUTHERN ECUADOR Andrea Villota. Department of Palynology and Climate Dynamics, Geo, Germany E-mail address: [email protected] The last 15,000 years of vegetation, fire and climate history were recon- structed from a core which was derived from a peat bog in the Páramo of Jimbura in the Cordillera Real of south Ecuador. Situated in the Andean depression, this Páramo is positioned at an altitude of only 3,600 m. Climatic influences from the northern Andes, as well as from the dry forest region of Tumbes in north Peru and the Amazon basin give this region its unique character.During the Late Pleistocene (ca. 15,000 - 12,000 years BP) a gradual shift of the forest line is indicated by rising percentages of upper mountain forest taxa. It was most probably caused by an increase in temperature during that period, which induced a retreat of glaciers, thus allowing montane forest expansion. In the early Holocene (ca. 12,000 – 4,800 years BP) higher percentages of Podocarpaceae, Polylepis/Acaena type and Hedyosmum are registered. This suggests that the upper forest line reached even greater heights than at present. Hence, páramo vege- tation was limited to elevations above 3,300–3,500 m, therewith indi- cating a much warmer and wetter climate. The Late Holocene, from 4,800 years BP until the present, is characterized by higher percentages of pár- amo taxa such as Poaceae and Cyperaceae. During this period, the upper forest line decreased, giving way to the current location of the páramo. A NEW DEEP ICE CORE IN THE NORTHERN PATAGONIAN ICEFIELD REVEALS A REGIONAL COOLING IN A WARMING WORLD Francoise Vimeux. LSCE-HSM, France E-mail address: [email protected] An increasing number of tropical and subtropical ice cores has been extracted along the Andes of South America. At polar latitudes, numerous Abstracts / Quaternary International 279-280 (2012) 462–565 521
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Abstracts / Quaternary International 279-280 (2012) 462–565 521
The Marmara region (Western Turkey) is expected to have included one ofthe principal pathways in the transcontinental dispersal of modernhumans from the Near East to the Balkans. Lake Íznik is located in the eastof the Marmara Sea, adjacent to the North Anatolian Fault and holdsa continuous sediment record. We recovered continuous sediment cores(max 14m) from Lake Íznik in 2005 and 2009. We are now able toreconstruct the environmental history and climate pattern on local andregional scale during the reestablishment of human habitats at the end ofthe MIS 3 and the dispersal of Neolithic economy (15,000-7,000 a BP). Firstresults of our sedimentological and geochemical analyses suggest a cyclic(�700 years) precipitation pattern with increased terrigenous input incontrary to in-lake carbonate production. Despite these results, records ofbiological indicators (Cladocera and Ostracoda) show little or no responseto environmental changes during the last 35,000 years. But intensivechanges of land use in the northern farmlands of Lake Íznik, startingaround 1950 are synchronously detected by sedimentological, geochem-ical and biological proxies in the sediment record. From 1950 to 1990,woodland was converted to farmland and a more intense farming began.Together with high sedimentation rates more weathered materials wereeroded and transported into the lake bassin (K/Na Ratios and Mnconcentration). The fossil monospecific ostracod fauna (Limnocythere-association) was replaced by a Candona- association during this shortperiod. Our project is integrated in the Collaborative Research Center (CRC)806: “Our Way to Europe - Culture-Environment Interaction and HumanMobility in the Late Quaternary”
ESTABLISHING A HOLOCENE SEDIMENT BUDGET FOR A SMALL RIVERCATCHMENT IN WESTERN FRANCE
Vincent Viel. Caen Basse-Normandie, FranceE-mail address: [email protected]
Geomorphological and paleoenvironmental research on Holocene sedi-mentation inWestern France provide evidence for long term fluvial systemchanges. In order to precise the rate of erosion and subsequent sedimen-tation in the valley bottom and the processes of sediment transfer, we havedeveloped a quantitative approach. An Holocene sediment budget basedon field data was constructed for the Seulles catchment (430 Km2, Nor-mandy) located at the junction between 2 morphological contexts(Armorican massif, sedimentary Paris Basin). Data from 39 cores and handauger cross-sections, regularly placed along the valley bottom, were usedto quantify alluvial storage. In total, 38 AMS radiocarbon dating on organicsamples from core drillings were used to define the chronostratigraphy ofthe alluvial filling. Slope erosion and depositionwas determined using 230soil profiles descriptions from auger coring transects within two smallcatchments and extrapolated to the entire river basin according to a soilerosion model.Soil profile description stresses the importance of slope erosion andcolluvial and alluvial deposits testify the migration of eroded sedimentsinto the valley bottom. Comparison between the Seulles floodplain and itsmain tributary highlight the role of the geological context in the variationof the sedimentation rate. Nevertheless, valley bottoms are finally filled bysilty deposits (overbank and colluvial material). Available radiocarbondatings on the last organic deposit date the onset of silty deposits and theincrease of sedimentation rate in between 800 BC and 500 AD. The causesof this widespread change are discussed with the available archaeologicaland palaeonvironmental data. It stresses the main role of the land use andsubsequent connectivity changes within the river basin but the role ofa wet oscillation registered by numerous fluvial systems in the Paris basinis also evocated.
A COMBINED NUMERICAL MODELLING AND MAPPING APPROACH TOTHE RECONSTRUCTING OF YOUNGER DRYAS STADIAL GLACIERS INTHE SOUTH-WEST ENGLISH LAKE DISTRICT
Andreas Vieli. University of Durham, United KingdomE-mail address: [email protected]
Glacial geomorphological records have been widely used to reconstructthe palaeo-climatic conditions during the Younger Dryas Stadial in theBritish Isles. However, all such studies are based on a non-dynamicapproach using a static glacier surface and extent along with some simple
rules on glacier flow and mass balance. We use a dynamic 2-dimensionalnumerical glacier model forced by changes in ELA and we apply it to theSouth-West English Lake District area. The modelling is compared withextensive glacial geomorphological mapping of the area and shows goodagreement with mapped glacier extents. Unlike previous reconstructions,the modelling suggests that the majority of the mapped moraines mayhave been produced during the Younger Dryas Stadial as a result of climaticfluctuations. Furthermore, modelled maximum positions in glacier extentare not synchronous in time as a result of different geometric settings andconsequently response times. Our modelling therefore puts an alternativeperspective into the interpretation of glacial geomorphology in the South-West English Lake District and questions the traditional approach ofassuming static glaciers at steady state conditions.
NEW DATA FOR THE CHARACTERIZATION OF MEDITERRANEAN UPPERMAGDALENIAN: THE CENDRES CAVE (TEULADA-MORAIRA, VALENCIANCOUNTRY)
Valentin Villaverde. Universitat de València, SpainE-mail address: [email protected]
The excavations carried out in Cendres cave since 1995 have documenteda long sequence of Upper Palaeolithic. These levels end with an importantoccupation during the Upper Magdalenian (levels IX and XI).Several radiocarbon dates obtained in the last years, have allowed us tolimit the main occupation during the Upper Magdalenian between ca.13400-13100 BP (16000-15400 cal. BP). In this level, we have recovereda large amount of materials, both industrial as economic and ornamental.The recovered remains provide some new data for the MediterraneanUpper Magdalenian, as the high presence of hipermicrolithic backedpoints (some of 6-7 mm). We have also recovered a large number of boneand antler industries, with an special abundance of harpoons and needles.Among the faunal remains, there is a significant amount of processedrabbit remains, while the deer is dominant in the good-sized mammals.Thus, the data from Cendres cave will serve us to expose the latest dataabout the Mediterranean Upper Magdalenian in Valencian Country.
VEGETATION, CLIMATE, AND FIRE HISTORY OF THE PÁRAMO OFJIMBURA, SOUTHERN ECUADOR
Andrea Villota. Department of Palynology and Climate Dynamics, Geo,GermanyE-mail address: [email protected]
The last 15,000 years of vegetation, fire and climate history were recon-structed from a core which was derived from a peat bog in the Páramo ofJimbura in the Cordillera Real of south Ecuador. Situated in the Andeandepression, this Páramo is positioned at an altitude of only 3,600 m.Climatic influences from the northern Andes, as well as from the dry forestregion of Tumbes in north Peru and the Amazon basin give this region itsunique character.During the Late Pleistocene (ca. 15,000 - 12,000 years BP)a gradual shift of the forest line is indicated by rising percentages of uppermountain forest taxa. It was most probably caused by an increase intemperature during that period, which induced a retreat of glaciers, thusallowing montane forest expansion. In the early Holocene (ca. 12,000 –
4,800 years BP) higher percentages of Podocarpaceae, Polylepis/Acaenatype and Hedyosmum are registered. This suggests that the upper forestline reached even greater heights than at present. Hence, páramo vege-tation was limited to elevations above 3,300–3,500 m, therewith indi-cating a much warmer and wetter climate. The Late Holocene, from 4,800years BP until the present, is characterized by higher percentages of pár-amo taxa such as Poaceae and Cyperaceae. During this period, the upperforest line decreased, giving way to the current location of the páramo.
A NEW DEEP ICE CORE IN THE NORTHERN PATAGONIAN ICEFIELDREVEALS A REGIONAL COOLING IN A WARMING WORLD
Francoise Vimeux. LSCE-HSM, FranceE-mail address: [email protected]
An increasing number of tropical and subtropical ice cores has beenextracted along the Andes of South America. At polar latitudes, numerous
