- Email: [email protected]
Temporal corridors of migration in the Southern Caucasus during late Early Pleistocene
72
Abstracts / Quaternary International 279-280 (2012) 9–120
geomorphic position, local slope-derived inputs and recent land-use changes. It is argued that the ‘apparent’ variation in driving-factors inferred from different temporal perspectives is the inevitable result of the interaction of climate-driven sedimentation coupled with changing rates of sediment supply from the catchment. This floodplain and catchment behaviour has major implications for fixed structures on floodplains and the management of catchment erosion and sedimentation. CENOZOIC DUNE GASTROPODS OF THE SOUTH AFRICAN WEST COAST: IMPLICATIONS FOR CLIMATE CHANGE Claire Browning. Council for Geoscience, South Africa E-mail address: [email protected]
Fossilized terrestrial gastropods are widespread in the geological record and can be used in the identification and delineation of Cenozoic geological formations in South Africa. They may also be used to determine the environmental conditions at the time of death. Both the species composition and the stable isotopes are employed in this regard. Some species, for example Trigonephrus globulus, are temporally distributed from the Miocene to the present. Individuals of this species vary greatly in size over time, with fossil examples from certain horizons being twice the size of present day specimens. The present distribution of T. globulus is along the West Coast of South Africa within the Mediterranean, winter rainfall climatic regime. The climate along the South African coastline is sensitive and diverse and climatic fluctuations would have played a role in the distribution and size of gastropods within the dune system. Dune snails are thus good potential palaeo-environmental indicators. Oxygen isotope analysis of both fossil material and host lithologies will be done in order to elucidate palaeoclimatic information. Seasonal growth rings of calcareous shell material will also be sampled in order for high resolution climatic data to potentially be obtained. Comparisons with other gastropod fossils within different climatic regimes along the South African coastline could be drawn, i.e. Acatina zebra along the south-eastern coast. A better understanding of dune gastropods as indicators of palaeoclimates along the West Coast will add to our ability to understand and properly map the Quaternary deposits of South Africa as well as contribute to our understanding of global climate change. QUANTIFYING EARLY PLEISTOCENE CLIMATE AND ENVIRONMENTAL CHANGE IN ARMENIA
QUANTIFYING PALAEOCLIMATE FROM SOUTH AFRICAN MSA SITES – PRELIMINARY RESULTS USING PLANT FOSSILS FROM SIBUDU CAVE, KWAZULU-NATAL, SOUTH AFRICA Angela A. Bruch. ROCEEH Research Centre at Senckenberg, Germany E-mail address: [email protected]
The isolated geographical situation of South Africa makes the unraveling of various parameters that influence its regional climate in time challenging. If the South African climate does not exhibit a linear correlation with global archives as suggested by some authors then the contribution of independent local data that provides direct information on the environment at a certain place and time is crucial. Fossil plant remains provide valuable information on past environmental conditions. Although few paleobotanical data are available from Southern Africa, some sites reveal rich and diverse fossil floras, most notably, Sibudu Cave, KwaZulu-Natal, South Africa, with its numerous fruits, seeds, pollen and charcoal flora. Such plant remains not only provide information on past vegetation, but also serve as a sound base for paleoclimate quantification with the Coexistence Approach (CA). Sibudu Cave has pulses of Middle Stone Age occupation separated by hiatuses that are as long as 10 ka. Pre-Still Bay, Still Bay, Howiesons Poort, post-Howiesons Poort and late and final Middle Stone Age industries are present. Variations in vegetation and the animals preyed on through time suggest that subtle environmental changes could have occurred during MIS4 and MIS3 in the Sibudu area. Whilst always semiforested, the region may have comprised a mosaic of uneven and changeable patches of coastal forest and savanna. These in turn might have influenced the numbers of forest versus plains animals in the area. Cultural factors could also have played a part in the faunal variability observed in Sibudu. Preliminary analyses of Sibudu Cave material confirm the potential of the CA for its application on Late Pleistocene African floras. In the future, comparison with other contemporaneous sites will help quantify spatial differences in the climate of the Late Pleistocene in South Africa, and may answer if environmental changes effected the cultural development from Still Bay to late MSA industries. TEMPORAL CORRIDORS OF MIGRATION IN THE SOUTHERN CAUCASUS DURING LATE EARLY PLEISTOCENE Angela A. Bruch. ROCEEH Research Centre at Senckenberg, Germany E-mail address: [email protected]
Angela A. Bruch. ROCEEH Research Centre at Senckenberg, Germany E-mail address: [email protected]
Armenia is situated in the Lesser Caucasus, between the marine climate to the west, influenced by the Atlantic Ocean circulation, and the today well established continental climate to the east, this area is of crucial interest for understanding the global climate system and its influence on vegetation and landscape evolution. Moreover, the Caucasus is the oldest area of human occupation in Eurasia. For the reconstruction of Early Pleistocene landscape evolution in the Caucasus the Vorotan basin proved to be a rich area for palaeobotanical and palaeontological studies. There, lake sediments form huge diatomitic sequences that are perfectly suitable for palaeoenvironmental studies. The highly precise age control of the sites studied so far is based on palaeomagnetic and Ar/Ar dating and enables us to reconstruct the environmental history of the Early Pleistocene between 1.15 and 0.95 Ma. The sedimentation rate for the diatomite is estimated to be about 20-30 cm per 1000 years, which allows for a resolution of about 250 years per sample. The profiles show a rich and diverse flora and entomofauna. Some parts of the sequences studied in high resolution show clear cyclicity which can be correlated to global climate cycles. The prominent warm phase MIS 31 at 1.07 Ma is well pronounced in the pollen and macroflora record and linked with a major expansion of the forest belt. This time of wide spread forest cover lasted for approximately 10 000 years in southern Armenia. This rich leaf assemblage was the basis of a quantitative climatic analysis based on the Coexistence Approach showing about 4 C warmer values than today. Before and afterwards vegetation was dominated by semi-arid steppes and montane meadows, very much similar to today.
During the Early Pleistocene obliquity forced glacial/interglacial cycles caused cyclic vegetation successions in Europe, which however were not always similarly developed and superimposed by a general cooling trend. Complicated furthermore by regional climate differentiations, those cycles may have provided several narrow windows of opportunity for hominins to disperse from Africa into Eurasia. The Southern Caucasus is the oldest area of human occupation in Eurasia, proven by the finding of Homo georgicus in Georgia with an age of 1.8 Ma. Also, in Armenia there are numerous Palaeolithic sites which occur in the vicinity to lacustral sediments giving evidence of a fast changing setting of environments. To define temporal windows of human expansion in or through the area of the Southern Caucasus, lake sediments from Vorotan Basin, Southern Armenia, were studied which are perfectly suitable for palaeoenvironmental studies as they are yielding various fossil remains. These fossils can give valuable information about the flora and fauna of the period, but also about climate, vegetation and lake history. The highly precise age control of the sites is based on palaeomagnetic and Ar/Ar dating and enables us to reconstruct the environmental history of the Early Pleistocene between 1.15 and 0.95 Ma. The high-resolution pollen sequences from Vorotan Basin show clear cyclicity which can be correlated to global climate cycles. The prominent warm phase MIS 31 at 1.07 Ma is well pronounced in the pollen and macroflora record and linked with a major expansion of the forest belt and a diverse mosaic landscape providing a high variety of habitats and resources to early humans. Distinct differences between vegetation development during the two interglacial stages MIS 33 and MIS 31 can be
Abstracts / Quaternary International 279-280 (2012) 9–120
used to define a climatic threshold for the development of habitats suitable to early humans in the Armenian highlands. MAMMALIAN COMMUNITIES AND HUMAN SETTLEMENTS IN THE NORTH-EASTERN AQUITAINE (FRANCE) DURING THE LATE PLEISTOCENE
73
diapirs. During less arid periods, vegetation cover protected the diapir surfaces. After the onset of an arid climate, the erosion rapidly accelerated thanks to vegetation degradation and consequent changes in the surficial deposits type and thickness. JEBEL DUWI AMD SODMEIN CAVE, EASTERN DESERT OF EGYPT: LATE PLEISTOCENE ENVIRONMENT AND HUMAN MIGRATION
Jean-Philip Brugal. CNRS UMR 6636, France E-mail address: [email protected]
Olaf Bubenzer. Heidelberg University, Germany E-mail address: [email protected]
The northeastern zone of the Aquitaine Bassin is bounded by the Massif Central and main rivers/valleys as Dordogne, Lot and Aveyron, tributaries of the river Garonne. It is essentially formed by limestone plateaux which are propitious to karstic development (caves, rockshelter, and pitfall) centred on the Quercy and Perigord regions. In this auspicious context, they yield very rich and well-dated archaeological and paleontological records. The former show a high density of human sites (with different occupations: short-term to more permanent camp, and even parietal caves) which document the presence of prehistoric groups more or less continuously for the whole late Pleistocene; from the last occurrences of Middle Palaeolithic groups until varied cultural complexes of Upper Palaeolithic. The latter is expressed by rich and diversified bone accumulations often found in pitfalls occurring through the late Pleistocene and coming from natural trapping processes of herbivore herds as well as carnivore dens. An overview is presented between these two faunal records and a global synthesis allows to precise the structure of bioceonosis and the components and succession of mammalian associations through times and climatic phases. Moreover, it depicts the density and stability of animal communities with frequent and rare taxa. Then it becomes interesting to compare faunal spectra coming both from natural versus anthropic origin which can in turn precise the human resources choices and their degree of exploitation, as well as the relation preypredators or the degree of competition between large social meat-eaters which seems to decrease especially in the middle of Late Palaeolithic. [Projects mainly funded by Min.of Culture : ACR 2002-2004 “Cultures et environnements Paléolithique : mobilités et gestions des territoires des chasseurs-cueilleurs en Quercy » (dir.M.Jarry) & PCR 2008-2010 « Accumulations accidentelles de faunes en contexte karstique » (dir.M.P.Coumont)] CAN INCREASE IN ARIDITY TRIGGER RAPID SURFACE EROSION OF DIAPIR SURFACES AND INTENSIFY THE BRINE FLOW IN SEMIARID CLIMATE? (ZAGROS MOUNTAINS, IRAN)
The poster presents results of the project ‘Out of Africa – Late Pleistocene Rock Shelter Stratigraphies and Palaeoenvironments in Northeast Africa’ as part of the German Collaborative Research Centre 806 ‘Our Way to Europe: Culture-Environment Interaction and Human Mobility in the Late Quaternary’ (www.sfb806.de) that started in the year 2009. The primary movement of modern humans out of Africa must have occurred before 90 000 years ago, as the earliest modern human remains outside Africa have been found in the Levant and date to 90 000 years ago. The ‘Northern Dispersal Route’ through Egypt to the Levant has been identified a likely route Out of Africa and is the focus of our research project. It is thought that the habitat expansion that accompanied the interglacial period of MIS 5e relaxed ecological constraints to such a degree that the movement of modern humans through the Eastern Desert of Egypt towards the North became feasible. However, except for some marine records (Red Sea, Arabian Sea) and a few sites in the Western Desert, there is a lack of precise terrestrial dating evidence and scant information about regional climatic changes. Living sites in this time range are rare, but close to Quseir in the Eastern Desert, such a site, occurs. Sodmein Cave, located in the northern part of Jebel Duwi, preserves stratified deposit of more than 4 metres dating to the Late Pleistocene. The lowermost levels are associated with the Nubian complex and have been dated by thermoluminescence to 118 8 ka in the 1990teens by a Belgium team (Moeyersons, Vermeersch and Van Peer). By integrating geo-archives and archaeo-archives, based on new data (e.g. radiocarbon and OSL ages and analyses of digital elevation models) the poster presents new results to examine to what extent the dispersal processes in the Late Pleistocene was influenced by the environmental and climatic conditions. SANDS AS ARCHIVES OF ENVIRONMENTAL CHANGE IN DRYLANDS: EXAMPLES FROM EGYPT, SUDAN AND NAMIBIA Olaf Bubenzer. Heidelberg University, Germany
Jiri Bruthans. Charles University in Prague, Czech Republic
E-mail address: [email protected]
E-mail address: [email protected]
Zagros Mts. host numerous salt diapirs, which differs in uplift rate and relief. Some diapirs are exposed to arid conditions; some are situated in higher altitude in less arid climate. Few diapirs are formed by vast surfaces build predominately by halite, at others, the rock salt is covered by up to 30 m thick surficial residuum, which even enable planting of crops thanks to recharge concentration at sinkholes bottoms. Variability of environments enabled us to study the relationships and feedbacks between climate, surficial deposits and vegetation cover. Erosion rates were measured for a period up to 10 years by plastic pegs as benchmarks. Recorded data were standardized to a horizontal surface. Amount of dissolved salt was also measured at basin scale. Salt exposures are eroded at rate 30-120 mm/year, while thick surficial deposits covered by vegetation shows negligible erosion. Salt exposures produce huge amounts of dissolved and clastic load, thus affecting the land use in vast surrounding of the diapirs. Based on field observation, most of the rainwater will infiltrate, while overland flow predominates on rock salt exposures. As most of the water evaporates from vegetated surfaces the amount of high TDS waters generated by percolation in underlying rock salt is very low. This enable to distinguish (based on aerial imaginary) the alluvial fans in diapir surroundings, which will be likely heavily polluted by brines from those potentially interesting for groundwater abstraction. Radiocarbon and U-series dating of calcretes capping some diapir surfaces indicates that diapirs reached largest extent during the Last Glacial. Since then, the original thick surficial deposits are undergoing erosion on many
Large parts of the arid zone lack clearly stratified sediment bodies with organic material. Therefore, the reconstruction of environmental changes is often a challenge. However, widely distributed sands can provide such geo-archives if they are examined interdisciplinary by different methods (geomorphology, sedimentology, chronology) and at different spatial and temporal scales. In combination with the archaeological findings, sands can also be used to reconstruct man-environment interactions. The poster presents examples of investigations from Egypt, Sudan and Namibia. The example from Egypt shows how a shallow playa can be reconstructed by sedimentological analysis of the surrounding (mega)dune sands. Its former existence is corroborated by near-by prehistoric sites. The example from Sudan studies an artefact-stabilized parabolic or blow-out dune. Its formation from a barchan dune and the environmental change involved can be deduced from sedimentological and archaeological analysis combined with luminescence and radiocarbon dating. The example from Namibia focuses particularly on the synthesis of methods at different scales: from the macro-scale approach of remote sensing via the mesoscale approach of field measurements and sampling to the micro-scale approach in granular sedimentology. HOLOCENE INSECT RECORDS FROM THREE ALPINE LAKES IN THE ABISKO AREA, NORTHERN SWEDEN – IMPLICATIONS FOR CLIMATE AND ECOSYSTEM CHANGES Philip Buckland. Umeå University, Sweden E-mail address: [email protected]
Abstracts / Quaternary International 279-280 (2012) 9–120
geomorphic position, local slope-derived inputs and recent land-use changes. It is argued that the ‘apparent’ variation in driving-factors inferred from different temporal perspectives is the inevitable result of the interaction of climate-driven sedimentation coupled with changing rates of sediment supply from the catchment. This floodplain and catchment behaviour has major implications for fixed structures on floodplains and the management of catchment erosion and sedimentation. CENOZOIC DUNE GASTROPODS OF THE SOUTH AFRICAN WEST COAST: IMPLICATIONS FOR CLIMATE CHANGE Claire Browning. Council for Geoscience, South Africa E-mail address: [email protected]
Fossilized terrestrial gastropods are widespread in the geological record and can be used in the identification and delineation of Cenozoic geological formations in South Africa. They may also be used to determine the environmental conditions at the time of death. Both the species composition and the stable isotopes are employed in this regard. Some species, for example Trigonephrus globulus, are temporally distributed from the Miocene to the present. Individuals of this species vary greatly in size over time, with fossil examples from certain horizons being twice the size of present day specimens. The present distribution of T. globulus is along the West Coast of South Africa within the Mediterranean, winter rainfall climatic regime. The climate along the South African coastline is sensitive and diverse and climatic fluctuations would have played a role in the distribution and size of gastropods within the dune system. Dune snails are thus good potential palaeo-environmental indicators. Oxygen isotope analysis of both fossil material and host lithologies will be done in order to elucidate palaeoclimatic information. Seasonal growth rings of calcareous shell material will also be sampled in order for high resolution climatic data to potentially be obtained. Comparisons with other gastropod fossils within different climatic regimes along the South African coastline could be drawn, i.e. Acatina zebra along the south-eastern coast. A better understanding of dune gastropods as indicators of palaeoclimates along the West Coast will add to our ability to understand and properly map the Quaternary deposits of South Africa as well as contribute to our understanding of global climate change. QUANTIFYING EARLY PLEISTOCENE CLIMATE AND ENVIRONMENTAL CHANGE IN ARMENIA
QUANTIFYING PALAEOCLIMATE FROM SOUTH AFRICAN MSA SITES – PRELIMINARY RESULTS USING PLANT FOSSILS FROM SIBUDU CAVE, KWAZULU-NATAL, SOUTH AFRICA Angela A. Bruch. ROCEEH Research Centre at Senckenberg, Germany E-mail address: [email protected]
The isolated geographical situation of South Africa makes the unraveling of various parameters that influence its regional climate in time challenging. If the South African climate does not exhibit a linear correlation with global archives as suggested by some authors then the contribution of independent local data that provides direct information on the environment at a certain place and time is crucial. Fossil plant remains provide valuable information on past environmental conditions. Although few paleobotanical data are available from Southern Africa, some sites reveal rich and diverse fossil floras, most notably, Sibudu Cave, KwaZulu-Natal, South Africa, with its numerous fruits, seeds, pollen and charcoal flora. Such plant remains not only provide information on past vegetation, but also serve as a sound base for paleoclimate quantification with the Coexistence Approach (CA). Sibudu Cave has pulses of Middle Stone Age occupation separated by hiatuses that are as long as 10 ka. Pre-Still Bay, Still Bay, Howiesons Poort, post-Howiesons Poort and late and final Middle Stone Age industries are present. Variations in vegetation and the animals preyed on through time suggest that subtle environmental changes could have occurred during MIS4 and MIS3 in the Sibudu area. Whilst always semiforested, the region may have comprised a mosaic of uneven and changeable patches of coastal forest and savanna. These in turn might have influenced the numbers of forest versus plains animals in the area. Cultural factors could also have played a part in the faunal variability observed in Sibudu. Preliminary analyses of Sibudu Cave material confirm the potential of the CA for its application on Late Pleistocene African floras. In the future, comparison with other contemporaneous sites will help quantify spatial differences in the climate of the Late Pleistocene in South Africa, and may answer if environmental changes effected the cultural development from Still Bay to late MSA industries. TEMPORAL CORRIDORS OF MIGRATION IN THE SOUTHERN CAUCASUS DURING LATE EARLY PLEISTOCENE Angela A. Bruch. ROCEEH Research Centre at Senckenberg, Germany E-mail address: [email protected]
Angela A. Bruch. ROCEEH Research Centre at Senckenberg, Germany E-mail address: [email protected]
Armenia is situated in the Lesser Caucasus, between the marine climate to the west, influenced by the Atlantic Ocean circulation, and the today well established continental climate to the east, this area is of crucial interest for understanding the global climate system and its influence on vegetation and landscape evolution. Moreover, the Caucasus is the oldest area of human occupation in Eurasia. For the reconstruction of Early Pleistocene landscape evolution in the Caucasus the Vorotan basin proved to be a rich area for palaeobotanical and palaeontological studies. There, lake sediments form huge diatomitic sequences that are perfectly suitable for palaeoenvironmental studies. The highly precise age control of the sites studied so far is based on palaeomagnetic and Ar/Ar dating and enables us to reconstruct the environmental history of the Early Pleistocene between 1.15 and 0.95 Ma. The sedimentation rate for the diatomite is estimated to be about 20-30 cm per 1000 years, which allows for a resolution of about 250 years per sample. The profiles show a rich and diverse flora and entomofauna. Some parts of the sequences studied in high resolution show clear cyclicity which can be correlated to global climate cycles. The prominent warm phase MIS 31 at 1.07 Ma is well pronounced in the pollen and macroflora record and linked with a major expansion of the forest belt. This time of wide spread forest cover lasted for approximately 10 000 years in southern Armenia. This rich leaf assemblage was the basis of a quantitative climatic analysis based on the Coexistence Approach showing about 4 C warmer values than today. Before and afterwards vegetation was dominated by semi-arid steppes and montane meadows, very much similar to today.
During the Early Pleistocene obliquity forced glacial/interglacial cycles caused cyclic vegetation successions in Europe, which however were not always similarly developed and superimposed by a general cooling trend. Complicated furthermore by regional climate differentiations, those cycles may have provided several narrow windows of opportunity for hominins to disperse from Africa into Eurasia. The Southern Caucasus is the oldest area of human occupation in Eurasia, proven by the finding of Homo georgicus in Georgia with an age of 1.8 Ma. Also, in Armenia there are numerous Palaeolithic sites which occur in the vicinity to lacustral sediments giving evidence of a fast changing setting of environments. To define temporal windows of human expansion in or through the area of the Southern Caucasus, lake sediments from Vorotan Basin, Southern Armenia, were studied which are perfectly suitable for palaeoenvironmental studies as they are yielding various fossil remains. These fossils can give valuable information about the flora and fauna of the period, but also about climate, vegetation and lake history. The highly precise age control of the sites is based on palaeomagnetic and Ar/Ar dating and enables us to reconstruct the environmental history of the Early Pleistocene between 1.15 and 0.95 Ma. The high-resolution pollen sequences from Vorotan Basin show clear cyclicity which can be correlated to global climate cycles. The prominent warm phase MIS 31 at 1.07 Ma is well pronounced in the pollen and macroflora record and linked with a major expansion of the forest belt and a diverse mosaic landscape providing a high variety of habitats and resources to early humans. Distinct differences between vegetation development during the two interglacial stages MIS 33 and MIS 31 can be
Abstracts / Quaternary International 279-280 (2012) 9–120
used to define a climatic threshold for the development of habitats suitable to early humans in the Armenian highlands. MAMMALIAN COMMUNITIES AND HUMAN SETTLEMENTS IN THE NORTH-EASTERN AQUITAINE (FRANCE) DURING THE LATE PLEISTOCENE
73
diapirs. During less arid periods, vegetation cover protected the diapir surfaces. After the onset of an arid climate, the erosion rapidly accelerated thanks to vegetation degradation and consequent changes in the surficial deposits type and thickness. JEBEL DUWI AMD SODMEIN CAVE, EASTERN DESERT OF EGYPT: LATE PLEISTOCENE ENVIRONMENT AND HUMAN MIGRATION
Jean-Philip Brugal. CNRS UMR 6636, France E-mail address: [email protected]
Olaf Bubenzer. Heidelberg University, Germany E-mail address: [email protected]
The northeastern zone of the Aquitaine Bassin is bounded by the Massif Central and main rivers/valleys as Dordogne, Lot and Aveyron, tributaries of the river Garonne. It is essentially formed by limestone plateaux which are propitious to karstic development (caves, rockshelter, and pitfall) centred on the Quercy and Perigord regions. In this auspicious context, they yield very rich and well-dated archaeological and paleontological records. The former show a high density of human sites (with different occupations: short-term to more permanent camp, and even parietal caves) which document the presence of prehistoric groups more or less continuously for the whole late Pleistocene; from the last occurrences of Middle Palaeolithic groups until varied cultural complexes of Upper Palaeolithic. The latter is expressed by rich and diversified bone accumulations often found in pitfalls occurring through the late Pleistocene and coming from natural trapping processes of herbivore herds as well as carnivore dens. An overview is presented between these two faunal records and a global synthesis allows to precise the structure of bioceonosis and the components and succession of mammalian associations through times and climatic phases. Moreover, it depicts the density and stability of animal communities with frequent and rare taxa. Then it becomes interesting to compare faunal spectra coming both from natural versus anthropic origin which can in turn precise the human resources choices and their degree of exploitation, as well as the relation preypredators or the degree of competition between large social meat-eaters which seems to decrease especially in the middle of Late Palaeolithic. [Projects mainly funded by Min.of Culture : ACR 2002-2004 “Cultures et environnements Paléolithique : mobilités et gestions des territoires des chasseurs-cueilleurs en Quercy » (dir.M.Jarry) & PCR 2008-2010 « Accumulations accidentelles de faunes en contexte karstique » (dir.M.P.Coumont)] CAN INCREASE IN ARIDITY TRIGGER RAPID SURFACE EROSION OF DIAPIR SURFACES AND INTENSIFY THE BRINE FLOW IN SEMIARID CLIMATE? (ZAGROS MOUNTAINS, IRAN)
The poster presents results of the project ‘Out of Africa – Late Pleistocene Rock Shelter Stratigraphies and Palaeoenvironments in Northeast Africa’ as part of the German Collaborative Research Centre 806 ‘Our Way to Europe: Culture-Environment Interaction and Human Mobility in the Late Quaternary’ (www.sfb806.de) that started in the year 2009. The primary movement of modern humans out of Africa must have occurred before 90 000 years ago, as the earliest modern human remains outside Africa have been found in the Levant and date to 90 000 years ago. The ‘Northern Dispersal Route’ through Egypt to the Levant has been identified a likely route Out of Africa and is the focus of our research project. It is thought that the habitat expansion that accompanied the interglacial period of MIS 5e relaxed ecological constraints to such a degree that the movement of modern humans through the Eastern Desert of Egypt towards the North became feasible. However, except for some marine records (Red Sea, Arabian Sea) and a few sites in the Western Desert, there is a lack of precise terrestrial dating evidence and scant information about regional climatic changes. Living sites in this time range are rare, but close to Quseir in the Eastern Desert, such a site, occurs. Sodmein Cave, located in the northern part of Jebel Duwi, preserves stratified deposit of more than 4 metres dating to the Late Pleistocene. The lowermost levels are associated with the Nubian complex and have been dated by thermoluminescence to 118 8 ka in the 1990teens by a Belgium team (Moeyersons, Vermeersch and Van Peer). By integrating geo-archives and archaeo-archives, based on new data (e.g. radiocarbon and OSL ages and analyses of digital elevation models) the poster presents new results to examine to what extent the dispersal processes in the Late Pleistocene was influenced by the environmental and climatic conditions. SANDS AS ARCHIVES OF ENVIRONMENTAL CHANGE IN DRYLANDS: EXAMPLES FROM EGYPT, SUDAN AND NAMIBIA Olaf Bubenzer. Heidelberg University, Germany
Jiri Bruthans. Charles University in Prague, Czech Republic
E-mail address: [email protected]
E-mail address: [email protected]
Zagros Mts. host numerous salt diapirs, which differs in uplift rate and relief. Some diapirs are exposed to arid conditions; some are situated in higher altitude in less arid climate. Few diapirs are formed by vast surfaces build predominately by halite, at others, the rock salt is covered by up to 30 m thick surficial residuum, which even enable planting of crops thanks to recharge concentration at sinkholes bottoms. Variability of environments enabled us to study the relationships and feedbacks between climate, surficial deposits and vegetation cover. Erosion rates were measured for a period up to 10 years by plastic pegs as benchmarks. Recorded data were standardized to a horizontal surface. Amount of dissolved salt was also measured at basin scale. Salt exposures are eroded at rate 30-120 mm/year, while thick surficial deposits covered by vegetation shows negligible erosion. Salt exposures produce huge amounts of dissolved and clastic load, thus affecting the land use in vast surrounding of the diapirs. Based on field observation, most of the rainwater will infiltrate, while overland flow predominates on rock salt exposures. As most of the water evaporates from vegetated surfaces the amount of high TDS waters generated by percolation in underlying rock salt is very low. This enable to distinguish (based on aerial imaginary) the alluvial fans in diapir surroundings, which will be likely heavily polluted by brines from those potentially interesting for groundwater abstraction. Radiocarbon and U-series dating of calcretes capping some diapir surfaces indicates that diapirs reached largest extent during the Last Glacial. Since then, the original thick surficial deposits are undergoing erosion on many
Large parts of the arid zone lack clearly stratified sediment bodies with organic material. Therefore, the reconstruction of environmental changes is often a challenge. However, widely distributed sands can provide such geo-archives if they are examined interdisciplinary by different methods (geomorphology, sedimentology, chronology) and at different spatial and temporal scales. In combination with the archaeological findings, sands can also be used to reconstruct man-environment interactions. The poster presents examples of investigations from Egypt, Sudan and Namibia. The example from Egypt shows how a shallow playa can be reconstructed by sedimentological analysis of the surrounding (mega)dune sands. Its former existence is corroborated by near-by prehistoric sites. The example from Sudan studies an artefact-stabilized parabolic or blow-out dune. Its formation from a barchan dune and the environmental change involved can be deduced from sedimentological and archaeological analysis combined with luminescence and radiocarbon dating. The example from Namibia focuses particularly on the synthesis of methods at different scales: from the macro-scale approach of remote sensing via the mesoscale approach of field measurements and sampling to the micro-scale approach in granular sedimentology. HOLOCENE INSECT RECORDS FROM THREE ALPINE LAKES IN THE ABISKO AREA, NORTHERN SWEDEN – IMPLICATIONS FOR CLIMATE AND ECOSYSTEM CHANGES Philip Buckland. Umeå University, Sweden E-mail address: [email protected]