- Email: [email protected]
Isotopic investigations of climate and seasonality in Central Europe during the Upper Palaeolithic
Abstracts / Quaternary International 279-280 (2012) 462–565
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highly variable accumulation rates, erosion of the record, bioturbation obscuring signals and no apparent straight-forward relationship to other wind-speed/source proxies such as grain-size. Much of this variability stems from the likely large number of influences on accumulation rate, both at source and sink. Furthermore, the new datasets present new methodological challenges such as the synthesis of data from different luminescence techniques and use of the most appropriate method of calculating mass accumulation rates. These findings will be outlined and some of the newly emerging challenges to accurately constraining past dust fluxes discussed through examples from the Chinese and Serbian loess sequences.
signatures provide information about the average climate conditions, whereas intra-tooth oxygen isotope signatures provide information about seasonal climate variations. Bone collagen carbon and nitrogen isotope signatures provide information about the diets consumed by the animals and the ecosystem and environments in which they lived. The climate signatures recorded in the skeletal remains provide information about the local climate during the human occupation of the archaeological sites. Our results further the debate on whether or not cultural innovation observed in central Europe during the Upper Palaeolithic were a result of innovative problem-solving in the face of climatic and environmental stress.
CONSTRAINING THE PROVENANCE OF MU US DESERT (CHINA) SANDS USING U-PB DATING OF DETRITAL ZIRCONS AND HEAVY MINERAL ASSEMBLAGES
ABRUPT CLIMATE WARMING AND THE LATE UPPER PALAEOLITHIC RECOLONISATION OF NORTHWEST EUROPE Rhiannon Stevens. University of Cambridge, United Kingdom
Thomas Stevens. Royal Holloway, U of London, United Kingdom E-mail address: [email protected]
The ultimate origin of the sediments that comprise sandy deserts is central to understanding the formation of such systems. However, the sources of this sediment and their spatial and temporal variability is often unknown. The sands of the Mu Us Desert, located in the Ordos Basin in Northern China, have been hypothesised to be sourced from underlying Quaternary sands, and in turn from underlying Cretaceous aeolianite. However, there has neither been a direct quantitative test of this hypothesis, nor characterisation of variability in geochemical signatures in sediment across the basin or through time. Furthermore, the only provenance work conducted on the Mu Us sands has used bulk geochemical analysis, which is inherently limited when there is a possibility of multiple source regions. Here we present single-grain detrital zircon U-Pb dates and morphology as well as heavy mineral assemblages from modern Mu Us sediments across the desert and from underlying sand bearing strata of the Quaternary and Cretaceous. Detrital zircon UPb ages can often be tied to protosource areas with distinctive age signatures representing specific tectonic events associated with granitic emplacement, especially when tied to zircon morphology and heavy mineral assemblage. The results allow us to interpret variability in the source regions across the Mu Us today, as well as at intervals in the past, thereby testing specific hypotheses over the origin of the desert sands. The results show that there is significant source variability across the desert, with clear geographical groupings displaying common source characteristics. Underlying Cretaceous and Quaternary formations contribute some material but far travelled components are significant in some regions of the desert. These findings will be discussed in terms of interpreting detrital zircon data, as well as in terms of the climatic, erosional and transport process implications for the origin of the Mu Us sands.
ISOTOPIC INVESTIGATIONS OF CLIMATE AND SEASONALITY IN CENTRAL EUROPE DURING THE UPPER PALAEOLITHIC
E-mail address: [email protected]
There has been much speculation about the relationship between the rapid warming at start of the Late Glacial and the sudden dispersal of Madgalenian human groups into northwest Europe that broadly coincided with widespread cultural changes. Some researchers have suggested that the re-colonisation occurred prior to the climate warming. Thus nonclimatic factors, most probably social developments, enabled humans to adapt better to the prevailing cold conditions, and hence to re-migrate into the region prior to any significant improvement in climate. Others have suggested, that the warming observed in the Greenland ice-cores and the re-colonisation occurred synchronously. Therefore the abrupt climate change triggered an equally abrupt and widespread response in human development at that time. Recently published radiocarbon dates from the earliest re-colonisation sites in the British Isles suggest that the re-colonisation was broadly contemporaneous with the Late Glacial abrupt climate warming. However due to the imprecision in radiocarbon calibration models as a result of the radiocarbon plateau it is impossible to tell from radiocarbon dates alone whether or not the re-colonisation and the climate warming recorded in the Greenland icecores occurred synchronously. It is therefore necessary to develop palaeoclimatic reconstructions that are not only local to the archaeological sites in the British Isles, but are directly linked to the period of human activity. Through oxygen isotope analysis of horse teeth that have been humanly modified and thus are directly linked to human activity, we have reconstructed the climatic conditions at Gough's Cave, King Arthur's Cave, Mother Grundy's Parlour, Kent's Cavern and Sun Hole Cave during the period of human occupation. Our results suggest that the re-colonisation of the British Isles and the abrupt climate warming were not synchronous. The implications of our finding will be presented. COMPARISON OF THE VEGETATIONAL AND HYDROCLIMATIC EVOLUTION DURING THE HOLOCENE AND LAST INTERGLACIAL IN WESTERN IRAN Lora Stevens. California State University, United States E-mail address: [email protected]
Rhiannon Stevens. University of Cambridge, United Kingdom E-mail address: [email protected]
The Upper Palaeolithic in the central European Plains was a critical period in human evolution marked by technological developments in lithic industries, extensive production of figurative and non-figurative art, the increased use of non-local raw materials, and the earliest development of ceramics and textiles. These developments took place during oxygen isotope stage 3 when rapid, large magnitude oscillations of climate known as Dansgaard- Oeschger (D-O) events occurred in Europe. It is generally accepted that the climate was a critical factor for humans during this period, but we have little understanding of precisely how the climatic context affected hominin populations in central Europe. To gain a better understanding of the climates and environments experienced by the upper Palaeolithic human groups it is necessary to develop a palaeoclimatic framework that is local to the central European archaeological sequences. We conducted isotopic analyses on animal remains from Gravettian sites located in Moravia (e.g. Pavlov, Dolni Vestonice, Milovice and Stranska Skala). Bulk tooth oxygen isotope
Interglacial climates of the Mediterranean region are recognized in numerous proxy records as periods of greater moisture and warmer temperatures with climatic optimum denoted by the expansion of taxa such as pistchio. Eastward in the Taurus-Zagros Mountains, a similar vegetation progression occurred with one major exception: the expansion of grasses between ca. 9.5 and 6.5 ka BP. The grass-pistachio zone peaks well before the establishment of the modern Zagros oak forest. This succession has been interpreted as evidence of a drier early Holocene relative to late Holocene. Stable isotope records show low d 18O values during the early Holocene followed by higher values, in apparent conflict with the vegetation. The ensuing “paradox” has created debate regarding the evolution of climate in southwest Asia. New insights occur when comparing the Holocene vegetation and hydroclimatic evolution with that of the Last Interglacial at Lake Urmia, Iran. The Urmia record spans the last 190 kyr but is of coarse resolution as the cores were not collected for scientific study. Previously published pollen data indicate that the Holocene succession was different than that of the Last Interglacial. There is no expansion of grass after the glacial and oak may not have lagged pistachio
467
highly variable accumulation rates, erosion of the record, bioturbation obscuring signals and no apparent straight-forward relationship to other wind-speed/source proxies such as grain-size. Much of this variability stems from the likely large number of influences on accumulation rate, both at source and sink. Furthermore, the new datasets present new methodological challenges such as the synthesis of data from different luminescence techniques and use of the most appropriate method of calculating mass accumulation rates. These findings will be outlined and some of the newly emerging challenges to accurately constraining past dust fluxes discussed through examples from the Chinese and Serbian loess sequences.
signatures provide information about the average climate conditions, whereas intra-tooth oxygen isotope signatures provide information about seasonal climate variations. Bone collagen carbon and nitrogen isotope signatures provide information about the diets consumed by the animals and the ecosystem and environments in which they lived. The climate signatures recorded in the skeletal remains provide information about the local climate during the human occupation of the archaeological sites. Our results further the debate on whether or not cultural innovation observed in central Europe during the Upper Palaeolithic were a result of innovative problem-solving in the face of climatic and environmental stress.
CONSTRAINING THE PROVENANCE OF MU US DESERT (CHINA) SANDS USING U-PB DATING OF DETRITAL ZIRCONS AND HEAVY MINERAL ASSEMBLAGES
ABRUPT CLIMATE WARMING AND THE LATE UPPER PALAEOLITHIC RECOLONISATION OF NORTHWEST EUROPE Rhiannon Stevens. University of Cambridge, United Kingdom
Thomas Stevens. Royal Holloway, U of London, United Kingdom E-mail address: [email protected]
The ultimate origin of the sediments that comprise sandy deserts is central to understanding the formation of such systems. However, the sources of this sediment and their spatial and temporal variability is often unknown. The sands of the Mu Us Desert, located in the Ordos Basin in Northern China, have been hypothesised to be sourced from underlying Quaternary sands, and in turn from underlying Cretaceous aeolianite. However, there has neither been a direct quantitative test of this hypothesis, nor characterisation of variability in geochemical signatures in sediment across the basin or through time. Furthermore, the only provenance work conducted on the Mu Us sands has used bulk geochemical analysis, which is inherently limited when there is a possibility of multiple source regions. Here we present single-grain detrital zircon U-Pb dates and morphology as well as heavy mineral assemblages from modern Mu Us sediments across the desert and from underlying sand bearing strata of the Quaternary and Cretaceous. Detrital zircon UPb ages can often be tied to protosource areas with distinctive age signatures representing specific tectonic events associated with granitic emplacement, especially when tied to zircon morphology and heavy mineral assemblage. The results allow us to interpret variability in the source regions across the Mu Us today, as well as at intervals in the past, thereby testing specific hypotheses over the origin of the desert sands. The results show that there is significant source variability across the desert, with clear geographical groupings displaying common source characteristics. Underlying Cretaceous and Quaternary formations contribute some material but far travelled components are significant in some regions of the desert. These findings will be discussed in terms of interpreting detrital zircon data, as well as in terms of the climatic, erosional and transport process implications for the origin of the Mu Us sands.
ISOTOPIC INVESTIGATIONS OF CLIMATE AND SEASONALITY IN CENTRAL EUROPE DURING THE UPPER PALAEOLITHIC
E-mail address: [email protected]
There has been much speculation about the relationship between the rapid warming at start of the Late Glacial and the sudden dispersal of Madgalenian human groups into northwest Europe that broadly coincided with widespread cultural changes. Some researchers have suggested that the re-colonisation occurred prior to the climate warming. Thus nonclimatic factors, most probably social developments, enabled humans to adapt better to the prevailing cold conditions, and hence to re-migrate into the region prior to any significant improvement in climate. Others have suggested, that the warming observed in the Greenland ice-cores and the re-colonisation occurred synchronously. Therefore the abrupt climate change triggered an equally abrupt and widespread response in human development at that time. Recently published radiocarbon dates from the earliest re-colonisation sites in the British Isles suggest that the re-colonisation was broadly contemporaneous with the Late Glacial abrupt climate warming. However due to the imprecision in radiocarbon calibration models as a result of the radiocarbon plateau it is impossible to tell from radiocarbon dates alone whether or not the re-colonisation and the climate warming recorded in the Greenland icecores occurred synchronously. It is therefore necessary to develop palaeoclimatic reconstructions that are not only local to the archaeological sites in the British Isles, but are directly linked to the period of human activity. Through oxygen isotope analysis of horse teeth that have been humanly modified and thus are directly linked to human activity, we have reconstructed the climatic conditions at Gough's Cave, King Arthur's Cave, Mother Grundy's Parlour, Kent's Cavern and Sun Hole Cave during the period of human occupation. Our results suggest that the re-colonisation of the British Isles and the abrupt climate warming were not synchronous. The implications of our finding will be presented. COMPARISON OF THE VEGETATIONAL AND HYDROCLIMATIC EVOLUTION DURING THE HOLOCENE AND LAST INTERGLACIAL IN WESTERN IRAN Lora Stevens. California State University, United States E-mail address: [email protected]
Rhiannon Stevens. University of Cambridge, United Kingdom E-mail address: [email protected]
The Upper Palaeolithic in the central European Plains was a critical period in human evolution marked by technological developments in lithic industries, extensive production of figurative and non-figurative art, the increased use of non-local raw materials, and the earliest development of ceramics and textiles. These developments took place during oxygen isotope stage 3 when rapid, large magnitude oscillations of climate known as Dansgaard- Oeschger (D-O) events occurred in Europe. It is generally accepted that the climate was a critical factor for humans during this period, but we have little understanding of precisely how the climatic context affected hominin populations in central Europe. To gain a better understanding of the climates and environments experienced by the upper Palaeolithic human groups it is necessary to develop a palaeoclimatic framework that is local to the central European archaeological sequences. We conducted isotopic analyses on animal remains from Gravettian sites located in Moravia (e.g. Pavlov, Dolni Vestonice, Milovice and Stranska Skala). Bulk tooth oxygen isotope
Interglacial climates of the Mediterranean region are recognized in numerous proxy records as periods of greater moisture and warmer temperatures with climatic optimum denoted by the expansion of taxa such as pistchio. Eastward in the Taurus-Zagros Mountains, a similar vegetation progression occurred with one major exception: the expansion of grasses between ca. 9.5 and 6.5 ka BP. The grass-pistachio zone peaks well before the establishment of the modern Zagros oak forest. This succession has been interpreted as evidence of a drier early Holocene relative to late Holocene. Stable isotope records show low d 18O values during the early Holocene followed by higher values, in apparent conflict with the vegetation. The ensuing “paradox” has created debate regarding the evolution of climate in southwest Asia. New insights occur when comparing the Holocene vegetation and hydroclimatic evolution with that of the Last Interglacial at Lake Urmia, Iran. The Urmia record spans the last 190 kyr but is of coarse resolution as the cores were not collected for scientific study. Previously published pollen data indicate that the Holocene succession was different than that of the Last Interglacial. There is no expansion of grass after the glacial and oak may not have lagged pistachio