CRC806-Database Data Feed (Atom)http://crc806db.uni-koeln.de/Neandertals or Early Modern Humans? A revised 14C chronology and geoarchaeological study of the Szeletian sequence in Szeleta Cave (Kom. Borsod-Abaúj-Zemplén) in Hungaryhttp://crc806db.uni-koeln.de/dataset/show/neandertals-or-early-modern-humans-a-revised-14c-chronology-and-geoarchaeological-study-1492598460/2017-04-19T10:40:28+02:00Szeleta Cave near Miskolc (Hungary) is the eponymous site for the Szeletian technological group thought to reflect the last occurrence of Neanderthals in Central Europe. Because the Szeletian lithic industry contains both Middle Paleolithic and Upper Paleolithic elements, it is usually regarded as a “transitional” industry. As such, the development of a precise age model for the Szeletian would add substantial information to a period of population replacements in Europe. This concerns the timing of Neanderthal disappearance and their possible cohabitation with Anatomically Modern Humans in Central Europe. Previous age models for the Szeletian either suffered from deficiencies of dating methods and/or poor stratigraphic control of the dated samples. Therefore, population replacement models based on the key archaeological sequence of Szeleta Cave remain ambiguous. For this reason, we developed a new age model for the Szeletian sequence of this cave combined with a geoarchaeological investigation. Our new radiocarbon chronology, based on AMS 14C dating results of in situ bone and charcoal samples, lends support to the argument that the Szeletian does not represent a transition towards, but rather contemporaneity with the Early Upper Paleolithic. The Szeletian now appears to be of the same age as the early Aurignacian in the region which is linked to the early Anatomically Modern Humans. Consequently, Neanderthals are the likely authors of the famous Szeletian leaf points – bifacially shaped implements that are important cultural markers for the MP-UP transition.Thomas HauckAfter the cold: Epigravettian hunter-gatherers in Blazi Cave (Albania)http://crc806db.uni-koeln.de/dataset/show/after-the-cold-epigravettian-huntergatherers-in-blazi-cave-albania1492591093/2017-04-19T08:37:41+02:00This paper presents the latest results of archaeological research in Epigravettian deposits of Blazi Cave in north-central Albania. This Epigravettian site is the first of its kind in Albania with a large sample of stone artifacts, faunal remains and dating material. The study material stems from the last remaining Late Pleistocene deposits in this cave and therefore characterizes the site in its totality. AMS 14C dates place the cultural layers between 18 and 17 ka cal. BP. This age model coupled with the density of anthropogenic remains attests an intensive use of the shelter by hunter-gatherers in the final phase of the Last Glacial Maximum. The radiocarbon results place the Blazi data into the early phase of the Late Adriatic Epigravettian complex. This chronology is corroborated by certain technological and typological traits identified within the stone tool sample. Analysis of the faunal remains suggests a repeated use of the shelter in the warmer summer period. Blazi Cave functioned as a specialized ibex hunting site and therefore fits into a larger complex of task localities in the wider region.Christian Willmes;Thomas HauckAnalyzing two-dimensional effects in central loop transient electromagnetic sounding data using a semi-synthetic tipper approachhttp://crc806db.uni-koeln.de/dataset/show/analyzing-twodimensional-effects-in-central-loop-transient-electromagnetic-sounding-data1492000318/2017-04-12T12:31:28+02:00We present a simple and feasible approach to analyze and identify two dimensional (2D) effects in central loop transient electromagnetic (TEM) sounding data and the correspondingly derived quasi 2D conductivity models. The proposed strategy is particularly useful to minimize interpretation errors. It is based on the calculation of a semi-synthetic TEM-tipper at each sounding and for each observational transient time point. The semi-synthetic TEM-tipper is derived from the measured vertical component of the induced voltage UI;z and the synthetically calculated horizontal component UI;x. The approach is computationally in-expensive and involves one two-dimensional forward calculation of an obtained quasi 2D conductivity section. Based on a synthetic example we demonstrate that the TEM tipper approach is applicable to identify which transient data points and which corresponding zones in a derived quasi 2D subsurface model are affected by 2D inhomogeneities. The 1D inversion of such data leads to false models. An application of the semi-synthetic TEM tipper to field data from the Azraq basin in Jordan reveals that in total eight of 80 investigated soundings are affected by 2D structures although the field data can be fitted optimally using 1D inversion techniques. The largest semi synthetic tipper response occurs in a 300 m wide region around a strong lateral resistivity contrast. The approach is useful to analyze structural features in derived quasi 2D sections and to qualitatively investigate how these features affect the transient response. To avoid misinterpretation, these identified zones corresponding to large tipper values are excluded from the interpretation of a quasi 2D conductivity model. Based on the semi-synthetic study, we also demonstrate that a quantitative interpretation of the horizontal voltage response (e.g. by inversion) is usually not feasible as it requires the exact sensor position to be known. Although a tipper which is derived purely from field data is useful as a qualitative tool to identify 2D distortion effects, it is only feasible if the sensor setup is sufficiently accurate. Our proposed semi-synthetic TEM tipper approach is particularly feasible as an a-posteriori approach if no horizontal components are recorded or if the sensor setup in the field is not sufficiently accurate.Pritam YogeshwarTwo-dimensional basement modeling of central loop transient electromagnetic data from the central Azraq basin area, Jordanhttp://crc806db.uni-koeln.de/dataset/show/twodimensional-basement-modeling-of-central-loop-transient-electromagnetic-data-from-the1491999783/2017-04-12T12:22:33+02:00Thick sedimentary sequences are deposited in the central area of the Azraq basin in Jordan consisting mostly of hyper-saline clay and various evaporates. These sediment successions form the 10 km × 10 km large Azraq mudflat and are promising archives for a palaeoclimatical reconstruction. Besides palaeoclimatical research, the Azraq area is of tremendous importance to Jordan due to groundwater and mineral resources.
The heavy exploitation of groundwater has lead to a drastic decline of the water table and drying out of the former Azraq Oasis. Two 7 and 5 km long transects were investigated from the periphery of the mudflat across its center using a total of 150 central loop transient electromagnetic (TEM) soundings. The scope of the survey was to detect the thickness of sedimentary deposits along both transects and to provide a basis for future drilling activities. We derive a two-dimensional model which can explain the TEM data for all soundings along each profile simultaneously. Previously uncertain depths of geological boundaries were determined along both transects. Particularly the thickness of the deposited mudflat sediments was identified and ranges from 40 m towards the periphery down to approximately 130 m at the deepest location.
Besides that, the depth and lateral extent of a buried basalt layer was identified. In the basin center the groundwater is hyper-saline. The lateral extent of the saline water body was determined precisely along both transects. In order to investigate the detectability of the basement below the high conductive mudflat sediments an elaborate two-dimensional modeling study was performed. Both, the resistivity and depth of the basement were varied systematically. The basement resistivity cannot be determined precisely in most zones and may range roughly between 1 and 100 Ym without deteriorating the misfit. In contrast to that, the depth down to the basement is detected accurately in most zones and along both transects. Varying the depth of the basement or removing it completely results in a poor data fitting and, therefore, proves its significance. From the modeling study we derived bounds for the resistivity and depth of the base layer as a measure of their uncertainty.Pritam YogeshwarVegetation and climate history of the Marmara region during the last ca. 30,000 years based on lacustrine sediments from Lake Iznik (NW Turkey)http://crc806db.uni-koeln.de/dataset/show/vegetation-and-climate-history-of-the-marmara-region-during-the-last-ca-30000-years-base1491994697/2017-04-12T10:57:47+02:00The reconstruction of the vegetation and climate history of the Marmara region in northwestern Turkey is of particular interest due to its key role for migration routes of modern men and its location between different vegetation zones. Geochemical and mineralogical investigations of the largest lake in the region, Lake Iznik, already registered striking changes during lake’s history (Roeser et al. 2012). However, a palynological investigation encompassing the late Pleistocene to Holocene transition was still missing. Here, the first pollen record of the last 31 ka cal BP from Lake Iznik sediments as an independent proxy for paleoecological reconstructions is presented.
Sediment samples were taken in a resolution of 50 cm along 13 m of the composite profile. The sampling resolution was increased along the Pleistocene-Holocene boundary. For the preparation of the pollen samples, a standard protocol described in Faegri and Iversen (1989) was followed. A biome reconstruction following the method described in Prentice et al. (1996) was performed.
Lake Iznik’s catchment area is located in a climatic transition area between the Mediterranean and Pontic climate zones. Today, the region is highly influenced by (sub-) Euxinian temperate deciduous and mixed forests dominated by deciduous oak (Quercus) and beech (Fagus). Coastal areas of the southeastern Marmara Sea and the Aegean Sea are dominated by (sub-) Mediterranean woods and shrubs with sclerophyllous and evergreen elements. Towards the southeast, the annual precipitation decreases and steppe-forests followed by dwarf-shrub steppe form the vegetation (Zohary, 1973).
The pollen record of Lake Iznik reflects typical pattern in vegetational and climatic changes of the Eastern Mediterranean with some regional variations. It illustrates the shift from steppe forest during the end of Marine Isotope Stage 3 and steppe vegetation during the Last Glacial Maximum towards an oak dominated mixed forest with Mediterranean elements. The steppe is dominated by grasses, Chenopodiaceae, Artemisia, and other Asteraceae indicating cool and/or dry conditions. A change in steppe components and a higher vegetation density suggest milder climate conditions since ca. 18 ka cal BP. This goes along with an increase of summer insolation (Berger, 1978; Berger et al., 2007). Deciduous oaks increase remarkably since the Late Glacial Interstadial indicating warmer temperatures. A short period of dryer and/or cooler climate (Younger Dryas) is marked by an increase of Artemisia and a decrease of several trees. Deciduous oaks predominate the vegetation since the early Holocene, and they are accompanied by other temperate trees like hazel (Corylus) and elm (Ulmus). The pollen record shows a typical pattern known from the Eastern Mediterranean: the Sarcopoterium spinosum pollen type and Pistacia occur constantly for the first time at the early Holocene. The increase of Fagus and Abies suggests moister conditions since the early Holocene. During an early settlement phase near Lake Iznik beginning ca. 8 ka cal BP (Roodenberg, 2012), only minor changes in the pollen assemblage are registered. Still, the occurrence of anthropogenic indicator species and the ongoing degradation of oak forests indicate human activity around 4 ka cal BP.
Local pollen assemblage zones are in accordance with previously defined sedimentary units (Roeser et al., 2012; P. A. Roeser, unpublished data). In addition, several prominent changes in pollen and non-pollen palynomorph ratios coincide with changes in the aragonite precipitation of Lake Iznik (P. A. Roeser, unpublished data).
Lake Iznik sediments have the potential for further detailed palynological investigations to improve the vegetation and climate reconstruction for the Marmara region. A higher resolution and extension of the present pollen record could reflect the implication of rapid climate changes and human influences on the local and regional environment more precisely.Andrea Miebach