Search results for "Dating"
showing 10 items of 288 documents
The end of the Upper Palaeolithic in the Mediterranean Basin of the Iberian Peninsula
2012
This paper presents a synthesis of the Magdalenian in the Mediterranean Basin of the Iberian Peninsula, with special attention to the lithic and bone/antler assemblages, rock art, economy and radiocarbon dates. The data obtained in Cendres cave, situated in the middle of the Mediterranean Iberian Peninsula, permit articulation of the discussion about the Lower, Middle and Upper Magdalenian in this region. Furthermore, the paper discusses the end of the Magdalenian sequence with the Epimagdalenian industries.
Where is the line? Phylogeography and secondary contact of western Palearctic coal tits (Periparus ater: Aves, Passeriformes, Paridae)
2013
In this study, a phylogeographic scenario of the coal tit (Periparus ater) was reconstructed based on a fragment of the mitochondrial control region, and within- and between-population genetic diversity was analysed with a focus on the western Palearctic breeding range. We inferred a first pan-European delimitation of a postulated secondary contact zone among coal tits from the north-eastern Palearctic ater subspecies group and those from the south-western Palearctic abietum group. Generally, between-population differentiation was greatest in the Mediterranean range, which was explained by a greater separation in multiple Pleistocene refuge areas compared to the lower differentiation across…
Climate change and population dynamics during the late Mesolithic and the Neolithic transition in Iberia
2009
This paper explores how Early Holocene climate changes in the Western Mediterranean would have affected Late Mesolithic settlement distribution and subsistence strategies in Iberian Peninsula, thereby giving rise to various adaptive scenarios. The current radiocarbon data set concerning the Neolithisation process has revealed the rapidity of the spread of farming in Iberia. Considering both the implications of the last hunter-gatherers’ adaptation strategies and the population dynamics of agro-pastoral communities, we address the migration patterns underlying the Mesolithic- Neolithic transition. In conclusion, we propose that the initial colonization process was the result of two successiv…
Current Thoughts on the Neolithisation Process of the Western Mediterranean
2017
The analysis of the Neolithisation process constitutes a recurrent theme in the scientific literature given the fundamental change for human populations implied in the transition from a hunting-fishing-gathering economy to one based on domestication and food production. Nonetheless, the majority of the regional syntheses on a European scale published to date have dealt mainly with the historical narrative of the process, focusing on discussing the Neolithisation process from a demographic and/or cultural perspective. In this respect, the work of Ammerman and Cavalli Sforza (1984) without doubt constituted a turning point in a number of aspects relevant to the study of the Neolithisation of …
New insigths relating to the beginning of the Neolithic in the eastern Spain: Evaluating empirical data and modelled predictions
2018
Abstract In this paper we present recent research concerning the neolithization process in the East of Spain, evaluating the time span between the last hunther-gatherer groups and the first farmers ( c . 5950–5150 cal. BC). To do that we have compiled and filtered current information about radiocarbon dates and sites in order to discuss the state of the art relating to the models used to explain the Neolithic spread in the region. In this sense we compare archaeological data with recent results of virtual model (ABM) in accordance with the scenarios and mechanisms proposed. On this basis we evaluate the empirical data relating to the current model for explaining the Neolithic spread at the …
South Asian monsoon climate change and radiocarbon in the Arabian Sea during early and middle Holocene
2002
The 1 4 C ages of planktonic foraminifers Globigerinoides sacculifer bracketing the Younger Dryas in a δ 1 8 O record of Globigerinoides ruber from a laminated sediment core on the Pakistani continental margin suggest thatsurface reservoir ages in the Arabian Sea were in excess of 1000 years during the deglaciation. A least squares error fit of a detailed 1 4 C chronology to the (atmospheric) tree ring record gave variable early Holocene reservoir ages between 780 and 1120 years, well above the prebomb value of 640 years. Mid-Holocene reservoir ages are less well constrained but were probably closer to the prebomb value. The method used to fit individual core sections to the tree ring recor…
The arid–humid transition in the Sahara and the Sahel during the last deglaciation
1990
At the time of the Last Glacial Maximum, the Sahara and Sahel regions of North Africa were extremely dry. New records of rainfall show that during the subsequent deglaciation, the transition from arid to humid conditions in these regions occurred synchronously in two main steps. Comparison with other records of palaeoclimate in Europe and the North Atlantic Ocean shows that certain common factors controlled changes in ocean and atmosphere dynamics during the deglaciation.
The Gravettian occipital bone from the site of Malladetes (Barx, Valencia, Spain)
2002
Abstract The juvenile occipital bone from the site of Malladetes in Valencia (Spain) is described and compared with other European Pleistocene representatives of the genus Homo . This specimen derives from a Gravettian cultural context and has been AMS radiocarbon-dated to 25,120±240 years bp . As such, it provides evidence on early modern human anatomy from the Central Mediterranean region of the Iberian peninsula. The clear evidence for a late survival of Neandertals in southern Iberia, has led to considerable debate surrounding the biological and cultural interactions between these Pleistocene humans and their early modern human successors, and it is within this context that the Malladet…
Absence of delayed fission in the? ?-decay of 2.3 min238Pa
1985
We have searched for beta-delayed fission in the decay of 2.3 min238Pa produced in the238U(n,p) reaction with 14.7 MeV neutrons. Through microprocessor-controlled chemical separations of protactinium about 109 atoms of238Pa were isolated and exposed to fission track detectors. From the absence of fission tracks an upper limit for the betadelayed fission probability of238Pa, i.e.Pβf<2.6 10−8, is obtained at 95% confidence level. This rules out positive evidence for this decay mode of238Pa reported elsewhere. Simple theoretical estimates ofPβf range from 10−7 to 10−9.
Comment on "Displacement along the Karakoram fault, NW Himalaya, estimated from LA-ICP-MS U Pb dating of offset geologic markers" published by Shifen…
2013
International audience; Field evidence for syn-deformation migmatization and crystallization along the Karakorum fault contradicts the study of Wang et al. (2012). The ages of such magmatic rocks provide minimum ages for the onset of deformation at similar to 23 Ma in North Ayilari and similar to 19 Ma in Tangtse. The onset of deformation at 12 Ma in the Ayilari range inferred by Wang et al. (2012) from a muscovite Ar/Ar age is a cooling age, thus only a minimum age. The similar to 60 Ma granodiorite bodies, the ophiolitic rocks and the south Kailash thrust that are correlated across the fault to provide a 52 +/- 2 km finite offset do not define reliable piercing points. Such observations a…