176 research outputs found
The 10Be contents of SNC meteorites
Several authors have explored the possibility that the Shergottites, Nakhlites, and Chassigny (SNC) came from Mars. The spallogenic gas contents of the SNC meteorites have been used to: constrain the sizes of the SNC's during the last few million years; to establish groupings independent of the geochemical ones; and to estimate the likelihood of certain entries in the catalog of all conceivable passages from Mars to Earth. The particular shielding dependence of Be-10 makes the isotope a good probe of the irradiation conditions experienced by the SNC meteorites. The Be-10 contents of nine members of the group were measured using the technique of accelerator mass spectrometry. The Be-10 contents of Nakhla, Governador Valadares, Chassigny, and probably Lafayette, about 20 dpm/kg, exceed the values expected from irradiation of the surface of a large body. The Be-10 data therfore do not support scenario III of Bogard et al., one in which most of the Be-10 in the SNC meteorites would have formed on the Martian surface; they resemble rather the Be-10 contents found in many ordinary chondrites subjected to 4 Pi exposures. The uncertainties of the Be-10 contents lead to appreciable errors in the Be-10 ages, t(1) = -1/lambda ln(1 Be-10/Be-10). Nonetheless, the Be-10 ages are consistent with the Ne-21 ages calculated assuming conventional, small-body production rates and short terrestrial ages for the finds. It is believed that this concordance strengthens the case for at least 3 different irradiation ages for the SNC meteorites. Given the similar half-thicknesses of the Be-10 and Ne-21 production rates, the ratios of the Be-10 and Ne-21 contents do not appear consistent with common ages for any of the groups. In view of the general agreement between the Be-10 and Ne-21 ages it does not seem useful at this time to construct multiple-stage irradiation histories for the SNC meteorites
Palaeopathological Study of the Mompaderno Cranium (Croatian Istria) Reveals Interpersonal Violence during Early Bronze Age
The Mompaderno cranium was found in 1883 at Baderna/Mompaderno in Croatian Istria. It was suspected to date from the Mesolithic or Neolithic period, but radiocarbon analyses, performed by accelerator mass spectrometry (AMS) on collagen extracted from two teeth, have provided an age range of 2,202–1928 cal. BC, which corresponds to the Early Bronze Age in the investigated region. Macroscopic observations and X-ray micro-tomography (micro-CT) of the cranium have shown antemortem sharp force trauma on the frontal bones, probably caused by a bronze axe, and a related osteomyelitis likely caused by an infection of the wound. The study has also revealed a previous depressed fracture and an osteolytic area interpreted as intradiploic meningioma. Results provide rare and earliest evidence of interpersonal violence in the northern Adriatic region
Whetstones from Bronze Age hill forts of North Eastern Italy
A group of Bronze Age whetstones from Protohistoric hill forts, locally called Castellieri, of eastern Friuli Venezia Giulia (north eastern Italy) has been studied using different techniques, including non destructive methods such as X-ray computed micro-tomography and portable X-ray fluorescence, in order to characterize the raw material and define its origin. The obtained results suggest that small pebbles of reddish subarkose and quartz arenites collected from the gravel deposits of river Isonzo, perhaps deriving from Val Gardena Formation outcrops, were exploited for the production of the studied artefacts during the Bronze Age. These data complement our knowledge about the lithic raw materials exploitation strategies during the ancient phase of Castellieri culture, almost exclusively based on local rock type
Polished stone axes from Varna/Nössingbühel and Castelrotto/Grondlboden, South Tyrol (Italy)
A collection of polished stone axes from a late Neolithic site and an Early Bronze Age hill fort in South Tyrol (Italy) have been analysed through a multi-analytical approach, mainly based on non-destructive techniques (i.e. Raman spectroscopy, X-ray fluorescence and prompt gamma activation analysis) to identify the raw materials used in the same area during different periods and compare them with those in use in the surrounding territories. The analytical results suggest raw material exploitation strategies based on local or close sedimentary, metamorphic and magmatic rocks. Most of the artefacts are made from antigoritic serpentinite, whose origin is probably from Hohe Tauern (Austria) or related secondary deposits. These data confirm the importance of such raw material for the production of polished stone axes during recent prehistory and integrate the present knowledge about the distribution of antigoritic artefacts in north-eastern Italy and neighbouring countries
X-ray computed microtomography of late copper age decorated bowls with cross-shaped foots from central Slovenia and the Trieste Karst (North-Eastern Italy): technology and paste characterization.
About 20 Late Copper Age bowls with cross-shaped foots from Deschmann\u2019s pile dwellings (Ljubljansko barje, central Slovenia) and Trieste Karst (North-Eastern Italy) have been investigated using X-ray computed microtomography (microCT) in order to study the vessel-forming technique, to characterise their pastes and to test the hypothesis that some Karst bowls could have been imported from nowadays central Slovenia or even more distant regions. In three selected virtual slices per sample, clay, lithic inclusions and pores have been segmented and quantified. In addition, the area, maximum length and width of each lithic inclusion have been calculated. Then, the microCT-derived results have been statistically analysed by principal component analysis (PCA). The orientation of pores and disjunctions in microCT volumes show that the basins of the bowls were built using mainly the coiling technique, while the base was shaped starting from a central piece, to which a layer of clay was added and then reshaped in order to produce the foots. The Slovenian bowls include both medium/coarse-grained and very fine- or fine-grained vessels mainly tempered with carbonate inclusions. The pastes of the Karst bowls are considerably heterogeneous. One bowl was most likely imported to the Karst but not from central Slovenia as it shows peculiar components, shape and decoration. The other two imported vessels show a very fine-grained paste comparable to the one of several samples from Deschmann\u2019s pile dwellings. Such technological similarity is confirmed by PCA of microCT data and petrographic observations. Our study confirms the existence of strong cultural connections between central Slovenia and the northernmost Adriatic coast during the Late Copper Age
A multi-analytical study of Bronze Age pottery from the UNESCO site of Al-Khutm (Bat, Oman)
The extensive investigation carried out in recent years at the UNESCO site of Al-Khutm (Ibri, Oman) has allowed to uncover the monumental remains of a tower dated back to the third millennium BC and to collect an abundant ceramic assemblage from the associated soil deposits. Eighteen selected pottery samples have been investigated using a multi-analytical approach including microfocus X-ray computed tomography, X-ray diffraction, optical microscopy and prompt gamma activation analysis to analyse the vessel-forming technique and to characterise their micro-structure, mineralogical and chemical composition to recognise possible local vs. non-local raw materials. The results provided new insights on ancient manufacturing processes and revealed that most of the vessels were locally produced exploiting raw materials from the surroundings of the site with the exception of a fragment of a black slipped jar. The chemical results suggest that the latter was imported from the Indus area in nowadays Pakistan. This evidence integrates our knowledge about the presence of this type of vessels in Oman and confirms the involvement of inland centres like Bat and Al-Khutm into a large-scale exchange system
Monte Carlo Simulations of Powerful Neutron Interaction with Matter for the Goals of Disclosure of Hidden Explosives and Fissile Materials and for Treatment of Cancer Diseases versus their Experimental Verifications
High-accuracy methodology for the integrative restoration of archaeological teeth by using reverse engineering techniques and rapid prototyping
The reconstruction of the original morphology of bones and teeth after sampling for physicochemical (e.g., radiocarbon and uranium series dating, stable isotope analysis, paleohistology, trace element analysis) and biomolecular analyses (e.g., ancient DNA, paleoproteomics) is appropriate in many contexts and compulsory when dealing with fossil human remains. The reconstruction protocols available to date are mostly based on manual re-integration of removed portions and can lead to an imprecise recovery of the original morphology. In this work, to restore the original external morphology of sampled teeth we used computed microtomography (microCT), reverse engineering (RE), computer-aided design (CAD) and rapid prototyping (RP) techniques to fabricate customized missing parts. The protocol was tested by performing the reconstruction of two Upper Palaeolithic human teeth from the archaeological excavations of Roccia San Sebastiano (Mondragone, Caserta, southern Italy) and Riparo I of Grotte Verdi di Pradis (Clauzetto, Pordenone, north-eastern Italy) (RSS2 and Pradis 1, respectively), which were sampled for physicochemical and biomolecular analyses. It involved a composite procedure consisting in: a) the microCT scanning of the original specimens; b) sampling; c) the microCT scanning of the specimens after sampling; d) the reconstruction of the digital 3D surfaces of the specimens before and after sampling; e) the creation of digital models of the missing/sampled portions by subtracting the 3D images of the preserved portions (after the sampling) from the images of the intact specimens (before the sampling) by using reverse engineering techniques; f) the prototyping of the missing/sampled portions to be integrated; g) the painting and application of the prototypes through the use of compatible and reversible adhesives. By following the proposed protocol, in addition to the fabrication of a physical element which is faithful to the original, it was possible to obtain a remarkable correspondence between the contact surfaces of the two portions (the original and the reconstructed one) without having to resort to any manipulation/adaptation of either element
Early Alpine occupation backdates westward human migration in Late Glacial Europe
Before the end of the Last Glacial Maximum (LGM, ∼16.5 ka ago) set in motion major shifts in human culture and population structure, a consistent change in lithic technology, material culture, settlement pattern, and adaptive strategies is recorded in Southern Europe at ∼18–17 ka ago. In this time frame, the landscape of Northeastern Italy changed considerably, and the retreat of glaciers allowed hunter-gatherers to gradually recolonize the Alps. Change within this renewed cultural frame (i.e., during the Late Epigravettian phase) is currently associated with migrations favored by warmer climate linked to the Bølling-Allerød onset (14.7 ka ago), which replaced earlier genetic lineages with ancestry found in an individual who lived ∼14 ka ago at Riparo Villabruna, Italy, and shared among different contexts (Villabruna Cluster). Nevertheless, these dynamics and their chronology are still far from being disentangled due to fragmentary evidence for long-distance interactions across Europe. Here, we generate new genomic data from a human mandible uncovered at Riparo Tagliente (Veneto, Italy), which we directly dated to 16,980–16,510 cal BP (2σ). This individual, affected by focal osseous dysplasia, is genetically affine to the Villabruna Cluster. Our results therefore backdate by at least 3 ka the diffusion in Southern Europe of a genetic component linked to Balkan/Anatolian refugia, previously believed to have spread during the later Bølling/Allerød event. In light of the new genetic evidence, this population replacement chronologically coincides with the very emergence of major cultural transitions in Southern and Western Europe.The research was supported by the European Union through the European Research Council under the European Union’s Horizon 2020 Research and Innovation Programme (grant agreement no. 724046 – Success awarded to S.B., http://www.erc-success.eu; grant agreement no. 803147 Resolution awarded to S.T., https://site.unibo.it/resolution-erc/en) as well as through the European Regional Development Fund (project no. 2014–2020.4.01.16–0030 to C.L.S. and T.S.) and projects no. 2014-2020.4.01.16-0024 and MOBTT53 (L.P.), by the Estonian Research Council personal research grant (PRG243; C.L.S.), and by UniPd PRID 2019 (L.P.).Peer reviewe
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