Shape Variation in Aterian Tanged Tools and the Origins of Projectile Technology: A Morphometric Perspective on Stone Tool Function

BACKGROUND: Recent findings suggest that the North African Middle Stone Age technocomplex known as the Aterian is both much older than previously assumed, and certainly associated with fossils exhibiting anatomically modern human morphology and behavior. The Aterian is defined by the presence of 'tanged' or 'stemmed' tools, which have been widely assumed to be among the earliest projectile weapon tips. The present study systematically investigates morphological variation in a large sample of Aterian tools to test the hypothesis that these tools were hafted and/or used as projectile weapons. METHODOLOGY/PRINCIPAL FINDINGS: Both classical morphometrics and Elliptical Fourier Analysis of tool outlines are used to show that the shape variation in the sample exhibits size-dependent patterns consistent with a reduction of the tools from the tip down, with the tang remaining intact. Additionally, the process of reduction led to increasing side-to-side asymmetries as the tools got smaller. Finally, a comparison of shape-change trajectories between Aterian tools and Late Paleolithic arrowheads from the North German site of Stellmoor reveal significant differences in terms of the amount and location of the variation. CONCLUSIONS/SIGNIFICANCE: The patterns of size-dependent shape variation strongly support the functional hypothesis of Aterian tools as hafted knives or scrapers with alternating active edges, rather than as weapon tips. Nevertheless, the same morphological patterns are interpreted as one of the earliest evidences for a hafting modification, and for the successful combination of different raw materials (haft and stone tip) into one implement, in itself an important achievement in the evolution of hominin technologies

La momie de Ramsès II au Musée de l'Homme

L'auteur décrit l'état de la momie de Ramsès II ainsi que les différents examens auxquels elle a été soumise, en France, en vue de sa restauration. Il s'agit, comme il est noté en conclusion, d'une extraordinaire opération scientifique multidisciplinaire comme l'archéologie n'en a peut-être jamais réalisée en France

Le Docteur Henri-Victor Vallois en Afrique du Nord. La Mission de 1949 et l'identification des Méditerranéens Capsiens

Balout (L.), Roubet (C). Le Docteur Henri-Victor Vallois en Afrique du Nord. La Mission de 1949 et l'identification des Méditerranéens Capsiens. In: Bulletins et Mémoires de la Société d'anthropologie de Paris, XIII° Série. Tome 9 fascicule 2, 1982. pp. 123-128

Computational investigation of interstitial neon diffusion in pure hematite

International audienceMulti-scale simulations were used to investigate the neon diffusivity in hematite for thermochronometry applications. Analyses of the magnetic, electronic, and structural properties of antiferromagnetic α-Fe2O3 are reported. At the microscopic scale, Ne insertion and atomic jumps in hematite are studied by means of the spin polarized Density Functional Theory + U, and the Transition State Theory. The minimum path energy of Ne migration between interstitial sites, and its position at the transition state, are determined by the climbing image-Nudged Elastic Band method (CI-NEB). Finally, these microscopic output data are used as inputs to a homemade code, based on Kinetic Monte Carlo (KMC) algorithms, in order to calculate the effective activation enthalpy and the diffusivity at infinite temperature for Ne in hematite. The Ne diffusion coefficient in pure hematite is calculated according to: D=9.78×10−3(cm2/s)exp(−2.42eVkBT) This formula shows very high retentivity of hematite relative to Ne at surface temperatures, and opens new geological dating fields

Helium diffusion in pure hematite (-Fe2O3) for thermochronometric applications : a theoritical multi-scale study

International audienceHe diffusion coefficient in iron oxide α-hematite crystal has been determined using computational multi-scale approach in the purpose of geological dating as He is produced during U-Th-Sm decay in this mineral. Natural hematite samples are generally made of nanometric to micrometric scale crystals leading to the difficulty to determine the total He diffusion behavior. A multi-scale theoretical approach will so bring new information on the He diffusion coefficient in 3D. Investigations, at microscopic scale, of helium insertion and atomic jumps into hematite crystal have been performed by DFT and transition state theory. The minimum path energy of helium migration between interstitial sites and its position at transition state are determined by the climbing image-Nudged Elastic Band method

Inserting Tin or Antimony Atoms into Mg2Si: Effect on the Electronic and Thermoelectric Properties

International audienceDensity functional and Boltzmann transport theories have been used to investigate the effect of constraints generated by substituting tin for silicon atoms or by inserting antimony atoms into Mg2Si on the electronic and thermoelectric properties of this compound. The investigated hypothetical structures are Mg2Si1-x Sn (x) with x equal to 0.125, 0.25, 0.375, 0.625, 0.75, and 0.875, and Mg8Si4Sb, Mg8Si4Sb3, and Mg2SiSb. The transport properties are presented with respect to the energy at three predefined temperatures and with respect to temperature for low and high electron and hole dopings. The effects of Sn-for-Si substitution are very similar to those observed for Mg2Si subjected to uniaxial and biaxial tensile strains. Overall, the power factor decreases as the doping level or tensile strain increases. In contrast, the maximum of the power factor increases with temperature. Irrespective of the temperature and electron or hole doping levels, the electrical conductivity of the Sb-inserted Mg2Si structures is far higher than that of Mg2Si. In the Fermi level energy region, the Seebeck coefficient S of the Sb-inserted Mg2Si structures is lower than that of Mg2Si. For Mg8Si4Sb3 and Mg2SiSb, the opposite is observed in the region where the electron density is very small (about 2 eV below the Fermi level). As a consequence, the power factor follows the same trends as the Seebeck coefficient