Knapping tools in Magdalenian contexts: New evidence from Gough’s Cave (Somerset, UK)

Our knowledge of the recolonization of north-west Europe at the end of the Last Glacial Maximum depends to a large extent on finds from Gough's Cave (Somerset, UK). Ultra-high resolution radiocarbon determinations suggest that the cave was occupied seasonally by Magdalenian hunters for perhaps no more than two or three human generations, centred on 12,600 BP (~14,950-14,750 cal BP). They left behind a rich and diverse assemblage of Magdalenian lithic and osseous artefacts, butchered animal bones, and cannibalised human remains. The faunal assemblage from Gough's Cave is one of the most comprehensively studied from any Magdalenian site, yet new and unexpected discoveries continue to be made. Here, we record previously unrecognized flint-knapping tools that were identified during a survey of the Gough's Cave faunal collection at the Natural History Museum (London). We identified bones used as hammers and teeth manipulated as pressure-flakers to manufacture flint tools. Most of the pieces appear to be ad hoc (single-use?) tools, but a horse molar was almost certainly a curated object that was used over an extended period to work many stone tools. This paper explores how these knapping tools were used to support a more nuanced understanding of Magdalenian stone-tool manufacturing processes. Moreover, we provide a standard for identifying minimally-used knapping tools that will help to establish whether retouchers and other organic stone-working tools are as rare in the Magdalenian archaeological record as current studies suggest

Understanding Traditional Anti-Seismic Strategies Beyond Their Disappearance and Distortions: Yazd Qajar Architecture Case Study

Understanding traditional seismic strategies is necessary to conduct appropriate restoration of historic buildings and city centers located in earthquake-prone areas. But, the fast disappearance of vernacular built heritage and of the associated popular knowledge and know-how, along with the spread of inappropriate maintenance works, make it very difficult. To overcome these obstacles, it is suggested to broaden the scope of observations by including both larger geographical areas and elements that do not appear as seismic features at first consideration. This paper illustrates the relevance and the limits of this approach by applying it to the case study of Yazd historic city center. Yazd is located in a moderate seismic area and is famous for its well-preserved historic city center, with a high number of Qajar adobe buildings in various conditions. The authors combined literature review, direct observation of numerous buildings and a deeper study of four Qajar houses to conduct the first part of their research. The data collected mainly relates to the geometrical features, the materials used and the interconnections between elements at different scales. Their analyses led to the elaboration of several assumptions on the seismic behaviour of the studied adobe buildings and vaults and on the distortions some features may have suffered. To validate these assumptions, two methodologies were used. Both are illustrated in this paper through the study of the insertion of baked bricks in adobe vaults. The first one is based on observation campaigns on damaged houses. The second one is based on experimental works, with tests conducted on the shear strengths of masonry made with mud mortars and adobes or baked bricks to better understand how builders benefited from mixing these materials in an adobe vault. Finally, the authors discuss the limits of the method and the extent to which restoration projects can benefit from it

ISOCAM view of the starburst galaxies M82, NGC253, and NGC1808

We present results of mid-infrared 5.0-16.5 micron spectrophotometric imaging of the starburst galaxies M82, NGC253, and NGC1808 from the ISOCAM instrument on board the Infrared Space Observatory. The mid-infrared spectra of the three galaxies are very similar in terms of features present. The > 11 micron continuum attributed to very small dust grains (VSGs) exhibits a large spread in intensity relative to the short-wavelength emission. We find that the 15 micron dust continuum flux density correlates well with the fine-structure [ArII] 6.99 micron line flux and thus provides a good quantitative indicator of the level of star formation activity. By contrast, the 5-11 micron region dominated by emission from polycyclic aromatic hydrocarbons (PAHs) has a nearly invariant shape. Variations in the relative intensities of the PAH features are nevertheless observed, at the 20%-100% level. We illustrate extinction effects on the shape of the mid-infrared spectrum of obscured starbursts, emphasizing the differences depending on the applicable extinction law and the consequences for the interpretation of PAH ratios and extinction estimates. The relative spatial distributions of the PAH, VSG, and [ArII] 6.99 micron emission between the three galaxies exhibit remarkable differences. The < 1 kpc size of the mid-infrared source is much smaller than the optical extent of our sample galaxies and 70%-100% of the IRAS 12 micron flux is recovered within the ISOCAM < 1.5 arcmin squared field of view, indicating that the nuclear starburst dominates the total mid-infrared emission while diffuse light from quiescent disk star formation contributes little.Comment: 25 pages, 12 figures, accepted for publication in Astronomy and Astrophysics; Figs. 3, 4, 5, 6, 7, 9, 10, 12 appear after Sect.

Comparing the Boxgrove and Atapuerca (Sima de los Huesos) human fossils: Do they represent distinct paleodemes?

The early Middle Pleistocene human material from Boxgrove (West Sussex, UK) consists of a partial left tibia and two lower incisors from a separate adult individual. These remains derive from deposits assigned to the MIS 13 interglacial at about 480 ka and have been referred to as Homo cf. heidelbergensis. The much larger skeletal sample from the Sima de los Huesos (Atapuerca, Spain) is dated to the succeeding MIS 12, at about 430 ka. This fossil material has previously been assigned to Homo heidelbergensis but is now placed within the Neanderthal clade. Because of the scarcity of human remains from the Middle Pleistocene and their morphological variability, this study assessed whether the Boxgrove specimens fit within the morphological variability of the homogeneous Sima de los Huesos population. Based on morphometric analyses performed against 22 lower incisors from Sima de los Huesos and published material, the data from the Boxgrove incisors place them comfortably within the range of Sima de los Huesos. Both assemblages present robust incisors distinct from the overall small recent Homo sapiens incisors, and Boxgrove also aligns closely with Homo neanderthalensis and some other European Middle Pleistocene hominins. Following morphological and cross-sectional analyses of the Boxgrove tibia compared to seven adult Sima de los Huesos specimens and a set of comparative tibiae, Boxgrove is shown to be similar to Sima de los Huesos and Neanderthals in having thick cortices and bone walls, but in contrast resembles modern humans in having a straight anterior tibial crest and a suggestion of a lateral concavity. Based on the patterns observed, there is no justification for assigning the Boxgrove and Sima de los Huesos incisors to distinct paleodemes, but the tibial data show greater contrasts and suggest that all three of these samples are unlikely to represent the same paleodeme

Triggered star formation on the borders of the Galactic HII region RCW 82

We are engaged in a multi-wavelength study of several Galactic HII regions that exhibit signposts of triggered star formation on their borders, and where the collect and collapse process could be at work. When addressing the question of triggered star formation it is critically important to ensure the real association between the ionized gas and the neutral material observed nearby. In this paper we stress this point, and present CO observations of the RCW 82 star forming region. The velocity distribution of the molecular gas is combined with the study of young stellar objects (YSOs) detected in the direction of RCW 82. We discuss the YSO's evolutionary status using near- and mid-IR data. The spatial and velocity distributions of the molecular gas are used to discuss the possible scenarios for the star formation around RCW 82.Comment: 17 pages, 20 figures. Accepted by A&

Triggered massive-star formation on the borders of Galactic HII regions. I. A search for `collect and collapse' candidates

Young massive stars or clusters are often observed at the peripheries of HII regions. What triggers star formation at such locations? Among the scenarios that have been proposed, the `collect and collapse' process is particularly attractive because it permits the formation of massive objects via the fragmentation of the dense shocked layer of neutral gas surrounding the expanding ionized zone. However, until our recent article on Sh 104, it had not been convincingly demonstrated that this process actually takes place. In the present paper we present our selection of seventeen candidate regions for this process; all show high-luminosity near-IR clusters and/or mid-IR point sources at their peripheries. The reality of a `collect and collapse' origin of these presumably second-generation stars and clusters will be discussed in forthcoming papers, using new near-IR and millimetre observations.Comment: To be published in A&