Towards a Better Understanding of Alteration Phenomena of Archaeological Bone by a Closer Look at the Organic/Mineral Association at Micro- and Nanoscale. Preliminary Results on Neolithic Samples from Chalain Lake Site 19, Jura, France

Abstract

In this paper we present the extension of existing analytical schemes for the precise evaluation of archaeological bone preservation states. The new methodological developments concerning the study of the morphological and structural features of archaeological bones at micro- and nanoscale are emphasized in order to elucidate fine diagenetic modifications and to better understand the underlying alteration mechanisms. A combination of synchrotron X-ray microtomography, infrared micro-spectroscopy imaging and quantitative scanning small-angle X-ray scattering (sSAXS) imaging allowed studying micromorphological changes and the distribution of the organic and mineral components of bone at a histological level. Transmission electron microscopy gives precise information on changes of apatite crystal dimensions, orientations, periodicity of collagen fiber arrangement and crystal distributions within the fibers in archaeological bone. It allows establishing criteria to evaluate more precisely the preservation state of archaeological bone material with respect to modern references. The potential of these methods is highlighted on the basis of the study of some macroscopically well preserved archaeological bone samples from the Chalain lake station 19, Neolithic period, Jura, France. The investigations allowed a differentiation in preservation state between these samples and the postulation of an alteration sequence in such humid chalk-rich burial environments.

Black Fish Bones in Waterlogged Deposits: The Case of the Neolithic Lake Settlement of Dispilio, Greece

“…Although color-based identification is the most common method used in zooarchaeological research, its results have been questioned by numerous authors who, instead, have proposed the application of modern analytical techniques in order to distinguish between burning and staining. These techniques included the use of Optical Microscopy, Scanning Electron Microscopy (SEM), Transmittance Electron Microscopy (TEM), X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), and Infrared Spectroscopy (Taylor et al, 1995;Shahack-Gross et al, 1997;Koon et al, 2003;Stathopoulou et al, 2004;Michel et al, 2006;Enzo et al, 2007;Hanson & Cain, 2007;Lebon et al, 2008;Marín Arroyo et al, 2008;Piga et al, 2008Piga et al, , 2009Stathopoulou, 2008;Chadefaux et al, 2009;Thompson et al, 2009;Reiche, 2010). A straightforward analytical protocol concerning the presence of burning in osteological material, however, still remains elusive to this day (White & Folkens, 2005;Weiner, 2010; a recent overview of the history of research and various methods in Gonçalves, 2012).…”

Early diagenesis of elephant tusk in marine environment

“…Two modern elephant tusks from custom seizures were used as reference materials. The analytical approach consists of chemical analysis by means of simultaneous micro-Particle Induced X-ray Emission / Gamma-ray emission / Rutherford and Elastic Backscattering Spectrometry (μPIXE/PIGE/RBS/EBS) (Reiche et al, 1999(Reiche et al, , 2003Calligaro et al, 2011;Müller and Reiche, 2011;Beck et al, 2012) and structural analysis using micro-X-ray diffraction (μXRD) (Durand et al, 2010), Scanning Electron Microscopy (SEM) and micro-Small Angle X-ray Scattering (μSAXS) (Wess et al, 2001;Hiller et al, 2004;Hiller and Wess, 2006;Gourrier et al, 2011;Reiche et al, 2011). These methods allow for the determination and quantification of micro-variations in the specific chemical composition of the mineral and organic parts of ivory, and also for determination of the nanometric HAP crystal dimension, mineralized collagen fibers (MCF) organization and orientation throughout the tusk.…”

Informative Potential of Multiscale Observations in Archaeological Biominerals Down to Nanoscale

“…Such multi-scale analytical approach combining different complementary methods was recently adapted to determine the preservation state of archaeological elephant ivories and bone. The investigation allowed characterizing both, the mineral and organic phase of ivory, with 2D and 3D structural information on the small samples at all length scales of the hierarchical tissue (Chadefaux and Reiche 2009;Large et al 2011;Müller and Reiche 2011;Reiche 2009aReiche and Chadefaux 2009;Reiche et al 2003Reiche et al , 2007Reiche et al , 2010Reiche et al , 2011aAlbéric et al 2014). …”

“…In medicine, the nanoscale bone structure is currently investigated to evidence pathological modifications (e.g. Ruppel et al 2008), while in archaeology and forensic sciences, this provides powerful markers of anthropological alterations or diagenetic processes (Chadefaux and Reiche 2009;Chadefaux et al 2009b;Reiche et al 2011a). Given that the archaeological bone artefact represents a structure "frozen" at a given time of life and setting aside the diagenetic modifications, one should thus be able to retrieve information concerning diet, ways of life and health of the indiviual by the thorough investigations of bones at all structural scales.…”

“…Nowadays, two and sometimes three-dimensional (2D and 3D) elemental, molecular, structural and isotopic imaging of entire objects has becomes possible owing to recent technological developments off ocused analytical probes used in scanning mode and detectors (e.g. Lebon et al 2011a;Reiche et al 2011aReiche et al , 2003Reiche et al , 2010Reiche and Chalmin 2008;Anne et al 2014;Bergmann et al 2010;Gueriau et al 2014;Gourrier et al 2007bGourrier et al , 2010.…”