Browsing by Author "Dyer, Chris"

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    Dark materials: pre-Columbian black lithic carvings from St Vincent and the wider Caribbean
    (Elsevier, 2020-06-07) Brock, Fiona; Ostapkowicz, Joanna; Collinson, Margaret Elizabeth; Bull, Ian D.; Dyer, Chris; Lane, David W.; Domoney, Kelly; Uden, Jeremy
    A small number of pre-Columbian black lithic carvings have been found at archaeological sites across the Caribbean, as well as in parts of neighbouring mainland South America. The identity of the material used to create these artefacts is often unknown, but suggestions include lignite, wood, petrified wood, manja(c)k, jet (or ‘jet-like’ materials) and hardened asphalt. These identifications are often historical and lacking any scientific basis, and as such can be unreliable. However, identification of the material has the potential to inform on the source of the carving and thereby pre-Columbian trade routes within the circum-Caribbean region. Four analytical techniques (reflectance microscopy, FTIR, Py-GC/MS, x-ray fluorescence) were applied to samples taken from two carvings found on St Vincent and five comparative materials. Both artefacts were found to be most likely carved from cannel coal, indicating that they originated in South America (where cannel coal is found extensively in locations in Colombia and Venezuela), as the material is not found within the Caribbean region.
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    Etton Causewayed Enclosure Bone Diagenesis data
    (Cranfield University, 2023-01-03 15:42) Brock, Fiona; Loy, Charlotte; Dyer, Chris
    XRF and FTIR data collected by Charlotte Loy as part of her Forensic Archaeology & Anthropology MSc thesis entitled 'Investigating the Peculiar Diagenesis of the Etton Causewayed Enclosure Bones' (2016). These Neolithic animal bones show unusual patterns of iron and manganese mineralisation.
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    Investigating diagenesis of archaeological bones from Etton Causewayed Enclosure, UK
    (Elsevier, 2023-01-02) Loy, Charlotte; Brock, Fiona; Dyer, Chris
    Diagenesis of archaeological bones proceeds via a complex combination of chemical, physical and/or microbial processes often over several millennia. These processes are influenced by the depositional environment, including fluctuations in pH, mineral availability and water table. This study investigates diagenetic alterations to the mineral and organic (collagen) phases of bones from a Neolithic site, Etton Causewayed Enclosure (Cambridgeshire, UK). Archaeological bones from some layers of the gravel site at Etton exhibit unusual staining patterns, including iron and manganese rich layers underneath the exterior bone surface and manganese speckling throughout the bone. A range of analytical techniques (micro-CT, FTIR, XRF and SEM-EDS) were employed to investigate the mineralisation within three bones from this site. Diagenesis appears to have occurred through a combination of bacterial degradation and mineral formation due to the changing redox conditions at the site caused by fluctuating groundwater. The reason for the positioning of the manganese layers beneath the iron layers at the surfaces of the bone remains unclear.