Browsing by Author "Ostapkowicz, Joanna"

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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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    Integrating the Old World into the New: an ‘Idol from the West Indies’
    (Cambridge University Press, 2017-09-20) Ostapkowicz, Joanna; Brock, Fiona; Widenhoeft, Alex C.; Schulting, Rick J.; Daviola, Donatella
    The Pigorini cemí is an icon of Caribbean colonial history, reflecting early trans-Atlantic cross-cultural exchanges. Although well documented, the piece has received surprisingly little systematic study. We present the first structural analysis and radiocarbon dating of the sculpture (modelled at AD 1492–1524), and a brief discussion of the materials from which it is comprised. These include indigenous shell and European glass beads, newly identified feather and hair fibres, and the enigmatic rhinoceros-horn mask carved as a human face. We also address the sculpture's hidden internal wooden base, which is shown to be a non-indigenous display mount made of European willow (Salix sp.).
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    Six centuries of adaptation to a challenging island environment: AMS 14C dating and stable isotopic analysis of pre-Columbian human remains from the Bahamian archipelago reveal dietary trends
    (Elsevier, 2021-01-29) Schulting, Rick J.; Snoeck, Christophe; Pouncett, John; Brock, Fiona; Bronk Ramsay, Christopher; Higham, Thomas; Devièse, Thibaut; Delancy, Kelly; Pateman, Michael; Keegan, William; Ostapkowicz, Joanna
    The limestone islands of the Bahamian archipelago provide a challenging environment for human settlement, one that was not taken up until after AD 700. The analysis of human skeletal remains offers new insights into how this challenge was met. A substantial program of AMS 14C dating on pre-Columbian humans (n = 66) provides a robust chronological framework for the period ca. AD 1000–1600, with the latter date suggesting the possible persistence of an indigenous Lucayan presence on the islands for some decades later than previously thought. Associated stable carbon (δ13C) and nitrogen (δ15N) isotope analyses imply an early focus on near-shore marine resources that seems to have rapidly led to their local over-exploitation, resulting in a shift towards horticulture based mainly on root crops. The Medieval Warm Period is very likely to have been a factor in the initial settlement of the islands; the impact of the Little Ice Age is less clear, with no marked changes in either δ13C or δ15N. Strontium isotope results are consistent with an origin of most individuals within the archipelago, with a limited (but potentially important for maintaining connections) presence of incomers from the Greater Antilles, and perhaps even further afield. Despite the relatively short history of pre-Columbian occupation, Lucayan adaptations to the Bahamian archipelago were dynamic and demonstrate resilience in the face of both human resource depletion and climate change.
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    Testing various pre-treatments on artificially waterlogged and pitch-contaminated wood for strontium isotope analyses
    (Frontiers, 2021-01-12) Snoeck, Christophe; Schulting, Rick J.; Brock, Fiona; Rodler, Alexandra S.; van Ham-Meert, Alicia; Mattielli, Nadine; Ostapkowicz, Joanna
    Strontium isotope ratios (87Sr/86Sr) are commonly used in archeological and forensic studies to assess if humans and fauna are local to the place they were found or not. This approach is largely unexplored for wooden artifacts recovered in archeological contexts, as wood – in the rare instances it does survive – is often poorly preserved. One of the most common ways wood is preserved is through the anoxic conditions found in waterlogged contexts. A more unusual form of preservation is through submergence in natural pitch. These depositional media contribute their own strontium values to the in vivo 87Sr/86Sr wood values, which needs to be removed prior to analysis. Here we test several pre-treatment methods to remove potential strontium contamination from wood samples that were artificially immersed in seawater and pitch from Trinidad’s Pitch Lake. Water rinses and acid-leaching tests were carried out with hydrochloric acid and acetic acid to remove exogenous strontium from experimentally waterlogged wood. These tests removed large amounts of strontium from the samples and did not enable the recovery of the endogenous 87Sr/86Sr signal. For samples artificially immersed in pitch, the pre-treatments tested were based on radiocarbon dating procedures and carried out with and without the aqueous-based acid-base-acid (ABA) step. The use of organic solvents alone (methanol and toluene) removed exogenous strontium originating from the pitch. However, the ABA step eliminates large amounts of in vivo strontium from the samples. These tests show that 87Sr/86Sr values of wood are altered by the presence of pitch and water. With adequate pre-treatment using exclusively organic solvents, it may be possible to remove this contamination for samples immersed in pitch. However, the aqueous-based ABA pre-treatment should be avoided. The removal of contamination from waterlogged samples was unsuccessful with the current pre-treatment protocols and more research is needed. More importantly, and unexpectedly, 87Sr/86Sr values may extend outside of the mixing line between the wood’s endogenous strontium and the water. These results indicate the need for extreme caution when attempting to determine the provenance of waterlogged wood.