Browsing by Author "Ostapkowicz, J."

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    Black pitch, carved histories: radiocarbon dating, wood species identification and strontium isotope analysis of prehistoric wood carvings from Trinidad's Pitch Lake
    (Elsevier, 2017-11-06) Ostapkowicz, J.; Brock, Fiona; Widenhoeft, A. C.; Snoeck, C.; Pouncett, J.; Baksh-Comeau, Y.; Schulting, Rick J.; Claeys, P.; Mattielli, N.; Richards, M.; Boomert, A.
    We report on the results of a multi-disciplinary project (including wood identification, radiocarbon dating and strontium isotope analysis) focused on a collection of pre-Columbian wooden carvings and human remains from Pitch Lake, Trinidad. While the lake's unusual conditions are conducive to the survival of organic artefacts, they also present particular challenges for analysis. There is a loss of any contextual association beyond that of the lake, and specific methodologies are required to deal with pitch contamination. A surprising taxonomic range of woods was employed for the various utilitarian and ceremonial items recovered. The 14C results range from ca. 3200 BCE to ca. 700 CE, and include the earliest known wooden carvings in the entire Caribbean. The strontium isotope results - interpreted with the aid of an isoscape developed for the project, based on extensive samples of modern trees across Trinidad and Tobago - indicate that most carvings are consistent with the site's immediate environs; however, a ‘weaving tool’ came from a more radiogenic region that is unlikely to be found on Trinidad, suggesting links with the South American mainland.
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    East-central Florida pre-Columbian wood sculpture: Radiocarbon dating, wood identification and strontium isotope studies
    (Elsevier, 2017-05-13) Ostapkowicz, J.; Schulting, Rick J.; Wheeler, R.; Newsome, L.; Brock, Fiona; Bull, I.; Snoeck, C.
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    Radiocarbon dating wooden carvings and skeletal remains from Pitch Lake, Trinidad
    (University of Arizona - Cambridge University Press, 2017-10-30) Brock, Fiona; Ostapkowicz, J.; Wiedenhoeft, A. C.; Bull, I. D.
    Since the mid 19th century, rare prehistoric wooden carvings and human skeletal remains have been dredged from Pitch Lake, Trinidad, during commercial asphalt mining. Establishing a chronology for these objects is challenging, due to both a lack of stratigraphic and contextual information and the necessity to completely remove any pitch to ensure accurate radiocarbon dates. A range of solvent extraction protocols was tested to identify the most suitable one for pretreating the Pitch Lake artefacts, and then applied to ten wooden objects and a human cranium recovered from the lake. Several of these objects yielded earlier dates than expected, raising concerns that pitch had remained after pretreatment and had affected the dates. Pyrolysis-GC/MS and optical microscopy techniques were applied to material from the human cranium, a weaving tool, and a small bowl. These techniques, as well as routinely applied laboratory quality assurance procedures, indicated that there was no residual pitch within the cranium or the weaving tool after pretreatment, giving confidence to the dates. However, the small bowl was observed to still be contaminated with pitch after extensive pretreatment, indicating that the date is too old and can only be considered as a terminus post quem.