Black pitch, carved histories: Radiocarbon dating, wood species identification and strontium isotope analysis of prehistoric wood carvings from Trinidad's Pitch Lake

Abstract

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 BC to ca. AD 700, 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.

Absence of Saharan dust influence on the strontium isotope ratios on modern trees from the Bahamas and Turks and Caicos Islands

“…Our study builds on previous work in the region, and serves in part as a test of the predictions made by Bataille et al’s (2012) strontium isoscape. Ultimately, the intention is to use these data, in conjunction with other isotopic datasets being produced in the circum-Caribbean, to facilitate studies of the origins and mobility of pre-Columbian humans, animals, and artifacts (Laffoon et al, 2012, 2014, 2016, 2017; Ostapkowicz et al, 2017). The results may also be of interest to those creating isoscapes in other parts of the world (Evans et al, 2010; Snoeck et al, 2016) and to those studying pedogenesis and soil processes using Sr as a tracer for calcium cycling (e.g., Åberg et al, 1990; Reynolds et al, 2012).…”

87Sr/86Sr and 14C evidence for peccary (Tayassuidae) introduction challenges accepted historical interpretation of the 1657 Ligon map of Barbados

“…This study provides evidence for a previously unrecognized peccary introduction to Barbados and indicates the presence of this animal on the island in the 17 th or 18 th century. Along with this new record of human-assisted introduction, our results expand bioavailable Sr data for Barbados and contribute to ongoing efforts to map the West Indian Sr isoscape [22, 25, 34, 51, 54, 55, 57]. Further investigation is required to determine the species, timing, source, and number of animals involved in peccary translocation, and the size and persistence of the population on the island.…”

“…The closest island with a similar mean Sr ratio to Barbados is Marie Galante (, n = 4) [51], a carbonate island 330 km to the northwest, where peccary is unknown historically and prehistorically. While Sr ratios for Trinidad generally fall above ~0.7100, localized areas in southern Trinidad exhibit bioavailable Sr comparable to Barbados (~0.7090) (Fig 11 in [54]). P .…”

“…In the West Indies, 87 Sr /86 Sr analysis has been applied to understand patterns of human and animal movement between islands and the continent [22, 24, 25, 49–53] and reconstruct exchange networks through the sourcing of wood and animal-tooth artifacts [34, 35, 54]. Modelling and empirical studies conducted in the last decade have produced a more robust understanding of the 87 Sr /86 Sr isoscape of the islands and South American circum-Caribbean [22, 51, 54, 55], with recent efforts expanded to include multi-isotopic approaches [25, 34, 52] and evaluation of Sr inputs from African dust transport, notably from Saharan and Bodélé Depression sources, to the Caribbean [56, 57] (see also [58–60]).…”

Fraud and misrepresentation in retail forest products exceeds U.S. forensic wood science capacity

“…Observations made at this scale were functionally qualitative, and relied on expert knowledge of wood patterns rather than measured data or a list of explicit character states. Slides for microscopic analysis were prepared as in [28].…”