East-central Florida pre-Columbian wood sculpture: Radiocarbon dating, wood identification and strontium isotope studies

A suite of scientific approaches are applied to four pre- Columbian wood sculptures from east-central Florida, comprising new radiocarbon determinations, wood identification and strontium isotope analysis. The dates for three large zoomorphic carvings recovered from the St. Johns River at Hontoon Island place them between ca. AD 1300 and 1600, suggesting that they belonged to a tradition of erecting largescale pine carvings spanning at least some centuries. Two of the carvings have strontium isotope signals consistent with the immediate vicinity of the site, while the third differs significantly. Baseline data for biologically available strontium from sampled modern trees indicates considerable isotopic variability over short distances, making it difficult to determine the source of the wood used for this third carving. The only anthropomorphic sculpture, recovered from the vicinity of Tomoka State Park, dates to a similar time period, ca. AD 1440-1620. Our study confirms the wood's previous identification as belonging to the genus Peltophorum, a tropical hardwood thought not to be native to Florida. Its strontium isotope value is consistent with its find location, but equally may be found over much of southern Florida, where perhaps the species grew in the past. The results clarify the chronology for a stylistically distinctive carving tradition, as well as raising questions concerning the exchange of organic materials over varying distances. Highlights • 14C results for four east-central Florida carvings (Hontoon Island; Tomoka State Park) range ca. AD 1300-1600, spanning the proto-historic/historic periods • 87Sr/86Sr results for two of the three Hontoon carvings are consistent with the immediate locale, while the third suggests a different provenance • Pinus sp. was used at Hontoon, while Peltophorum sp., currently not native to Florida, was used at Tomoka</p

Radiocarbon dating wooden carvings and skeletal remains from Pitch Lake, Trinidad

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

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

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

Testing various pre-treatments on artificially waterlogged and pitch-contaminated wood for strontium isotope analyses

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

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

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

New wealth from the Old World: glass, jet and mirrors in the late fifteenth to early sixteenth century indigenous Caribbean

One of the most momentous cross-cultural collisions occurred in the Caribbean in 1492, heralding a period of rapid change in both ‘New’ and ‘Old’ Worlds. During the early years of the colonial period, when new relationships were being established, material objects became active agents in the interactions between the indigenous Taíno and the Spanish. The Taíno gifted the Spanish with objects that had significance in their own world, in an attempt to enmesh the Spanish into Taíno socio-political and economic networks. In turn, the Spanish objects entered into Taíno value systems. Glass and jet beads, mirrors and brass ornaments were integrated into prestigious objects, such as the two surviving Taíno cotton sculptures that form the focus of this paper: a belt in the collections of the Weltmuseum Wien, and a composite sculpture in the Museo Nazionale Preistorico Etnografico ‘Luigi Pigorini’, Rome. These pieces offer a glimpse into how Old World exotics were reinterpreted and integrated into indigenous value systems during a period of cultural transition and change