Meet the team
Joanna Ostapkowicz (PI)
On the edge of Pitch Lake, photo courtesy of Jameel Mohammed
As principal investigator (PI) on the project, I am involved in the study of the Pitch Lake artefacts and their wider context – ranging from photographic inventories of each carving, to the study of their depositional environment (Pitch Lake, its history and archaeology) to collecting herbarium samples in order to establish a strontium baseline for Trinidad and Tobago.
I had the pleasure of visiting the institutions involved in the project, to study their collections in detail (National Museum and Art Gallery of Trinidad and Tobago, Peter Harris collection at the Pointe-a-Pierre Wildfowl Trust and the Peabody Museum of Natural History), and to travel across the islands of Trinidad and Tobago for the fieldwork – the latter a collaborative venture involving the National Herbarium (Yasmin Baksh-Comeau) and Trinidad and Tobago's Forestry Division.
Together with colleagues from the Oxford Radiocarbon Accelerator Unit (Fiona Brock, Co-I), the Center of Wood Anatomy Research, USDA (Alex Wiedenhoeft), Vrije Universiteit Brussel (Christophe Snoeck), and Leiden University (Arie Boomert), our task is to better integrate the Pitch Lake artefacts within the region’s prehistory, and to explore their meaning to the people who created them.
Fiona Brock (Co-I)
Fiona and Cyril sampling fresh pitch at Pitch Lake
My role in the Pitch Lake project was to sample the pieces and undertake the radiocarbon dating, and this was always going to be a challenge!
Firstly, collecting a small amount of material from each object required careful consideration of various critical aspects – from targeting the outermost tree rings within the carving to ensuring that we were taking sufficient material to achieve a date, whilst sampling away from adhering pitch, areas with particular stylistic or diagnostic features, and anywhere that would be too visible once the piece was redisplayed.
An even bigger challenge was ensuring that any pitch was removed from the samples before dating. As the pitch is extremely old, any remaining in a sample could result in an artificially old date. A range of decontamination experiments was run to find the most effective chemical method for removing the Trinidadian pitch, based on published protocols used for dating wood and bone samples from the Rancho La Brea Tar Pits in California. This was then applied to some known-age archaeological wood that I’d deliberately contaminated at Pitch Lake, to demonstrate that the expected dates could be achieved.
A range of techniques (including visual, microscopy and chemical methods) was then used to demonstrate that no pitch contamination remained in the samples prior to dating, and hence that the radiocarbon results are accurate and reliable.
My involvement with the Pitch Lake dates back to the 1980s when I was attached to Trinidad’s campus of the University of the West Indies as a Senior Research Fellow in Archaeology. Intrigued by the wooden artefacts, which have been retrieved from the asphalt mass irregularly, I studied these objects and the archaeological sites around the lake, together with the late Peter O’Brien Harris of the Trinidad and Tobago Historical Society (South Section).
I also researched the physiography, history, and Amerindian mythology of the Pitch Lake. The latter, explaining the origin of the lake, appeared to be most interesting. The myth in question turned out to be part of a larger mythological cycle, still told at present among the Arawak (Lokóno) of the coastal region of the Guianas on the mainland of South America.
It is obvious that the indigenous beliefs regarding the lake’s origin and relevance to the Amerindian universe are of prime importance to understanding the reasons of deposition into the lake of the wooden artefacts which at present are the subject of our multidisciplinary research project.
Alex working on the mortar sample in his lab at the Center of Wood Anatomy Research
I am a Research Botanist and the Team Leader for the Center of Wood Anatomy Research in the USDA, Forest Service, Forest Products Laboratory in Madison, Wisconsin, USA. We curate the world’s largest xylarium and conduct research on a range of topics related to wood, trees and forests.
My work on this project focused on a melding of his lab’s research areas of biocentric wood science and forensic wood science. Once I received the artefact wood ID samples, I used traditional light microscope wood identification techniques to determine the botanical identification to the lowest possible taxonomic level. This information gives insights in woods that carvers used – their botanical and physical properties, especially density.
Together with project colleagues, we then use the identifications to explore the material properties of the species in question – wood and tree, when possible – and how these unique properties may have influenced not only species selection by Trinidad’s indigenous wood carvers, but also the physical processes required for working the wood, and the curation of the objects through time.
Yasmin comparing Andira inermis specimens back at the National Herbarium. Courtesy of Terry Sampson, Audio Visual Technician, Faculty of Food and Agriculture.
My involvement in the project began with a request from Dr Joanna Ostapkowicz, curator, Americas collections, National Museums Liverpool, to assist with the collection of herbarium samples from select tree species, including Andira sp, Brosimum alicastrum, Carapa guianensis, Guaiacum sp, Platymiscium trinitatis and Terminalia dichotoma. These trees were used by the Amerindians centuries ago to carve the 10 wooden artefacts recovered in Pitch Lake, La Brea, Trinidad in the 1900s.
This invitation provided an opportunity to participate with an international multidisciplinary team. Joanna teamed up with herbarium technical staff, foresters and myself, and travelled throughout the islands in search of these selected tree samples from a wide range of different geological sites, which was a new approach to field sampling of timber species.
We know something about the biology, ecology and the ethno-botany of these trees. But the application of isotopic techniques to provenance (to geological region) the timber our indigenous people used, brings new information and insight into the utilization of these trees. These data, which will be added to the voucher specimens we collected in this study, are the first of their kind to connect us to our indigenous inhabitants.
Christophe working on the samples at the Vrije Universiteit Brussel’s lab
My involvement in this project concerns the measurement of strontium isotopes in wooden artefacts and modern plant samples used to provide a context for the results obtained from the artefacts.
A major issue I am faced with when measuring the strontium isotopes in wooden artefacts is the series of preservation agents applied on them, as well as pitch when the artefacts are recovered from pitch lakes. These can contain some strontium and affect the original composition of the artefacts. To attempt to remove this contamination, I must carry out a series of chemical pre-treatments on the artefacts before analysing them by mass spectrometry.
An additional challenge I have to overcome is the extremely low amount of material available for analyses as we take great care in limiting the damage done to the artefacts. I cannot carry out the usual ashing of plant material and must design another way of removing organic matter through further chemical pre-treatments.
Modern plants are much easier to analyse since they were not contaminated and available in much large amounts. I can simply ash them in a furnace prior to analysis.
Once the measurements are obtained for the artefacts and modern plants, I will work in close collaboration with the rest of the team to interpret them and try and understand the different artefact style and trade links in and around Trinidad.