Periodic Reporting for period 1 - Fire-Tools (Tools for the identification of anthropic Fire in low visibility contexts during the Middle Pleistocene)
Reporting period: 2023-01-01 to 2024-12-31
Fire is an element that has profoundly changed the way human groups live. However, we know very little about where, when and how this process took place, especially in relation to the earliest evidence of fire in the Middle Pleistocene. There is a consensus that the first uses of fire were associated with human groups catching fire from natural wildfires. However, there is a great deal of controversy and debate around this phenomena, related to the type of evidence that would support these first uses of fire, how to identify them in the archaeological record, and how to distinguish them from natural fires.
This project has included two Middle Pleistocene sites on the Iberian Peninsula (Sima del Elefante and La Cansaladeta) that have limited evidence for the use of fire, but are within the period of 300-400 thousand years when previous research suggests that the use of fire became commonplace.
The Fire-Tools project will provide a good opportunity to test the suitability of the new methods for identifying the anthropogenic origin of fire, and to generate new analytical and methodological approaches that can be widely applied to any type of fire or fire-related feature, without chronological or geographical constraints.
Despite the difficulties presented by the initial evidence of fire, the Fire-Tools project proposes to develop a multi-proxy analysis with three successive objectives:
- Identification: to test the use of PAHs, phytoliths and the applicability of phytolith CMRs at two specific sites to detect traces of fire and determine the anthropogenic origin of concealed fire evidence.
- Integration: to bring together the results of PAHs and phytoliths with other archaeological data provided by archaeologists and researchers to integrate all fire evidence into a contextual framework.
- Evaluation: to provide guidelines for the detection of anthropogenic fire in future studies related to pyroarchaeology, after considering the limitations and potential of our methodological proposal based on archaeobotanical and chemical approaches.
In summary, Fire-Tools aims to generate new data that will have an impact on the debate about the habitual use of fire, relying on a powerful methodological structure to position the project results in a prominent place to advance knowledge of pyrotechnics in the genus Homo.
This project has included two Middle Pleistocene sites on the Iberian Peninsula (Sima del Elefante and La Cansaladeta) that have limited evidence for the use of fire, but are within the period of 300-400 thousand years when previous research suggests that the use of fire became commonplace.
The Fire-Tools project will provide a good opportunity to test the suitability of the new methods for identifying the anthropogenic origin of fire, and to generate new analytical and methodological approaches that can be widely applied to any type of fire or fire-related feature, without chronological or geographical constraints.
Despite the difficulties presented by the initial evidence of fire, the Fire-Tools project proposes to develop a multi-proxy analysis with three successive objectives:
- Identification: to test the use of PAHs, phytoliths and the applicability of phytolith CMRs at two specific sites to detect traces of fire and determine the anthropogenic origin of concealed fire evidence.
- Integration: to bring together the results of PAHs and phytoliths with other archaeological data provided by archaeologists and researchers to integrate all fire evidence into a contextual framework.
- Evaluation: to provide guidelines for the detection of anthropogenic fire in future studies related to pyroarchaeology, after considering the limitations and potential of our methodological proposal based on archaeobotanical and chemical approaches.
In summary, Fire-Tools aims to generate new data that will have an impact on the debate about the habitual use of fire, relying on a powerful methodological structure to position the project results in a prominent place to advance knowledge of pyrotechnics in the genus Homo.
In relation to the objectives and work plan set out in the project, we have carried out the following activities and achieved the following objectives.
Creation of a modern reference collection of plants:
• I have collected 10 arbustibos taxa for the modern reference collection, separated by their different parts: leaves, fruit, inflorescence and wood.
• I trained in the identification of these taxa in their environment, understanding their ecology and differentiating their different parts.
Sampling of Middle Pleistocene deposits
• I sampled the two sequences included in the project, Sima del Elefante and La Cansaladeta, following the anti-contamination protocols required by the protocols for chemical analysis of sediments.
• I was able to carry out continuous and representative sampling of the units analysed for subsequent analysis and I also learnt how to take samples for chemical analysis. I also learnt the importance of blanks in this type of analysis and the criteria to follow to ensure they are valid for the proposed analyses.
Biomarker analysis
• I analysed a total of 120 samples from the two sites to obtain qualitative and quantitative results for PAHs.
• This activity involved intensive training in basic chemistry, analytical chemistry, preparation of calibrations, preparation of deuterated compounds, preparation of sediment samples, extraction of analytes from sediment samples and obtaining results using gas chromatography-mass spectrometry. This training took place at the University of the Basque Country under the supervision of Prof. Asier Vallejo and lasted 5 months.
Phytolith analysis
• Carrying out the analysis of the 120 samples to obtain the phytoliths.
• I learnt to analyse contexts from the Middle Pleistocene, with low preservation and conservation of these microparticles.
Data Integration
• This activity involved reviewing the entire event at the sites studied, activating stalled analyses and encouraging the inclusion of new analyses, searching for researchers who could carry them out, sampling materials and coordinating a relevant group of researchers, together with the directors of the sites.
• A systematic collection was made of all the available bibliography; other analyses were carried out, such as palaeomagnetic analyses of the sediments, taphonomic analyses of the fauna, molecular analyses of the bones, macroscopic and experimental analyses of the burnt and unburnt lithic tools, micromorphological analyses and pH analyses of the sediments. For my part, I carried out analyses not included in the proposal, such as the determination of n-alkane values and FTR analyses of the sediments. We have also started a ground-breaking experimental project to understand how PAHs are deposited and preserved in relation to a flat combustion structure such as may have occurred in the deposits studied. We have also started a pioneering experimental project that will help us understand how PAHs are deposited and preserved in relation to a flat combustion structure such as the one that could have occurred in the deposits studied. We have also started a ground-breaking experimental project to understand how PAHs are deposited and preserved in relation to a flat combustion structure such as may have occurred in the deposits studied.
Creation of a modern reference collection of plants:
• I have collected 10 arbustibos taxa for the modern reference collection, separated by their different parts: leaves, fruit, inflorescence and wood.
• I trained in the identification of these taxa in their environment, understanding their ecology and differentiating their different parts.
Sampling of Middle Pleistocene deposits
• I sampled the two sequences included in the project, Sima del Elefante and La Cansaladeta, following the anti-contamination protocols required by the protocols for chemical analysis of sediments.
• I was able to carry out continuous and representative sampling of the units analysed for subsequent analysis and I also learnt how to take samples for chemical analysis. I also learnt the importance of blanks in this type of analysis and the criteria to follow to ensure they are valid for the proposed analyses.
Biomarker analysis
• I analysed a total of 120 samples from the two sites to obtain qualitative and quantitative results for PAHs.
• This activity involved intensive training in basic chemistry, analytical chemistry, preparation of calibrations, preparation of deuterated compounds, preparation of sediment samples, extraction of analytes from sediment samples and obtaining results using gas chromatography-mass spectrometry. This training took place at the University of the Basque Country under the supervision of Prof. Asier Vallejo and lasted 5 months.
Phytolith analysis
• Carrying out the analysis of the 120 samples to obtain the phytoliths.
• I learnt to analyse contexts from the Middle Pleistocene, with low preservation and conservation of these microparticles.
Data Integration
• This activity involved reviewing the entire event at the sites studied, activating stalled analyses and encouraging the inclusion of new analyses, searching for researchers who could carry them out, sampling materials and coordinating a relevant group of researchers, together with the directors of the sites.
• A systematic collection was made of all the available bibliography; other analyses were carried out, such as palaeomagnetic analyses of the sediments, taphonomic analyses of the fauna, molecular analyses of the bones, macroscopic and experimental analyses of the burnt and unburnt lithic tools, micromorphological analyses and pH analyses of the sediments. For my part, I carried out analyses not included in the proposal, such as the determination of n-alkane values and FTR analyses of the sediments. We have also started a ground-breaking experimental project to understand how PAHs are deposited and preserved in relation to a flat combustion structure such as may have occurred in the deposits studied. We have also started a pioneering experimental project that will help us understand how PAHs are deposited and preserved in relation to a flat combustion structure such as the one that could have occurred in the deposits studied. We have also started a ground-breaking experimental project to understand how PAHs are deposited and preserved in relation to a flat combustion structure such as may have occurred in the deposits studied.
On the basis of the objectives proposed, the methods used and the activities carried out, we have obtained some results that contribute to the advancement of knowledge about the use of fire by human groups in the Middle Pleistocene. Progress has been made in the methodological and referential aspects, but also in the archaeological part of the project. On the one hand, we have begun to establish modern references for arboreal taxa in order to identify and characterise the phytoliths that make them up; on the other, we have started an experimental project to understand how key biomarkers in this type of ancient sequence, such as PAHs, are deposited and degraded. At the archaeological level, we have been able to clearly identify the presence of PAHs in the sequences studied, and in both cases we have initiated research projects on fire, which were not previously available, although there was indirect evidence of combustion. The project has generated a number of synergies with other researchers working along the same lines, helping to build robust data that will help us to identify the presence of fire in these sequences and its anthropogenic or natural origin. All of this has allowed us to reflect on the limitations and potential of different approaches to the study the pyroarchaeological record, to understand the main challenges in identifying anthropogenic fire when it does not present a macroscopically, and to contribute a multidisciplinary proposal that will allow the assessment of the first evidence of fire in Middle Pleistocene sequences.