Periodic Reporting for period 1 - A-LIGHT (Archaeology of the Light: multiproxy, interdisciplinary and experimental approach to the knowledge of palaeolithic subterranean activities)
Reporting period: 2022-10-01 to 2024-11-30
The control of fire is a milestone in human evolution. Artificial lighting is a crucial resource for the expansion of social and economic behaviour in Palaeolithic groups beyond the day hours. Besides, this allowed the potential development of the first symbolic comportment located in deep caves probably at least 176ky ago. This would increase during the Upper Palaeolithic when archaeological remains proliferate in darkness linked to the rock art. The A-LIGHT project, Archaeology of the Light, aims to improve our knowledge of palaeolithic activities in caves through a pioneering and interdisciplinary methodology applied to rarely-studied remains: the residues of Palaeolithic light. Its multi-analytical approach provide multifaceted information, including the widely debated chronology of the first cave art. Additionally, it supply useful data for other researchers who delve into topics related to cave art and the symbolic world of the Palaeolithic (visibility, accessibility, space perception...). The experimental reproduction permit evaluating the efficiency of the light systems deduced from the previous multi-analytical study and reach a Virtual Scientific Reproduction , with its economic potential in heritage dissemination and tourism activities. It also includes an ethnographic section which help shedding some light on alternative interpretations to the utilitarian aspect of the firelight. The host institution (UBx), under the supervision of Dr. Ferrier, conduct and train Dr. Medina, a specialist in Subterranean Archaeology from Spain, to advance her training in Archaeo-pyrotechnology in caves (multiproxy, multi-analytical and experimental approach, with special incidence about on-site analysis). Dr. Medina contribute to the charcoal analysis from the inner of the caves and provide an opportunity for the host to expand the study area to new geographical contexts and recently discovered caverns.
In the two years we have been developing the A-LIGHT project, we have made significant progress on the major objectives we set out to achieve. Below, we detail the activities carried out and the main achievements for each of the caves included in the project. Each cave has different timelines and years of research, which has influenced the degree to which the objectives have been met (Altxerri, Alkerdi II, Bruniquel, Cussac, Atxurra, Nerja). However, we have advanced in the study of combustion residues in all of them. Furthermore, over the last year we have begun the study of two caves not initially included in the project (Navarro, Commarque). In them we have discovered previously unknown remains, which help us to understand the diachronic complexities of illumination in Prehistory, as well as to analyse caves with varying degrees of conservation.
Research objective 1. Define and analyze the lighting systems used by Paleolithic hunter- gatherers in each cave, through multiproxy and multi-analytical approaches (prioritizing on-site and non-destructive methods).
Activities and achievements by cave:
Bruniquel Cave:
- Reviewed all paved surfaces in the cave using portable microscopy.
- Identified previously unknown torch residues, which represent the oldest evidence of this lighting system in human history inside the caves.
- First identification of the use of woody fuel in the cave, complementing bone fuel in the fires found in the singular structure.
- Anthracological identification of oak and Scots pine used in these lighting fires and torches.
- Active participation of Dr Medina in the writing of 2 collective research reports (1 per project year).
Cussac Cave:
- Partial review of paved surfaces using portable microscopy.
- Identified previously unknown torch residues, adding to the catalog of evidence of Paleolithic human activity in this emblematic cave with Paleolithic art.
- Publication of a collective article (2024) in the journal Bilan scientifique (Direction régionale des affaires culturelles Nouvelle-Aquitaine, Service régional de l'archéologie), ISSN 2650-8346.
- Active participation of Dr Medina in the writing of 2 collective research reports (1 per project year).
Altxerri Cave:
- Revision of all paved surfaces using portable microscopy.
- Identification of previously unknown torch residues in areas A and B.
- Identification of woody fuel (pine and juniper) and bone in zone B.
- Beginning of the interdisciplinary study and radiocarbon characterization of the Palaeolithic context of zone B of the cave (linked to the artistic creation of one of the oldest Palaeolithic painting groups in Europe).
- Dr. Medina have developed/coordinated 2 research reports (1 per year of the project).
Atxurra Cave:
- Excavation and prospecting had already been completed when the project began.
- Within A-LIGHT, we advanced the interdisciplinary study in laboratory of combustion residues inside the cave.
- Conducted anthracological studies of these residues to identify the wood species used for torches and obtained new dates for the determination of various visits to the area with Paleolithic art.
- Characterized and identified a block used as a lamp.
- Results on combustion/lighting residues in this cave were co-published in Scientific Reports in 2023, and an overview of this work was presented at the ASP 2022 conference.
Alkerdi II Cave:
- Excavation and prospecting had already been completed when the project began.
- Within A-LIGHT, we analyzed the combustion residues from a small fixed fire inside the cave, fueled with bone and wood.
- Obtained new dates for this structure, dating back to the beginning of the Upper Paleolithic.
Nerja Cave:
- Prospection and micro-excavation to locate lighting residues had already been completed when the project began.
- Within A-LIGHT, we advanced the interdisciplinary study in laboratory of combustion residues of this cave, analyzing previously unknown wood torch residues (mainly Scots pine), several lamps, and fixed fires.
- Conducted extensive radiocarbon dating to establish precise chronologies of prehistoric visits, including studying charcoal and soot inside a stalagmite.
- This work was completed and published in Scientific Reports in 2023. This article has had a great repercussion in our field of study, extending the origin of human occupation of this cave by 10,000 years and documenting more than 70 different visits to the interior of this cavity; an unprecedented number of visits to a prehistoric cave at that time. All this has been possible thanks to the multi-analytical study of the combustion/lighting residues, archaeological remains rarely studied in deep caves until the implementation of this project, hitherto unparalleled.
Navarro Cave:
- Beginning of the survey of the cave using portable microscopy.
- Identification of previously unknown palaeolithic torch residues.
- This work was presented in a paper at the EAA International Congress in Rome in 2024.
- Dr. Medina have developed 1 research reports.
Commarque Cave:
- Beginning of the survey of the cave using portable microscopy.
- Different types of instruments have been tested for the microscopic observation of charcoal on site (HIROX, Dinolite and reflex camera with ultra-macro lens), to ascertain the advantages and disadvantages of each and thus advance in the
development/application of the technique best suited to the endokarst context for the study of charcoal without sampling and without contact.
- This work will presented in an oral communication in GMPCA 2025 (France).
- Participation of Dr. Medina in the writing of 2 collective research reports (1 per year of the project).
Research objective 2. Quantify the physical parameters and elemental characteristics, including their residual aspects, through experimental replication and monitoring.
Building on the results of our work published in PLOS ONE in 2021 and the outcomes of Objective 1, we conducted several monitored experiments on Paleolithic lighting systems within the A-LIGHT project framework.
These experiments were carried out in endokarstic environments to closely mimic the subterranean context in which these fires were made, which influences their pyrogenic dynamics.
- Torch experiments: Focused on Scots pine torches, the most frequently documented lighting system in Objective 1 and the studied caves. We obtained new luminescence data and reference archaeological residues for comparative analysis.
- Lamp experiments: Conducted experiments on Paleolithic lamps to better characterize the residues left by their use and facilitate their identification in the archaeological record (especially for an element of complex identification located in the Atxurra Cave).
These experiments were conducted in two different sites:
- A monitored artificial quarry (in collaboration with C. Ferrier, the project supervisor).
- A laboratory cave prepared by the Pregraphity team (in collaboration with D. Garate, University of Cantabria).
Additionally, we conducted experiments on Paleolithic torches to quantify and define the dispersion of archaeological residues caused by their use. This work was carried out by
G. Rousseau for a Master's thesis co-directed by Dra. M. Medina (the project’s PI) and other colleagues. This work will be presented at the GMPCA Congress in April 2025.
Finally, we conducted experiments on the famous Paleolithic lamp from Lascaux Cave to better understand its use. This work was also funded by the GPR Human Past (University of Bordeaux) through the LAMPAST project. Results were presented in 2022 at the EAA International Congress (Budapest).
3. Synthesize the data and evaluate the role of firelight in Paleolithic hunter-gatherer societies, including its significance for cave anthropization and the performance of early symbolic activities.
Thanks to the A-LIGHT project, we have identified new Paleolithic lighting remains, particularly for the three main systems (torches, fireplaces, and lamps). The interdisciplinary study of these remains has led to the establishment of characterization protocols and methods to obtain archaeological inference regarding Paleolithic visits in deep caves.
The A-LIGHT project has provided essential data for the understanding of Palaeolithic underground activity (new dating, number of visits, lighting systems used, quantity and type of fuel, etc.). It has also provided: (1) the numerical data necessary for the development of GIS in caves. It provides reliable data on visibility, accessibility, etc. in dark spaces. This aspect has been developed and published in collaboration with I. Intxaurbe. (2) Progress has been made in microscopic study for in situ identification without sampling (and without contact), which is greatly benefiting the analysis of coals in unique places such as caves with PA, which are sometimes very protected. (3) In addition, pioneering techniques have been applied to our archaeological context, especially several techniques linked to nanotechnology (for example, TEM-EDX) for the study of combustion residues in caves. (4) Essential data has also been provided for the development of realistic virtual recreations of cave spaces with Palaeolithic art. This work was carried out in collaboration with the research project "Scientific virtual reality for the study and dissemination of scenarios of artistic creation in Paleolithic caves (RealCaveART)" (PDC2022-133124-I00), directed by PI Diego Garate and funded by MCIN/AEI/10.13039/501100011033 and the European Union Next Generation EU/PRTR. The results of this collaboration were published in 2024 in Virtual Archaeology. and the European Union Next Generation EU /PRTR. The results of this collaboration were published in 2024 in Virtual Archaeology.
Research objective 1. Define and analyze the lighting systems used by Paleolithic hunter- gatherers in each cave, through multiproxy and multi-analytical approaches (prioritizing on-site and non-destructive methods).
Activities and achievements by cave:
Bruniquel Cave:
- Reviewed all paved surfaces in the cave using portable microscopy.
- Identified previously unknown torch residues, which represent the oldest evidence of this lighting system in human history inside the caves.
- First identification of the use of woody fuel in the cave, complementing bone fuel in the fires found in the singular structure.
- Anthracological identification of oak and Scots pine used in these lighting fires and torches.
- Active participation of Dr Medina in the writing of 2 collective research reports (1 per project year).
Cussac Cave:
- Partial review of paved surfaces using portable microscopy.
- Identified previously unknown torch residues, adding to the catalog of evidence of Paleolithic human activity in this emblematic cave with Paleolithic art.
- Publication of a collective article (2024) in the journal Bilan scientifique (Direction régionale des affaires culturelles Nouvelle-Aquitaine, Service régional de l'archéologie), ISSN 2650-8346.
- Active participation of Dr Medina in the writing of 2 collective research reports (1 per project year).
Altxerri Cave:
- Revision of all paved surfaces using portable microscopy.
- Identification of previously unknown torch residues in areas A and B.
- Identification of woody fuel (pine and juniper) and bone in zone B.
- Beginning of the interdisciplinary study and radiocarbon characterization of the Palaeolithic context of zone B of the cave (linked to the artistic creation of one of the oldest Palaeolithic painting groups in Europe).
- Dr. Medina have developed/coordinated 2 research reports (1 per year of the project).
Atxurra Cave:
- Excavation and prospecting had already been completed when the project began.
- Within A-LIGHT, we advanced the interdisciplinary study in laboratory of combustion residues inside the cave.
- Conducted anthracological studies of these residues to identify the wood species used for torches and obtained new dates for the determination of various visits to the area with Paleolithic art.
- Characterized and identified a block used as a lamp.
- Results on combustion/lighting residues in this cave were co-published in Scientific Reports in 2023, and an overview of this work was presented at the ASP 2022 conference.
Alkerdi II Cave:
- Excavation and prospecting had already been completed when the project began.
- Within A-LIGHT, we analyzed the combustion residues from a small fixed fire inside the cave, fueled with bone and wood.
- Obtained new dates for this structure, dating back to the beginning of the Upper Paleolithic.
Nerja Cave:
- Prospection and micro-excavation to locate lighting residues had already been completed when the project began.
- Within A-LIGHT, we advanced the interdisciplinary study in laboratory of combustion residues of this cave, analyzing previously unknown wood torch residues (mainly Scots pine), several lamps, and fixed fires.
- Conducted extensive radiocarbon dating to establish precise chronologies of prehistoric visits, including studying charcoal and soot inside a stalagmite.
- This work was completed and published in Scientific Reports in 2023. This article has had a great repercussion in our field of study, extending the origin of human occupation of this cave by 10,000 years and documenting more than 70 different visits to the interior of this cavity; an unprecedented number of visits to a prehistoric cave at that time. All this has been possible thanks to the multi-analytical study of the combustion/lighting residues, archaeological remains rarely studied in deep caves until the implementation of this project, hitherto unparalleled.
Navarro Cave:
- Beginning of the survey of the cave using portable microscopy.
- Identification of previously unknown palaeolithic torch residues.
- This work was presented in a paper at the EAA International Congress in Rome in 2024.
- Dr. Medina have developed 1 research reports.
Commarque Cave:
- Beginning of the survey of the cave using portable microscopy.
- Different types of instruments have been tested for the microscopic observation of charcoal on site (HIROX, Dinolite and reflex camera with ultra-macro lens), to ascertain the advantages and disadvantages of each and thus advance in the
development/application of the technique best suited to the endokarst context for the study of charcoal without sampling and without contact.
- This work will presented in an oral communication in GMPCA 2025 (France).
- Participation of Dr. Medina in the writing of 2 collective research reports (1 per year of the project).
Research objective 2. Quantify the physical parameters and elemental characteristics, including their residual aspects, through experimental replication and monitoring.
Building on the results of our work published in PLOS ONE in 2021 and the outcomes of Objective 1, we conducted several monitored experiments on Paleolithic lighting systems within the A-LIGHT project framework.
These experiments were carried out in endokarstic environments to closely mimic the subterranean context in which these fires were made, which influences their pyrogenic dynamics.
- Torch experiments: Focused on Scots pine torches, the most frequently documented lighting system in Objective 1 and the studied caves. We obtained new luminescence data and reference archaeological residues for comparative analysis.
- Lamp experiments: Conducted experiments on Paleolithic lamps to better characterize the residues left by their use and facilitate their identification in the archaeological record (especially for an element of complex identification located in the Atxurra Cave).
These experiments were conducted in two different sites:
- A monitored artificial quarry (in collaboration with C. Ferrier, the project supervisor).
- A laboratory cave prepared by the Pregraphity team (in collaboration with D. Garate, University of Cantabria).
Additionally, we conducted experiments on Paleolithic torches to quantify and define the dispersion of archaeological residues caused by their use. This work was carried out by
G. Rousseau for a Master's thesis co-directed by Dra. M. Medina (the project’s PI) and other colleagues. This work will be presented at the GMPCA Congress in April 2025.
Finally, we conducted experiments on the famous Paleolithic lamp from Lascaux Cave to better understand its use. This work was also funded by the GPR Human Past (University of Bordeaux) through the LAMPAST project. Results were presented in 2022 at the EAA International Congress (Budapest).
3. Synthesize the data and evaluate the role of firelight in Paleolithic hunter-gatherer societies, including its significance for cave anthropization and the performance of early symbolic activities.
Thanks to the A-LIGHT project, we have identified new Paleolithic lighting remains, particularly for the three main systems (torches, fireplaces, and lamps). The interdisciplinary study of these remains has led to the establishment of characterization protocols and methods to obtain archaeological inference regarding Paleolithic visits in deep caves.
The A-LIGHT project has provided essential data for the understanding of Palaeolithic underground activity (new dating, number of visits, lighting systems used, quantity and type of fuel, etc.). It has also provided: (1) the numerical data necessary for the development of GIS in caves. It provides reliable data on visibility, accessibility, etc. in dark spaces. This aspect has been developed and published in collaboration with I. Intxaurbe. (2) Progress has been made in microscopic study for in situ identification without sampling (and without contact), which is greatly benefiting the analysis of coals in unique places such as caves with PA, which are sometimes very protected. (3) In addition, pioneering techniques have been applied to our archaeological context, especially several techniques linked to nanotechnology (for example, TEM-EDX) for the study of combustion residues in caves. (4) Essential data has also been provided for the development of realistic virtual recreations of cave spaces with Palaeolithic art. This work was carried out in collaboration with the research project "Scientific virtual reality for the study and dissemination of scenarios of artistic creation in Paleolithic caves (RealCaveART)" (PDC2022-133124-I00), directed by PI Diego Garate and funded by MCIN/AEI/10.13039/501100011033 and the European Union Next Generation EU/PRTR. The results of this collaboration were published in 2024 in Virtual Archaeology. and the European Union Next Generation EU /PRTR. The results of this collaboration were published in 2024 in Virtual Archaeology.
The "Archeology of the Light" (A-LIGHT) project aims to improve our knowledge of Palaeolithic cave activities through an interdisciplinary methodology applied to rarely-studied remains: the residues of Palaeolithic light from lamps, fireplaces and torches (specially, charcoal and soot).
Methods
The methodology includes different stages such as: 1. Research in caves and sampling, 2 Laboratory analyses (multi-analytical approach adapted to the type of combustion residue analysed, including Anthracology, C14 dating, Bayesian analysis, SEM-EDX, TEM.EDX Raman), 3. Ethnographic review of firelight, 4. Experimental reproduction and monitoring of Palaeolithic firelight. 5. Analyses, integration of data and synthesis.
Results
This approach contributes multifaceted data about the Palaeolithic activities inside the caves (lighting systems selected, fuel used, chronology and intensity of visits or paleo-paths). Experimental reproductions have enabled evaluation of the Palaeolithic lighting potential. This provide essential information for research the visibility and the accessibility of Rock Art from GIS, and allow to more realistic
Conclusions
These data demonstrate that the Archaeology of the Light is “here to stay” and that it is an essential approach for a holistic understanding of Palaeolithic caves. Especially on the lighting systems used by paleo- groups in the underground environment (functioning, selected fuels, duration, light intensity), on the minimum number and date of prehistoric incursions, as well as on aspects related to the visibility and accessibility of Palaeolithic cave art.
For more information, see the article published about the project on the ORE platform: https://doi.org/10.12688/openreseurope.17712.1(opens in new window)
Methods
The methodology includes different stages such as: 1. Research in caves and sampling, 2 Laboratory analyses (multi-analytical approach adapted to the type of combustion residue analysed, including Anthracology, C14 dating, Bayesian analysis, SEM-EDX, TEM.EDX Raman), 3. Ethnographic review of firelight, 4. Experimental reproduction and monitoring of Palaeolithic firelight. 5. Analyses, integration of data and synthesis.
Results
This approach contributes multifaceted data about the Palaeolithic activities inside the caves (lighting systems selected, fuel used, chronology and intensity of visits or paleo-paths). Experimental reproductions have enabled evaluation of the Palaeolithic lighting potential. This provide essential information for research the visibility and the accessibility of Rock Art from GIS, and allow to more realistic
Conclusions
These data demonstrate that the Archaeology of the Light is “here to stay” and that it is an essential approach for a holistic understanding of Palaeolithic caves. Especially on the lighting systems used by paleo- groups in the underground environment (functioning, selected fuels, duration, light intensity), on the minimum number and date of prehistoric incursions, as well as on aspects related to the visibility and accessibility of Palaeolithic cave art.
For more information, see the article published about the project on the ORE platform: https://doi.org/10.12688/openreseurope.17712.1(opens in new window)