Lascaux Cave Research Articles

Analytical Pyrolysis of the Fungal Melanins from Ochroconis spp. Isolated from Lascaux Cave, France

Analytical pyrolysis is a tool widely used for investigating the nature of macromolecules. This technique has been applied with success for solving the chemical structure of geo- and biopolymers. However, with complex macromolecules, such as fungal melanins, analytical pyrolysis presents some drawbacks due to the fact that they rarely can be obtained in a pure grade and contains a mixture of polysaccharides, chitin, proteins, nucleic acids, and lipids, among other materials. Analytical pyrolysis permits the characterization of the compounds co-extracted or linked to the melanin. Nevertheless, our data revealed that under the conditions usually employed in the pyrolysis of melanins, the technique presented serious limitations due to the complex structure and diversity of components that suffer extensive thermal degradation through secondary reactions with the production of considerable number of artifacts. To the light of pyrolysis data, the melanin of Ochroconis spp. is not based on 3,4-dihydroxyphenylalanine (DOPA) or 1,8-dihydroxynaphthalene (DHN), and it is suggested that it could be a type of pyomelanin, based on the polymerization of homogentisic acid and other phenolic compounds.

Collection Storage: A Window into the Richness of Cultural Heritage.

Gaël de Guichen is a key figure in the world of conservation and collection storage. His career has taken him from the Lascaux cave in France's Vézère Valley to the International Centre for the Study of the Preservation and Restoration of Cultural Property (ICCROM) in Rome, Italy. At the latter, he developed the concept of ‘preventive conservation' and set up numerous study programmes for heritage preservation, including the RE-ORG method, which has since become an international standard in collection storage. In his words, ‘a museum's storage room is the place where unexhibited collections are brought together in optimal conditions, ready to be displayed in galleries, studied by specialists, and, if possible, seen by the public.’ In this interview, he tells us how he came to this definition and what it implies. His journey, however, is part of a larger story: one that also paves the way for the future of collection storage around the world.

Acoustics of the Lascaux cave and its facsimile Lascaux IV.

Access to the original Lascaux cave, a UNESCO World Heritage site famous for its 18 000 year old paintings, has been restricted since 1963. In 2016, an accurate facsimile, Lascaux IV, was designed and built. In the original cave, Lascaux I, classical contemporary room acoustics measurement systems could not be used. However, it has been possible to perform simplified measurements in a few minutes. Similar measurements were made in Lascaux IV once completed. The data provide a unique insight of the acoustic behavior of the Lascaux cave: it shows that the two caves, the original and the copy, have similar acoustical characteristics. In both cases, in the famed Hall of Bulls, the impulse response is smooth, reverberation time is relatively long, and speech intelligibility is fair; this environment is suitable for the ceremonies that presumably took place there. Because of the precision of the copy, Lascaux IV could be used as a 1/1 scale-model of Lascaux I. Therefore, sophisticated acoustical tests could be undertaken in Lascaux IV to help specialists in their archeological investigations. For example, resonances could be precisely documented to explore the potential relationship between parietal painting positions and echoes or sound effects that may have been used in ritual ceremonies.

Detection of undercover karst features by geophysics (ERT) Lascaux cave hill

The study of karst features under a detrital cover is difficult to obtain using punctual traditional tools. This paper presents a 3D geostatistical modeling of ERT (Electrical Resistivity Tomography) data to describe undercover karst features. A case study was carried out on the karstic site of the prehistoric decorated Lascaux cave (France). Geophysical measurements were used to define the limit between outcropping Coniacian or Santonian limestones (southwest) and clayey sands (northeast), with a main orientation of N140°. A geometrical description of the scarp was also constructed; pinnacles and notches were found under the clayey sand detrital formation. By combining 3D ERT with geomorphological and geological observations, the geometry of the stratigraphic limit between the Coniacian and Santonian limestone could be determined. This stratigraphic limit separates two domains, one is a potential aquifer, and acts as a feeder for the intermittent spring at the cave entrance, while the other is less permeable, resulting in a permeability contrast with the later rock type. All these observations help define the geological cave environment and ensure better protection for the paintings.

Aerobiological behavior of Paleolithic rock art sites in Dordogne (France): a comparative study in protected sites ranging from rock shelters to caves, with and without public access

Microbial organisms can cause huge crises in decorated caves, as seen in emblematic sites such as Lascaux cave. The preservation of such sites involves understanding the healthy microbial behavior of caves before the damage occurs. Indeed, knowledge of normal cave behavior is a prerequisite to identifying potential imbalance. This study seeks to determine whether models of aerobiological behavior could be identified in several caves of different sizes, ranging from rock shelters to large caves that are open or closed to the public. Aerial rates of fungi and bacteria were monitored over 3 years in nine sites in Dordogne (France). This study revealed that in a context of caves where public visits were carefully managed, fungal and bacterial rates were more affected by the size of the caves than by the opening of sites to the visitors. The study confirmed that large caves can generally be described as “self-purifying caves” as they were strongly affected by the exterior environment at their entry but much less so at locations further inside the cave, while small caves can be described as “non-self-purifying caves” since they were strongly affected by the exterior environment throughout their whole length. The results also highlighted the difficulty to determine a limit value of microbial rates valid for all caves because of the specificities of each one.

Cave art reveals human nature

Summary Prehistoric artworks have been discovered on numerous cave walls around the world. They tell us about the minds and lives of ancient humans as well as about their relationship with the now extinct megafauna that surrounded them. Michael Gross reports.

Twenty years on, a new date with Lascaux. Reassessing the chronology of the cave’s Paleolithic occupations through new 14C AMS dating

Aside from the stylistic debates and quarrels fueled by the studies of its painted and engraved walls, the Lascaux Cave stands out by its very weak and contradictory radiometric framework (Delluc and Delluc 2012). In addition to this, no comprehensive, interdisciplinary study of the rich archaeological assemblages has been conducted for almost forty years (Leroi-Gourhan and Allain 1979). The LAsCO project (Langlais and Ducasse coord.) aims to fill this gap by proposing a global reassessment of the osseous and lithic artifacts, ornaments, ochres and lamps. As part of this work, a new effort has been made to clarify the Paleolithic chronology of the human activities documented by this stratified evidence. Five reindeer remains taken from the cave’s main areas (Axial Gallery, Passageway, Nave, Shaft), some showing clear evidence of anthropic exploitation, were therefore selected to be dated in order to test (1) the chronological homogeneity of the occupations, as already suggested by a high typo-technological coherence and, if this was confirmed, (2) the hypothesis of an attribution to the Badegoulian-to-Magdalenian transition phase, as indicated by prior inter-site comparisons (Langlais 2010 ; Ducasse et al. 2011; DEX_TER project: Ducasse and Langlais coord.). All the selected samples were sent to the Oxford Radiocarbon Accelerator Unit (ORAU) and run on a MIni CArbon DAting System (MICADAS) after an ultrafiltration pretreatment. While the sample from the Passageway area failed due to low collagen yield, the other four produced reliable and highly comparable measurements centered on a 14C age of 17,600 uncal. BP (21.5-21 cal ka BP). These results confirm the two basic assumptions described above and contradict the diachronic framework defined by the 1948-2002 radiometric data, while restoring a certain degree of chronological consistency which fits well with the main typo-technological features of the lithic and osseous equipment (Allain 1979, Leroy-Prost 2008 and ongoing analysis). After a brief outline of the existing radiometric data and a detailed description of the sampling and dating strategy, the reliability of the results and their impact on our understanding of the cave’s phase(s) of occupation(s) are discussed in depth. While the issue of the precise “cultural” attribution of the dated assemblages and the links between the latter and the parietal art are beyond the scope of this paper, these new data represent a first but significant step towards a global renewal of the highly controversial chronological framework of the Lascaux Cave.

Shared Aesthetics: A Commentary on Collaborative Art

Shared Aesthetics: A Commentary on Collaborative Art

Climatology in shallow caves with negligible ventilation: Heat and mass transfer

The present numerical study investigates the effect of a cavity located at shallow depth below ground surface. The temperature field in the rock matrix surrounding the cave is significantly deformed compared to the case without cavity. Fluxes at cave wall, related to radiation, air-convection and evaporation/condensation (in case of a humid cave), all contribute to a significant homogenisation of wall temperatures. In case of high humidity, simulations of evaporation/condensation periods show that some parts of the wall may be durably (several months) subjected to significant condensation (or evaporation). Real meteorological data, i.e. 77 years of external temperature data of the Gourdon station in France, have been used as input of the model. Results of simulations have been compared to experimental temperature of Lascaux cave, with good agreement considering some simplifying hypotheses assumed for this modeling. The asset of such a model is the low computing time required to simulate several years, and thus its ability to follow long time evolution. Results significantly improve our understanding of conditions taking place in a shallow cavity, what will help improving the management of caves, especially those with very fragile decorations such as Paleolithic paintings. The model may help to identify areas which are the most exposed to weathering and to test the effect of past and potential changes in nearby conditions. It may also be useful for managing shallow underground constructions (e.g. a mine or even a cellar).

Rock substrate rather than black stain alterations drives microbial community structure in the passage of Lascaux Cave

BackgroundThe World-famous UNESCO heritage from the Paleolithic human society, Lascaux Cave (France), has endeavored intense microclimatic perturbations, in part due to high touristic pressure. These perturbations have resulted in numerous disturbances of the cave ecosystem, including on its microbial compartment, which resulted in the formation of black stains especially on the rock faces of the passage. We investigated the cave microbiome in this part of Lascaux by sampling three mineral substrates (soil, banks, and inclined planes) on and outside stains to assess current cave microbial assemblage and explore the possibility that pigmented microorganisms involved in stain development occur as microbial consortia.MethodsMicrobial abundance and diversity were assessed by means of quantitative PCR and high-throughput sequencing (Illumina MiSeq) of several DNA and cDNA taxonomic markers. Five sampling campaigns were carried out during winter and summer to embrace potential seasonal effect in this somewhat stable environment (based on measurements of temperature and CO2 concentration).ResultsWhile the season or type of mineral substrate did not affect the abundances of bacteria and micro-eukaryotes on or outside stains, mineral substrate rather than stain presence appears to be the most significant factor determining microbial diversity and structuring microbial community, regardless of whether DNA or cDNA markers were considered. A phylogenetic signal was also detected in relation to substrate types, presence of stains but not with season among the OTUs common to the three substrates. Co-occurrence network analyses showed that most bacterial and fungal interactions were positive regardless of the factor tested (season, substrate, or stain), but these networks varied according to ecological conditions and time. Microorganisms known to harbor pigmentation ability were well established inside but also outside black stains, which may be prerequisite for subsequent stain formation.ConclusionsThis first high throughput sequencing performed in Lascaux Cave showed that black stains were secondary to mineral substrate in determining microbiome community structure, regardless of whether total or transcriptionally active bacterial and micro-eukaryotic communities were considered. These results revealed the potential for new stain formation and highlight the need for careful microbiome management to avoid further cave wall degradation.

Assessment of fungi proliferation and diversity in cultural heritage: Reactions to UV-C treatment

Fungi are present in natural and non-touristic caves due to the presence of organic matter provided mainly by insects or animals such as bats. In show caves, however, tourist infrastructure and the visitors themselves are an important source of organic matter. In addition, photosynthetic biofilms provide a high amount of carbon and nitrogen sources for fungi. This study was conducted to identify the fungal communities present in caves along with the potential use of UV-C treatment against their proliferation. Thus, fungal communities proliferating in biofilms in six French and Swiss show caves were analyzed using high throughput sequencing. The results show 385 species recorded, some of them previously described in cases of fungal outbreak. This preliminary study also aimed to test the use of UV-C light as an environmentally friendly method to treat fungal proliferation. Six fungal strains, from three different sources (Lascaux cave, La Glacière cave, a church in Vicherey, France), were cultivated in an agar dish. Spores, mycelia and the entire colony were irradiated using several UV-C intensities. Results showed that four of the six fungi spores and mycelium died following a low-intensity UV-C treatment (2 kJ m−2, 160 s), though Ochroconis lascauxensis and Penicillium bilaiae spores showed higher resistance. Finally, it was demonstrated that the fungal colony could resist the UV-C light due to a shadow effect. The structure of the fungal colony was affected from the periphery to its inner part. However, after four 30 kJ m−2 treatments (39 min irradiation) all strains there definitively eradicated. Further studies will be necessary to examine the potential of UV-C light under cave conditions as a preventive and curative treatment.

Sangkulirang Mangkalihat: The Earliest Prehistoric Rock-Art in the World

Abstract. Borneo island, a part of Sundaland – a great mainland in South East Asia thousands of years ago – is the largest island in Indonesian Archipelago. In the middle-eastern of East Borneo, lies a peninsula karst region named Sangkulirang Mangkalihat. The region’s biodiversity contains many species of flora and fauna which are part of karst ecosystem. Surprisingly, thousands prehistoric rock art paintings and engraving were found here, spread over 48 inland caves in seven different karst mountain areas. The rock arts are painted on the ceiling, wall, and hollow of the cave depends on the meaning. They illustrate forms such as spiritual images (zoomorphic and antropomorphic) for sacred spiritual meaning, and social phenomenon images (tools and weapons) for description of daily life. From all those rock-arts, hand paintings are the most common elements appeared. Compared to other paintings, these are the only negative images using different techniques. Radiocarbon dating indicated that the rock-arts at Tewet Cave in Sangkulirang Mangkalihat is 40,000 BP. It is much earlier compared to Lascaux Cave (35,400 BP) and Chauvet Cave (32,000) in France which were previously known as the earliest one in the world. Rock arts and some archeological findings also indicate the migration of Austronesian People. During the migration, Borneo’s climate and land cover were changing from time to time. Continental climate occurred when all Sundaland was still dry (40,000–21,000 BP), followed by tropical savanna climate and archipelagic climate (12,000–7.000 BP), and then Tropical Rainforest consecutively (1,000 BP). Correlatively, geological interpretations from such areas indicate land cover changes. These changes effected Austronesian ways of living, e.g. from hunting to fishing, and were depicted clearly on their paintings. Today, – as observed from time series satellite images – industrial activities such as karst exploitation for cement production and land clearing for palm oil plantation are threatening Sangkulirang Mangkalihat as they are approaching this particular areas. Efforts were conducted to preserve these particular sites, from establishing local regulations to a great step to propose it as one of UNESCO’s World Cultural Heritage. To disseminate its importance as the world’s earliest known rock arts, a particular map should be designed. The map should be able to describe multiple aspects regarding these sites, i.e. its location and position among other world rock arts, detail locations in the sites, climate and geomorphological changes occurred and its effects to these rock arts, its correlation to prehistoric migration, and threats faced today from industrial activities. An integrated, multiscale representation of such geospatial informations is considered.

The Replica Project: Building a visual search engine for art historians

From the time of prehistoric etchings on the walls of the Lascaux cave to the present day, people have always been creating art. With millions of artistic artifacts filling museums, churches, cultural institutions, and private collections across the globe, connecting to our shared cultural and artistic past is no longer impossible.

Structure of melanins from the fungi Ochroconis lascauxensis and Ochroconis anomala contaminating rock art in the Lascaux Cave

Two novel species of the fungal genus Ochroconis, O. lascauxensis and O. anomala have been isolated from the walls of the Lascaux Cave, France. The interest in these fungi and their melanins lies in the formation of black stains on the walls and rock art which threatens the integrity of the paintings. Here we report solid-state cross polarization magic-angle spinning 13C and 15N nuclear magnetic resonance (NMR) spectroscopy and surface-enhanced Raman spectroscopy (SERS) of the melanins extracted from the mycelia of O. lascauxensis and O. anomala in order to known their chemical structure. The melanins from these two species were compared with those from other fungi. The melanins from the Ochroconis species have similar SERS and 13C and 15N NMR spectra. Their chemical structures as suggested by the data are not related to 3,4-dihydroxyphenylalanine, 5,6-dihydroxyindole or 1,8-dihydroxynaphthalene precursors and likely the building blocks from the melanins have to be based on other phenols that react with the N-terminal amino acid of proteins. The analytical pyrolysis of the acid hydrolysed melanin from O. lascauxensis supports this assumption.

Determination and quantification of major climatic parameters influencing the CO2 of Lascaux Cave

High and low CO2 partial pressure (Pco2) levels can induce consequences to the internal system of a karstic cave. This then can further affect the state of the cave. Subsequently, speleothem growths and the walls with prehistorical paintings and engravings will be affected with either calcite dissolution or precipitation. Thus, pinpointing the major components of Pco2 is found indispensable. In this paper, a method is proposed in order to (1) identify the major components of the Pco2 and (2) quantify each specific contribution to the Pco2. Pco2, air temperature, air pressure, and water flow were measured from 2008 to 2010 in Lascaux Cave (Southwest of France). Pco2 varied from 0.62% (6200 ppm) in summer to 0.04% (400 ppm) in winter. We identified three major components: (1) seasonal: component A; (2) low frequency: component B; and (3) high frequency: component C. The method is applied to estimate the contribution of each component. Component A was modelled with a sinusoid curve fitted to the Pco2 measures. This component was subtracted from the measured Pco2. Then, from the remaining value of Pco2, Fourier transform, frequency filtering, and inverse Fourier transform were applied to separate high- and low-frequency components. As a result, the seasonal component A contributes 77% of the measured Pco2, while components B and C supply 13 and 11%, respectively. The three identified components have links with environmental parameters such as temperature, water flow, and atmospheric pressure. Hypotheses were proposed to describe these links. Knowledge on these aspects can help in cave management and protection specifically in answering the question: which parameter should be given more attention.

Is Palaeolithic cave art consistent with costly signalling theory? Lascaux as a test case

ABSTRACTSeveral proponents of costly signalling theory (CST) have noted its potential for understanding prehistoric art. We use the Late Upper Palaeolithic art of Lascaux Cave (Dordogne, France) as a test case as to whether we may be able to identify an assertive, individual style in Palaeolithic art. The cave’s abundant images represent one of the most stunning examples of European Upper Palaeolithic cave art and, in terms of the material provisioning of the cave, demonstrable artistic skill, and difficulties accessing decorated areas, it represented a huge cost to its hunter-gatherer creators. But does it represent group cost or can any CST element be identified? We approach this question using several characteristics we regard as central to costly signalling, and explore the various ways by which this occurred within the cave. We conclude that it is best viewed as a group signal, and that no CST component can be identified.

A clustering approach applied to time-lapse ERT interpretation — Case study of Lascaux cave

The Lascaux cave, located in southwest France, is one of the most important prehistoric cave in the world that shows Paleolithic paintings. This study aims to characterize the structure of the weathered epikarst setting located above the cave using Time-Lapse Electrical Resistivity Tomography (ERT) combined with local hydrogeological and climatic environmental data. Twenty ERT profiles were carried out for two years and helped us to record the seasonal and spatial variations of the electrical resistivity of the hydraulic upstream area of the Lascaux cave. The 20 interpreted resistivity models were merged into a single synthetic model using a multidimensional statistical method (Hierarchical Agglomerative Clustering). The individual blocks from the synthetic model associated with a similar resistivity variability were gathered into 7 clusters.We combined the resistivity temporal variations with climatic and hydrogeological data to propose a geo-electrical model that relates to a conceptual geological model. We provide a geological interpretation for each cluster regarding epikarst features. The superficial clusters (no 1 & 2) are linked to effective rainfall and trees, probably a fractured limestone. Another two clusters (no 6 & 7) are linked to detrital formations (sand and clay respectively). The cluster 3 may correspond to a marly limestone that forms a non-permeable horizon. Finally, the electrical behavior of the last two clusters (no 4 & 5) is correlated with the variation of flow rate; they may be a privileged feed zone of the flow in the cave.

Assessing cave internal aerology in understanding carbon dioxide (CO2) dynamics: implications on calcite mass variation on the wall of Lascaux Cave (France)

Carbon dioxide gas is a key component in dissolution and precipitation of carbonates in karst and cave systems. Therefore, characterizing the internal aerology of a cave is essential to obtain the spatiotemporal distribution of temperature and CO2 level. In this research, Lascaux Cave (France), an important adorned cavity, was studied. First, the spatiotemporal distribution of CO2 and temperatures were examined using continuous monitoring at a per minute basis. High-resolution spatial measurements (14 PCO2 locations and 27 locations for temperature) were carried out for a year in the epikarst and the cave (February 2015 to February 2016). The spatiotemporal analysis presents that air and rock temperatures vary for less than a degree Celsius (12.4–12.9 °C). These are controlled by the conduction of the external thermal waves through the overlying calcarenite massif. As a consequence, two seasonal internal aerologic regimes were identified: stratification and convection. These regimes govern the spatiotemporal distribution of the CO2 levels (1.1–3.7%), showing that this parameter is a good natural marker of the internal air movements. Second, a method was proposed to estimate the calcite mass potentially affected by condensation water (dissolution process) and exfiltration water (precipitation process). This method, based on numerical simulations, relies on CO2 and air and rock temperature spatiotemporal distributions in the cave. Third, the method was applied using the case of the left wall of the Hall of the Bulls (one of the most adorned part of the cave). Results showed that the calcite mass, possibly dissolved, varies from 0.0002 to 0.006 g when the mass potentially precipitated is higher (from 0.013 to 0.067 g) depending on the aerologic conditions. This method allows determining which alteration process (e.g., precipitation or dissolution) could eventually lead to the largest variation of calcite on the wall. The results can serve as useful data to the cave experts of the French Ministry of Culture and Communication in terms of Lascaux Cave management policies.

3D geostatistical modeling of Lascaux hill from ERT data

The Lascaux cave, located in southwest France, is one of the most important prehistoric caves in the world that show Paleolithic paintings. This study aims to simulate the 3D geological environment of the cave by geostatistical modeling based on 2D Electrical Resistivity Tomography (ERT) data. Seventeen ERT profiles were carried out resulting in 64,195 geolocated resistivity values, covering about 14,500m2 of the Lascaux site. From this dataset, 3D resistivity geo-model has been built by geostatistical method. We used geotechnical data from 36 boreholes and cone penetrometer tests to validate the geo-model. By modeling from 2D data, we can establish a good estimation of the 3D geological environment of the Lascaux site. Our results show that the site can be generally separated in two parts: the limestone promontory in the center and the detrital formations located in both east and west sides. There is a high contrast between resistivity of the two formations: 45Ω·m (detrital formation) to 556Ω·m (limestone) with a rough boundary. In the center, the limestone could also be separate into two parts: a superficial layer of weathered limestone (150Ω·m) and a deeper layer with compact limestone (556Ω·m).

The social dimension of human depiction in Magdalenian rock art (16,500 cal. BP–12,000 cal. BP): The case of the Roc-aux-Sorciers rock-shelter

The rock shelter of Le Roc-aux-Sorciers is one of the major Upper Palaeolithic sites of Europe, along with the caves of Chauvet and Lascaux. At the foot of the cliff of Le Roc-aux-Sorciers, from the 1930s onwards, the research carried out by Lucien Rousseau (1927–1933), S. de Saint-Mathurin (between 1947 and 1990), and then by G. Pincon (since 1993) has led to a better understanding of this place that was occupied by hunter-gatherers 15,000 years ago. This is a rare example of an archaeological site that features a rich regular occupation (between 15,000 BP and 14,000 BP) attributed to the Middle Magdalenian associated with monumental parietal art. The sculpted frieze, an exceptional testimony to the artistic mastery of these peoples, contains – over a distance of almost 20 m – more than thirty animal and human depictions. The human figures, which are very prominent in this parietal art, make this place even more remarkable. The humans depicted on the shelter's wall and ceiling enable us to discuss these people's thought processes. The images pose the question of how these hunter-gatherers conceived the body, as well as the constructions of identity that may stem from that. In this article I propose to present a synthesis of the human depictions of Le Roc-aux-Sorciers and to analyse the role of these images in the occupation of the territory, and the inscription of the human groups in the landscape. It appears that, in the mechanisms of otherness of the ethnic groups of the Upper Palaeolithic, human depictions played an important role in the expression of identities.