Multianalytical and multiproxy approach to the characterization of a Paleolithic lamp. An example in Nerja cave (Southern Iberian Peninsula)

Understanding the illumination systems used by Paleolithic groups in caves gives us essential information about the Paleo-speleological capabilities of our ancestors and their activities in dark spaces. In this paper, we present a multianalytical and multiproxy approach (wood charcoal and soot) to characterize a Paleolithic lamp. The methodology was employed on an endokarstic clastic block (speleothem) with a natural concavity located in decorated galleries in Nerja cave, Spain. Anthracological analysis has demonstrated that the Pinus tp. sylvestris/nigra (Scots pine/Black pine) was used as fuel for this illumination system. 14C-AMS dating shows that this light point was lit during the Solutrean period. Paleolithic art from chambers near this fixed lamp present a similar chronology. HD/HG ratio calculus obtain of mu-Raman spectra from pine charcoal shows that burning reached temperatures of more than 700 degrees C. Thus, wood suffered complete combustion without sudden extinguishing. Furthermore, spherical particles of soot aggregates on the edge of the lamp have been identified, obtained from wood combustion, through TEM-EDX analysis. Finally, 3D modelling of the lamp was carried out. Concerning interpretation, the singular location of the light point suggests that it could have encompassed more functions than just the illumination of the cave.