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LSCE > News > 35,000 years of recurrent visits inside Nerja cave (Andalusia, Spain) based on charcoals and soot micro-layers analyses
35,000 years of recurrent visits inside Nerja cave (Andalusia, Spain) based on charcoals and soot micro-layers analyses

35,000 years of recurrent visits inside Nerja cave (Andalusia, Spain) based on charcoals and soot micro-layers analyses

Charcoal and micro-layers of soot trapped in speleothems from the inner galleries of Nerja Cave were analysed through an interdisciplinary study.

The absolute dating of the prehistoric subterranean activity of the cave and the identification of different phases of visits to the deep parts are presented and discussed. The charcoal analysis includes anthracological analysis and SEM– EDX. The soot analysis includes optical microscopy, Raman spectroscopy and TEM–EDX, and the microcounting of soot microlayers. The C dating of 53 charcoals identified 12 phases of prehistoric visits to the cave between 41,218 and 3299 cal. BP, putting back the origin of human occupation of this emblematic cave by 10,000 years.

Figure 1: Materials. (A) Black mark (dating number 33). (B) Micro-charcoal inside fixed lamp (dating number 43). (C) Scattered charcoals (dating number 54). D. GN16-08 stalagmite section.

The interdisciplinary analysis of the soot microlayers allowed us to perform a high-precision zoom on the last three visitation phases identified by Bayesian analysis (8003–2998 cal. BP.), demonstrating that these phases contain at least 64 distinct incursions, with an average of one visit every 35 years for the Neolithic period. Spatial analysis showed that not all areas of the cave were used in the same periods, highlighting the repetition of visits to certain specific sectors of the Lower Galleries of the cave. Lastly, the anthracological data indicate a cross-cultural and unique use of Pinus tp. sylvestris-nigra wood for lighting activities over an extended period between the Gravettian and Upper Magdalenian.

Figure 2: Curve plot with the different phases of visits to the interior of Nerja cave identified by a Bayesian model from charcoal (in red) and image of the different micro-layers of soot and micro-charcoal of the GN16-08 stalagmite. The succession of soot films in the carbonates is represented as barcode diagrams.

Reference: Medina-Alcaide M.A., Vandevelde S., Quiles A., Pons-Branchu E., Intxaurbe I., Sanchidrián J.L, Valladas H., Deldicque D., Ferrier C., Rodríguez E., Garate D., 2023. 35,000 years of recurrent visits inside Nerja cave (Andalusia, Spain) based on charcoals and soot micro-layers analyses. Scientific Report article: 5901.