Archaeobotanical investigations and experimental activity performed at Bàsura Cave (Toirano, NW Italy) reveal clues on Epigravettian cave lighting systems

Abstract

The B`asura Cave (Toirano, NW Italy) is one of the most important caves in northern Italy conserving the fossilisedfootprints of a walking trail left by a small group of humans accompanied by a canid dating to the Epigravettianand an impressive cave bear bone deposit of the middle Pleistocene. In 2016 a new research projectentitled “The B`asura Revisited”, returned to fieldwork through a multidisciplinary approach, with the aim ofunderstanding the nature of the human and animal presence in the cave.In this paper we present the results of a multidisciplinary investigation of archaeobotanical remains, stratigraphicsequences, and experimental reconstructions relating to Late Upper Palaeolithic human activity in theB`asura Cave. The study is centered on the anthracological and palynological remains which led to the identificationand interpretation of cave lighting system based on controlled experiments. The study provides newinsights into the patterns of human exploration in Palaeolithic cave systems, highlighting the reliance on smalldiameterpine twigs as a source of light. The interpretation of the local vegetation environment has been inferredfrom palynological evidence.The palynological analysis conducted on samples from the innermost space of the cave (“Hall of Mysteries”)suggests that the landscape around the cave consisted of a sparse pine forest of Pinus sylvestris/mugo-typeinterspersed with steppe herbaceous formations. In the upper level, this is enriched with modest amounts ofmesophilous broadleaved trees and thermophilic species. The pollen input likely derived from particles adheringto the fur of bears and infiltrations from the external environment of the cave. Finally, we performed anexperimental study aimed at understanding the cave's lighting systems adopted at B`asura Cave, reconstructingthe nature of the lighting instruments and the way the prehistoric explorers moved in the cave. The testconfirmed the burning of small twigs rather than the use of torches. The use of twigs is inferred by the traces of small-diameter branches obtained from Pinus sylvestris-type, used individually or tied in small bunches. Theexperiment revealed that, despite the small size, burning twigs produces enough light to ensure a longerpermanence in the cave depth and a safe pathway back, and at the same time minimises dazzling and fastconsumption of wood fuel.