Archaeological chert artifacts from Atapuerca sites (Burgos, Spain): characterization, causes of decay and selection of compatible consolidating products

Chert tools from Galeria and Gran Dolina Caves, located in the Sierra de Atapuerca site complex (Burgos, Spain), were characterized (macro-visual inspection, mineralogical phases, degree of crystallinity, soluble salts, surface morphology and optical surface roughness) and compared to chert samples collected from the surrounding Atapuerca mountain range. The chert tools were studied to determine their causes of decay and for selecting the most compatible consolidation treatments. It was found that samples solely containing quartz were not significantly altered and required little conservation treatment compared to those that contained quartz and moganite, which were more weathered and powdery, requiring consolidation. The efficacy of the consolidating products traditionally used by conservators (acrylic resin and ethyl silicate) to preserve these chert remains, together with novel nanoparticle-based products (SiO2 and a mixture of SiO2 and Ca(OH)(2) nanoparticles) were assessed in this study. Changes produced by these consolidating products in the physical (surface morphology and cohesion) and aesthetic properties of the chert tools were evaluated using non-destructive techniques (peeling test, spectrophotometry and optical surface roughness), followed by destructive techniques, such as SEM and XRD.

Automated summary

Chert tools from the Galeria and Gran Dolina Caves in Spain were studied to determine causes of decay and select appropriate consolidation treatments. Samples containing quartz only showed minimal alterations and required less conservation treatment, while those containing quartz and moganite were more weathered and required consolidation. Traditional consolidating products like acrylic resin and ethyl silicate, as well as novel nanoparticle-based products, were evaluated for their effectiveness in preserving these chert remains.