Archaeometric study of a Romanian cave dwelling: mineral composition and conservation aspects

This study evaluates the conservation potential of nano-sepiolite, a natural magnesium silicate, applied to micaceous quartz arenite from the Piatra Lată cave dwelling (Jac, Romania). The site, carved into friable sandstone, typifies vulnerable traditional Romanian cave habitats, threatened by environmental degradation as well as microbial colonization. Integrated analyses revealed angular quartz grains in a clay-rich, weakly cohesive matrix, affected by moderate burial diagenesis. Pre-treatment SEM showed high interparticle porosity, weak cohesion, and a microporous surface prone to moisture retention. Nano-sepiolite was applied by brushing, improving the cohesion of the granules, partially filling the pores and forming a consolidating crust, without severely modifying the mineralogy of the substrate. Concurrent indoor air monitoring over 1 year revealed high humidity and poor ventilation, factors that accelerate physical, chemical, and biological decay. Results confirm that nano-sepiolite is a compatible, non-invasive consolidant, enhancing structural stability and durability of porous lithologies. Its use may support long-term preservation strategies for similar vulnerable rock-carved heritage sites.