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Maltravieso cave (Estremadura, Spain) was recently the subject of ATR-FTIR spectroscopy of 8 figures (four hand stencils, a red horse figure, a black bull figure, a pair of black lines, and a pair of brown lines). These artistic representations are composed of different colors including red, brown, and black figures. The analyses showed that different naturally occurred material compounds in the cave (such as kaolinite) were used in the creation of the ochre to obtain different hues. Hand stencils are made of earth pigment that is naturally present in the cave which contained hematite, magnetite, and goethite as chromophores material. The red horse figure was made with kaolinite-based ochre. The black bull figure was made with charcoal (identified with Raman spectroscopy). The pigmental composition analyses show that they are composed of the same natural matter found inside the cave. Our results suggest that different paintings in the cave have been produced by different techniques and these techniques are linked to different chronological periods. [ABSTRACT FROM AUTHOR]

Microscopic observation correlated with chemical-mineralogical characterization was performed on pigment samples from "Abrigo del Lince" rock art site (V-IV millennium BC), in order to provide contributions to the study of prehistoric schematic art on granite in the province of Badajoz (Spain). The research objectives include the understanding of technological and cultural aspects, as well as of conservation and deterioration issues related to the pictographs. The multi-analytical approach encompasses the integration of microscopic observation, SEM-EDS analysis, micro-Raman spectroscopy, and ATR-FTIR and allowed to achieve a multispectral overview of the samples and to describe their varied composition and the alteration pattern which connects them. The main phases overlying the granitic bedrock and involved in this sequence are as follows: hematite, whewellite, and gypsum. While hematite could be stratigraphically considered the most ancient layer and assigned to the use of red ochre as a pigment, whewellite and gypsum are the main constituent of the alteration layer which forms a patina over the pictographs, due to weathering processes. Finally, the role of biofilms in rock art conservation is discussed, suggesting that, especially for what concern thin and homogenous layers of oxalates, their presence should not be necessarily considered an issue., (© 2022. The Author(s).)