Petroglyph sites exist all over the world. They are one of the earliest forms of mankind’s expression and a precursor to art. Despite their outstanding value, comprehensive research on conservation and preservation of rock art is minimal, especially as related to biodeterioration. For this reason, the main objective of this study was to explore the factors involved in the degradation of petroglyph sites in the Negev desert of Israel, with a focus on biodegradation processes. Through the use of culture-independent microbiological methods (metagenomics), we characterized the microbiomes of the samples, finding they were dominated by bacterial communities, in particular taxa of Actinobacteria and Cyanobacteria, with resistance to radiation and desiccation. By means of XRF and Raman spectroscopies, we defined the composition of the stone (calcite and quartz) and the dark crust (clay minerals with Mn and Fe oxides), unveiling the presence of carotenoids, indicative of biological colonization. Optical microscopy and SEM–EDX analyses on thin sections highlighted patterns of weathering, possibly connected to the presence of biodeteriorative microorganisms that leach the calcareous matrix from the bedrock and mobilize metal cations from the black varnish for metabolic processes, slowly weathering it.
Bibliographical noteFunding Information:
The authors gratefully acknowledge the Austrian Science Fund (FWF, Der Wissenschaftsfonds) and the Ministry of Science and Technology (MOST), Israel for funding the project. We would also like to acknowledge Dubravka Jembrih-Simbürger, Academy of Fine Arts, Vienna, for help with initial XRF analysis, Mirsky Yelena, Ben-Gurion University, for WDXRF analysis, Chris Mckay, NASA-Aimes, U.S.A for climatic measurement support, and the Israel Nature and Parks Authorities (INPA) for sampling permission.
© 2022 by the authors.
- Negev desert
- analytical techniques
- nanopore sequencing technology
ASJC Scopus subject areas
- Materials Science (all)
- Engineering (all)
- Process Chemistry and Technology
- Computer Science Applications
- Fluid Flow and Transfer Processes