Biological contributions to manganese oxides in rock varnish at Murujuga (Western Australia)

Rock varnish at Murujuga, Western Australia, contains a high concentration of manganese (Mn) oxides, predominantly in amorphous to poorly crystalline phases that evade traditional detection methods. Nanoscale analysis reveals biogenic Mn oxide structures, supported by metagenomic evidence showing dominance of Chroococcidiopsidaceae and Rubrobacter_F, known for intracellular Mn accumulation. Functional annotation confirms a community-level genomic potential for biologically influenced Mn utilization, suggesting ongoing biomineralization driven by environmental stressors. This process holds significant potential as a long-term paleoenvironmental and climate proxy, marking the first microbiomic characterization of rock varnish in this UNESCO World Heritage Site.

Wu, Y.-L., Fairweather, J. H., Campbell, M., Hergt, J., Yusiharni, E., Smirk, M., Dodd, A., Sun, X., Clode, P., Hubbard, A., Allentoft, M. E., & McDonald, J. (2026). Biological contributions to manganese oxides in rock varnish at Murujuga (Western Australia). Scientific Reports, 16(1). https://doi.org/10.1038/s41598-026-61982-w