2025/09/17 by Federico A. Vignale, Laura Sánchez‐García, Daniel Carrizo +9 · 1 voice
Earth and Planetary Sciences · Environmental Science · #Paleontology and Stratigraphy of Fossils #Microbial Community Ecology and Physiology #Geology and Paleoclimatology Research
paper · pdf · doi:10.1038/s43247-025-02764-6
openalex publication_date 2025/09/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/29
Abstract Microbialites are organosedimentary structures that have existed since the Precambrian and have endured through geological time, serving as archives of Earth’s environmental evolution. Today, they persist in only a few environments markedly different from those in which they first arose. Here, we report a modern microbialite reef in Laguna Pozo Bravo (Puna region, Argentina), exposed to high radiation, low oxygen pressure, and volcanic inputs reminiscent of early Earth. Through physicochemical, mineralogical, spectroscopic, electron microscopy, and metagenomic analyses, we identified diverse microbial communities with metabolic capacities that induce mineralisation. Seasonal environmental fluctuations drive cyclical changes in community composition, producing potential mineralisation patterns. Our findings suggest that carbon fixation and the metabolic drivers of alkalinity in microbialites may have evolved over time. Moreover, the variability in prokaryotic compositions among modern microbialites demonstrates that carbonate precipitation is governed by metabolic potential rather than taxonomy, reinforcing their role as dynamic records of environmental conditions.