Microbial carbonates are found throughout most of the geological record and have formed under varying atmospheric and hydrospheric conditions. Recent advancements in analytical techniques have enabled the use of novel, highly promising geochemical proxies, such as metals and their isotopes, to reconstruct ancient microbial habitats. Here, we review recent discoveries and the benefits of applying…
Stromatolites rank among the most productive ecosystems on Earth, with extremely high rates of element cycling, especially carbon, oxygen, nitrogen, iron, and sulfur. Their study provides critical insights into early microbial life evolution, environmental conditions, and associated biogeochemical cycling. Specifically, carbon, nitrogen, and sulfur isotopes can be used to assess metabolic…
Stromatolites are widespread in Precambrian sedimentary successions and provide important insights into life, environmental processes, and surface conditions on the young Earth. Shaped by interactions among microbial processes, sediment deposition, and mineral precipitation, stromatolites have a record spanning most of Earth’s history and are sensitive indicators for past hydrodynamic conditions…
This chapter describes the biological composition of modern microbialites, aiming at identifying the major microbial actors that may contribute to their mineralization and growth. Despite the vast diversity in community composition, environmental conditions, and dominant mineral phases, certain key components emerge as critical drivers of these processes. Additionally, the dominance of specific…
Accurately interpreting ancient microbialites requires a detailed understanding of how they form, including teasing apart the respective roles of environmental factors versus microbial activity. Modern microbialites serve as essential tools for this purpose. Currently, microbialites form in both marine and continental settings, displaying remarkable diversity in terms of formation environments,…
Stromatolites represent some of the oldest and most persistent records of life on Earth. These organo-sedimentary structures have formed through complex interactions between microorganisms and their environment for nearly 3.5 billion years. Here, we trace the evolving scientific narrative surrounding these structures, from their early 19th-century descriptions to their integration into the broader…
Quartz is the most popular and widely used gemstone of the SiO 2 family with its phenomenal varieties and spectacular colors, e.g., near-colorless (rock crystal), purple (amethyst), yellow (citrine), smoky (smoky quartz), and pink. The colors of these varieties are mostly caused by trace contents of foreign ions, which in turn are activated by treatment with high-energy radiation and/or…
The use of microcrystalline silica has been documented among early hominins, with significant diversification over the last ~3 million years, from early toolmaking to applications in personal adornment and symbolic contexts. From the Oldowan onwards, both microcrystalline quartz and amorphous silica are consistently observed in the archaeological record, and they shaped aspects of human…
Humankind’s use of silica raw materials began at least 1.85 million years ago with production of flint tools and spans to today’s more than 1000 industrial applications, all relying on its chemistry and specific physical properties. Among the key achievements are the discovery of the piezoelectric effect of quartz for timekeeping, the critical importance of silicon-based semiconductor technologies…
Quartz is a key archive of Earth surface processes, recording erosion, burial, transport, and landscape evolution across a wide range of timescales. Recent advances in quartz-based analytical techniques have expanded the potential for integrative geochemical and geochronological approaches. Fourier-transform infrared spectroscopy (FTIR) enables detailed characterization of quartz provenance and…
