Microbial fossils preserved by early diagenetic chert provide a window into the Proterozoic biosphere, but seawater chemistry, microbial processes, and interactions between microbes environment that contributed to this preservation are not well constrained. Here, we use fossilization experiments explore processes preserve marine cyanobacterial biofilms precipitation of amorphous silica in mediu...

The concentric layers of ooids from the modern environment are mostly aragonite and those ancient calcite Mg-calcite. Dolomitic rare usually formed via replacement or calcite. Here, dolomitic were found in Pliocene Shizigou Formation Qaidam Basin, Northern Tibet Plateau. This paper focuses on whether is a primary precipitate. Optical microscope scanning electron observation, combined with X-ray...