Biologically mediated silicification of marine cyanobacteria and implications for the Proterozoic fossil record

Moore, Kelsey R.; Pajusalu, Mihkel; Gong, Jian; Sojo, Victor; Matreux, Thomas; Braun, Dieter; Bosak, Tanja (2020): Biologically mediated silicification of marine cyanobacteria and implications for the Proterozoic fossil record. In: Geology, Vol. 48, No. 9: pp. 862-866

Abstract

Silicification was a major mode of fossilization in Proterozoic peritidal environments, but marine silica concentrations and the chemical and biological mechanisms that drove microbial silicification and formation of early diagenetic chert in these environments remain poorly constrained. Here, we use taphonomy experiments to demonstrate that photosynthetically active cyanobacteria that are morphologically analogous to the oldest cyanobacterial fossil, Eoentophysalis, mediate the formation of magnesium-rich amorphous silica in seawater that is undersaturated with respect to silica. These results show that microbes in Proterozoic tidal environments may have mediated their own silicification at lower silica concentrations than previously assumed.

• Item Type: Journal article
• Faculties: Physics
• Subjects: 500 Science > 530 Physics
• ISSN: 0091-7613
• Language: English