LAB-CREATED SILICA GELS: ENVIRONMENTAL INSIGHTS INTO SILICIFICATION PROCESSES OF THE PROTEROZOIC

Early diagenetic chert deposits are common in Meso- and Neoproterozoic peritidal carbonates and can preserve microbial morphologies. These deposits formed as silica gel precipitated from seawater enriched in dissolved silica. The process of silicification is still not understood. Building on previous experiments by Newbille et al. (2023), we performed laboratory experiments using artificial Proterozoic seawater spiked with 35 ppm, 70 ppm, 100 ppm, and 120 ppm of sodium silicate (Na₂Si₃O₇) and explored the effects of varying temperatures and humidities on silica gel precipitation. The composition of the gels and associated evaporite phases was determined using environmental scanning electron microscopy (ESEM) and X-ray diffraction spectrometry (XRD). ESEM-energy dispersive spectroscopy (EDS) was used to map the spatial relationship of these phases. Preliminary data confirmed the presence of a hydrated or amorphous magnesium-rich silica phase and halite. Ongoing experiments may provide insights into the silicification process during the Proterozoic.