Diagenesis of siliceous deposits: recent advancements, from sedimentology to biogeochemistry

Siliceous deposits are excellent targets for deciphering paleoclimatic and paleoceanographic dynamics occurred during Earth history, as well as for reconstructing the past biogeochemical cycle of silicon, the second more abundant element in the Earth’s crust. Nevertheless, early and late diagenetic processes involving silica, such as reverse weathering or formation of opal-CT and quartz from biotic and abiotic sources, may lead to significant variations of the former mineralogical and paleobiological content of siliceous sediments, introducing potential biases and controversies in their interpretation. At the same time, silica diagenesis results in dramatic changes of petrophysical properties of sedimentary rocks, with deep implications for seismic stratigraphy, basin analysis, georesource exploration and managing geohazards.This challenging research topic can be addressed through a combination of different approaches aimed at reconstructing controlling factors, modalities and timing of diagenesis. Destructive and non-destructive techniques can be applied, from high-resolution sedimentological and petrographic observations (e.g., light, fluorescence, scanning and transmitted electron microscopic techniques, cathodoluminescence imaging) to geochemical (e.g., stable isotopes, trace elements, biomarkers) and mineralogical (e.g., X-ray diffraction, Raman spectroscopy) analyses. In addition, both field and laboratory experimental studies (e.g., silica preservation vs alteration under variable environmental parameters, such as temperature, pressure, pH, salinity, oxygen level and biological mediation) can greatly contribute to the comprehension of mechanisms behind silica diagenesis.This research topic aims at summarizing the current state of knowledge, the most recent advancements and the still open questions and controversial aspects of this intriguing research topic. We welcome original research articles, short communications, reviews, mini-reviews and methodological papers. Topics of interest include, but are not limited to the following:• Early to late diagenesis of modern and ancient siliceous deposits in marine and continental settings• Basin evolution and silica diagenesis• Authigenic minerals associated with silica diagenesis• Silica diagenesis in extreme environments• Relationship between climate, oceanography and silica diagenesis• Biotic triggers of silica diagenesis, with special emphasis on the role of bacteria• Abiotic precipitation of silica polymorphs• Application of stable isotopes and trace elements to the study of silica diagenesis• Organic matter and silica diagenesis• Experimental studies on silica dissolution• Petrophysical and geochemical properties of diagenetically altered siliceous rocks• Innovative techniques for constraining silica diagenesis Topic editors: Luca Pellegrino, Shahab Varkouhi, Agata Jurkowska Source: https://www.frontiersin.org/research-topics/69300/diagenesis-of-siliceous-deposits-recent-advancements-from-sedimentology-to-biogeochemistry