Clay authigenesis in carbonate-rich sediments and its impact on carbonate diagenesis

published in Geochimica et Cosmochimica Acta (https://doi.org/10.1016/j.gca.2023.02.002). It is a multi-proxy perspective on clay authigenesis in carbonate sediments from the modern ocean, though there is a strong focus on Mg isotopes. We present elemental (Sr/Ca, Mg/Ca, Na/Ca) and isotopic (Sr, Mg, Ca) data from three ODP sites (762, 806, and 807), as well as high resolution SEM and nano-SIMS data from Site 762.

The observations made suggest that clay authigenesis occurs in carbonate-rich sites, which is a hypothesis also made by Andrews et al (2020) at IODP Site U1338. Chanda et al. (2023) also suggest that clay authigenesis impacts the rate at which carbonate recrystallizes; if this impact is not homogeneous in the section, it can create spurious geochemical records that may be misinterpreted (the example in this case is most pronounced in the Na/Ca record).

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