Fingerprinting local controls on the Neoproterozoic carbon cycle with the isotopic record of Cryogenian carbonates in the Panamint Range, California

Neoproterozoic carbon isotope excursions are commonly attributed to changes in the global fraction of organic burial associated with climate instability and/or oxygenation. Here we show that carbonate sediment deposited during ca. 661 – <651 Ma Cryogenian non-glacial interlude between Sturtian and Marinoan glaciations exhibit lateral offsets carbonate-carbon values from coeval units by as much 10‰. Within Thorndike submember succession Panamint Range, California, USA, can be linked a laterally discontinuous dolomitization front: limestones ?13Ccarb ?+4 +9‰, whereas stratigraphically equivalent dolostones consistently lower, ?-4 +4‰. Field observations analyses clasts overlying glacial diamictite offset resulted pre- syn-Marinoan dolomitization. Further, ?44/40Ca ?26Mg data indicate this isotopic variability sediment-buffered diagenesis. We propose extremely positive record local primary productivity within restricted platform surface waters oxygenated pore fluids negative reflect anaerobic remineralization waters. In scenario, neither original calcite/aragonite nor subsequent dolomite precipitates representative seawater, instead they archive evolution dissolved inorganic pools.