Constraints on the preservation of proxy data in carbonate archives – lessons from a marine limestone to marble transect, Latemar, Italy

This work evaluates an exceptionally complex natural laboratory, the Middle Triassic Latemar isolated platform in northern Italian Dolomite Mountains and explores spatial temporal gradients processes products related to contact metamorphism, dolomitization dedolomitization of marine limestones. The relation between petrographic change re-equilibration geochemical proxy data is evaluated from perspective carbonate-archive research. Hydrothermal limestone units triggered by dykes associated hydrothermal fluids radiating nearby Predazzo Intrusion. Detailed petrography, fluid inclusion analysis, δ13C δ18O 87Sr/86Sr isotope ratios shed light on extreme textural complexity. Metamorphic diagenetic patterns include: (i) peak-metamorphic retrograde-metamorphic phases including three dolomite marbles, two dedolomite brucite, magnesium silicates late-stage meteoric/vadose cement at aureole; (ii) four spatially defined episodes dolomitization, authigenic quartz, low calcite meteoric platform; (iii) kilometre-scale values aureole towards interior. Results shown here are relevant for reasons: first, analysis alteration ranging high-grade metamorphic overprint marbles temperatures 700°C moderately altered limestones interior <100°C, allows observation that commonly occur along vertical (prograde) shallow burial metamorphism depths >20 km. Second, under rock-buffered conditions, irrespective fluid−rock interactions, both low-temperature dolomites have conservative values. fact precursor early dolostones did not per se reset environmental interest those concerned with carbonate archive research Earth’s deep time.