Formation of dolomite at 40–80 °C in the Latemar carbonate buildup, Dolomites, Italy, from clumped isotope thermometry

Replacement dolomite in the Latemar carbonate buildup of the Dolomites formed at temperatures between 42–72 °C, with a fluid δ^(18)O(H_(2)O) averaging –0.3‰, mirroring conditions of modern mid-ocean ridge fluids. This finding aligns with prior hypotheses about dolomitizing fluid origins but introduces clumped isotope thermometry as a precise method to independently estimate temperature and fluid composition. The study reveals that while calcite preserves original δ^(18)O, its clumped isotope temperatures suggest a reset during dolomitization, highlighting the method's potential for unraveling burial and diagenetic processes with uncertainties as low as ±5 °C and ±0.75‰.

Ferry, J. M., Passey, B. H., Vasconcelos, C., & Eiler, J. M. (2011). Formation of dolomite at 40–80 °C in the Latemar carbonate buildup, Dolomites, Italy, from clumped isotope thermometry. Geology, 39(6), 571–574. https://doi.org/10.1130/g31845.1