Dolomite formation in the shallow seas of the Alpine Triassic

Recent research on the Dolomites reveals that some dolomite formations, previously thought to be late diagenetic or hydrothermal, actually formed during or shortly after sedimentation under specific ancient depositional environments. Three distinct Triassic systems—Latemar Platform in Northern Italy, San Giorgio Basin in Southern Switzerland, and the Dolomia Principale Formation—demonstrate contrasting palaeoenvironmental conditions for dolomite formation, including shallowing-upward lagoonal cycles, anoxic deeper water settings, and hypersaline sabkha-like environments. These findings challenge modern dolomitization models, suggesting that Triassic processes differed significantly in distribution and scale from contemporary ones. Advanced stable-isotope geochemistry and high-resolution geochemical probing provide new insights into Triassic palaeoceanographic conditions, advocating for a non-actualistic approach to better understand these ancient formations.

Meister, P., Mckenzie, J. A., Bernasconi, S. M., & Brack, P. (2013). Dolomite formation in the shallow seas of the Alpine Triassic. Sedimentology, 60(1), 270–291. Portico. https://doi.org/10.1111/sed.12001