Nanoscale Pathway of Modern Dolomite Formation in a Shallow, Alkaline Lake.

ABSTRACT: Dolomite [CaMg(CO₃)₂] formation under Earth surface conditions is considered largely inhibited, yet protodolomite (with a composition similar to dolomite but lacking cation ordering), and in some cases also dolomite, was documented in modern shallow marine and lacustrine, evaporative environments. Authigenic carbonate mud from Lake Neusiedl, a shallow, episodically evaporative lake in Austria consists mainly of Mg-calcite with zoning of Mg-rich and Mg-poor regions in μm-sized crystals. Within the Mg-rich regions, high-resolution transmission electron microscopy revealed < 5-nm-sized domains with dolomitic ordering, i.e., alternating lattice planes of Ca and Mg, in coherent orientation with the surrounding protodolomite. The calcite with less abundant Mg does not show

SUBMITTER: Meister P 

PROVIDER: S-EPMC10162443 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature