Figure 9
From: Carbonation and serpentinization of diopsidite in the Altun Mountains, NW China
Sketch representing the formation processes of the studied serpentinized diopsidite. (a) Fresh diopsidite with abundant cleavages. (b) CO2-rich fluids flow along the grain boundaries and cleavages of diopsides. Diopsides dissolve to form abundant etch structures (e.g., etch pits); simultaneously, calcite and chrysotile nucleate and grow around the etch peaks. Then, diopsides are completely altered by calcite and chrysotile and form pseudomorphic textures. Moreover, this process allows the altered diopsidite to acquire additional H2O, CO2, LREEs, and FMEs but lose SiO2. (c) Serpentinized diopsidite further undergoes antigoritization that results in the formation of antigorite and coarse-grained calcite.
