Dolomitization

Dolomitization is a geological process where magnesium ions replace calcium ions in the mineral calcite, resulting in the formation of dolomite.

Dolomitization conditions are present in Abu Dhabi, the Mediterranean Sea, and some Brazilian hypersaline lagoons (most notably Lagoa Vermelha Lagoon). The areas where dolomitization take place are limited, as modern seawater is less suited to dolomite formation. This is evident in the noticeable decrease in modern dolomite depositions compared to older depositions. Dolomitization involves substantial recrystallization which can be described by the following equation:

2 CaCO3(calcite) + Mg2+ ↔ CaMg(CO3)2(dolomite) + Ca2+

The conditions for dolomitization depend on several factors, including temperature, saturation state, Mg:Ca ratio, and the presence of inhibitors and microorganisms.Microorganisms allow the precipitation of preliminary dolomite stages through certain metabolic pathways. Dolomitization occurs in kinetic intermediate stages. First, a protodolomite is formed, then it is transformed to dolomite in a dissolution-recrystallization process.

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.