Calcarean

Calcarean refers to a group of clay known for its propensity to form large amounts of calcium carbonate during the course of metamorphism, so much so that the rock undergoes significant changes in terms of its composition and properties.

Geologically, calcarean clays are typically encountered in regions that have experienced or are still experiencing high levels of tectonic activity. The process of metamorphism occurs when such clays are subjected to intense heat and pressure over an extended period of time. As a result, the clay minerals undergo a series of chemical reactions and transformations that ultimately result in the formation of calcite, which is the primary mineral component of calcium carbonate.

Characteristics of calcarean formations include the presence of large crystals of calcite, a hard and dense texture, and a resistance to weathering. The chemical composition of calcarean rocks is dominated by calcium and carbonate ions, with smaller quantities of other elements present. In terms of economic significance, some calcarean formations are rich in stratigraphically sensitive sedimentary rocks that have commercial value, such as coal deposits.

Environmental factors also play a key role in determining the extent to which calcarean metamorphism occurs. Regions with high levels of tectonic activity are more likely to exhibit evidence of calcarean metamorphism, as are areas with high levels of groundwater flow that facilitate the mobilization of carbonate ions.