Carbonatite
Carbonatite ( /kɑːrˈbɒnətaɪt/) is a type of igneous rock. It has greater than 50% carbonate minerals.[1] Carbonatites may be confused with marble, so may need geochemical analysis to make sure.
Carbonatites usually occur as small plugs, or as dikes, sills, breccias, and veins. They are almost all near or in continental rift-related tectonic settings.
It seems that there has been a steady increase in the carbonatitic igneous activity through the Earth's history, from the Archean eon to the present. Carbonates in general are typical products of life-forms.
Carbonatite Media
Magnesiocarbonatite, from Verity-Paradise Carbonatite Complex of British Columbia. Specimen is 75 mm wide.
Okaite, an ultramafic rock found near the carbonatite of the Oka Carbonatite Complex, Oka, Quebec
Thin section of apatite-rich carbonatite in cross polarised transmitted light. The sample is from Siilinjärvi apatite mine.
References
- ↑ Bell, Keith (editor) 1989. Carbonatites: genesis and evolution. London, Unwin Hyman.