The Alnö Carbonatite Complex, Central Sweden / Карбонатитовый комплекс Ално, Центральная Швеция

Carbonatites are by the International Union of Geological Sciences classified as igneous rocks containing more than 50% (modal) of primary (i.e. magmatic) carbonate minerals and less than 20 wt.% SiO2. Depending on the dominating carbonate mineral(s), the carbonatites can be further subdivided into Ca-rich (calciocarbonatites), Mg-rich (dolomite carbonatites), Fe-rich (ankerite carbonatites) and Na-rich (natrocarbonatites). They occur on all continents on Earth, including Antartica, and range in age from approximately 3 billion years old until the present day (Woolley and Kjarsgard 2008). <...>