Siilinjärvi carbonatite complex
The Siilinjärvi carbonatite complex is located in central Finland near the city of Kuopio .
It is named after the nearby town of Siilinjärvi , which is about 5 km west of the southern extension of the complex. Siilinjärvi is the second largest carbonatite complex in Finland after the Sokli opencast mine and one of the oldest ( Neo-Archean - 2530 ± 45 million years BP) carbonatite discovery sites on earth. The carbonatite complex consists of a lenticular body about 16 km long that is abruptly surrounded by granite gneiss . The maximum width of the site is 1.5 km and covers 14.7 km². The complex was discovered in 1950 by the Geological Survey of Finland with the help of local mineral collectors. Exploration drilling began in 1958 by Lohjan Kalkkitehdas Oy. Typpi Oy continued drilling from 1964 to 1967 and Apatiitti Oy continued to drill from 1967 to 1968. After drilling, laboratory and pilot plant work was carried out. The mine was opened in 1979 by Kemira Oyj as an open pit . The company was sold to Yara International in 2007 .
Web links
Individual evidence
- ↑ O. Kouvo: GTK internal report to H. Lukkarinen ., 1984
- ↑ O. Härmälä: Siilinjärven kaivoksen mineraaleista ja malmin rikastusmineralogisista ominaisuuksista. Master's thesis, University of Turku, Department of Geology and Mineralogy, 1981.
Coordinates: 63 ° 6 ′ 46.3 ″ N , 27 ° 44 ′ 6.8 ″ E