Alkaline Rocks and Carbonatites of the World

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Occurrence number: 
Mato Grosso
Longitude: -58.75, Latitude: -10.08

Canama is an oval-shaped intrusion of syenites of 21x12 km. The principal rocks are nordmarkites, but alkali granites also occur which are composed essentially of orthoclase or perthite with riebeckite, hastingsite/barkevikite, aegirine-augite, a little biotite and quartz and accessory apatite, zircon, sphene, fluorite and rutile (?perovskite). Strong geochemical anomalies for Ti, Zr, Nb etc. have been detected (Issler, 1977).

A whole rock Rb-Sr isochron (five syenites and a granite) gave 1175±15 Ma and K-Ar on biotite 1169±57 Ma (Issler, et al. 1974 quoting Basei, Radam unpublished internal Report).
ISSLER, R.S., ANDRADE, A.R.F. de, MONTALVAO, R.M.G. de, GUIMARAES, G., SILVA, G.G. da and LIMA, M.I.C. de, 1974. DNPM Projeto Radambrasil. Folha SA.22 Belem. Levantamento de Recursos Naturais, Geologia, 5. ISSLER, R.S. 1977. Esboco geologico-tectonico do Craton do Guapore. Revista Brasileira de Geociencias, 7: 177-211
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