Alkaline Rocks and Carbonatites of the World

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Catrimani

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Occurrence number: 
025-00-003
Country: 
Brazil
Region: 
Roraima Federal Territory
Location: 
Longitude: -61.82, Latitude: 0.7

Catrimani is an oval-shaped intrusion of about 2x1 km, elongated northwest-southeast, which is composed essentially of sodalite-nepheline syenite (litchfieldite) with numerous phonolite dykes; accessories in the syenite include cancrinite, a hastingsitic amphibole, aegirine, melanite, biotite, zircon, apatite and carbonate. The phonolites contain abundant acicular aegirine and minor cancrinite, fluorite and apatite. Chemical analyses are given in Montalvao et al. (1975).

Age: 
K-Ar on sanidine from nepheline syenite gave 180±5.2 Ma (Santos and Salas, 1974) and Rb-Sr on nepheline syenite 100 Ma (Montalvao et al. 1975).
References: 
ISSLER, R.S., LIMA, M.I.C. de, MONTALVAO, M.B.G. de and SILVA, G.G. da, 1975. Intrusivas feldspatoididas no Craton Guianes. Congresso Ibero-Americano de Geologia Economica, II: 363-82. MONTALVAO, R.M.G. de, MUNIZ, M. de B., ISSLER, R.S., DAL'AGNOL, R., LIMA, M.I.C.de, FERNANDES, P.E.C.A. and SILVA, G.G.da 1975. DNPM ProjetoRadambrasil. Folha NA.20 Boa Vista e parte das Folhas NA.21 Tumucumaque, NB.20 Roraima e NB.21. Levantamento de Recurcos Naturais, Geologia, 8: 13-135. SANTOS, J.O.S. and SALAS, H.T. 1974. Notas sobre a primeira ocorrencia de rochas alcalinas no Territorio Federal de Roraima. Congresso Brasileira de Geologia, 1: 412-3
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