Alkaline Rocks and Carbonatites of the World

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Chicacimo (Macico Tama)


Occurrence number: 
Longitude: 13.58, Latitude: 13.92

This occurrence comprises tuffs and feldspathoidal syenites. A nepheline-sodalite syenite comprises 49% orthoclase, a little oligoclase, 29% nepheline, 4% sodalite, 13% aegirine-augite, 1% biotite and accessory opaques, titanite, apatite and calcite. A more leucocratic variant contains 67% orthoclase, 4% oligoclase, 15% nepheline, 6% sodalite, 3% aegirine-augite, a little hornblende and accessories. Analyses of both rock types are given by Gonçalves (1965).

GONÇALVES, F.G. 1965. Nota sobre algumas rochas alcalinas da região Impulo-Chongorói. Boletim. Serviços de Geologia e Minas Angola. Luanda. 12: 95-107.
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith