Morro Do Engenho

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Occurrence number:

025-00-042

Country:

Brazil

Region:

Goias

Location:

Longitude: -51.67, Latitude: -15.53

Carbonatite:

Yes

This is a zoned intrusion of about 5 km diameter forming a hill and emplaced in Devonian Furnas sandstones. There is a central core of dunite surrounded by peridotites and pyroxenites and these in turn by a border group of alkaline gabbros and nepheline syenite. The dunites are partially serpentinized. The pyroxenites, as well as 'augite', contain olivine and a little plagioclase. These rocks pass gradually into biotite-bearing gabbros. The nepheline syenites are coarse rocks with nepheline phenocrysts up to 1. 5 cm, perthite, 'sanidine' phenocrysts and Ti-augite zoned to aegirine. A small area of rock composed essentially of pyroxene and magnetite and described as jacupirangite occurs, while small veins of carbonatite with phlogopite cut the dunite.

Economic:

Garnierite occurs in laterite, with an estimated reserve of 70 million tons averaging 1.27% Ni (Rodrigues and Lima, 1984).

References:

PENA, G.S. and FIGUEIREDO, A.J.A. 1975. Projeto Goiama II, relatorio final. Departamento Nacional da Producao Mineral. Companhia de Pesquisa de Recursos Minerais, 1: 121-61. RODRIGUES, C. de S. and LIMA, P.R.A. dos S. 1984. Carbonatitic complexes in Brazil. Companhia Brasileira de Metalurgia e Mineracao: 1-17

Map:

Fig. 1_196 The Ipora Group of occurrences of alkaline intrusions of central Goias.

Location:

Earth > South America > Brazil > Goias

References:

PENA, G.S. and FIGUEIREDO, A.J.A. 1975. Projeto Goiama II, relatorio final. Departamento Nacional da Producao Mineral. Companhia de Pesquisa de Recursos Minerais, 1: 121-61.

RODRIGUES, C. de S. and LIMA, P.R.A. dos S. 1984. Carbonatitic complexes in Brazil. Companhia Brasileira de Metalurgia e Mineracao: 1-17

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