Descrição

Artigos

1. Gisements de Calamine et de Smithsonite du Sud du Portugal.
A. Bernardo Ferreira (3 páginas)
Resumo: Calamine occurs in the Beja district, 21 Kms, SE, of Moura, in a country where schists, quartzites and limestones appear at the surface, striking in a NW-SE direction, crossed by tonalites, gabbros, dioritic porphyries and quartz veins, and partially covered by formations of Miocene. Calamine, together with smithsonite, limonite, hematite, and clay minerals, sometimes together with silica, fills brecciation solution spaces as well as fractures in limestones. By means of supergenic action, a formation of sulphides with blende dominant (seldom found) was transformed to iron oxides and smithsonite, and eventually calamine was formed.It is possible that in the formation of this mineral, hydrothermal solutions have also taken part. The ore deposits were worked by the Romans and as recently as 1919-25 calamine was exported. At present an intense technical-economical study is taking place.

2. Planificação Histórico-cronológica das Pesquisas de Petróleo em Portugal.
F. A. C. Gonçalves Macieira (97 páginas)

3. Resumo da Actividade do Serviço de Fomento Mineiro Durante o Primeiro Semestre de 1948.

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