Alkaline Rocks and Carbonatites of the World

Setup during HiTech AlkCarb: an online database of alkaline rock and carbonatite occurrences

Parambu

stripes

Occurrence number: 
025-00-031
Country: 
Brazil
Region: 
Ceara
Location: 
Longitude: -40.5, Latitude: -6.33
Carbonatite: 
No

Perambu is a peralkaline granite intrusion which cuts Precambrian gneisses and migmatites along its northern margin, but in the south is in contact with molasse-type sediments and associated volcanics. The granite contains biotite, aegirine and a little riebeckite. Associated peralkaline dykes are very numerous, particularly in the gneiss terrain to the north, and contain aegirine, riebeckite and arfvedsonite. Very little information is available.

Age: 
Probably 'Brazilian' by correlation with dated granites and dykes further north (Sa, 1981).
References: 

SA, E.F.J, de, 1981. A orogenese Brasiliana e suas relacoes com faixas supracrustais no sudoeste do Ceara. Atas do X Simposio de Geologia do Nordeste. Recife: 337-50

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith