Alkaline Rocks and Carbonatites of the World

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

Seis Lagos


Occurrence number: 
Longitude: -66.68, Latitude: 0.28

Located during the RADAM Project, Seis Lagos consists of three circular structures aligned north-south with approximate diameters of 5.5, 0.75 and 0.5 km. They form laterite covered hills surrounded by gneisses and migmatites of the peneplained Guianense complex. The laterites have an average depth of about 230 m and are radioactive. Siderite, ankerite, dolomite, baryte, goethite, pyrite and niobian rutile have been identified in carbonatite from drill holes.

Anomalously high values for a range of elements have been detected in the lateritic cover with grades of 0.15% Nb2O5, 1.50% Re2O3, 0.07% ThO2 and 0.09% V2O5 reported.
BONOW, C. de W. and ISSLER, R.S. 1980. Reavaliacao e aspectos economicos do jazimento de terras rares a ferro-ligas do lago esperanca complexo carbonatitico dos Seis Lagos - Amazonas - Brasil. Anais do Congresso Brasileiro de Geologia, Santa Catarina, 31(3): 1431-5. ISSLER, R.S. 1978. The Seis Lagos carbonatite complex. Proceedings of the First International Symposium on Carbonatites, Pocos de Caldas, Brasil: 233-40. RODRIGUES, C. de S. and LIMA, P.R.A. dos S. 1984. Carbonatitic complexes in Brazil. Companhia Brasileira de Metalurgia e Mineracao: 1-17
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith