Alkaline Rocks and Carbonatites of the World

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

Cerro Sarambi (Juan Caballero Ii)

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Occurrence number: 
130-00-007
Country: 
Paraguay
Region: 
Concepcion
Location: 
Longitude: -56.25, Latitude: -22.75
Carbonatite: 
Yes

This complex forms an approximately circular structure about 5 km in diameter emplaced in Precambrian metamorphic rocks which are domed and surrounded by Silurian and Permo-Carboniferous sedimentary rocks. The principal rock types are pyroxenite and aegirine-nepheline syenite, which are intruded by trachyte and phonolite dykes and thin veins of apatite-magnetite sovite. The country rocks have been subjected to potassium fenitization.

Age: 
Post Jurassic. Probably Lower to Middle Cretaceous by analogy with nearby Brazilian alkaline complexes.
References: 

MARIANO, A.N. and DRUECKER, M.D. 1985. Alkaline igneous rocks and carbonatites of Paraguay. Abstracts with Programs, Geological Society of America, 17: 166.
MARIANO, A.N., personal communication, 1985.
PALMIERI, J.H., PLUGFELDER, P.M. and CUEVAS, F.K. 1974. Contribucion a la geologia regional del area NE'A - Cerro Sarambi, Departamento de Concepcion (Paraguay). Revista Sociedad Cientifica, Paraguay, 14: 63-6.
PALMIERI, J.H., personal communication, 1981

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