Alkaline Rocks and Carbonatites of the World

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

La Garita (Atenas)

stripes

Occurrence number: 
039-00-001
Country: 
Costa Rica
Region: 
Alajuela
Location: 
Longitude: -84.38, Latitude: 9.95
Carbonatite: 
No

In the vicinity of the village of Atenas along the Rio Grande de Tarcoles occurs a basanite flow associated with andesites, ignimbrites and tuffs. The rock is rich in phenocrysts of olivine (Fo85-70), augite and labradorite/bytownite in a matrix of plagioclase, opaques, augite, a little biotite and interstitial analcime.

References: 
ROBIN, C. and TOURNON, J. 1978. Spatial relations of andesitic and alkaline provinces in Mexico and Central America. Canadian Journal of Earth Sciences, 15: 1633-41. TOURNON, J. 1973. Presence de basaltes alcalins Recents au Costa Rica (Amerique Centrale). Bulletin Volcanologique, 36: 140-7
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith