Alkaline Rocks and Carbonatites of the World

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

Arrua-I

stripes

Occurrence number: 
130-00-010
Country: 
Paraguay
Region: 
Central
Location: 
Longitude: -57.35, Latitude: -25.6
Carbonatite: 
No

A steep sided hill 1.2x1 km rising some 150 m from a flat alluvial plain forms a shonkinite stock emplaced in Upper Jurassic sandstones. Dykes of phonolite with analcime ("gauteite") and basalt occur. Not known in detail, but some data on Sc and REE contents are available (Facetti and Prats, 1973).

Age: 
Probably Cretaceous.
References: 

FACETTI, J.F. and PRATS, M. 1973. Correlaciones de escandfio, tierras rares y otros elementos en el stock de Arrua-i. Revista Sociedad Cientifica, Paraguay, 13: 7-17.
PUTZER, H. 1962. Geologie von Paraguay. Gebruder Borntraeger, Berlin - Nikolassee 183 pp

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