Alkaline Rocks and Carbonatites of the World

Funded by HiTech AlkCarb - New geomodels to explore deeper for Hi-Tech critical raw materials in Alkaline rocks and Carbonatites

Centurion

stripes

Occurrence number: 
130-00-004
Country: 
Paraguay
Region: 
Concepcion
Location: 
Longitude: -57.05, Latitude: -22.02

This is probably a complex of dykes, but shown as a major intrusion by Milton and Eckel (1959, Plate 1). It is described as 'phonolite' but comprises phenocrysts of aegirine-augite, orthoclase and andesine/labradorite in a groundmass of partly serpentinized olivine, biotite and feldspar, with crystals of nosean, magnetite and apatite, and secondary zeolite and carbonate.

References: 
MILTON, C. and ECKEL, E.B. 1959. Igneous and metamorphic rocks. In Geology and mineral resources of Paraguay - a reconnaissance. Professional Paper, United States Geological Survey, 327: 12-50
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith