stripes
Occurrence number:
130-00-026
Country:
Paraguay
Region:
Guaira
Location:
Longitude: -56.3, Latitude: -25.78
Carbonatite:
No
A 4 m thick biotite porphyry dyke cuts sandstones in an area east of Villarica and passes into a sill within the sandstones. Brown biotite phenocrysts are set in K-feldspar, (?)nepheline and opaques. On Plate 1 of Milton and Eckel (1959) other alkaline dykes are indicated in the same vicinity.
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
Location: