Alkaline Rocks and Carbonatites of the World

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

Calvin Township

stripes

Occurrence number: 
031-00-089
Country: 
Canada
Region: 
Ontario
Location: 
Longitude: -78.9, Latitude: 46.28
Carbonatite: 
No

A small area (1.3 km2) of nepheline syenite gneiss occurs 19 km southwest of the town of Mattawa. The gneiss contains 5-25% nepheline, sodic hastingsite, 40-60% oligoclase and sometimes garnet. A pyroxene, which is present in some rocks, is described as omphacite.

References: 

LUMBERS, S.B. 1976. Omphacite-bearing nepheline syenite in an anorthosite complex, Grenville Province of Ontario. (Abstract). Geological Association of Canada - Mineralogical Association of Canada, Annual Meeting, Edmonton, Program with Abstracts, 1: 73.

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