Alkaline Rocks and Carbonatites of the World

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

Ste-Monique

stripes

Occurrence number: 
031-00-119
Country: 
Canada
Region: 
Montreal area
Location: 
Longitude: -74, Latitude: 45.67
Carbonatite: 
No

The Ste-Monique sill caps a number of small hills over an area of approximately 3x1 km. It is probably 6-7 m thick, although contacts are not exposed. The principal rock type consists of phenocrysts of augite, olivine, usually with margins of monticellite, and biotite in a groundmass of abundant poikilitic brown biotite, monticellite, calcite and accessory brookite, perovskite, apatite and opaques (Howard, 1922, pp. 61-8). Currie (1976a, p. 68) states that analcime and augite are the most abundant constituents, and that felsic ocelli are sometimes present.

References: 

CURRIE, K.L. 1976a. The alkaline rocks of Canada. Bulletin, Geological Survey of Canada, 239: 1-228.
HOWARD, W.V. 1922. Some outliers of the Monteregian Hills. Transactions of the Royal Society of Canada, Series 3, 16: 47-95.

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