stripes
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.
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.