Alkaline Rocks and Carbonatites of the World

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

Brossard

stripes

Occurrence number: 
031-00-128
Country: 
Canada
Region: 
Montreal area
Location: 
Longitude: -73.52, Latitude: 45.5
Carbonatite: 
No

Excavations for the St Lawrence Seaway uncovered igneous rocks which are, however, no longer to be seen. The form of the intrusion is not known. The rocks are banded and consist of kaersutite phenocrysts, rare grains of serpentinized olivine and pyroxene, and a fine groundmass of titanomagnetite, kaersutite, clinopyroxene, a little red biotite, nepheline and possible feldspar. Some rocks contain ocelli of analcime and dolomite. Numerous rock analyses are available.

References: 

GUNN, B.M. 1972. The fractionation effect of kaersutite in basaltic magmas. Canadian Mineralogist, 11: 840-50.

Map: 
Fig. 1_61 Distribution of alkaline rocks in the area of Montreal.
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith