February 28, 1918. 
Canada 
Geological Survey 
Museum Bulletin No. 27. 
GEOLOGICAL SERIES No. 35. 
Contributions to the Mineralogy of Black Lake Area , Quebec . 
By Eugene Poitevin and R. P. D. Graham. 
INTRODUCTION. 
The minerals described in the following pages were collected by the 
writers at different times during the summers of 1913-14-15, from some 
of the asbestos and chromite mines and pits in the neighbourhood of 
Black lake (Plates I and II). The region is situated in the southeastern 
and northwestern portions, respectively, of Ireland and Coleraine 
townships, Megantic county, province of Quebec (Figure 1). The area 
is one of the most productive sections of the so-called “serpentine belt” 
of the Eastern Townships, and includes many of the most important 
asbestos properties; in addition, there are a number of deposits of chro- 
mite which have been profitably, though intermittently, worked for the 
past thirty years. 
Although mining operations have been carried on in the district 
for many years, and the geology of the area has been investigated in 
some detail, very Httle attention has been paid hitherto to the mineralogy 
of these deposits. J. A. Dresser, in 1910, was the first to call attention 
to the peculiar dykes of lilac vesuvianite at the Montreal chrome pit, 
and the specimens he collected were at that time examined and described 
by one of the writers. In this connexion it is interesting to note that 
several very poorly crystallized specimens of this material were subse- 
quently found, unlabelled, in McGill University mineral collections, 
having been apparently collected, or received, several years ago and 
set aside for examination; the locality given for these is the St. Francis 
mine, Coleraine district, Megantic county, which at the present time 
is known as the Black Lake quarry of the Dominion Mines and Quarries, 
previously known also as the Montreal chrome pit. 
Special attention was first called by Robert Harvie to the wealth 
of mineralogical material which the district affords. He pointed out 
that a study of the minerals might throw some light on the genesis of 
