MINERALOGY OF BLACK LAKE AREA. 
5 
and granite appears only in the form of dykes. Further, although these 
igneous rocks are usually referred to collectively as the "serpentine 
belt/' this is owing to the economic importance of the serpentine and not 
to its prominence; serpentine itself is the least abundant rock present, 
and is, of course, of secondary origin, having been derived from the 
alteration of peridotite and pyroxenite. 
As a general rule in this area, foliation of the igneous rocks due 
to regional compression, although observable, is not so pronounced as 
it is in the Broughton region farther to the northeast. Faults of small 
displacement are numerous in the serpentine, but are less frequent in 
the other igneous rocks; many of these are due to small movements and 
have produced much slickensiding. Displacements of several feet are 
also frequently found. The rocks have a well-defined system of joints, 
which, in the peridotite, have determined the positions of many of the 
larger serpentine bands; in the serpentine itself the joint system is 
obscured by the shattered condition of the rock. 
The general distribution of the rocks is shown in Figure 1, on which 
also are marked the locations of the principal asbestos and chromite 
pits. In each case these are indicated by a numeral, which for asbestos 
is inscribed within a circle, and for chromite within a square. These 
numerals are taken from Dresser’s report, where they are shown on 
Map 23A. The more important occurrences of each of the two minerals 
are given below; in these lists, the principal localities at which specimens 
were collected are printed in italics. 
(4) Coleraine 
(5) Ireland 
(6) Coleraine 
(7) 
( 8 ) 
(9) 
( 10 ) 
(ID 
( 12 ) 
<13} 
(14) 
(15) 
(16) 
(17) a 
(18) 
(19) 
[ 11 ] 
[ 12 ] 
17 
18 
[19] 
[20 
121 ] 
[ 22 ] 
Coleraine 
a 
a 
« 
a 
a 
a 
u 
Occurrences of Asbestos. 
block A, Black Lake Chrome and Asbestos Company, 
range III, lot 26, King Bros. 
block A, Black Lake Chrome and Asbestos Company. 
“ “ Standard Asbestos Company. 
u u American Asbestos Company. 
range B, lots 30 and 31, American Asbestos Company. 
block A, American Asbestos Company. 
range B, lots 29 and 30, Johnson's Asbestos Company. 
block A, American Asbestos Company. 
“ u American Asbestos Company. 
range B, lots 27 and 28, west half, Union pit. 
“ “ lot 28, east half, Southwark pit. 
range A, lot 29, Dr. James Reed. 
range A, lot 28, Dr. James Reed. 
range B, lot 27, east half, BelVs Asbestos Company. 
range A, lot 27, Dr. James Reed. 
Occurrences of Chrome Iron Ore . 
block A, Black Lake Chrome and Asbestos Company. 
u « u a a 
a u “ a a (Black Lake chrome pit), 
u u a a a (Black Lake chrome pit). 
u “ Black Lake Chrome and Asbestos Company, 
range X, lot 19 northwest. 
block A, Black Lake Chrome and Asbestos Company. 
* m Black Lake Chrome and Asbestos Company. 
