47 



clouded types of singular beauty. These are 

 produced by differential movements accom- 

 panied by more or less intense metamorphism 

 induced in beds of limestone and dolomite of 

 varying degrees of purity. Among the more 

 important varieties may be mentioned the 

 following : 



(i) "Bancroft Cipollino," so called from its 

 resemblance to the Italian Cipollino, is a green 

 and white variety. 



(2) " Laurentian Vein, 1 ' This consists of 

 broken and faulted bands of magnesian lime- 

 stone, drab and cream in colour, cemented to- 

 gether by a relatively small amount of dark 

 matrix, which consists of magnesian limestone 

 with much biotite and a smaller amount of a 

 nearly colourless hornblende. This variety 

 passes into a breccia with a dark base and 

 fragments of lighter colour. 



(3) " Laurentian Blue." A fine-grained bluish 

 grey marble in which the original bluish colour- 

 ing matter has not yet been entirely destroyed 

 by metamorphism. 



(4) "Rose Fantasia." A marble irregularly 

 banded or streaked, presenting a great variety 

 of colours, often of great brilliancy. The 

 colours represented are white, pale pink, bright 

 red, and cream colour. 



(5) "Bancroft Green." This is a fine-grained 

 light green rock composed chiefly of a very pale 

 green hornblende with some calcite. The 

 variety called "serpentine" is almost identical 

 in character, the hornblende, however, being 

 more fibrous (actinolite), while in addition pale 

 brown biotite is present. 



A white granular marble (dolomite) also 

 occurs near the railway station at Bronson. 



The company has installed. a complete plant 

 for quarrying and sawing these marbles. 



Three small fine-grained black dykes of mal- 

 chite cut the marble in one part of the quarry. 

 These are composed essentially of a dark green 

 hornblende and plagioclase. These minerals are 

 allotriomorphic in form, although the plagio- 



