CRYSTALINE ROCKS OF N; S. AND GC. B.—HONEYMAN, 125 
¢hanges to yellow, dark blue, light blue, yellow, orange. We 
have thus a triclinal feldspar, oligoclase. Crossing the nicols, 
we observe on the right side of the last described, a lovely 
green, giving the polariser half a turn the green is changed to a 
bright purple. This is a dichroism indicating hornblende. Sur- 
veying the field while turning the polarizer the pleochroism and 
dichroism is constantly appearing. The rock is thus evidently a 
diorite, there are also black forms constantly appearing. (b.) 
Hxamining there with the Microscope they are seen to con- 
sist of magnetite and pyrite. The minerals of the rock are 
oligoclase, hornblende, magnetite, pyrite. 
5, This is the section of a rock which I observed at Cranberry 
Head, Yarmouth County. It is associated with Lower Cambrian 
rocks, and in close proximity to the auriferous strata of the gold 
mine. On this account it is singular and interesting. (Vide 
paper, Transactions.) I described it as a diorite. Looking 
at the section with crossed nicols, we see a pleochrism of pretty 
much the same character as that of the preceding, but not so 
brilliant. Turning the polariser, the changes also bear a close 
resemblance. Parallel lines are equally numerous. There is also 
a corresponding dichroism throughout the section. We have 
thus as constituents of the rock oligoclase and hornblende. 
There is also mica, an accidental mineral, whose presence 
is readily enough observed macroscopically. Opaque forms are 
abundant. (b.) The microscope shows that the opaque forms 
are of magnetite and pyrite. The minerals of this rock are 
oligoclase, hornblende, mica, magnetite and pyrite. 
6. Diorite of Nictaux. The rock of our section belongs to a 
very important series of intrusive rocks which I have pointed 
out and described in my papers (1) “On the Geology of Kings 
Counties;” (2) “On the Geology of Annapolis County;” (3) “On 
the Geology of Digby and Yarmouth Counties.” (Vide Trans- 
actions. ) 
On geological considerations, and from macroscopical examina- 
tions, I have named these diorites. Members of the series have 
been pointed out as occupying the dividing line between the 
lower and middle Silurian and the lewer Cambrian (auriferous) 
