1870. | HIND—GNEISSOID SERIES OF NOVA SCOTIA. — 475 
an area of about 120 square miles. Around this nucleus the gold- 
districts of Cochran’s Hill, Sherbrooke, Wine Harbor, Isaac’s Har- 
bor, and Country Harbor are arranged, also on the crown of anti- 
clinals, which have a general easterly and westerly direction. 
The profound Silurian valley shown in the map (fig. 1), between 
Halifax and Windsor, divides the Atlantic portion of Nova Scotia 
proper into two distinct geological areas, in both of which the old 
porphyritic Laurentian gneiss forms the axis around which Huronian 
and Silurian series are arranged; but, with respect to the precise 
limits of these formations, little is known west or east of the area 
shown on the plan. 
From Dr, Dawson’s published maps and descriptions, Mr. Poole’s 
manuscript map of the western part of the peninsula, and the nume- 
rous rock-specimens collected by that gentleman, and placed at my 
disposal by the Commissioner of Mines, coupled with valuable infor- 
mation derived from other sources, I infer that this coarse Laurentian 
eneiss extends in one unbroken sheet of strata, but of variable 
width, a distance of ninety miles west of Windsor, and occupies a 
large portion of the uninhabited wilderness in that part of the 
Province. Much of the gneiss, schist, and mica-slate seen by 
Mr. Poole, and described in his Report, and illustrated by his 
specimens, together with the gneiss, mica-schist, and chloritic beds 
alluded to by Dr. Dawson, and by that geologist long ago spoken 
of as probably older than the Lower Silurian, are doubtless the 
representatives in many instances of the Huronian in the district 
where they occur. 
In the autumn of 1868, Dr. Honeyman, then engaged on the 
Geological Survey of Canada, discovered on the Gulf-coast of Nova 
Scotia, in the Arisaig district, and near the base of the Antigonish 
mountains, syenites, diorites, and crystalline limestone, with ser- 
pentine. Specimens were sent to Montreal for examination; and 
instructions were given by Dr. Hunt to the lapidary to prepare 
sections of the serpentinous rock for microscopical examination. By 
some mischance this was neglected, and the specimens remained 
unexamined, and indeed forgotten, until quite recently, as Dr. Hunt 
informs me, under date Feb. 3, 1870. When submitted to the 
microscopic test, forms resembling Hozoon canadense were distinctly 
seen. These may be of Laurentian age*. 
In other parts of Nova Scotia the Laurentian is yet known only 
in the form of coarse porphyritic gneiss; but the area it occupies is 
a lake and forest wilderness, frequented only by the lumberman and 
hunter. 
The descriptions given by Sir W. E. Logan of a similar rock in 
the Laurentian of Canada apply exactly to the characteristic strata 
in Noya Scotia. ‘The coarse-grained granitoid and porphyritic 
varieties, which often form mountain masses, sometimes have, at 
* The existence of the Hozoon has recently been established in limestones and 
serpentines, now known to be of Laurentian age, by Dr. Sterry Hunt, in Massa- 
chusetts. An account of this discovery is given in the last number of the 
‘American Journal of Science,’ Feb. 1870. 
2m 2 
