NORTHWEST SHORE OF LAKE SUPERIOR. 373 
darker-coloured, of a finer and more compact texture, and bearing no little resem- 
blance to the metamorphosed sandstone of Black River. These beds contain nodules 
of chalcedony and agate. 
On the tops of the highest ridges of this range, and overlying the great green- 
stone ridges, is a rock in all respects like the amygdaloid, except that it contains 
no amygdules; and the peculiar green mineral (thalite), so abundant in the cells of 
the amygdaloid, appears to be disseminated through it in small particles, giving to 
the rock an aspect of homogeneousness, and a very peculiar, rough, irregular frac- 
ture. It is red, coarse-grained, and, upon exposure, weathers with a grayish- 
coloured, nodular fracture. It is distinctly bedded, and conforms to the dip of the 
amygdaloid, which is east-southeast and southeast, from 18° to 19°. 
_ In proceeding down the lake-shore from Two Island River to the Inaonani River, 
the rocks are exposed in detail for nearly the whole distance, consisting of beds of 
trap, volcanic grits, and metamorphosed sandstone. About two hundred yards 
above the mouth of Inaonani River, the following section occurs : 
4. Same as th a clay intervening. 
5. Voleanic grit; very amygdaloidal; in 
irregularly bedded layers. 
6. Voleanic grit; more compact : fewer amyg- 
dules; and regularly bedded. 
1. Basaltic rock. 3, wi 
2. Voleanic grit; amygdaloidal. 
3. Brecciated conglomerate ; the fragments 
being amygdaloidal, and the cement a 
ferruginous clay, with thin clay seams. 
About seventy-five yards above this place is a fine exposure of corrugated or 
wrinkled strata. The wrinkled beds are about two feet thick, the upper part show- 
ing the corrugations most, although they pervade the whole rock. The position 
this rock seems to occupy here, is between the layers of volcanic grit at the bottom 
of the preceding section, and a still lower bed of the same rock. These rocks are 
all traversed by veins of ferruginous clay, from half an inch to eight inches wide, 
and carrying calcite, zeolites, and occasional traces of copper ore. 
A little further up the Lake the section exhibits the following members : 
Basaltic bed. 
Voleanie grit; no amygdules. 
Voleanic grit; amygdaloidal. 
Shaly amygdaloid. 
Volcanic grit. 
Volcanic grit. 
Fe Le O° 
These rocks dip southeast into the Lake, and each bed seems’ to have been depo- 
sited on a very irregular surface. j 
Beyond this point, and in the direction of Two Island River, the following Section 
occurs, in ascending order :* 
* See Section from Inaonani River towards Two Island River, Pl. 1 N, Sect. 4. 
