

B. N. A. BOUNDARY COMMISSION, 





of glacier ice, but that they have not been produced in this way, is 
dent, as a rounded and glaciated surface may sometimes be seen p eel 
off under the action of the weather, and exposing the subjacent plane. — 
82. Here a fragment of dolomitic limestone, 2 feet 6.inches in grea r 




diameter, was found, being the only limestone boulder observed in the : ia 
whole northern part of the lake. It did not appear to have travelled fa . it 
and differs much in character from those subsequently to be mentioned — 
as occuring in the southern part of the lake; being hard, coarsely crys- a 
talline, highly magnesian, and weathering to a deep-brown colour. 1 oa 
ZZ much resembles the dolomites found in the Eastern Townships of Quebeat! 
























1G 
in association with the altered rocks there; and such limestones may * 
very probably occur inter-bedded with the dolomitic schists already ie 
described, but in parts of the series, which from their more readily de-- a 
composable nature, are generally concealed by water or overgrown by | a 
woods. ae 
\ 2) 

‘ 83. North of this on a small island, a rough greenish schist appears, 4 ae 
Be: spotted where weathered, and having a strike of N. 75° KE. Itis in contact 
te | to the north with a thinly cleavable nacreous schist, minutely undulating ; : 
i and of white and reddish colours. Another small island nearly on the a 
* same line of strike shows a rough, green, and rather hard chloritie dees ee 
P| - dip N. 5° E. < 55°. 3 ae 
84. Lacrosse Island, so-called on Dr. Bigsby’s map,* and deriving its 
name from the fact that some parts of it are level and open, and have been oa 
. used by the Indians at one time, for this, their favourite game, lies about 
nine miles south of Rat Portage. Its extreme south-western point is 
composed for at least 100 feet of dark-coloured diorite, rather fine-grained, — 
and with little segregations of epidote where in contact with the slates; 
but coarser and porphyritic at some distance from them. ‘The line of 
junction with the stratified rocks is vertical, and runs very straight, with 
a course of 8. 25° EK. North of this, for nearly half a mile; the western ‘a 
shore is composed of Very thinly cleavable schists, whitish and greenish in “ee 
tint, and though regularly bedded, minutely undulated throughout; strike 7 
N. 58° E., dip northward < 88°. The shore for about a mile, is then 
occupied by greenstone conglomerate and associated rocks, forming a 
belt, with a breadth of about half a mile across the strike, which was 
observed to be N. 46° E. at the southern, and N. 78° E., at the northern — 
edge. The rocks are hard and compact, and though breaking with a 
Ph 
he : 
>» 

* Called by the Indians Pa-ga-ta-wa-minis, 

