28 TRANSACTIONS OF THE [oct. 28, 
Diorite.*—The massive moraines on the eastern side of Muir 
glacier are made up in the main of fragments ofa quartz free 
diorite, which is a more basic rock than the quartz diorite. 
Numerous blocks of hornblendic gneiss and schist also occur, 
which may represent foliated phases of this diorite. The large 
content of such rocks in the moraines leading from the valleys 
occupied by the McBride, Casement and Girdled glaciers and 
Berg lake, and from Granite canon, shows that the enclosing 
mountains are in great part of diorite, and the color and 
aspect of these mountains when viewed from a distance give 
evidence to the same effect. None of these mountains have been 
reached by parties exploring Muir glacier, so that the nature of 
the argillite-diorite contact is unknown. But there is a total 
absence of anything indicating shore conditions as this contact 
is approached ; no pieces of conglomerate have been noted on 
the moraines, and pieces of fine grained diorite, evidently from 
dikes, have been found. The diorite is therefore likely to prove 
of later date than the Carboniferous sediments. So faras known 
it shows no tendency to grade into the quartz-diorite. They 
may represent phases of the same intrusion, or different intru- 
sions from the same magma. 
Crystalline Schists.—In the collection of rocks made by Dr. 
Reid in 1892 are specimens of mica schist and actinolite schist, 
obtained from erratic blocks on the west shore of Glacier Bay, 
mainly at the northwest corner of Hugh Miller inlet and at the 
eastern side of the entrance to Geikie inlet. It is of the highest 
degree of probability that these erratics were brought hither by 
the glaciers which at present debouch into these inlets, and that 
therefore outcrops of these schists lie in that direction. Daw- 
son reports frequent areas of schists and gneisses as occurring 
in the Coast range granite beit, and quite subordinate to the 
granite in amount, and these may have come from such patches. 
On the other hand, granites are not represented in Dr. Reid’s 
collection. 
Megascopically, the mica schists are finely granular, very 
schistose rocks with abundant biotite, all of which carry small 
garnets, and some contain staurolite in addition. Except in the 
size of the garnets, they precisely resemble the well-known gar- 
netiferous mica schist from the mouth of the Stikine river. The 
actinolite schists are finely fibrous green schists, mainly com- 
posed of actinolite. 
Dikes.—All the rocks so far described are cut by numerous 
dikes, of varying nature but largely of diabase. They are not 
only younger than the other rocks, but also younger than the 
*G, H. Williams, Nat. Geog. Mag., Vol. IV., pp. 65-67. 
