74 
ALASKA GEOLOGY 
and dying out on either side slope. These terraces aver¬ 
age about three feet in width, with two or two and a half 
feet rise between them; their surfaces are very level and 
paved with angular fragments of rock, not lying loose 
but firmly embedded in sandy material. The front slopes 
are densely covered with grass and other matted plant 
growth so that the appearance, looking up the slope, is 
of a continuous grassy covering, while looking down, all 
appears rocky and bare. The terraces often run from 
side to side of the slope without break, but again they 
anastomose like cow paths on a hillside. The down¬ 
ward shifting of the slide rock against the resistance of 
the matted plant covering would probably sufficiently 
account for the terrace structure, but the curiously even 
paved surface of the terraces was to me inexplicable. 
The summits of the higher peaks are angular and 
craggy, and nowhere was any evidence seen of glacial 
action even of a local nature. 
The rocks occupying most of the area studied about 
Chichagof Cove (see fig. 17) are a series of marine sedi¬ 
ments containing abundant fossil remains, which show 
them to be of Lower Eocene age. To this series the 
name Stepovak Series will be applied. The beds have 
been considerably folded and faulted, and invaded by a 
laccolithic intrusion of diorite-porphyrite, which sends off 
into the surrounding sediments numerous radial dikes of 
varying petrographic character. 
THE STEPOVAK SERIES 
The Stepovak Series may be divided on lithologic 
grounds into upper and lower beds. 
The lower beds comprise coarse breccias or agglomer¬ 
ates and fine tuffs composed wholly of igneous material. 
They show only a rude stratification, but as far as it can 
be made out it is accordant with that of the overlying, 
