184 J. C. GWILLIM 
gravels, bowlder clay and morainic material, all of which is 
quite local in origin, the country rock being itself local and 
characteristic. 
Elevated valleys— The lower portions of Pine and Spruce 
creeks are terraced, the middle portions have false bedded 
material and bowlder clay. The upper valley of Spruce Creek 
is covered with little hills of morainic material. Occasional 
bowlders of rock, foreign to the present drainage basin, are 
attributed to the erratics of the regional glaciation. (See 
accompanying photograph.) ; 
The streams now flowing through these valleys appear small 
in comparison with the wide troughs through which they run. 
Although rapid, and at times torrential, these streams have only 
cut narrow gutters into the drift and the rock floor beneath it. 
In doing this they have cut down to an older pre-glacial drain- 
age and stream bed. The direction, grade and level of these 
pre-glacial stream gravels is very much the same as that of the 
present creeks, Pine and Spruce. These earlier gravels were 
traced, and apparently undisturbed, for two miles along Spruce 
Creek, lying directly beneath the mantle of gray blue glacial 
drift. They contain coarse gold. If it is assumed that coarse 
gold is concentrated by mechanical action in fairly rapid streams 
these gold bearing gravels should have been on the stream bed 
of a pre-glacial V-shaped valley, otherwise they would not have 
represented concentrations from the adjacent mountains, unless, 
like the present streams, they derived their gold and gravels 
from earlier stream or glacial deposits. 
It appears probable that these pre-glacial gravels existed in 
the ordinary \V-shaped troughs of mountain drainage originally, 
and that, local ice action, cleared out and widened the existing 
valleys without doing much towards deepening them. Such 
action appears to be borne out by a consideration of the exist- 
ing glacier immediately to the south of Atlin Lake. 
Llewellyn Glacier.—From the southern shores of Atlin Lake, 
flat-bottomed, fjord-like valleys lead up to tongues or lobes of 
the Llewellyn Glacier. These ice fronts are, in some cases, only 
