528 ALLEN DAVID HOLE 
In Savage basin above 12,000 feet in elevation, there are found 
usually rock streams, and talus slopes at the bases of the precipitous 
bounding walls; below this elevation, as in the case of Marshall and 
Middle basins, there is usually a rock floor with roches moutonnées 
and numerous striae; unlike Marshall basin, however, Savage basin 
has a number of small rock basins, some of which contain water. 
The rock streams here are of two periods, as is the case in Middle 
basin, and the arrangement of the two with respect to each other is 
likewise for the most part the same, that is, the older lying as a 
narrow belt outside or below the more recent. In a few places, 
however, the older, more rounded slopes are farther up the valley 
than those made up of bare, angular rock fragments; this seems to 
be due to the movement of the fragments transported in more 
recent time around the older deposit, much in the way that a glacier 
is seen to move around an island or a promontory of rock which is 
a little too large to be overridden. 
The maximum thickness of ice for the area drained by Marshall 
Creek was probably about 800 feet. 
VALLEY OF INGRAM CREEK 
The greater part of the area drained by Ingram Creek lies in the 
Silverton quadrangle. The north branch of the basin has but few 
good examples of roches moutonnées, though many projecting points 
and ledges are distinctly rounded. Striae bearing S. 88° W. 
occur on the east side of the stream at an elevation of 12,000 feet. 
In the upper part of the north branch are the usual precipitous 
bounding walls, talus slopes, and rock streams of two different 
periods: 
The central subdivision of the basin is deeply carved. Channels 
up to too feet wide and 50 feet deep occur in the bed rock, approxi- 
mately parallel to the length of the valley; the sides of these 
channels are precipitous, and in many places well smoothed. 
Striae in general parallel to the course of the stream are abundant. 
Talus slopes are found at the north side and the east end. 
The south branch has many roches moutonnées; some of the 
surfaces are striated, some are weathered rough. Ice passed over 
the 12,400-foot ridge situated between the central and south 
