28

be examples of all gradations between normal talus or felsenmeer and rock
glaciers; and there should be some sign of a meltwater stream issuing from
those well-established rock glaciers that are advancing over ground carry-
ing nearby surface streams. These features are not found in the typical
rock glaciers examined. It seems more probable that if ice is the main

| Size of fragments Size of fragments on
70 on surface of talus 70-| surface of rock glacier
Upper part of slope ...__ _

60-4 Lower part of slope... ___ 05
2
& (rican
a
2 50-4 504
S
vn
§
E
2 40-1 40-
>
S
2
ra}
&
s 3075 304
e
vo
oO
i)
a

204 20-4

107 10

O— = o- — |
1064 32 16 08 04 02 LORGYATIES 2 er lkowan OG uO Aum
Mean diameter of fragment in feet Mean diameter of fragment in feet

Rock: serpentinized peridotite
Pp i)

Each histogram based on count and measurement of fragments in an area of 10,000 square feet

GS GC

Figure 2. Illustrating size of fragments distributed on the surface of talus and
rock glacier in Lay Range.

lubricating medium, there is an optimum condition in which interstitial ice
is sufficiently abundant to decrease the internal friction of the mass, but
not enough to provide an anchoring matrix. The surrounding talus may
‘perhaps contain either more or less interstitial ice. Certainly some of the
dying glaciers, choked with ablation moraine, contain more ice; this ice