42 
ALASKA GLACIERS 
now, but our meager facts include nothing to indicate either 
the date of their deposition or the date and manner of their 
deformation. The overlying gravel and till are clearly of 
glacial origin, and the gravel was laid down at or near sea- 
level. As it is now about 150 feet above the sea, it is evident 
that there has been a change here in the relation of land 
and ocean. The buried tree trunks tell of an advance of 
the glacier over a tract that had existed as dry land. 
FIG. 24. PUSH-MORAINE NEAR LA PEROUSE GLACIER. 
The glacier is out of sight at the left (compare fig. 23). The moraine, here 10 feet high, is 
crowded against forest trees, and includes crushed trees. Photographed in June, 1899. 
The remnant of timber standing east of the stream val¬ 
ley was separated from the glacier at the time of our visit, 
by a belt of barren ground from ioo to 200 yards wide (fig. 
23). This ground was occupied by bouldery till containing 
bruised and macerated branches and trunk fragments, and 
the margin of the timber showed unmistakable evidence 
of recent attack by the ice (fig. 24). The till had been 
