12 The Mountaineer 
and earried by the winds to points rather far removed from the 
mountain. It has been found at points more than 20 miles 
away on the north and the west. 
One of the most interesting incidents connected with the 
lava eruptions was the fact that as the lava arose through the 
tube or conduit in the earth’s crust, it broke off many frag- 
ments of the sohd rock along the way and brought these to the 
surface. In other words, the rising lava broke off and eneulfed 
much of the solid rock with which it came in contact on its 
way to the surface and such rock is now generally disseminated 
through the erupted material. All over the northwestern slope 
of the mountain the lava blocks, large and small, have many 
angular fragments of some other rock contained within them. 
The ineluded rock at first sight seems to be granite, but in 
reality it is syenite. It is rather coarsely crystalline and_ be- 
cause of its mottled color it appears as conspicuous inclusions 
in the lava blocks. The syenite fragments occur in all sizes 
and are always angular in outline. The lava was plastic enough 
to completely engulf the blocks of syenite and yet not hot 
enough to change their character and appearance. The vol- 
eano, St. Helens, seems to be situated upon a floor or platform 
of syenite. This basal rock is hidden by the spreading cone 
and its presence would not be readily detected if blocks from it 
had not been torn off and brought to the surface by the rising 
lava. The original conduit must have been in the syenite and 
through this throat or tube the molten rock escaped to the 
surface in the earliest stages of the voleano’s history. It is 
probable that each succeeding eruption extended the walls of 
the conduit by breaking off portions of the syenite and hence 
securing the inclusions which we now find abundantly in the 
lava bloeks. 
The glaciers of Mt. St. Helens are small. It is not probable 
that any one of them exceeds a leneth of one and one-half miles. 
They are narrow streams of ice, largely buried by debris near 
their melting ends, and giving rise to small rivulets only. The 
mountain is not high enough to receive a great snow-fall and 
hence there is an absence of the necessary snow fields which 
serve as feeding grounds for glaciers of maximum size. After 
all, the chief glory of St. Helens is in its capacity of a sleeping 
voleano and not as a center of an important glacial system. 
