The Elk Mountain pilot., 1881-08-18

heaped mountain high on the ice
fields beneath. This snow by its
pressure gradually packed down and
condensed into ice, thus contributing
to the thickness of the glacial body.
Owing to the inclined character of its
bed, and the great weight of the ice
mass, the glacier had slow down
ward movement that pressed it toward
the gulches and lower valleys. In the
vicinity of Irwin it met with but little
obstruction until it encountered the
range of mountains lying southwest
from town. These split the sheet in
two, forcing great tongue of ice on
one side down Anthracite creek, and
on the other down the pass and wesl
of Mt. Carbon. In taking these courses
and during this forward movement,
great changes were wrought in the
bed ofthe glacier and along the noun.
tain sides where it lmpringed. The
force of such mass of moving ice is
prodigious and sufficient to crumble
the mountain sides with its power.
Huge masses of rock were enveloped
by the congealing SHOWS, torn from
their place with loud reports, and held
with giant grip until'they were broken
and crumbled against projecting
cliffs, or with their keen exposed
points acted as chisels to cut away the
bed, or the sides exposed to the gla.
cier.
As the power of the sun became
stronger the ice melted away anc
dropped these boulders far from theil
original location. Some of a .lnt
dred tons weight may be seen nea,
the Pioneer mill that have rldder
down from the head of Ruby basin
Most of them have become smooth
and rounded from their contact with
other rocks. Some of them have
been caught up the second and thire
time and pushed on towards the val
leys below. From the top of RUBY
basin to the foot of Mt. Carbon, anc
far down Anthracite creek is a con
tinuous bed of glacier boulder drift
Such causes of drift are called morains
Irwin is located on such morain OF
glacier dump, and the drift below the
lake likely attains depth of 200 feet
As the heat of the sun gradually re-
turned and the glaciers became les:
extensive, their points being at :
strong angle with the foot of the
mountains, were forced like grea
plows into the loose debris and drift
and scooped out large areas, massin&
the drift in front of them and leaving
numerous basins that now serve a
lakes. Lake Brennand was produced
in this manner and is fine exhibition
of glacial mechanism. The heapec
up drift between it and Irwin show!
the stupendous force exerted by Eict
masses.
All this occurred long after tn,
lodes from which silver is now bein,
taken was formed. As the glacier
passed over these lodes they lore ava,
their quartz groupings, leaving then
exposed to greater depth, thus ia
voring the miner in his labors to-day
by bringing pay ore nearer to the sur
face. All the great veins of Rub,
basin have been more or less affected
by these causes, and large masses o
their float quartz are strewn abou
Irwin, the hill west of town, and fal
down Anthracite creek. In fact tn,
discovery of some of these ore de
posts is due to erosion from glacia
action, which stripped them of over
laying material and exposed their 10
cality to the prospector. 1t must D,
borne in mind however, that glacier
in no way modified the character o.
contents of the vein itself. They wer.
established long previous to the gla
cial era and during what might bt
called the youth OF the mountains
when more potent energies were oper
ating than those of snow and ice;
Glaciers are simply mechanical il
their work, while the filling of or.
veins or their after notifications n,
chiefly due to chemical forces.
! c. H. MURRAY.