St. Johnsbury Caledonian. [volume] (St. Johnsbury, Vt.) 1867-1919, 1892-02-04

edCn OlneI Dy q SI1CSldi PiOHiuShNN
for the benefit of man. But it is
natural process. The principal in
gradients of granite are feldspar and
quartz. AS the granite was crushed
in the great ice-how, the quartz made
the sand and the feldspar the clay,
and as they were brought along in
the water the sand was deposited
first, then the clay beyond. 1t is at
the south part of the plain that the
different layers of sand, gravel and
cobble stones are best seen.
But what occasioned this great
formation? 1t was formerly sup
posed that the land was depress-
ed beneath the ocean and lcebergs
from the north swept over the coun-
try grinding and dwelling the hills,
but this theory does not harmonic
all the facts and is generally bandon-
ed The glacier theory is the one
now held. Glaciers exist at the
present time in Switzerland, Green
land, Alaska and in Northern Cali
fornia Scientific men have visited
and studied these glaciers. They are
found to flow like water in a stream
faster at the top and center than on
the sides and bottom. They move
from foot to thirty or forty feet a
day. On the surface are gravel,
stones, and powders. In the sum-
mer the ice melts and great streams
are formed which flow on and
plunge into great cracks or crevasses.
The glacier may be mile or two
miles in thickness, rolling and crush
ing everything beneath it; noun
tain peaks and lodges are rounded
off, soft stones crushed, hard ones
rounded and sometimes striated.
Bowlders are carried over valleys
and deposited on hills, scratches are
made on the rocks. All the phenom-
ina that are found in connection with
present glaciers are found to exist all
over New England and the northern
part of the middle and western sta ties.
The head of the glacier is fixed in the
northern part of Canada. It's posi-
ton is determined by the stria or
scratches, which in New England are
from the northwest to southeast.
The powders are carried in the same
general direction. The powders
have not been carried a great distance
from a mile to one hundred miles
perhaps, showing that they have not
been brought by icebergs from Green
land. Bowlders from the peculiar
nodular granite of Craftsbury are
found in towns lying to the south
east, but none west or north.
Bowlders from the peculiar syenite of
Mt. Ascutney have been varied over
into New Hampshire forty or fifty
miles. The powders of Massachu-
sets and Connecticut are mainly
from New Hampshire and Vermont.
Large potholes are found III
solid rock one hundred or two
hundred feet above the present
rivers. These are believed to have
been formed by the great floods
from the melting glacier and
it must have taken centuries to
form them. This glacier swept over
the Green mountains and the White
mountains except about four hundred
feet of Mt. Washington.
From this brief sketch it can be
seen how St. Johnsbury plain was
formed. Centuries may have elapsed
between the bottom and the top lay
ers. At times there was a rush of
waters carrying everything, before it,
granite, pebbles and powders; then
the gentle flow of the waters formed
| the beautiful layers of sand and clay.
The unsorted drift or till is supposed
to have been deposited when the
glacier was sweeping on, but the
terraces towards the close of the ice
period. Probably the glacier gradual
ly disappeared, little more melting
during the summer than formed dur
ing winter. The St. Johnsbury ter
race is what is called a delta terrace
formed by the union of two rivers,
which makes deeper and larger ter
race. At the present time when there
is great freshet, the banks of a river
are often torn away and carried
down stream and deposited on the
opposite bank 1t was so in ancient
time The swollen stream, one
hundred or more feet deep, full OF
sand, gravel and debris of every kind