The Idaho Republican. [volume] (Blackfoot, Idaho) 1904-1932, 1920-11-01

osoiogIst Traces History Of Range BY
Strata Of Different Formative Perl.
ods-The Forms Of Mountains and
Valleys az They Now Exist Have
Been Largely Carved Out by Erosion
During Last Era Of Geologic Time.
Tens Of millions Of years ago, in the
ArcheOz0fc era, which Is the most re-
mote age known in the history of the
earth, there were no Adirondack
mountains, according to William ].
Miller, professor of geology at Smith
college. In tracing the history Of the
mountains. Ocean water spread over
the whole region, as well as much Of
Southeastern Canada. On that sea
bottom layers Of sands, muds and
lines were deposited, the strata &C.
cumulating through long ages until
the pile was thousands Of feet thick.
The sands and muds were formed
by the wearing away Of lands which
have left no known records; while the
lines represent the remains Of shells
Of organisms that inhabited that
ancient ocean.
Through the agency Of heat and
crystallization," says Prof. Miller,
writing In the Conservationist, "the
strata became altered into rocks
known as quantities., schists and crys-
talline lime stones or marbles. These
rocks comprise what is known as the
Greenville series of strata-the old
est Of all Adirondack rocks. These
traces of forgotten world, which
still mostly preserve their arrange
ment in layers, may be observed in
numerous areas throughout the Adj
rondack region today, particularly in
the vicinity of Port Henry, Paradox
Lake, Keene and Minerva, In Essex
county; Blue Mountain Lake and
Indian Lake Village, in Hamilton
county; Graphite North Greek and
Chestertown,. in Warren county and
G0uverneur and Edwards in st,
Lawrence county.
"At some later date 1t is evident
that great masses of molten rock
were forced upward into the Granville
strata, lifting, fitting, or breaking
them to pieces. There were at least
two such invasions by molten masses
the first of which Is represented by
rock known as anorthosite. Much of
this rock is dark blush gray and
coarse grained, but some of 1t Is light
gray and medium grained. It is the
principal rock throughout an area of
about 1000 square miles, mostly in
Essex and Franklin counties. The
dark variety forms the main bulk Of
rock in the Marcy-McIntyre range. the
Sentinel range. and the mountains
Just west of Lake Placid. The light
gray anorthosite is finely exhibited in
the northern half Of Mount White
Face, including its summit.
Action Of Weather and Streams.
''The other molten mass, forced up.
ward somewhat later than the an
,rthosite, is now represented by gran.
tie, varying to rock called syenite.
On weathered surfaces these rocks
'ange in color from brown and green
sh gray to pink. Outside Of the an
,rthosite area, the granite and syenite
make up far greatest bulk of the
Adirondack rocks now visible, and
Constitute nearly all of the more
prominent ridges and peaks.
"For millions of years this first
nown land of Northern New York was
objected to the action of weather
nd streams, until at the beginning
f the so-called Paleozoic era which
y most conservative estimate began
twenty-five million years ago, the
'hOle Adirondack region was worn
own to the condition Of more or
ass perfect plain. Early in the
'aleOzOic era. part Of this great low
ving district must have become sub
lerged under an encroaching sea, be-
ause very interesting strata carry
lg shells of animals, which are not
renville strata, can be seen at few
laces In the Adirondacks. Some ex-
client example Of these strata. which
biologists can readily prove belong to
Re early Paleoz0ic age. occur near
IeIlS in Hamilton county.
"Later in the Paleozoic era. the
dirondack region. including the large
lbmerged portion. became upraised
bove sea level. and from that time
, the present no sea water ever again
bread over the district. During the
illions of years of later Paleozoic
me and all Of the succeeding Meso-
bic era, the whole region was again
orn down. by the ceaseless action Of
Gather and streams, to an area Of
low relief.
"About the close Of the Mesozoic era
lis smooth, worn area gradually be-
lme appraised few thousand feet,
lus causing a revival Of the activity
the streams. Since early in the
resent, or Cenezoic era of geologic
me--a few million years ago-the
reams have been at work carving out
network Of channels and valleys in
re plateau. Thus, although the Ad-
L.