Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1912-10-15
The Great 0nondasa Sea.
MIDDLE ATLANTIC STATES ONCE COW
ERED WITH WATER.

It has been shown BY geologists that ct
various times during the moro ancient
eras of the earth's history great seas, di.
verse In size and form, existed In regions
now lying in the interior Of the continent
of North America. These great seas,
some OF which had outlets to the ocean
of the Arctic and others were connected
by straits with the Atlantic, or possibly
opened out into great gulf to the south.
we're constantly changing, In accordance
with the deep seated earth movements OF
the continent. Complicated and always
varied warping Of the earth's crust, COM
bined With downward or upward thrusts
Of the land masses, accomplished sweep
ing changes In the geography, some.
times burying large regions below sea
level and leaving only remnants-skele.
tons of the land, as 1t were-of large por-
tious OF the old continent surrounding
interior seas. At other times the land
rose, more warping took place, the seas
were banished from the interior regions,
and the continent stood larger and high
or even than It does now. Even at the
present moment large stretches OF our
coasts are subsiding below sea level.
The history of this earth movement
and the conditions surrounding the diff
ferent invasions Of the sea into the con-
tinent are revealed by the study OF the
rock strata and their fossils. Az the
animal and plant life has changed from
period to period, differing In each OF the
inland seas, It is particularly to the study
of these fossils that geologists owe their
knowledge of the time relations OF each
period In geologic chronology. The fos-
sils show the climatic conditions, the
nature of the shores, and the depths to
the oceanic connections.
An important addition to our knowl-
edge of one of these very ancient seas
the Onondaga-has been made by z. N.
Kindle, In paper just published by the
United States Geological Survey as
Bulletin sos. This sea, which Is very
far from being one Of the most ancient
of the Paleozoic, though 1t dates back
probably more than hundred times as
far as the great Ice Age, is known as the
Onondaga, because the criteria revealing
and characterizing 1t were first brought
to light In Onondaga County, in northern
New York. Mr.. Kindle shows that the
peculiar forms inhabiting the Onondaga
sea extended through Pennsylvania,
Maryland, and Virginia for hundreds OF
miles In the waters Of sea whose east
ern shore line was not far west OF the
site where the Blue Ridge now stands.
From southwestern Virginia this shore
line appears to have trended westward
not far from the Kentucky Tennessee
line as far az the present valley OF Ten
uessee River aud at some point was con-
nected with the great inland sea covering
the present Mississippi Valley. The
Onondaga waters were warm, - 10 shown
by the presence of corals and other trop-
icsl or subtropical types of sea life. The
technical descriptions Of these fossils
compose the main part Of the bulletin,
which is OF interest especially to those
concerned with the study of the extinct
molluscan fsunas.
The great basin occupied by the Ono1'
daga sea was later warped and greatly
changed and its eastern portions were
filled to a thickness of 5000 to 10000
feet BY sediment, mostly derived from
the elevated but comparatively narrow
remnants of tho continent lying east OF
the present Blue Ridge. II these sedi-
ments were piled upon level plain they
would form mountain range equaling
In height and extent the Sierra Nevada
of California.
Bulletin 50S, which is technical In ma
ture, may be had free on application to
the Director OF the U. 8. Geological Sur
vey, Washington, D. @.