The Republican journal. [volume] (Belfast, Me.) 1829-current, 1899-06-15
A Geological Excursion.

A small party from the Agassiz Associ-
alton and Nature Club made geological
excursion short distance up the Pas
sagassawaukeag River last Thursday at
ternoon under the direction of MI. A. l.
Brown. The route was up the railroad
track from the Lower Bridge and the first
point of interest was the Wool Factory
stream, which shows unmistakable signs
of having been at one time considerable
torrent with good head of water behind
it. Other small streams showed as plain
ly that they were merely temporary and
fed by the intermittent rains and the
wash of the nearby hill-sides. Near the
semaphore signal the party left the track
and went to the shore, which was followed
to the Upper Bridge. Between these two
points the nature of the rock in the river
bank changes from the talcose schist, the
soft slaty rock which underlies the city,
to the micaceous schist, a much more
compact formation, which underlies the
talcose, The change is quite abrupt,
there being a narrow vein in which the
two rocks are blended, the talcose pre-
dominating as We approach the south, and
the micaceous as we go north until the one
or the other disappears altogether.
One of the most interesting geological
features of this section is to be found at
the railroad cut above the Upper Bridge.
Here the river is perhaps 700 feetlwide,
each side. These banks are of mcaceous
schist, in nearly perpendicular strata, the
drift lying northeast and southwest, or
more accurately speaking, north IS de-
grees east. Many interesting minor fea-
lures are observed in these rocks, brought
to view by the cutting on the railroad,
strata between the strata of the harder
rock, etc, bat space does not permit going
into these details. Following the direc-
ton of the drift to the opposite side of
the river the same strata are found, with
corresponding soft layers, and, at tie
water edge. the marks of the work Of
the ice of the present day, showing the
great power that even the small amount
OF ice Low in the river exeIts. The ascent
to the brow Of the hill is over a series of
terraces IN the reotls. varying from to
10 feet il height. The rocks all the way
NJ show marks of ice and water action as
plainly as do those at the present water
level. Biologists believe that these bluffs
on the opposite sides Of the river are
but the Iemaius of an immense natural
dam, which IN the early ages held back
the waters If a large river and flooded
large section of territory now known as
the Poor Mills Basin and extending
through Knox and Freedom TO the inte-
rior. They argue that the terraces in the
rock and the water markings thereon
were caused by the gradual breaking
away OF thi, barrier, the height of the
water in the basin gradually decreasing
as the dam broke away piece by piece.
1t is also noticed that the settlement at
the Upper Bridge is on a small hillock,
with the rive! on one side and a valley on
the other This valley was once a water
course, bat the &C lformation of the land
is such that its only source of supply
which could have existed must have been
the main river. Hence at one time the
present site of the Upper Bridge settle
ment must have been an island, with a
torrent Oh the east coming from break
in the natural dam, then 80 feet OF more
in height, while the main torrent follow
ed the present channel Of the river.
The student of geology who is interest
ed in questions of the formation of the
earth crust can find no more interesting
field for his study than the vicinity of
Belfast AS field for the collection of
rare or beautiful specimens it is not
recommended They do not exist here,
but Tor the deeper study of the rocks,
many features exist that are not to be
found elsewhere The features mention
ed above are ut an index to what may be
learned by careful study Of that section,
and by following up the basin to its
source. If one is interested in the up
heavals which brought the granite to the
surface, Oak Hill and Mt. Waldo present
fine fields; OF if one is searching for gla-
cial markings they may be found in many
places within few miles of this city, not
ably at Mt. Percival in Northport on the
Belmont road near the Hayford farm, and
other points The other strata, talcose
mica schist, micaceous schist, ETC., each
present interesting features.
Prose, and Worse.