Morning journal and courier. [volume] (New Haven [Conn.]) 1848-1894, 1892-01-26
OUR LOST VOLCANOES.

The Blue Hills and Hanging Hills
Near Meriden-The Workings of Fire
in a Prehistoric Age in the Connecti-
cut Valley.
It is fact not generally known that
there are volcanic remains right here in
Connecticut within 20 miles of New
Haven. They lie about II miles from
Meriden, and are known by the name of
the Blue Hills, Hanging Hills and several
other individual peaks. They consist of
thick beds of greyish-greenish rock, not in
layers like limestone or sandstone, not
crystalline like granite Or gneiss, but of o
loose, struotureless texture, here and there
carrying roughly rounded blocks of a
dense dark rock which is known by geolo-
gists as an old lava, from it's resem blance
to the rocks elected from modern vol
canoes. 1t is a question which never has
been definitely settled as to how the forma-
ton took place in the prehistoric ages
Professor William M. Davis, in a recent
issue of the Popular Science Monthly,
says that the lava formations near
Aeriden were due to the same kind of ac-
ton as formed the Zuni buttes in New
Mexico and the Black Hills in Dakota and
Montana. There are formations in Scot
land of the same kind also. The point
that gives biologists trouble is that there
are no remains of the ancient vent or era
ter, through which this outpouring took
place. OF the explanation that they are
formed in the same way as the Zuni
buttes is accepted, it would seem that
these lava sheets and ash bed are simply
tho worn edges of lava sheets that still
plunge underground eastward and that
once rose high in the air to the westward. The
beautiful Hanging Hills and Mt. Lamenta-
ton in the same neighborhood are of the
same formation. Professor James D.
Dana of Yale college, in that interesting
and instructive little book which he issued
last year, Con the Four Rocks of the New
Haven Region, East Rock, West Rock, Pine
Rock. and Mill Rock" with Q guide to
walks and drives about New Haven, be-
ing of inestimable value to the amateur
geologist, thus describes the formation of
the Hanging Hills, which are supposed to
be of the same formation as the lodges in
question:
Sandstone throughout the Connecticut
valley is almost every where in an up
turned condition as result of subter-
Ianean movements.
The beds have consequently with few OK
captions an eastward pitch of from Is to
IS degrees. After the upturning had been
to a large extent completed in the New
Haven region, eruptions of trap rock took
place from great assures through the
sandstone and the underlying rocks of the
earth's crust. The lava which then came
up and filed the assures and in many
places outhowed is the rock we now call
trap. The trap of the Hanging hills of
Meriden and of the line of heights reaching
to Mt. Tom and MT. Holyoks in Massachu-
sets was elected in this period of New
England history"
Following this it is interesting to note
the composition of the rock called trap:
"Trap is essentially identical in COM
position with the lavas of the Sandwich
Islands and the basalt rock of the Giants
Causswsy in Ireland. It consists of the
minerals pyroxene, a silicate of iron, lime
and magnesia, and the fusible field spar
called labradorite, along with some mag
netite. The iron rust color which so fire.
quently covers the surfaces of the trap
proceeds from the oxidation of the iron in
the pyroxsne and the ordinary decay of
trap is largely consequence of the same
process"
During the period of these eruptions the
population of this now beautiful valley
consisted entirely of reptiles of a size and
opPc6IhACo W UO 1OuAu AO"AOAo b0SO LII
the geological remains Of this age. Many
of the tracks left by these animals in their
flight from the moulten lava have been dis
covered and perhaps some patient searcher
may find one of the skeletons of the old
reptiles whose tracks are found on the
sandstone beds at various points of the
valley.
Another interesting point among these
hills is Cold Spring gorge. Here bubbling
up from recess between immense masses
of trap rock is a spring where ice usual
ly keeps the year around, the
shade and shelter making the spot natu-
raj ice house. Professor Silliman, who
was professor of geology in Yale seventy
years ago, brought to New Haven, after a
visit to this spring July %, 1891, a mass
of ice weighing several pounds. This is
the earliest mention made of the place.
These points of interest have been taken
considerable interest in by people imme-
distely in the naighborhood of Meriden.
There have also parties from Harvard Wis
tied the lodges. These lost volcanoes are
among certainly the most interesting points
of interest to those who take an interest in
changes which have been wrought in the
country by geological causes.
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