Daily globe. [volume] (St. Paul, Minn.) 1878-1884, 1883-08-21
Section E.-GeOlogy and Gea5rapJty.

IIs-OCOtOn9
AGAINST THE DRIFT THEORY.
The paper on evidences from southern
New England against the iceberg theory
of the drift by j. D. Dana was the first
paper read yesterday in this section. The
following is the full text:
In presenting to the association evidence
from southern New England with regard
to the insuficiency OF the iceberg theory
of the drift, Ishall have to say some things
that have often been said before and by
various investigators. But I may claim
for what is here brought forward that it is
in my own mind, the fortified conclusion
Of long continued investigation.
The arguments on the subject are de-
rived from three sources
I. The scratches and groovings over
the rocks.
II. The transported boulders and other
material.
III. The facts as to the relative level
of the land and sea.
Under the first head there is first, the
old argument on the universal distribution
of the scratches over the region Of all New
England. These effects of abrasion are to
be found everywhere beneath the soil,
each fresh exposure of the rocks bringing
them to light. This was said years ago,
and the conviction of its truth has been
gaining force With every year educational
observation. It view of this fact it is urged
rightly that only an abrading agent that
pressed heavily against the broad rocky
surface could have produced the effects,
and such is not an occasionally grounding
iceberg, or a succession OF them. Neither
is it the still more locally acting shore ice.
Secondly, floating ice would have found
little bare rock over the sea bottom to be
abraded. Like the bottom of existing
seas, and eminentiy those of the CONT
mental borders, the submerged region
would have had for the most part a bottom
of detritus-its former detritus and addi-
tional detritus from later dispositions; the
removals would have been local and rela-
lively of small area. Consequently the
drifting ice would rarely have reached
down 20 the rocks. Shore ice carried
along by the currents would have had
better chance, and yet poor one for the
work to be done.
Thirdly-The character of the grooyings
and plowings is to great extent such as
over the metamorphic rocks in many
places.
Boulders of trap, from fifty to 1000
| tons, are numerous in the New Haven re-
gion. especially along its western border.
All are Connecticut valley travellers; for
the trap ridges of the valley are the only
possible source. They were gathered up
by the ice from these trap ridges and car
ried fifteen to sixty miles down the valley
It is mechanically impossible that the lar
ger boulders should have been taken up or
gathered in any way by floating
ice, either shore ice, where the
water was but 1000 feet deep
and less; or by that of icebergs, where the
depth was greater. 1t is we'll known that
the distance of drift transportation is in
| general less than twenty miles. Hills OF
but 100 feet often have their long trails.
A moving glacier would easily gather and
carry along the material from hills, high
or low, wherever loose or detached masses
of rock or gravel existed to be gathered;
while floating ice would be very poor at
gathering and hence inefficient in dis
tributing.
have examined carefully along south
ern New England for proofs Of the quater-
nary submergence which the iceberg theo-
ry assumes to have existed and the glacial
era. l thought at one time that 1 saw evi
dence about New Haven of submergence
of forty five to fifty feet. But the terrace
that afforded the evidence was situated six
miles back from Long Island Sound ad
joining the rivers and on further exami
nation found thai the deposits had pre-.
cisely the structure of those along the
river valleys farther north and that in fact
they were nothing but fuvial formations
The highest terraces On or near
the shores of the sound, in the vicinity o.
} New Haven, have height above mean tidt
of twenty three to twenty-six feet; and or
Milford bay, nine miles west, similarly
situated terrace has height of thirty t.
thirty-fve feet. Along tie hills facing
: the waters and the southern extremity OF
the valleys no traces OF any higher leve
exist, twenty-five to thirty-tive feet is tn
) greatest amount of submergence the fact
sustain. Sea border deposits exist at
: higher level on the$coast OF Maine and OF
the shores of the st. Lawrence and shov
what was the position of the shore line il
: those regions. But the level along south
ern New England is not proven by tn
facts there gathered; neither is it estab
lished by the demands Of the iceberg theo
: ry. In conclusion, if icebergs, c
} floating masses Of ace, were not capable o
covering WITH scratches great cOnunuOu
t areas, and would have had chance 70
> little rock-abrasion on account of tn
5 covering of detritus; if they could no
3 have made, in their hitching and swinging
way OF action, when touching bottom
t scratches over the great areas that had tn
I even course of parallelism characterizinj
} those Of drift regions, or could not hav
t ploughed out the dsep burrows; if the
3 could not have gathered the great bowlder
r for transformation; and if the sea alop
: the sound did not cover the Ian
r in any part of the er
? of ice to greater depth than thirty c
7 thirty five feet, the iceberg theory of th
, drift may be reasonably pronounced III
t satisfactory for southern New England
D And similar facts show that it is equal
I unsatisfactory for the rest of New Enc
land.
9 ANIMAL REMAINS.
q The second paper was by VIM. McAdan
on the "Animal Remains from the Loe'
and Glacial Clays."
! After considering this paper the sectio
- Cd inT1r-,c1