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THE
PALEOLITHIC IMPLEMENTS
OF THJ-;
VALLEY OF THE DELAWARE,
I. Historical sketch of their discovery. By 0. C. Abbott, p. 124.
II. Their comparison with palaeolithic implements from Europe. By II.
W. Haynes, p. 132.
III. On the age of the Trenton gravel. By G. F. Wright, p. 137.
IV. Statement relating- to the finding of an implement in the gravel.
By Lncien Carr, p. 145.
V. On the lithological character of ihtj implements. By M. E.
Wadsworth, p. 14G.
VI. Concluding remarks. By F. W. Putnam, p. 147.
OF NATURAL HISTORY,
JANUARY 19, 1 88 1.
Reprinted IVom the I'uoCKKDi.MiS OF TILK SOCIKTY, VOL. XXI. for the Peubo<ly
inn of Ain;jri'';in A iv.li ecology jnul Ktiinolou'v.
CAMBRIDGE :
1881.
IS ISO 8
ANCH6FT LIBRARY
[From the Proceedings of the Boston Society of Natural History,
Vol. XXI, January 19, 1881.]
AN HISTORICAL SKETCH OF THE DISCOVERIES OF
PALAEOLITHIC IMPLEMENTS IN THE VALLEY OF THE
DELAWARE RIVER.
BY C. C. ABBOTT, M.D.
In March, 1872, I published a brief notice in the American
Naturalist of the various patterns of stone implements found
in New Jersey, and therein described certain rude implements
that I had found associated with the ordinary forms of flint
arrowheads and other relics of the Indians; and I then remarked
that these rude and elaborate forms, although associated, appeared
to indicate that the Indian, while an occupant of our Atlantic sea
board, had passed "from a palaeolithic to a neolithic" condition ;
and also called attention to the marked similarity between these
surface-found rude implements, and the palaeolithic implements
found in the river valleys of England and France.
This similarity was also remarked by the late Professor Wyman,
to whom I had forwarded specimens. He says, in the Fifth Annual
1881.] 125 [Abbott.
Report of the Peabody Museum, that " they closely resemble the
celts of the drift period of Europe, especially those found at St.
Acheul, two or three of which, except for their material, could
hardly be distinguished from them."
In April, 1873 also in the American Naturalist I again
called attention to these rude implements, and while realizing that
they were certainly older, did not ascribe to them other than an
Indian origin, but did see in them, as I believed, evidence that the
Indian was in a palaeolithic stage of culture when he reached our
shores ; thus classing these objects with the ordinary relics of the
surface.
At this time, also, I gave a detailed description of three speci
mens of chipped pebbles, which had been picked up, at different
times, while in search of mineralogical specimens; for at that
time, I never imagined that any traces of Man would occur at
other than unimportant depths from the surface. ' One of these
chipped pebbles was found at a depth of sixteen feet; another four
feet from the surface. As it did not appear possible for these to
have reached these depths by natural means, I was led to remark
that these were even older than surface-found rude implements,
and that "we must admit the antiquity of American man to be
greater than the advent of the so-called Indian ; i. e., supposing
the latter to be a comparatively recent comer to the Atlantic
coast."
The discovery of these first suggested to me that there might
be a commingling of two classes of stone implements upon the
surface, which had diverse origins, and this came the more forci
bly to my mind, as I had already noticed and remarked, that in
the gravel that has only the cultivated soil above it very
many of the rude implements have occurred indeed the great
majority had been found in the loose gravels, wherever exposed.
Thus it will be seen, that from the first, while the character of
these implements was recognized, their whole significance had
not been, except in the case of two specimens (the third prob
ably being a natural form), and these were considered at the time
as apparently indicative of what has since been demonstrated.
In January, 1877, the Annual Report of the Smithsonian Insti
tution for 1875 was published. This contained a more extensive
Abbott.] 1 26 [Jnnnnry 19,
notice, written by me, in 1872, of the stone implements of New
Jersey, and I there devoted a chapter to the consideration of rude
stone implements, where I maintained that they were older than
jasper and quartz arrowheads. One of these rude forms I referred
m "a fair representative of the implements met with ....
in the gravelly bluff or bank of the Delaware River, south
of Trenton, New Jersey, and occasionally on the surface of the
ground in the same neighborhood"
Thus while pursuing my collecting of Indian relics, it was ^r. du
ally forced upon my mind that these rude implements were more
intimately associated with tlie gravel than with the surface of the
ground and the relics of the Indians found upon it.
Acting upon this, I continued for two years to most carefully
examine both the surface of our fields and every exposure of the
underlying gravels; and in June, 1876, after having found several
chipped implements in situ, expressed the opinion that the Dela
ware river, "now occupying a comparatively small and shallow
channel, once flowed at an elevation of nearly fifty feet above its
present level ; and it was when such a mighty stream as this, that
man first gazed upon its waters and lost those rude weapons in its
swift current, that now in the beds of gravel which its floods
have deposited, are alike' the puzzle and delight of the archaeolo
gist. Had these first comers, like the troglodytes of France,
had convenient caves to shelter them, doubtless we would have
their better wrought implements of bone to tell more surely the
story of their ancient sojourn here ; but wanting them, their
history is not altogether lost, and in the rude weapons, now deep
down beneath the grassy sod and flower-decked river bank, we
Irani, at least, the fact of the presence, in the distant past, of an
earlier people than the Indian/"
Thus it will be seen that I have been fairly cautious in my
statements, and slow in reaching any conclusions with reference
to these implements which separated them from ordinary Indian
relics, the identity of which cannot, of course, be questioned.
Furthermore, it is difficult to see why there should not have
leen that succession of stages of culture, known as pcdaeolit/iic
and neolithic, in North America, as has been so clearly shown as
true of Europe. Had the Delaware river been a European
1881.] 127 [Abbott.
stream, the implements found in its valley would have been ac
cepted at once as evidence of the so-called palaeolithic man;
but being in another continent, and one supposedly beyond the
reach of this early man, as theoretical ethnologists have considered
him, my claims that I had discovered in America traces of this
primitive chipper of pebbles, have been strenuously denied, especially
by a few, who have never visited the locality or seen a specimen
of chipped implement taken therefrom, as altogether unwarranted
by the facts.
In this matter there has been, as rny several publications show,
no attempt to make the facts conform to a pre-conceived theory.
The pre-conception, on the contrary, being that all traces of man
in America were to be referred to the neolithic Indian, and the
many facts in the case, finally forced me to relinquish it.
In September, 1876, Mr. Putnam, the Curator of the Peabody
Museum of Archaeology at Cambridge, Mass., favored me with a
visit, ;md together we carefully examined the river bluff below
Trenton, ?md succeeded in finding two specimens in situ, such as I
had previously described in the American Naturalist, and at his re
quest I continued my examinationh of these gravels, acting under
an appropriation made by the Peabody Museum for this purpose;
and, in November of the same year, submitted to him a report On
the Discovery of Supposed Palaeolithic Implements from the
Glacial drift in the Valley of the Delaware JRiver, near Trenton,
New Jersey. Still realizing how all important it was in this matter
to make haste slowly, I purposely referred to these chipped stones
as supposed palaeolithic implements, and gave, in detail, my rea
sons for thus considering them.
Referring to this report Mr. Putnam remarked, in his annual
report to the trustees of the Peabody Museum, that "from a visit
to the locality with Dr. Abbott, I see no reason to doubt the
general conclusion he has reached in regard to the existence of
man in glacial times on the Atlantic coast of North America."
Before this report was published these gravel deposits were
visited by Prof. N. S. Shaler, who was fortunate enough to find a
characteristic specimen, bnt not in situ. I also found one^
likewise in the talus. Of these specimens, Professor Shaler says,
"Although the whole face of the escarpment is in motion, creep-
Abbott.) 128 [Jannnry 1!',
in-jT slowly under the influence of frost and gravity towards its
base, it was difficult to believe that these specimens, found about
twelve feet below the top of the bank, had travelled down from
the superficial soil."
Continuing my own researches, in 1877, I made a second report
on the occurrence of these implements, and re-affirmed my convic
tion that in the specimens of artificially chipped pebbles, from
these gravel deposits, we have evidence of man's presence at an
earlier date than the supposed advent of the Red Indian; and
referred them geologically to the Glacial epoch, in accordance
with the writings of Professor Cook, our State Geologist, who had
pronounced these gravels as of glacial origin.
This, briefly, is the history of my own labors in this field.
As the result, in material gathered, there are now in the
Peabody Museum about four hundred specimens, of which about
sixty have been taken from recorded depths ; about two hundred
and fifty from the talus, at the bluff facing the river, and the
remainder from the surface or derived from collectors who did
not record the positions or circumstances under which they were
found. While these figures are approximative only they do not
materially vary from the notes that I have taken, which, generally
being packed away with the specimens, I have not the time to
carefully go over and repeat to you verbatim.
Somewhat similar conditions occur also in other river valle\s
as the Schuylkill and Susquehanna, in Pennsylvania, and in the
valley of the Potomac, near Washington. The geological struc
tures of these valleys, with rock formations coming near to or
constituting the surface, not improbably explains much of this
difference as compared with the Delaware valley, wherein, south
of Trenton, N. J., there is no living rock in place except at ^reat
depths.
In the valleys of the Schuylkill and Potomac, Mr. Berlin, of
KYadhiu,, I 'a., and Dr. Hoffman, of Washington, I ). ('., have found
implements of palaeolithic character under circumstances point
ing to a remote- antiquity, although none have occurred at as ^rcat
depths as at Trenton, N. J.
Prof. Ilaldeman also found rude implements iu the Susque
hanna valley, which, as his own statement regarding them clearly
1881.] 129 [Abbott.
shows, were, in all probability of like age and origin as those
found in the valley of the Delaware.
The published account of Mr. Berlin's " finds " is in the first
volume of the American Naturalist ; that of Dr. Hoffman in the
thirteenth volume of the American Naturalist, and that of Dr.
Haldeman in the Peabody Museum Reports, Vol. II, p. 255.
Col. C. C. Jones, Jr., in his instructive volume on the Antiqui
ties of the Southern Indians, published in 1873, records the
discovery of drift implements of precisely the same type and
under similar conditions as those found in the valley of the Dela
ware River. (Chap, xii, p. 292, pi. xvi, fig. 10.)
Furthermore, I desire now to call attention to the fact that the
archaeological interest centering in these gravels, does not rest
solely on my own labors. Others have examined them carefully,
and have published, or will do so, the results of their visits to the
locality.
In October, 1877, the late Thomas Belt visited the locality, and
gathered specimens therefrom. His account of his visit will be
found in the Quarterly Journal of Science, London, for January,
1878, p. 55.
In September, 1878, Prof. J. D. Whitney and Mr. Carr, of the
Peabody Museum, visited the locality, and of this visit Mr. Carr
has stated, in the Twelfth Annual Report of the Museum, " in
September last, in company with Prof. J. D. Whitney of Harvard
College, I visited Trenton, and we were fortunate enough to find
several of these implements in place. Professor Whitney has no
doubt as to the antiquity of the drift, and we are both in full
accord with Dr. Abbott as to the artificial character of many of
these implements."
In June, 1879, and again, in June, 1880, Mr. Putnam visited
Trenton, and he also has gathered excellent specimens from the
undisturbed gravels, at various depths. As both he and Mr. Carr
are present, they will refer to these themselves.
Lastly, in November, 1880, Prof. W. Boyd Dawkins, Prof.
Henry W. Haynes, Rev. G. Fred. Wright, and Henry Carvill
Lewis of the Geological Survey of Pennsylvania, gave these
gravels a critical examination. The results in part of this visit
will be given this evening by two of these gentlemen, and it
PROCEEDINGS B. S. N. H. VOL. XXI. 9 NOVEMBER, 1881.
Abbott.] 180 [January 19,
remains for me only to briefly call attention to one or two points
that may not In- touched upon by those who will further discuss
the significance of these chipped implements.
In the spring of 1877, Mr. Henry C. Lewis was detailed by tin-
State Geologist of Pennsylvania to critically examine and map
out the various gravels in the neighborhood of Philadelphia, Pa.
The result of his studies showed that these several gravel beds
were to be referred to different geological eras, as the Bryn JVIawr
gravel (Upper Tertiary), Glassboro gravel (Pliocene), Phila
delphia brick clay (containing boulders), the Trenton gravel, and
the recent Alluvium; the oldest being that first named, and
coming down to the present in the order named ; and further
showed that the "yellow gravel" (a marine gravel), which forms
the boundaries of the newer Trenton gravels, was high and dry
during the deposition of the circumscribed Trenton gravel, which
is purely river drift, derived from the terminal moraine lying in
the upper valley of the Delaware, and extending across the State.
This most important discovery has an important bearing on the
age of the palaeolithic implements, in that, he shows, that there
was an extensive area of habitable land from Trenton southward
during the close of the glacial period ; and which Professor Cook,
the State geologist of New Jersey, has asserted in his latest reports,
to have been submerged during this same period; thus demon
strating that a habitable country enclosed or bordered the latest
in time, or Trenton gravels, during the time that they were accu
mulating and further showing, beyond question, that if any
where, relics of man are to be found, other than on the surface, it
would be in this Trenton gravel. Furthermore, Mr. Lewis care
fully mapped this gravel, and practically completed his labors
before he was aware of my discoveries.
THEN, on comparing his results with my own, he found that
the implements I had collected, in situ, were gathered only from
those localities where this Trenton, or newest gravel, occurs.
Thus, he, from a geological standpoint, working upward, to the
present ; and I, pushing my researches backward, from the his
torical point, met upon common ground, and each in total igno
rance of the other's labors, until our respective studies brought us
face t
1881.] 131 [Abbott.
What further evidence of the substantial correctness of my
own conclusions, as to the existence of palaeolithic man, can be
asked ?
To the subject of erosion of the present surface of the locality,
whereby the uplands are being worn away, and the valleys filled
I can but briefly refer; merely calling attention to the fact
that by this agency the recent Indian relics are brought
down, as it were, to the level of the gravels ; and likewise, the
implement-bearing gravels are brought to the surface ; thus com
mingling objects, in many cases, that originally were separated by
the stratum of soil that capped the gravels in former times. To
return to the consideration of the Trenton gravel I will say, in
conclusion, that it is clearly evident, as Mr. Wright will explain to
you, that the accumulation of these gravels was gradual, and
considerable time may have elapsed from the date of the first
or lowest of the gravels, before additional material was brought
from above. Beyond the limits of these gravels stretched in
every direction a vast area of habitable ground, as I have men
tioned, with a fauna adapted to supply man with every need ;
and how natural that the primitive American should have gone
to these then accumulating beds of shingle, to select and chip
into proper shape, the pebbles, that thus worked upon, constituted
his only known weapons ; the same the world over : Europe, Asia
Africa and America I
No cataclysm drove him from the spot, and all those years
that the ever increasing beds of sand, gravel and boulders
were accumulating, he dwelt here, familiar, it is now known, with
the mastodon, and likewise with the bison, reindeer, musk-ox
and the fauna of the present time : and when the last of these
transporting floods had wholly passed away this primitive man
was America's sole occupant, and left upon the surface of the
latest stratum of sand and pebbles, that floods from a once gla
ciated valley brought from the mountains beyond, the same rude
implements of stone that his ancestors had lost in the underlying
gravels beneath his feet.
We are to-day contemporary with vast accumulations of allu
vium that are steadily increasing in our river valleys ; why then
might not palaeolithic man as readily have been contemporary
with the almost as gradual growth of these older beds of gravel ?
Haynes.] 132 [January 19,
I do not presume to boldly assert that America's early man,
at least on the Atlantic coast, was jt?re-glacial ; but that he ante
dates the Red Indian, if it be true that the latter is a recent comer,
I do confidently maintain, backed as I am by the unquestionable
testimony of the Trenton gravel.
THE ARGILLITE IMPLEMENTS FOUND IN THE GRAVELS
OF THE DELAWARE RIVER, AT TRENTON, N.J., COM
PARED WITH THE PALAEOLITHIC IMPLEMENTS OF
EUROPE.
BY HENBY W. HAYNES.
The first question to be decided in regard to the rude imple
ments, mostly made out of argillite, and alleged to have been
discovered in the gravels of the Delaware, is as to their authen
ticity. Were they actually found where, and under the circum
stances in which, they are claimed to have been discovered ? Upon
this fundamental point we are not restricted to the unsupported
testimony of a single observer, whose prepossessions may possibly
have misled him, or whose observations may be objected to as
lacking in exactness. In addition to the very extensive series of
these objects found by Dr. Abbott, Professor Putnam, Mr. Carr
and Professor Whitney all alike report that they have discovered
precisely similar objects themselves, in the same localities and
under like conditions.
During the past autumn I visited the region myself in company
with the Rev. Geo. Fred. Wright, Professor W. Boyd Dawkins,
and Mr. H. C. Lewis, of the Penn. Geol. Survey, under Dr. Abbott's
guidance. Several implements were taken by the others, either
from the gravel, or the talus on the river bank, in my presence, and
I found five myself. All these objects were precisely similar
in appearance, material and' method of fabrication, to those placed
by Dr. Abbott in the Peabody Museum at Cambridge. They
were all found under exactly the same circumstances, and in like
situations, as were the greater part of those described by him in the
two accounts of his discoveries published in the Reports of the
Museum for the years 1877 and 1878. Other examples, however,
were taken by him from undisturbed gravels at varying depths.
1881.] 133 [Haynes.
For my own part I consider it absolutely and incontestably
established that these objects have come, as alleged, from the
gravel-beds of the Delaware valley, and that occasionally only have
they been found on the surface.
A second question then arises in regard to the character of
the objects themselves.
Do they show incontestable marks of human workmanship ?
This is a problem to be decided only by the verdict of such per
sons as have had large experience in searching for and studying
pre-historic stone implements, and who have thus acquired the skill
of the expert in discriminating between the natural and the
artificial fracture of the various kinds of stone out of which the
early man manufactured his first rude implements. I venture to
offer my own opinion upon this question because I think my op
portunities for this kind of study have been unusually great. For
six years I have studied the stone age in various countries of
Europe, in all of them searching diligently for implements, and I
have handled stones artificially broken literally by the hundreds
of thousands. I have also carefully examined the celebrated
collections of such objects to be found in the various museums
of different countries, and I have enjoyed the personal acquain.
tance and companionship of many of the leading cultivators of pre
historic studies. In this way I have participated in a great deal
of inquiry and discussion in regard to the characteristics and
peculiarities which such implements present. Applying the
experience thus acquired, I trace many striking resemblances
between these argillite objects and the palaeolithic implements
of Europe, made from flint or quartzite. It is undeniable that
the argillite implements are of ruder workmanship, but I think
this arises solely from the circumstance that the material from
which they are fabricated is much less susceptible of being finely
worked. Especially is the flint derived from the chalk, of which
nearly all the European implements are made, capable of being
chipped into much more perfect and symmetrical shapes than
is the coarse-grained variety of clay-stone, from which the New
Jersey implements are fashioned. But the types of the two
classes of implements are remarkably similar. To whatever
uses and purposes the European implements were capable of
Haynes.] 134 [January 10.
being applied I regard these Delaware objects as being equally
well adapted. The same general description applies to both
classes of implements alike. The characteristic European pal
aeolithic implement is commonly known to archaeologists there
by the name of the " axe of the type of St. Acheul." This des
ignation is derived from the old Abbey of this name, close to
Amiens, in the valley of the Somme, in Northern France, where
they were first discovered by Boucher do Perthes in 1841, and
where they have since been found in greater numbers than in
any other locality. This " axe of the type of St. Acheul " may
be described as being usually of large size, longer than it is wide,
thick in the middle and sharpened at the edges. One end is
more or less pointed, and the other, which was doubtless intended
to be held in the hand, is thick and rounded. Their most distin
guishing characteristic is that both sides, or faces, are chipped into
a shape more or less convex and symmetrical. An implement of
this description, it will be seen at a glance, is entirely unlike the
ordinary Indian axe, or tomahawk, made of polished stone, and
very generally provided with a groove around the middle, intend
ed to hold a handle made of twisted wythes. Accompanying these
St. Acheul axes there are also found in Europe smaller objects,
such as spear-heads, and knives fashioned out of flakes detached
from blocks of flint. All such flakes bear a peculiar mark, called
the "bulb of percussion," which proves them to be of man's
fabrication, as it is never found upon chance-broken splinters
of flint. It indicates the spot where an intentionally directed
blow was struck upon the nucleus from which the flake was
detached. Similar flakes of argillite are also found in New
Jersey accompanying the larger objects made from that material,
which proves that such implements were manufactured on or near
the spot where the flakes occur ; but the number of such flakes
that has hitherto been found is quite limited.
It would be incorrect, however, to suppose that the European
archaeologists discriminate between the palaeolithic implements
(the oldest objects of human workmanship thus far discovered, and
which all present the type that I have described) and those that
belong to the later neolithic period, or the age of "Polished
Stone" (to which is to be referred the common Indian axe or
1881.] 135 [Haynes.
tomahawk of North America), merely by their shape and mode
of fabrication. The term palaeolithic is primarily restricted in
meaning to such objects as 1 have described, when met with under
peculiar geological conditions ; that is to say, when found embed
ded in the gravels which have been deposited by certain rivers
during the period known to the geologists as the quaternary or
pleistocene period. At that time their volume of water was much
greater than it now is, which was caused by the melting of the great
ice-cap that once covered the northern portion of both continents,
accompanied by a climate much more humid than we have at
present. Such accumulations of gravel are often of very great
thickness, and embedded in them, side by side with th^e stone im
plements above described, are found the fossil bones of extinct
species of animals, such as the mammoth, the rhinoceros tichor-
rhinus, and numerous others, or of animals like the reindeer, or the
musk-sheep, which have since migrated to the colder regions of the
north, or which are now restricted to the higher Alpine slopes.
This leads us to the third question to be considered, viz , the
localities and geological conditions, under which these New Jersey
implements have been discovered. Though the objects themselves
may present the right type, shape, and general appearance, we must
look carefully at the conditions under which they have been discov
ered before we can pronounce judgment as to whether they are to
be regarded as " palaeolithic implements," or not. Of course
when found in gravel beds, accompanied by fossil animal bones,
no such question can be raised. But since the pleistocene period
these gravel beds have been subjected to a constant process of
denudation and removal by the action of the rain and other nat
ural causes, with the result that in some localities they have either
partially or entirely disappeared. The same causes that would
sweep away the finer and lighter particles would not be power
ful enough to affect the heavy palaeolithic implements, which
would accordingly be left behind. Consequently we sometimes
find such implements upon the surface in localities where
the pleistocene gravels are no longer to be seen. Such is the
case, for example, in the Valley of the Nile, where there are now
no longer pleistocene deposits, though these occur in the adjacent
Desert of the Sahara. Yet in the bottoms of the dry ravines or
Haynes ] 136 [January 19,
wadys, which pierce the hills that bound the valley of the Nile,
1 have found numerous specimens of flint axes of the type of St.
Acheul, which have been adjudged to be true palaeolithic imple
ments by some of the most eminent cultivators of prehistoric
science.
Each particular discovery accordingly must be tested by the
peculiar conditions of locality and circumstances under which it
has occurred.
Now it has been my good fortune to find palaeolithic imple
ments in Europe in several localities, both where they have been
accompanied by the characteristic fossil bones, and where these
have been wanting. I have thus had the opportunity of making
myself familiar with the general character of such localities and
the appearance of the country in the vicinity, together with
the nature and quality of the gravels in which the implements are
found. I have especially studied the gravel beds of the valley of
the Seine, in the vicinity of Paris, and of the Tiber, near Rome, for
several successive years, and in a very great number of visits, and
from both these localities I have obtained fossil bones of the
mammoth, the rhinoceros, the hippopotamus, the bos antiquus,
the great extinct elk, the horse, the reindeer, etc. Accompanying
these fossil bones were found the characteristic palaeolithic imple
ments. I have also visited the famous locality of St. Acheul,
and the well-known gravel-pits near Salisbury, England, in both
of which spots have occurred numerous finds of palaeolithic imple
ments, accompanied by similar fossil bones. In another locality,
near Dinan, in Normandy, where the pleistocene deposits no
longer exist, as is also the case in the valley of the Nile, I have
found a large quantity of palaeolithic implements made out of
quartzite. From these various experiences I feel myself warranted
in stating that the general appearance of the country, and the
character of the gravels, at Trenton, N. J., present a most striking
resemblance to what I have seen in the various localities in the
Old World to which I have referred. There is the same rudely
stratified mingling of coarse materials marked by a similar
absence of clay. It is true that in the gravels of New Jersey thus
far not many fossil bones have been discovered, but only a few of
the mammoth, the bison, the reindeer and the walrus, some of
1881.] 137 [Wright.
which, like the animals of Europe under similar circumstances,
have since migrated to the colder regions of the north. But
the fact remains that fossil animal bones have actually been
discovered in these gravels, and when we call to mind to what
a limited extent they have as yet been examined we may reason
ably expect more to be found hereafter.
I limit myself to a general statement like this in regard to
the marked resemblance of the locality, and the precisely similar
character of the gravels at Trenton, New Jersey, to what I have
seen in many localities in Europe, which have yielded true
palaeolithic implements, and I leave in more competent hands the
discussion and determination of the true geological character of
the gravels of the Delaware valley.
Speaking then merely from an archaeological stand-point, I do
not hesitate to declare my firm conviction that the rude argillite
objects found in the gravels of the Delaware river, at Trenton,
New Jersey, are true palaeolithic implements.
AN ATTEMPT TO ESTIMATE THE AGE OF THE PALAEO
LITHIC-BEARING GRAVELS IN TRENTON, N. J.
BY G. FREDERICK WEIGHT.
Four years ago Professor Shaler concluded his brief and.
cautious report upon the gravel beds which form the subject of
the present paper, by expressing the " hope hereafter to furnish a
detailed account of the geology of these gravel beds, and to
support these preliminary statements by evidence in the way of
sections and maps." (Report of Peabody Museum for 1876, Vol.
II. p. 47.) It is greatly to be regretted that the pressure of other
duties prevented him from carrying out his designs. Meanwhile,
facts bearing upon the solution of this interesting problem have
been rapidly accumulating, until now we apparently see the
beginning of the end.
Briefly stated, the progress of discovery has been this : In the
Annual Report of Professors Cook and Smock, State Geologists
of New Jersey for 1877, the southern limit of the ice field
during the glacial age was indicated. (See pp. 9-19.) The
Wright.] 138 [January 19,
boundary of this field crosses the state by a curve convex to the
south from PC- rth Amboy to Belvidere on the Delaware River,
about sixty miles above Trenton. As bearing in a general way
upon the ([iiestion in hand, we should mention the conclusions of
Col. Charles Whittlesey in 1866, and of Prof. N. H. Wiiichell, T.
C. Chamberlain, and R. D. Irving, a few years later, concerning
the terminal moraine in Wisconsin and other western states.
The investigations of Professor Hilgard touching the bluff depos
its in the lower Mississippi valley, and of Col. D. K. Warren upon
those of the upper portion of this valley, are also of great signifi
cance in connection with this question. Nor should we fail to
mention the extremely valuable papers of Professor J. D. Dana
upon the condition of southern New England during the melting
of the great glacier. (See Am. Journ. Science for 1875, Nos. 57,
58, 59, and 60.) My own study of the kames and moraines of
New England, the results of which are published in the Proceed
ings of this Society, and that of Mr. Warren Upham (see New
Hampshire Geological Report, Vol. III.)? and of Professor George
H. Stone of Maine, serve to connect the operation of a wide
spread cause with the particular effects produced in the Delaware
valley. It is also proper to repeat that the first announcement in
1877 of the line of the terminal moraines across southern New
England was made in a publication of this Society, in a commu
nication to the writer by Mr. Clarence King. (See Proceedings,
Vol. XIX. pp. 50-63.)
A second step in advance was made by the New Jersey geolo
gists (see Report for 1878, p. 22 ; Clay Report for 1878, p. 17)
in recognizing a distinction between the implement-bearing grav
els of Trenton and the general deposit of yellow gravel which
spreads over the southern part of the state. But the credit of
accurately describing the peculiar character and limits of these
Trenton gravels must be given to Professor H. C. Lewis, of Phil
adelphia. (See Proc. Min. and Geol. Section Acad. Nat. Sci.,
Phila., for Nov. 1878 and Nov. 1879.)
A third step of great importance was also made by Professor
Lewis in pointing out the relations of the Philadelphia brick clay
to the other superficial formations of the Delaware valley.
Having recently spent two weeks with Professor Lewis in going
1881.] 139 [Wright.
over this ground and in extending investigations to the upper waters
of the Delaware, I will now endeavor to put into intelligible
shape the facts, both new and old, which bear upon the inter
esting question announced as the subject of this paper.
The city of Trenton is built upon a horse-shoe shaped gravel
deposit which is about three miles in diameter, extending back
about that distance to the east from the present river. This
deposit is somewhat lower along its inland boundary than along
the river. The prongs of this horse-shoe rest, one at Trenton,
and the other about two miles below, just this side the house
of Dr. Abbott.
The characteristics of this gravel are thus accurately described
by Professor Shaler :
<c The general structure of this mass is neither that of ordinary boulder
clay nor of stratified gravels, such as are formed by the complete rearrange
ment by water of the elements of simple drift deposits. It is made up of
boulders, pebbles, and sand, varying in size from masses containing one
hundred cubic feet or more to the finest sand of the ordinary sea beaches.
There is little trace of true clay in the deposit. There is rarely enough to
give the least trace of cementation to the masses. The various elements
are rather confusedly arranged ; the large boulders not being grouped on
any particular level, and their major axes not always distinctly coinciding
with the horizon. All the pebbles and boulders, so far as observed, are
smooth and water-worn ; a careful search having failed to show evidence of
distinct glacial scratching or polishing on their surfaces. The type of
pebble is the sub-ovate or discoidal, and though many depart from this
form, yet nearly all observed by me had been worn so as to show that their
shape had been determined by running water. The materials comprising
the deposit are very varied, but all I observed could apparently with reason
be supposed to have come from the extensive valley of the river near which
they lie, except, perhaps, the fragments of some rather rare hypogene rocks."
It is now settled beyond controversy that the rocks from which
these beds were derived are all in place in the upper Delaware
valley. (See N". J. Rep., 1877, p. 21 ; Lewis on Trenton Gravel,
p. 5.)
The distinction between the river gravel and that which
overlies the larger part of southern New Jersey is marked in
several ways. The Trenton gravel is much coarser than the
Wright.] 140 [January 19,
general deposit, it is also largely composed of fresher looking and
softer pebbles, showing that it has been subject to much less
abrasion than the other, and that it is of more recent age ; it is
also limited to the river valley, and finally is not overlaid by the
Philadelphia brick clay which, so far as it extends, rests uncon-
formably upon the general deposit of gravel. The general deposit
of gravel in this region is composed almost exclusively of small,
well rounded pebbles of quartz and of hard limestone which " are
not fresh looking, but are eaten and weather-worn by age."
The elevation of this implement-bearing gravel at Trenton is
not far from forty feet above the present high water limit ; and
Trenton is now at the head of tide-water. These gravels are
continuous as a terrace all along up the river. As one ascends the
river, however, their height (at least below the Water Gap) is
reduced to fifteen or twenty feet above the present flood plain.
But most significant of all the facts indicated are the character
and position of the Philadelphia brick clay. This also is confined
to the river valley and its tributaries, and rests unconformably
upon the older gravel formations, rising to a height of one hun
dred and fifty feet above the river, and there ceasing. This
elevation relative to the river is maintained with tolerable con
stancy as far up as Easton, where the bed of the river itself
is one hundred and fifty-seven feet above tide level. Finally,
this Philadelphia brick clay contains numerous boulders of
considerable size, derived from the ledges of Medina sandstone
and other rocks above. This marks it as a deposit of the glacial
flood sometime during the declining centuries of the great ice
period.
The succession of events would seem to be as follows : During
the early part of the glacial period the ice accumulated -in the
upper portion of the valley of the Delaware to a depth of many
hundred feet. Two and one half miles north of the Delaware at
Martin's Creek, Professor Lewis and myself saw, in going south, the
last distinct evidences of direct glacial action at a height of six
hundred and forty feet above the river and eight hundred and
forty feet above the sea. Penobscot Knob, on the water-shed
between the Susquehanna and the Lehigh east of Wilkesbarre,
and only a few miles north of the southern limit of glaciation,
1881.] 141 Wright.
itself bears every mark of glaciation. This is two thousand one
hundred feet above the sea and one thousand six hundred feet
above the level of the Lehigh at Mauch Chunk, and one thousand
eight hundred feet above the level of the Delaware at the Water
Gap. The area in the valley of the Delaware covered by the ice
is not far from six thousand square miles. It is not improbable
that the average depth of the ice accumulated over the region
was one thousand five hundred feet, or a quarter of a mile, making
the total accumulation of ice not far from fifteen hundred cubic
miles, with its southern border sixty miles above Trenton. All
this as it melted must find its outlet to the sea through the
Delaware River. It is evident at a glance that during the decline
of the glacial period, when the process of melting was proceeding
with greatest rapidity, the floods in the valley below must have
been upon a scale of surprising magnitude.
And yet it is impossible that these glacial floods in the Dela
ware should have been so enormous as to have filled the valley
below Trenton to the height of one hundred and fifty feet, for
this valley is no where less than five miles in width and constantly
enlarges towards the sea. If the water at Trenton were raised
one hundred and fifty feet, the slope would be about two feet per
mile to the bay. Now a current of five miles per hour, one
hundred and fifty feet deep and one mile wide would discharge a
cubic mile of water every eight hours or three cubic miles per
day. (The mean rate of the Ohio River, with an average descent
of five inches to the mile, is three miles per hour that of the
Mississippi very nearly the same.) To supply such a volume of
water as this, the whole accumulation of ice in the upper Dela
ware would suffice for only five hundred days, or for about sixteen
months. And to furnish this amount of water there would need
to be, during such floods, a daily accumulation by rains and the
melting ice over the whole upper valley of the Delaware of about
three feet of water, which of course is incredible, even if we
suppose the floods confined to a single month of each successive
year. Hence, without doubt, we may conclude that the deposi
tion of the boulder-bearing brick clay in the Delaware valley
below Trenton implies a depression of that region to the extent
of one hundred or more feet.
Wright.] 142 [January 19,
Doubtless the region north of Trenton shared in this depres
sion, but, being above tide-water, the effects would not be equally
evident. The valley above Trenton is narrow. At Lambertville
about twelve miles up the stream, a trap dike contracts the valley
to a width of not more than one quarter of a mile. Above this
point the supposition of floods sufficient to deposit the boulder-
bearing clay is, perhaps, not incredible. For though the descent
in the stream is now about four feet to the mile from the Dela
ware Water Gap down to tide level (about eighty miles), it was
probably less during the Champlain epoch. For the depression
of that period proceeded at increased rate northward. In
Montreal it was five hundred feet ; in Vermont, three hundred
feet; and how much more or less in the vicinity of Lake Erie
we cannot tell, though the phenomena of the lake ridges would
indicate that it was considerable, perhaps three hundred or four
hundred feet. A depression gradually increasing north-westward
would greatly dimmish the velocity of the torrent of the Cham-
plain epoch and the narrow places in the valley would greatly
retard it. Professor Dana has shown that in the lower part
of the valley of the Connecticut River the floods rose during the
Champlain epoch from one hundred and fifty to two hundred
feet above the present high water mark. The Connecticut River
valley below Middletown is contracted by trap dikes much as the
Delaware is at Lambertville. But the drainage basin of the
Connecticut is three times as extensive as that of the Delaware
(being twenty thousand square miles). This, however, is partly
offset by the branch currents which, as Professor Dana shows, set
off from the Connecticut at various places above Middletown.
At any rate in the Delaware valley we find boulder-bearing
clay rising to a height of one hundred and fifty feet above the,
present high water level. In the Lehigh valley, at Bethlehem, a
few miles above its junction with the Delaware, and several miles
south of the limit of the ice field, Professor Lewis and I found this
boulder-bearing clay containing scratched pebbles and lying
unconformably upon thick deposits of coarse stratified gravel at
a height of one hundred and eighty feet above the river. Farther
up the Lehigh valley also, near Weissport, we ascertained the
limit of ice-carried boulders to be one hundred and eighty feet
above the river.
1881.] 143 [Wright.
We are probably safe in assuming that these floods, depositing
clay and boulders at the height above mentioned, mark both the
period of greatest depression during the Champlain epoch and
the period when the ice was most rapidly melting away. Of
course the deposition of what Professor Lewis styles " red gravel "
and the high gravels at Bethlehem occurred earlier, since the clay
overlies them. These gravels I should assign to the early stages
of the Champlain epoch.
It is evident that the deposition, both of this red gravel and
the boulder-bearing clay is separated from that of the implement-
bearing gravel at Trenton by a period of vast physical changes,
if not Of vast time. BANCROFT UBRARY
Considering, now, this Trenton gravel, we find it to be
limited at the head of tide water to a level of about forty feet,
and diminishing in height relatively to the river both as one
ascends and as one descends the channel, until at Yardleyville, a
few miles above Trenton, it merges into the terrace which main
tains a pretty uniform height of fifteen or twenty feet above the
river all the way to the Water Gap. Above the Water Gap the
gravel terraces rise to a much greater height. At Stroudsburgh
a second terrace stands seventy-five feet above the first terrace
which is about fifteen feet above Broadhead Creek. But this
upper terrace is kame-like in its structure, and hence would be
explained in part by the lingering presence of the glacier itself.
The descent of the river valley from Belvidere, where the ice
sheet terminated, to Trenton is two hundred and thirty-two feet,
or at the rate of nearly four feet per mile, as the river runs.
The transportation of gravel by a river is dependent both upon
the amount of material accessible to the running stream and upon
the rapidity of the current. Toward the close of the glacial
period the pebbles accessible to the stream were superabundant,
having been deposited in excessive amount by the melting of- the
glacier in the lower latitudes. The water-worn pebbles at Tren
ton were probably largely derived from this source. Even a
glacial torrent may have more loose material than it can manage,
and so may silt up its bed with gravel. Hence it is not necessary
to suppose the river at this point to have been of sufficient
volume to fill the whole valley with water to the height of the
Wright.] 144 [January 19,
terrace, fifteen or twenty feet. The river may have flowed upon
the surface of the gravel in a shallower current than the terrace
would seem to imply.
But when the current, passing down this declivity of four feet
to the mile, reached the level of the sea at Trenton, its transport
ing power would be greatly diminished and thus we should have
an accumulation of gravel at the head of tide water, without
bringing into the problem the supposition of any very extraor
dinary increase in the volume of the river. The loss of trans
porting power upon diminishing the rapidity of a current of
water is enormous. The transporting capacity of a stream of
water is estimated to vary as the sixth power of the velocity, i.e.,
if a current is checked so that it moves at only half its former
rate, its transporting capacity is diminished to one sixty-fourth.
It is easy to see that the sudden enlargement of the valley just
above Trenton, as well as the occurrence there of tide water,
would diminish the rapidity of the river and hence cause an
extraordinary deposition of gravel when it was abundant above.
The most likely time for this deposition to have occurred was
near the very close of the glacial period, when the lower moraines
were fresh and when ice fields still lingered in the southern
valleys of the Catskills. The process of deposition must have
been so rapid that it could not have been much subsequent to the
withdrawal of the continental glacier north of the Catskills. The
time required for the river under present conditions to erode the
channel it now occupies was of much greater duration.
I hope another season to devote a month or two to further
investigations and will now but briefly indicate what seems very
probable and what is still in doubt.
1. It seems altogether probable that the Philadelphia brick
clay was deposited during the height of the Champlain epocli
when the Delaware valley was considerably depressed below
its present level.
2. Towards the close of that period when the land had
resumed nearly its present level and the ice had nearly all disajv
peared south of the Catskills, the still swollen stream brought
down the superabundant loose material from the kames and
moraines and deposited it in the valley below. The material was
1881 -1 145 [Wright.
so abundant that doubtless the whole channel was silted up so
that the bed of the river was considerably above that it now
occupies. At Trenton it flowed over and through an extensive
delta of coarse gravel forty feet above its present level ; and
above Trenton, over an accumulation of gravel from fifteen to
twenty feet above the present high water mark. This period was
marked by the presence of the mastodon and other extinct
animals (the skeleton of a mastodon having been found in the
Trenton gravels) and by the advent of palaeolithic man to the
neighborhood of Trenton.
3. During the Terrace epoch the river worked its way down
through the delta of gravel at Trenton, and has since eroded its
present channel which is about two miles wide at that point.
Higher up, where the current is swift, the lateral erosion in
recent times has been small.
4. To determine approximately the date of the earliest
evidence of man's appearance at Trenton we have as data, (1)
The amount of erosion in the palaeolithic gravels at Trenton.
(2) The general evidence from other sources bearing upon the
date of the close of the Champlain epoch in this country. As
bearing upon this, several terrestrial time-measures are accessible,
the most important of which are the recession of various water
falls, like those of Niagara and St. Anthony, which occupy
post-glacial beds ; and the extent to which sediment and peat
have accumulated in post-glacial lakes and kettle holes. It will
be much safer to draw conclusions from such tangible data as
these, than from the distant regions of astronomy, or from the
uncertain rate at which the evolution of plants and animals has
proceeded, or the development of man has progressed.
Mr. Lucien Carr said that in September 1878, he had visited
Trenton in company with Professor Whitney of Cambridge, and
that together they had examined the implement-bearing gravel
bed. During the investigation it was his good fortune to find one
specimen in place, under such circumstances that it must have
been deposited at the time the containing bed was laid down. It
was in the ravine which cuts through the bluff near Dr. Abbott's
house, in a fresh exposure made by a recent heavy storm, and
PROCEEDINGS B. S. N. H. VOL. XXI. 10 NOVEMBER, 1881.
\V:.,Uworth.] 146 [.January 19,
was about three feet deep in the ground and one foot in fn>m
the perpendicular face of this newly exposed surface. lie also
stated that, although neither Dr. Abbott nor the officers of the
Peabody Museum had any doubt as to the artificial character
of these implements, yet he had recently submitted a series of
them to leading archaeologists in London, Paris and Copenhagen.
all of whom unhesitatingly confirmed their decision.
Dr. M. E. Wadsworth having been requested by the Curator
of the Peabody Museum of Archaeology to give some account of
his observations on the specimens in the Peabody Museum said to
have come from the Trenton (N. J.) gravels, remarked as
follows :
Certain of these specimens were placed in my hands in 1876
for examination, their lithological character then being unknown.
They were found by macroscopic and microscopic examination
to have been made from argillite, greatly indurated, and breaking
witli a conchoidal fracture. The specimens were weathered to
a greater or less extent and showed plainly that the fractures
must have been made long ago. A few small fractures of sec
ondary character occur. This secondary chipping evidently took
place long after the original fracturing, but also long ago, as is
shown by the weathering of the surfaces of both the primary
and secondary fractures. The few secondary fractures are prob
ably natural, and could easily occur if subjected to the action Dr.
Abbott supposes. The original chipping could not have taken
place by any known natural causes- .-.cling upon rocks, so far as
the writer has any knowledge. Of course it then brings n^ to
the only agency that could do the 1 work : man. The characters
of the specimens, petrographically, bore out the statements made
to me by Mr. Putnam, of the conditions under which they were
found, whether upon the surface or in the gravels. I do not >ee
how it is possible that such Correspondence of characters could
exist unless the specimens were found under the conditions
reported.
The lithological characters then show that the specimens are
not natural forms; that being composed of a slow weathering
rock, they must have been made IOIIL: year- ago; that many years
1881-] 147 [Putnam
later they were subject to other conditions, probably natural, by
which part have been modified ; that since then, they have lain
for many, many years exposed to weathering agencies; some
showing that they have been subject to this action while lying on
or near the surface, and others while buried to some depth.
Their weathering corresponds to that observed on pebbles of
similar composition in gravels elsewhere. It is to be remembered
that all the weathering has taken place since the Abbott speci
mens were originally chipped.
The term weathering as here employed means the alteration
and decay that has taken place on the surface of the specimen,
but does not imply that it has been exposed on the surface of the
ground ; it may or may not have been ; the weathering itself
shows with greater or less clearness whether this occurred from
surface exposure or not.
Part of the specimens shown me bore evidence that they had
originally been exposed to weathering on the surface of the
ground and been covered since, but the covering evidently took
place ages ago, if the weathering that they have been subjected
to since is any criterion.
The term "argillite," as employed by me, is used to designate
all argillaceous rocks, in which the argillaceous material is the
predominant characteristic; slate or clay-slate, clay-stone, etc.
are simply varieties of it, the term slate being only rightfully used
when slaty cleavage is developed. The argillite out of which
these specimens were made has ho trace of cleavage.
Mr. F. W. Putnam said: It is left for, me Mr. President, to
say a few words, in conclusion, on the subject of Palaeolithic man
on the Atlantic coast of America, which has been so forcibly pre_
sented by the several speakers this evening ; but first I wish to give
the reason, apart from my long personal relations with Dr. Abbott,
that has so closely identified the Pe-ibody Museum of Archaeol
ogy with Dr. Abbott's discoveries in New Jersey.
In Mr. Peabody's letter of gift to the gentlemen he appointed
as Trustees of the Museum of American Archaeology and Ethnol
ogy, which he then founded, under date of Oct. 8, 1866, are the
following words : " In the event of the discovery in America of
Putnam.] 1 4^ (.January lit.
human remains or implements of an earlier geological period than
the present, especial attention l>e _riven to their studv, ami their
comparison with those found in other countries." This request
of Mr. Peabody makes it incumhent on tin 1 Trustees of the
Museum to do what they can in aid of such explorations as those
conducted by Dr. Abbott, and on my eallin-j,- the attention of the
Board of Trustees to the importance of his investigations, appro
priations were at once granted to enable him to continue his \vork
in connection with the Peabody Museum. The results of this
work have been presented to-night, and they have certainly
shown that palaeolithic man lived on the Atlantic coast of
America at a time so remote that the implements which he made
were now found buried in the same glacial gravel and reassorted
river drift which contained the remains of the bison and the
mastodon, and under conditions corresponding with those under
which implements of the same character had been buried in the
gravels of the river valleys of Europe.
Dr. Abbott, with proper scientific caution, has not mentioned
the discovery of a peculiar human skull under such reported
conditions as would, if true, show it to be contemporaneous with
the stone implements of the gravel. Still as the skull was not
secured by Dr. Abbott until some time after it was said to have
been dug out of the gravel several feet below the surface, its
consideration must be deferred until furl her evidence 1 is obtained
of human bones in the Trenton gravel.
As Dr. Abbott has stated, inhis historical summary of the
discovery of the implements in the gravel, it has been my good
fortune to take, with my own hands, live unquestionable palaeo
lithic implements from the gravel at various depths and at differ
ent points. The relation of the circumstances under which one
of these (now on the table) was found will be sufficient to
convince you that, the implement was in the position where it
was buried by the four feet of gravel which had been deposited
over it.
A short distance from Dr. Abbott's house and very near where
the Trenton gravel joins the marine gravel, there is a deep gully
throuirh which flows a small brook. In this gully the gravel bank
i> constantly washing away and presenting new surface exposures.
1881.] 149 [Putnam.
After a heavy rain in June, 1879, I visited the spot with Dr.
Abbott and his son. Here I noticed a small boulder of about six or
eight inches in diameter, projecting an inch or two from the face
of the bank about four feet from the surface of the soil above ; I
worked the stone from the gravel in which it was firmly imbed
ded and drew it out. At the back part of the cavity thus made I-
noticed the pointed end of a stone and after working it up and
down a few times, so as to loosen the gravel about it, I drew out
the implement now exhibited.
On the same day I discovered a second specimen in place eight
feet from the surface, and Dr. Abbott's son Richard found another
about four feet from the surface. These three specimens were
found within twenty or thirty feet of each other, after a heavy
shower had made the most favorable conditions for their discov
ery. A long continued search on several following days, at
various places along the gravel bluff, failed of success in finding
other specimens in place, although several were obtained from the
talus. This shows how seldom the implements are likely to be
found, and it may be from this cause that some unsuccessful
hunters have doubted the occurrence of the implements in the
gravel. Certainly the evidence that has been^brought forward
to-night will clear away all doubts as to the importance and reli
ability of Dr. Abbott's discoveries and investigations, which have
proved the former existence of palaeolithic man in the valley of
the Delaware.