232
GEOLOGICAL NOTES
GLACIAL HISTORY OF COVEY HILL'
GEOLOGIC
ce came from the northeast, whereas
unger one came from the northwest.
PAUL MACCLINTOC$ AND J. l ~ R A s I b f . 4 ~ ~
ABSTRACT
INTRODUCTION
Covey Hill has long been a spectacular
landmark in the glacial history of North
America. I t is the bold northern terminus
of the Adiron&& upland where this latter
projects northward, as a ~ b ~ ~ from
~ i
New York State across the border three
miles into Quebec Province. The hjll rises
900 feet from the St. Lawrence lowland,
on the north, to an altitude of 1,100 feet.
Its summit is separated from the upland
in N~~ york by a gentle flat-bottomed
col a half-rnile wide and a mile long of a]titude 1,010 feet, known as Covey Hill Gap.
This col has been washed clean of the glacial
drift which litters surrounding terrain. I t s
flat bottom is now covered with a layer
of peat six feet thick lying on the bed rock.
I t was hoped that a sample of this peat
might give a radiocarbon age that would
date the glacial events.
A small box-canyon has been cut down
the eastward descent of the col, from 1,000
feet altitude descending to about 750 feet.
This little canyon in places is 75 to 100
feet deep, with vertical sides, cut in hori~ o n t a lPotsdam sandstone. I t contains two
deep little lakes. The upper, western lake,
which is locally known as "the Lake," lies
a t the foot of what was evidently a vertical
I
Manuscript received June 12, 1959.
Princeton University, I'rinceton, New Jersey.
Geological Survey of Canatla, Ottawa, Ontario
or overhanging rim before large slabs collapsed. Soundings show a depth of 75 feet
Water above a muddy bottom, at the
end, shoaling to about 35 feet in
the mid-~ortionand to feet at the eastern
wet-weather trickle of water enters
~end.
~ A
, M
at the west end and leaves at the east
end among the
Of rock that litter
the
bottom.
a
farther down
the little canyon, and crossed
the
national boundary, lies a second
pool locally known as "the Gu1f"and locally
described as 70 feet deep (fig. 3, longitudilul
profile Of Covey Hi'' Gap). Good descrip
tion' have been published by 'Toodwod
(1905), by Fairchild (1912), and by Wa'' Of whom
Goldthwait
the phenomena to have been made
and
erosion Of a major
when "the ice sheet," during its re
from the Adirondacks, still damme
St. Lawrence and diverted the outletwat
'ILake
Iroquois" across this Covey
G a p It has long been a question in
minds of many people just how a
remain at the right PIac
stand
to produce the phenomena as
DAMMING BY READVANCE
Current investigations of the Heist
history of the St. Lawrence lowIan
S e w York State Museum ( ~ a c c l i n t
1954, 1958) has shown that there
ice invasions in the region. The e
- ,/'
BOUNDARY OF
FORT COVINGTON DRIFT
I
,-.?I
,'
/ -4
1
\
MALONE
/'
- - 3&Ts&-/
PLAT1
1'1~.
1 .-Index
ma,J of
MALONE
he Malone ;nvasion overran tile whole
shown by striae and till fabrics
lowlands at the north, on the crest
Covey Hill, and on the uplands of the
urubuscoregion to the south (fig. 2).
FORT C O V I N G ~
ON
Covington ice crossed the low-
' where it deposited a blanket of till,
,
th
CC
On
tal
CIlor
Ch
ter
2),
B~,
GEOLOGI( AL NOTES
:AL NOTES
ee came from thc northeast, whereas
Y OF COVEY HILL'
?
AND J. IEKASMAER
KACT
younger one came from the northwest.
se directions of movement are recogd by striae, shear and tension cracks,
by till fabric orientation. The earlier
ante is designated the "Malone" and
the "Fort Covington." Gravel,
varied clay deposits commonly
between the till sheets of these
des, showing a lake to have been
ring the time of deglaciation.
20
10
30
40
50
233
and impinged against the base of the Adirondack upland with lobes pushing into the
re-entrants excavated by Oswegachie, Grannis, Raquette, St. Regis, and Salmon rivers,
to deposit a fairly good terminal moraine.
This moraine exhibits knob-and-kettle topography above the altitude of 525 feet;
but where it lies below this altitude, it
has been softened and flattened by waves
of the Champlain Sea. The drift, however,
is still recognizable as Fort Covington by
60
SCALE IN MILES
or overhanging rim before 1
lapsed. Soundings show a d
of water above a muddy
western end, shoaling to a
the mid-portion and to 5 feet a t the e
end. A wet-weather trickle of water
a t the west end and leaves a t the
end among the blocks of
the phenomena to have been ma
erosion of a major torrent and
when "the ice sheet," during its
from the Adirondacks, still
St. Lawrence and diverted the outlet
of "Lake Iroquois" across this Covey
/'
BOUNDARY OF
FORT COVINGTON DRIFT
FIG.1.-Index ma] of Covey HiU area
MALONE
the northwest orientation of its till fabric.
GEOLOGTC
River, causing them to flow "slantdown the northwest slope of the hill.
thin about 100 feet of the summit.
ummit, however, has the striae, north
-0
.0
r
4
FIG..?.-Profile of
east
south of Covey Hill village. This boundary
is thence traced eastward passing a mile
brth of Mooers and a mile south of the
hllage of Champlain to Lake Champlain,
Joutheast of Chazy. North of this moraine
235
(BEOI,O(:TC\T, NOTES
of Earlville. I t is thence traced northard up the northwest flank of Covey
1, where it determine.; the couries ol
2jtchel Brook and the ea\t branch of Outerde River, causing them to ljow "slant&e" down the northwest slope of the hill.
vopography and till fabrics show the mopine to mount the north slope of the hill
U, within about 100 feet of the summit.
The summit, however, has the striae, north
70°E. and north 50" E. of the Malone glaciition. On the east slope of the hill, a t
altitude 850 feet, northwest till fabrics show
that the Fort Covington boundary passes
into the United States a mile
0
of Malone age 011 the Churubusco area a
few miles to the south, which are of progreiilvcly lower altitude from south to north,
ix., 1,,<05 it., 1,290 ft., 1,150 ft., and l,OO(~
ft. (fig. 2). Occasional and poorly developed
shore features at one or more of these levels
are found farther west, indicating shortlived lakes. This type of record of ephemeral
lakes would be expected during recession
of an ice front, whereas a longer-lived and
more important lake level might be expected
at the climax of a major reGvance. Major
deltas and shore-line features seen to the
westward a t the level of Covey Gap show
this lake of Fort Covington age to have
2
I
I
,3 Miles
4
L
FIG.3.-Profile
of east slope of Covey Cap
south of Covey Hill village. This boundary
is thence traced eastward passing a mile
north of Mooers and a mile south of the
village of Champlain to Lake Champlain,
southeast of Chazy. North of this moraine
boundary, as thus traced, striae and till
fabrics are from the northwest (fig. 4),
whereas south of this boundary they are
from the northeast, i.e., Malone (fig. 5).
Evidently, therefore, the Fort Covington
@
, pushed southward across the lowland,
damming the St. Lawrence drainage, and
nged against Covey Hill, thus impounda lake and causing i t to overilow a t
Covey Hill Gap into the Lake Champlain
ression. I t may well be, also, that waters
an older ice-marginal lake during the
ing of the Malone ice flowed through
Covey Gap, for there are four such cols
been of considerable duration. This is also
shown by the mile of retreat of the waterfall
in the spillway from "-the Gulf" to the headwall of "the Lake." I t is proposed, therefore,
that the major episode of lake and spillway
a t Covey Hill was of Fort C~vingtontime.
I t follows, therefore, that since Covey Hill
overflow was caused by Fort Covington
ice, this water flowed into Lake Vermont
a t its Coveville stage, whose shore line
now stands a t 800-foot altitude a t the international boundary (Chapman, 1937, fig. 12)
This Coveville lake was therefore being
dammed by the Fort Covington ice edge.
This edge presumably was calving into the
lake waters to form the boundary of Fort
Covington drift as found across the northern
end of the Champlain lowland. If it had not
been a calving edge, a loop of drift (produced
GEOLOGIC
-
-
t
1
Covey Hill. East Slope
Foundation Excavation Mr. White 'a
House
X
-t
-
V
I
-
Franklin Center,
-I1
+
-E
1/2 mile S.B. of Franklin Center.
Crest of Fort Covington 1~loraine
Roadoide exposure
Y
-91
I
: mlles N.N.E.
-Mooers Forks,
1 mile
5;
+
-
Cannons Corners Mooers QuadrsnRle
Y
-
IIJl
+
Champlain, 2 miles' S.W.,
:. 4,-Diagrams
-E
Rouse's
Point 2uadrawle
of Fort Covington till fabrics showing th
v
-
4
3 miles east
Mooers Quadranele. Sm
FIG.5.-Diagrams of Malone till fabrics
I
237
GEOLOGICAL NOTES
a lobe of ice projecting into a lowland)
ght have been expected. The large number
ice-rafted striated stones embedded in
e v a r ~ e dsediments attests also to calving.
overflow waters a t Covey Gap cut a
ey down only to the 800-foot level a t
Gulf" (fig. 31, below which morainal
"
drift topography is still present. There are
a few sandy shore features a t 800 feet but
no delta. The overflow waters evidently
carried little or no sediment across the col.
Upon withdrawal of Fort Covington ice,
the channel was abandoned as the lake level
fell to the Fort Ann stage (Chapman, 1937).
+
1 1/2 mile north o f Mooers,
0
,
'6
....
.;
+
-
K
%
+
&..---
IIIL E
Franklin Center, 1 1/2 mile south
+
North slope of Covey H i l l
4 . 2 miles E. of Franklin Center
Altitude 720 roadside exposure
-\2.. <f t
,
,
0%
-21
-+
V
IIIlltItl
+
-Mooers Forks. 1 mile S.W.,
arc
0
Ill
Mooers Quadranfile
-=
t
Covey Hi11 villa&-e 4 1/2 miles East.
-2 11x111
- If
V
Rouse's Point B.R.
%dews=
trike of the long axes of the flat-lying (diagnos
-
+
I I L E
3 miles e a s t o f I.looers
Mooers Quadrangle. Small roadside eXpO8W
FIG.5.-Diagrams of Malone till fabrics showing the strike of the flat-lying stones
GEOLOGICAL NOTES
where a large body of water was confluent
in the Champlain and St. Lawrence lowlands
with shore lines a t present level of 725
feet in Covey Hill area. The large delta
of the Salmon River a t Malone was built
into this lake, as well as that of Saranac
River a t Morrisonville. Also varved lake
clays were deposited on the Fort Covington
till-now found as far north as Ottawa
-/.d
GEOLOG
or two of the underlying till is oxid
to buff color, whereas the overlying ma
clay is still the slate-gray color of unoxid
clay. Furthermore, in exposure, marine
in places lies directly on Fort Covinl
till, showing that v a n e d clay either had
been deposited or had been eroded F
to marine deposition. Therefore there
an episode of emergence during which
/
-300 ft
1 shelld
I t f,t l '
88s
ee
I
'
cllmtio
mxlmum
El,
Frc 6 -Isostatic rise of land and eustatic rise of sea during late glacial and postglacial time.
largely on (1) general rise of sea level after Godwin, Suggate, Willis (1958); (2) Champlain Sea shells (10,300
to 11,300 C14 yrs.) Y-215, Y-216, Y-233, Gro-1696, Gro-1697; (3) Port Huron (12,800), Y-240; (4) St. Gep
main bog (9,500), Lamont 441C; (5) top of Lake Fort Ann varves 325 ft. below marine shore line,
Hill.
and northeast as Drummondville. The best varved clays were dried out, cracke
exposures, as might be expected, were seen broken, and chips washed together t
in the great excavations for the St. Lawrence the "breccia." The varved clays were
Seaway and Power Projects, and a great idized and were fluvjally eroded prior
many test drill cores contain the varved ial by marine clays. hi^ meant, th
clays between till below and marine clays
that when the ice dam broke that
above. The marine clays are not varved
Lake
Fort Ann and the lake was drained,
and very commonly contain fossil shells.
In both the cores and the exposures the bottom was dry land above the gla
upper foot or two of the varved clays are Sea level
the time. This relati'
fractured into a sort of "breccia" and then shown in figure 6, which Portrays
welded together again into a solid lnass rise of land and eustatic rise of sea in Po
of day. The varved clay and the top foot glacial time.
CORRELATION AND AGE OF THE FORT
COVINGTON GLACIATION
No material which could be dated b:
radiocarbon has yet been found in the drifi
However, the Champlain Sea sediment:
&ove the Fort Covington till, do contai!
shells which have been variously dated fron
10,300to 11,300years (Y-233, Y-215, Y-216
Y-217, Gro-1697, Gro-1696 [Preston, Per
son, and Deevey, 1955; de Vries, 19581)
Doubt has been expressed as to the reliabili
ty of these dates, since the organisms werc
living in estuarine environment of "dead'
carbon. But recent work (Broecker and 0rr
1958; de Vries, 1958) shows that the carbor
in the surface waters was so nearly in equi
librium with that in the atmosphere thal
"dead" carbon affected the age determina
tion less than 3 per cent for shallow-watel
forms, like Mya, Macoma, and Hiatella
with which we are dealing.
- I t has also beer
suggested that postdepositional replacemeni
of the carbonate in the shells has brought
in "dead" carbon to make the dates appeal
older than they really are. The shells, however, show little, if any, evidence of replacement of carbonate. Some are somewhat
chalky, but the majority are still dense
Numbers of them retain some mother-ofPearl and greenish-brown or bluish color
nd, in many cases, the
X-RAY DLFPRACTION
validity of the replacement
idea, samples of Macoma and Hiatella (Sahamplain Sea deposits
to X-ray diffraction analysis.
hell material showed arago.2", 31.0°, 33.2", 36.2", 37.g0,
calcite peaks. The Hiatella
aragonite peaks a t 33.2",
38.6"; also no calcite peaks.
coma and Hiatella likewise
peaks with no calcite
tdepositional replacement
ith
this evidence
as been no replacement.
iocarbon dates are trustseem to be, the Cham-
L NOTES
~r two of the underlying till is oxidi;r4
o buff color, whereas the overlying marine
lay is still the slate-gray color of unOxidized
lay. Furthermore, in exposure, marine clay
places lies directly on Fort Covingtoo
ill, showing that varved clay either had not
been deposited or had been eroded prior
o marine deposition. Therefore there was
n episode of emergence during which th,
,tic
Lmun
i
GEOTdOC.TCAT, NOTES
I
Jtom was dry land above the glacial
I. level of the time. This relatio
own in figure 6, which portrays
e of land and eustatic rise of sea in
~cialtime.
.
plain Sea was of about Two Creeks age.7'..
Confirmation of this age comes from the
No material which could be dated by radiocarbon date of 9,500 years (Terasmae,
@diocarbonhas yet been found in the drift. 1959a) for the basal layers of peat in the
However, the Champlain Sea sediments, St. Germain bog near Drummondville, Quethe Fort Covington till, do contain bec, showing that this area had emerged
shells which have been variously dated from from the Champlain Sea a t least 9,500 years
10,300to 11,300years (Y-233, Y-215, Y-216, ago. Since Fort Covington drift is overlain 2I,
.
y-217, Gro-1697, Gro-1696 [Preston, Per- by Champlain Sea clays, it is therefore preson, and Deevey, 1955; de Vries, 19581). Two Creeks in age and to be correlated
~ o u bhas
t been expressed as to the reliabili- with the Port Huron episode of the 'Iliistv of these dates, since the organisms
were consin.
&ing in estuarine environment of "dead"
DESCKTPTION O F THE POLLEN PROFILE
Parbon.
---- But recent work (Broecker and Orr.
A reconnaissance of the bog, made by
1958; de Vries, 1958) shows that the carbon
in the surface waters was so nearly in equi- test borings with the Hiller peat sampler,
librium with that in the atmosphere that showed that generally the peat cover over
"dead" carbon affected the age determina- bedrock is thin, about 3-5 feet. The peat
CORRELATION AND AGE O F THE FORT
COVlNGTON GLACIATION
forms, like Mya, Macoma, and Hiatella,
with which we are dealing. I t has also been
suggestedthat postdepositional replacement
of the carbonate in the shells has brought
in "dead" carbon to make the dates appear
older than they really are. The shells, however, show little, if any, evidence of replacement of carbonate. Some are somewhat
chalky, but the majority are still dense.
Numbers of them retain some mother-ofpearl and greenish-brown or bluish color
11 and, in many cases, the
X-RAY DIFFRACTION
rved clays were dried out, cracked
oken, and chips washed togethe
e "breccia." The varved clays were
ized and were fluvially eroded prior to
by marine clays. This meant, there
239
To test the validity of the replacement
acoma and Hiatella (Sarom Champlain Sea deposits
subjected to X-ray diffraction analysis.
Macoma shell material showed aragopeaks a t 27.2', 31.0°, 33.2", 36.2', 37.8',
38.4' and no calcite peaks. The Hiatella
d aragonite peaks a t 33.z0,
38.6'; also no calcite peaks.
acoma and Hiatella likewise
only aragonite peaks with no calcite
stdepositional replacement
have been with calcite, this evidence
that there has been no replacement.
adiocarbon dates are trustseem to be, the Cham-
by a thin layer of sand. The pollen profile
was sampled through the thickest peat section, and the underlying lacustrine deposits
were encountered during this reconnaissance. At the sampling site the thickness
of the organic deposits was 190 cm. (6'3'').
A palynological study of the peat has been
compiled in a pollen diagram (fig. 7). Correlation of this pollen profile with the others
of postglacial deposits in the St. Lawrence
lowlands (Terasmae, 19593) shows that the
pollen record obtained from the Covey Hill
bog extends back to pollen zone IV. The
pollen profiles in the lowlands near Drummondville extend back to pollen zone VI,
which is dated a t about 9,500 years by
Lamont 441C. Pollen zone I V probably
dates about 7,500 years B.P. Therefore, it
appears certain that the pollen record from
the Covey Hill channel does not reach
back to the time when this channel was
abandoned because of ice retreat from the
Covey Hill. Two probable reasons can be
suggested: (1) owing to the large size of
this bog, its oldest sediments were not found
during this reconnaissance, and (2) because
the channel was cut into the Potsdam sandstone and all drift removed by the fastflowing river, a rather sterile, shallow lake
remained after the channel was abandoned,
and conditions for a long time were unfavor-
GEOLOGIC
ulation of lacustrine organic
the palynological studies made
the St. Lawrence lowlands as well as
dates clearly indicate that the
retreat from the Covey Hill must have
re the Champlain Sea episode;
channel must have been abann Two Creeks time, because
n Sea episode was a t least
REFEREN(
BARENDSEN,G. W., WATERBOLK,
H. T.,
1958, Groningen radiocarbon dates. 11: Science,
the Hudson, Champlain, and St. Lawrence Valleys: ibid., p. 209, 210.
~ D W I N ,SUGGATE,
R. P., and WILLIS, E. H., 1958,
Racliocarbon dating of eustatic rise of sealevel:
Nature, v. 181, p. 1518.
~ L D T H W A I T ,R. P., 1958, Wisconsin Age forests
In western Ohio. Ohio Jour. Sci. ,v. 58, p. 218.
241
GEOLOGICAL NOTES
u l a t i o n of lacustrine o r g a n i c
s u l t s of t h e palynological s t u d i e s m a d e
t. L a w r e n c e lowlands a s well as
o n d a t e s clearly indicate t h a t the
VeY H i l l must have
e C h a m p l a i n S e a episode;
a n n e l m u s t h a v e been a b a n -
i n p a r t c o n t e m p o r a n e o u s with t h a t interval
( T e r a s m a e , 1050i1).
A
c
~
~
~
~
~
E
~ exl,cnses
G ~ ~ of~
MacClintock were covered by a g r a n t from
the Higgins Fund, Princeton University.
T h a n k s a r e expressed for valuable field and
office discussion to C. H. Denny, H . d e Vries,
REFERENCES CITED
-
DE VRIES,H., 1958, Personal discussion in the field.
BARENDSEN,G. W., WATERBOLK,
H. T.,
1958, Groningen radiocarbon dates. 11: Science,
v. 127, p. 129-137.
FAIRCHILD, H. L., 1912, Report of the director:
N.Y. State Mus. Bull. 158, p. 32-35.
1919, Pleistocene marine submergence of
the Hudson, Champlain, and St. Lawrence Valleys: ibid., p. 209, 210.
GODWIN,
SUGGATE,
R. P., and WILLIS,E. H., 1958,
Radiocarbon dating of eustatic rise of sealevel:
Nature, v. 181, p. 1518.
GOLDTHWAIT,
R. P., 1958, Wisconsin Age forests
in western Ohio: Ohio Jour. Sci. ,v. 58, p. 218.
PRESTON,R. S., PERSON,E., DEEVEY,E. S., 1955,
Yale natural radiocarbon measurements. 11: Science, v. 122, no. 3177, p. 954-60.
RUBIN,M., and S u ~ s sH.
, E., 1955, U.S. geological
survey radiocarbon dates. 11: Science, v. 121,
no. 3145, p. 481-488.
TERASMAE,
J., 1959a, Notes on the Champlain Sea
episode in the St. Lawrence lowlands, Quebec:
Science, v. 130, p. 334-335.
--- 1959b, Contributions to Canadian palynology. 11. Part I, A palynological study of postglacial deposits in the St. Lawrence lowlands:
Geol. Survey Canada Bull. no. 56.
WOODWARD,
J. B., 1905, Pleistocene geology of the
Mooers Quadrangle: N.Y. State Mus. Bull. 83.
,,
-77
~
~
,