SILURIAN.
_Islands of Group I._
Flat-lying beds of light-coloured yellow and drab limestone occupy the
lowlands of the southern and western parts of Southampton island, and
also form outliers in depressions in the crystalline rocks on the north
side of the island, notably at Duke of York bay.
A considerable collection of fossils was brought home from the beds
forming the southern half of the west coast of the island. These have
been examined by Dr. Ami and Mr. Lambe, whose determinations will be
found in Appendix iv. The fossils show that the rocks contain a fauna
closely resembling that of the Lake Winnipeg basin, and extend over a
period from the Galena-Trenton to the Guelph and Niagara, or from the
upper part of the Cambro-Silurian to high up in the Silurian.
Soundings taken on the even bottom of Fisher strait show that the
limestones extend without a break to Coats island (to the southward of
Southampton), where they occupy all of its surface except the portion at
the east end of the island where the Archæan ridge crosses it. A few
fossils from Mansfield island show that it also is formed of limestones
of these horizons.
At Cape Chidley a collection of fossils from loose pieces of limestone
corresponds with fossils from Akpatok island, and the direction of ice
movement out of Hudson strait leaves little doubt that the loose
limestone of Chidley came from that island. These fossils show a
slightly wider range in age than the rocks of Southampton do; they
extend from the Lower Galena-Trenton to the Lower Heidelberg.
_West Coast of Hudson Bay._
The wide fringe of limestones which is found along the west shores of
Hudson bay to the southward of Churchill do not come within the limits
of this report. To the northward only Archæan rocks are found along the
mainland until the northern half of Melville peninsula is reached, where
Parry describes a wide area of sandstone, probably the base of the
Cambro-Silurian, as separating the highlands of the interior from the
western shores of the northern part of Fox channel. These rocks are
continued on the north side of Fury and Hecla strait, where they are
found on the west side of Baffin island fronting on Prince Regent inlet.
_Islands of Group II._
The only known occurrence of Silurian limestone on the eastern side of
Baffin island is at Silliman’s Fossil Mount, near the head of Frobisher
bay, where the limestone forms a hill 1,000 yards long and 350 feet
high, resting almost flat upon the crystalline rocks. Seventy-two
species were identified by Schuchert from fossils brought back from this
locality; he refers them all to the Galena-Trenton.
Little is known of the limestone about the great lakes, Nettilling and
Amadjuak, in the interior of Baffin, beyond the meagre observations of
Boas, who briefly refers to the limestone about Nettilling and along the
east side of Fox channel. These limestones are probably an eastern
extension of the Southampton area, but their exact age will remain
unknown until fossils have been collected from them.
On the east side of Prince Regent inlet the rocks composing the high
cliffs of Baffin island are the basal sandstone and shale overlaid by
limestones, which in places are interbedded with beds of gypsum. These
high cliffs of limestone extend eastward along the south shore of
Lancaster sound to the mouth of Admiralty inlet, when they give place to
the Archæan crystalline rocks, which rise slowly to the eastward from
beneath the level of the sea, in a manner similar to that already
described, on the north side of Lancaster sound.
_Islands of Group III._
The large islands of this group are mainly built of Silurian limestones.
North Somerset was the only island of this group visited in the
_Neptune_, and all information concerning the others is derived from the
observations made on earlier expeditions, and contained in Dawson’s
summary of the northern geology.
Silurian limestones form the southern third of Banks island, being
overlaid in the northern part by beds of Devonian and lower
Carboniferous age. Dr. Rae reports the entire southern coast of Victoria
island as being composed entirely of Silurian limestone.
‘The northern part of King William land, with Matty island to
the east of it, are described by Sir John Ross as of limestone.
Simpson states the eastern part of the south shore to be also of
limestone, and Haughton dealing principally with the results of
M’Clintock’s voyage writes as follows: “The east side of King
William island, though composed of Silurian limestone like the
rest of the island, is strewed with blocks of black and red
micaceous gneiss, like that of Montreal island, and black
metamorphic clay-slate, in which the crystals of mica are just
commencing to be developed. It is probable that the granitoid
rocks appear at the surface somewhere to the eastward of this
locality.”
‘Numerous excellent though brief notes on the geology of the
eastern and southwestern coasts of the Boothian peninsula occur
in Sir John Ross’ remarkable narrative referred to. From these
we learn that the eastern shore is composed of limestone to Port
Logan (latitude 71° 21´), where a high range of hills—which is
seen at a distance estimated at thirty miles inland at Creswell
bay (further north) and runs north-and-south—impinged on the
shore, and was found to consist of granitoid and gneissic rocks.
Thence southward, from notes given in the body of the narrative,
a narrow border of limestone may skirt the shore to about
latitude 70° 35´, though the geological appendix does not make
any mention of this.’
‘The narrow neck of the Boothian peninsula, which was crossed by
Ross on several lines, is, from his description, composed of
granitic rocks, with some outliers of limestone. One of these,
definitely mentioned in the narrative but not in the geological
appendix, is shown on the present map. On the coast of the
mainland, west of the isthmus, the limestone formation is found
resting on the granites of Lake Wittersted. Northwest from the
isthmus the southwest coast of Boothia presents a range of
granitoid hills, running northward, but becomes fringed by a low
border of limestone near Cape Isabella, and this increases in
width to the north, till an extensive flat limestone region is
found in the vicinity of the magnetic pole.’
At Bellot strait a junction occurs between the granite and horizontal
beds of Silurian limestone.
‘The entire western portion of Prince of Wales island is
composed of Silurian limestone, which in the extreme west, at
Cape Acworth, becomes chalky in character and non-fossiliferous,
resembling the peculiar Silurian limestone found on the west
side of Boothia Felix.’
The northern and eastern shores of North Somerset are of limestone,
usually rising from the water in precipitous cliffs. These were examined
at Port Leopold, where the cliffs rise sheer 1,000 feet from the sea.
The bedding of the limestone is very distinct, and the face of the cliff
has been sculptured by every runlet, so that between the horizontal and
vertical markings the cliffs resemble on a gigantic scale the fluted
walls of a castle. Fossils were collected from the lower beds of the
cliff by M’Clintock, but none were collected on the present voyage.
_Islands of Group IV._
The discovery of the Silurian limestone of the southern cliffs of North
Devon and Cornwallis was made by Parry, while his collection of fossils
was supplemented by those found by the Franklin search expeditions. Our
knowledge of the geology of Ellesmere was, previous to the Sverdrup
expedition, mainly due to the work of Feilden and De Rance in connection
with the British expedition of 1875-76. Mr. P. Schei, the geologist who
accompanied Sverdrup, collected much valuable information concerning the
rock formations of Ellesmere. A summary of his observations is published
as an appendix to Sverdrup’s ‘New Land,’ and is freely quoted from in
the following.
The rocks found on the north side of the Archer plateau, in the eastern
part of Ellesmere to the north of Cape Sabine, are very interesting
geologically, as they show the only trace of an unbroken sequence of
beds from the Huronian up through the Cambrian to the Silurian
limestones so widely distributed on the Arctic islands. These rocks are
described by Schei as follows:
‘At Cape Camperdown, on Bache peninsula, is found granite
overlain by an arkose-like conglomerate sandstone, in flat
strata, the dip being north-northwest. Its thickness here
probably does not exceed 500 feet, though the contour swells to
considerably greater magnitude by reason of intrusions of
diabase, occasioning an additional thickness of perhaps 300
feet. At its upper part this sandstone merges gradually, by
interstratification, into a series of gray, sandy and marl-like
schists and limestone conglomerates. From a few inches up to a
couple of yards in thickness these conglomerates and schists,
continuously interstratified, build up a series 600 to 900 feet
in thickness, interrupted by two compact beds of yellowish-gray
dolomitic limestone about 150 feet in thickness. These are again
overlain by a series similar to the underlying one, excepting
that here the limestone conglomerates exceed the schists.’
‘In a detached block, in all probability originating from one of
the two 150-foot beds, were traces of fossils, of which one,
_Leptoplastus_ sp., can be identified. In another detached
block, whose mother rock is not known, was found _Anomocare_ sp.
It may be said with certainty after the finding of these fossils
that this series contains deposits of the Cambrian age.’
‘The second series of conglomerates is overlain by a light
grayish-white limestone in a bed some 300 feet in thickness,
observed in the midst of the section of Cape Victoria Head.
Indistinct Orthoceras, Lichas and Symphysurus assign this
limestone to the Lower Silurian period.’
‘Above the othoceras-bearing, light-coloured limestone bed are
some less extensive strata of alternating limestone and
quartz-sandstone, and finally a 100-foot bed of close brown
limestone of which certain layers are fossiliferous, and gave an
_Asaphus_, traces of other Trilobites and some Gasteropods.’
‘Following the direction of the dip to the north side of
Princess Marie bay we find it again, though seemingly somewhat
abrupter, in the limestone beds of Norman Lockyer island. A
fauna with _Halysites_ sp., _Zaphrentis_ sp., _Orthisina_ sp.,
_Rhynchonella_ sp., _Leperditia_ sp., _Illœnus_ sp., &c.,
assigns this limestone to Lower Silurian. It is again found with
its fauna at the base of Cape Harrison; in this case with a
thick super-incumbent bed of marly sandstone, quartz-sandstone,
and finally extensive limestone conglomerate. This also occurs
near the shore in Cape Prescott, indicating by its presence in
the strike of the limestone of Norman Lockyer island the
disturbance undergone by these tracts.
‘The line along which this disturbance took place is refound on
the west side of Franklin Pierce bay, where the beds of
limestone conglomerate dipping from the heights of Cape Harrison
are cut off in the strike by a limestone, dark-gray in colour
and broken into a breccia.’
In another place Schei hints that the rocks of the Cape Rawson beds,
consisting largely of dark shales and impure limestones, found along the
northern parts of the eastern shores of Ellesmere, may be of Triassic
age, in sharply folded troughs of the older rocks, and consequently much
younger than Cambrian, to which age they were referred by Fielden and De
Rance.
Writing of the Silurian beds found on the southern coast of Ellesmere,
Schei describes them as answering to the northern series, and their
occurrence is as follows:—
‘There are at Havnefjord, in Jones sound, above some layers of
quartz-sandstone, which entirely cover the gneiss-granite there,
a series of limestone conglomerates with marly schists and pure
limestones of a thickness of 1,200 to 1,500 feet. These are
again overlain by a series of beds at least 2,000 feet thick, of
hard, impure limestones, brown or yellowish-gray in colour, and
often remarkably heavy.’
‘At South cape, which is entirely composed of this brown
limestone, are found in the lower parts _Maclurea_ sp., and
_Halysites_ sp., referable to the Middle Silurian, while west of
it, at Bjorneborg, the upper parts of the series contain badly
preserved remains of Orthocerata, Corals, and _Pentamerus_ cfr.
_tenuistriatus_. Hereafter the upper part of the limestone seems
to be equivalent to the older Upper Silurian (Landovery). This
brown limestone occurs from South cape westward to Kobbebugten
in Hell Gate, and is broken at Lille Sandor, tectonic
disturbance bringing up the underlying conglomerate series, and
even the Archæan.’
‘On the south side of Rendalen appears the brown limestone of
the capes, Series A, with a flat dip to the north-northwest; but
on the north side of the valley is a division of dark schist,
Series B, lying conformably above the beds of brown limestone.
Associated with these schists, particularly in their lower and
upper parts, are numerous layers of pure dark limestone,
frequently fossiliferous. In Rendalen and in Kobbebugten, where
this same division also appears, a quantity of material was
collected, of which fifteen species are provisionally
determined, among them being _Favosites_ sp., _Strophomena_ cfr.
_euglypha_, _Meristella_ in numbers, _Rhynchonella_ cfr.
_borealis_, _Pentamerus_ cfr. _galeatus_, _Spirifer_ cfr.
_elevatus_. The period of this division in Series B is Wenlock.’
‘The upper part of Series B appears, among other places, at the
headland north of Tunneldalen, in Hvalrosfjord. Above a black
shale containing _Monograptus_ sp. and _Leperditia_ cfr.
_phaseolus_ is a bed of fragmentary limestone with _Favosites_,
_Strophomena_ cfr. _pecten_, _Atrypa reticularis_, _Pterniea_
cfr. _Sowerbyi_. From a locality in Gaasefjord, on the same
horizon, were taken _Favosites_ cfr. _Hisingeri_, _Favosites
Gothlandicus_, _Thecia Swinderenana_, _Spirifer elevatus_,
_Spirifer_ cfr. _crispus_, _Strophomena corrugatella_, _Dav._,
_Pterinea_ sp. According to these, the period of this upper part
of Series B should be Ludlow. The thickness of the series is
about 1,000 feet.’
‘In Hell Gate, as well as in Gaasefjord, these strata are
overlaid by Series C; in its lower parts consisting of
interstratified light and dark marl schists, which are somewhat
sandy, while in its upper part appear pure quartz-sandstone beds
and argillaceous sandstone. The collective thickness of these
strata is about 1,000 feet in Gaasefjord, while in Hell Gate it
is probably somewhat greater. No fossils were found in this
series.’
‘At the base of the high cliffs at Indra Eide and Borgen appears
Series C. In both of these places it is overlain by a dark
limestone and black shale, partially fossiliferous. This dark
limestone and shale are the lowest layers in a series of strata
at least 1,500 feet in thickness, Series D, which appears in the
profiles on both sides of Gaasefjord, from Borgen to the foot of
Vargtoppen (Wolf Top), and from Indre Eide to Skrabdalen.’
‘In Series Da occurs _Atrypa reticularis_ in great quantities,
but little else. On the other hand, there are preliminary
determined in Db about fifty-five species, of which may be
mentioned: _Favosites_ sp. div., _Columnaria_ sp.,
_Cyathophyllum_ sp. cfr. _hexagonum_, _Recaplaculites_ sp.,
_Fenestella_ sp., _Homalonotus_ sp., _Burmeisteria_ sp.,
_Dechenella_ sp., _Proetus_ sp., _Orthis striatula_, _Leptaena_
sp., _Strophomena_, _Streptorhyncus_, _Atrypa reticularis_,
_aspera_; _Rhynchonella (Pugnax)_ cfr. _reniformis_, _pugnus_,
_Productus_ cfr. _prolongus_, _Spirifer_ of the _Verneuilli
Murch._ type, a peculiar _Pentameride_, _Terebratula_ cfr.
_Dielasma_, _Pterinea_ sp., _Modiolopsis_ sp., _Lucina_ sp.
div., _Bellerophon_ sp., _Platyceras_ sp., _Orthoceras_ sp.,
_Gomphoceras_, gigantic nautilus and ganoid scales.’
‘The fauna in Dc is merely a repetition, and in the case of
certain species, a further development, of the forms found in
Db. It will thus be seen that there is a spring in regard to the
fauna between the upper layers in Series B and the lower ones in
Series D, which more particularly resemble Lower or Middle
Devonian. The concordantly embedded (?) Series C might,
therefore, be thought to represent uppermost Silurian as well as
lowest Devonian.’
‘Divisions Dd and Df are poor in fossils, and are partly shale
divisions. In the impure limestone of Dg occur again numerous
fossils, among which are _Atrypa reticularis_, _Rhynchonella_
cfr. _cuboides_, _Spirifer_ cfr. _undifera_, _Productus_ sp.,
_Terebratula_ cfr. _Dielasma_, _Pterinea_ sp., _Avicula_ sp.,
_Modiolopsis_ sp., _Pleurotomaria_ sp., _Proetus_ sp. Traces of
placoderm fish are also met with. Above these strata are beds of
purer limestone Dh, and above these again some less pure, Di.
The uppermost strata of Di alternate with strata of light-gray
quartz-sandstone terminating in a clay-sandstone, which in
places is richly fossiliferous, though the fossils are in a bad
state of preservation. Among these are lamellibranchiata,
_Dechenella_ sp., remains of _Holoptychius_, &c.’
‘This argillaceous sandstone is simultaneously the last link in
Series D and the first in Series E. This is a huge collection of
quartz-sandstone strata building up the mountains on both sides
of the inner part of Gaasefjord. The lowest part, which is 900
to 1,200 feet in thickness, consists almost exclusively of
quartz-sandstone. On the north side of Skrabdalen, in the
sandstone profile, occur conglomerate strata, half an inch to an
inch in thickness. In these were found considerable remains of
_Coccosteus_ sp., _Holoptychius_ sp., and _Modolia angusta_. In
the same strata with these were also seen indeterminable
plant-fossils. Slightly higher up in the profile, however, in a
black shale which occurred in two lentiform masses, eighteen
inches and six feet in thickness, were found numerous
plant-fossils.’
‘Professor Nathorst, of Stockholm, who has kindly undertaken the
examination of these, says that among others are _Archœopteris
fissilis_ Schmalh. and _Arch. archetypus_ Schmalh., both
characteristic of Upper Devonian. In examining the material
collected, Professor Nathorst also found with the plant remains
some remains of fishes.’
From the above it will be seen that on the southern side of Ellesmere
there is a complete succession of strata, bearing fossils from Middle
Silurian age up to the Upper Devonian. These strata have an aggregate
thickness of 8,000 feet, and form the thickest and most carefully
measured section of the Silurian and Devonian beds of the Arctics.
On the southern and southwestern parts of North Devon the Silurian
strata are much thinner than those described by Schei. At Cuming creek
the Archæan gneisses were found overlain unconformably by red and purple
arenaceous shales and thin bedded sandstones having an aggregate
thickness of fifty to one hundred feet. These in turn were succeeded by
beds of impure limestone of light-gray or creamy colour. The beds are
usually under two feet in thickness, and separated by thinner beds
containing a considerable amount of clay. These light-coloured
limestones have a thickness of over 1,000 feet in the cliffs on both
sides of the creek. The sides of the cliffs are covered with broken
limestone, so that it was impossible to measure a section up them, but
in two or three places a darker coloured limestone conglomerate was
found, made up of small pebbles cemented by a dark shaly matrix. Fossils
are only found in the beds immediately overlying the dark shales and
sandstones of the base. These show that the lower limestone is of
Silurian age, about the horizon of the Niagara.
[Illustration: LIMESTONE CLIFFS OF NORTH DEVON ISLAND.]
Similar conditions prevail in the cliffs at Beechey island, where a
large collection of fossils was obtained from the lower limestone beds,
while others, picked up loose, but evidently fallen from the cliffs
above showed that the upper beds passed close to if not into the
Devonian, as stated in Appendix IV.
Similar Silurian limestones constitute the island of Cornwallis, to the
westward of North Devon, while in the remaining Parry islands farther
west the Silurian strata are lost beneath the Devonian and Carboniferous
rocks of those islands.
DEVONIAN.
The work of the older geologists, which was summarized by Haughton and
later by Dawson, took no account of the Devonian in their divisions of
the Palæozoic rocks of the islands north of Lancaster sound. All the
lower limestones were classed as Silurian, while the overlying
sandstones were placed in the Carboniferous. Fossils of Devonian age
were collected, by the expedition of 1876, from the northern part of
Ellesmere, but their occurrence and relations were only finally settled
by Schei as given above. From his observations it is plain that the
upper part of the limestones and the lower 1,000 feet of the overlying
sandstones are of Devonian age. The early explorers were not trained
geologists, and it could hardly be expected that they would discover the
thin bands containing fossils in these great thicknesses of barren beds.
Owing to this supposed lack of fossils the rocks were separated into
Silurian and Carboniferous almost wholly on lithological differences,
the limestones being classed as Silurian and the sandstones as
Carboniferous.
There is no doubt that Devonian rocks are included in the Carboniferous
of the western Parry islands, but as they occur only in the cliffs
underlying the Carboniferous beds that cover the surface of the islands,
it would be impossible to map them on the scale used in illustrating
this report, and in consequence the old colouring is followed here.
CARBONIFEROUS.
The southern boundary of the Carboniferous sandstones with their
included coal seams crosses the southern part of Banks island in a
north-northeast direction, and they consequently cover the northern
two-thirds of that island, while the extreme northwest portion of
Victoria island is also occupied by these rocks. The western Parry
islands on the north side of Melville sound are almost wholly formed of
these rocks, whose southern boundary strikes northeast across the
northern half of Cornwallis island. They are found again in Grinnell
peninsula, the northwest portion of North Devon, and again on the
western side of Ellesmere, in the vicinity of Store Bjornekap, being
probably largely developed in the northeast part of that great island.
These rocks are described as follows by Professor Haughton:
‘The Upper Silurian limestones, already described, are succeeded
by a most remarkable series of close-grained, white sandstone,
containing numerous beds of highly bituminous coal and but few
marine fossils. In fact the only fossil shell found in these
beds, as far as I know, in any part of the Arctic Archipelago is
a species of ribbed _Atrypa_, which I believe to be identical
with the _Atrypa fallax_ of the Carboniferous slate of Ireland.
These sandstone beds are succeeded by a series of blue limestone
beds containing an abundance of marine shells, commonly found in
all parts of the world where the Carboniferous deposits are at
all developed. The line of junction of these deposits with the
Silurian on which they rest is N. E. to E. N. E. (true). Like
the former, they occur in low flat beds, sometimes rising into
cliffs, but never reaching the elevation attained by the
Silurian rocks in Lancaster sound.’
Coal, sandstone, clay-ironstone and brown hematite, were found along a
line stretching E.N.E. from Baring island, through the south of Melville
island, Byam-Martin island and the whole of Bathurst island.
Carboniferous limestones, with characteristic fossils, were found along
the north coast of Bathurst island, and at Hillock point on Melville
island.
From the comparison of different coal exposures noted by M’Clintock,
M’Clure, Austin and Parry in the Parry islands, Professor Haughton has
laid down the approximate outcrops of some of the coal beds. These he
finds to agree remarkably well with the trend of the boundary of the
formation drawn from totally different data. Lists of fossils and rocks
from the following places, with notes, are given:
‘Hillock point, Melville island (latitude 76° N., longitude 111°
45´ W.). Bathurst island, north coast, Cape Lady Franklin
(latitude 76° 40´ N., longitude 98° 45´ W.). Princess Royal
island, Prince of Wales strait, Baring island (latitude 72° 45´
N., longitude 117° 30´ W.). In connection with this place it is
noted that the Carboniferous sandstones underlie the limestones,
and that it is probable that the coal beds of Melville island
are very low down in the series, and do not correspond in
geological position with the coal beds of Europe. Cape Hamilton,
Baring island (latitude 74° 15´ N., longitude, 117° 30´ W.).
Cape Dundas, Melville island (latitude 74° 30´ N., longitude
111° 45´). Cape Sir James Ross, Melville island (latitude 74°
45´ N., longitude 114° 30´). Cape Providence, Melville island
(latitude 74° 20´ N., longitude 120° 30´ W.). Winter Harbour,
Melville island (latitude 75° 35´ N., longitude 110° 45´ W.).
Bridgeport inlet, Melville island (latitude 75° N., longitude
109° W.). Skene bay, Melville island (latitude 75° N., longitude
108° W.). Hooper island, Lyddon gulf, Melville island (latitude
75° 10´, longitude 112° W.). Byam-Martin island (latitude 75°
10´ N., longitude 104° 15´ W.). Graham-Moore bay, Bathurst
island (latitude 75° 30´ N., longitude 102° W.). Bathurst
island, Bedford bay (latitude 75° N., longitude 95° 50´ W.).
(Vesicular scoriaceous trap rocks were found here by M’Clintock,
though no such rocks are mentioned elsewhere in connection with
the Carboniferous.) Cornwallis island, McDougall bay. Silurian
and Carboniferous fossils were found together at the last
mentioned place.'————
Professor Haughton also notes that
‘the sandstone of Byam-Martin island is of two kinds—one red,
finely stratified, passing into purple slate, and very like the
sandstone of Cape Bunny, North Somerset, and some varieties of
the red sandstone and slate found between Wolstenholm sound and
Whale sound, West Greenland, latitude 77° N. The other sandstone
of Byam-Martin island is a fine, pale-greenish, or rather
grayish-yellow, and not distinguishable in hand specimens from
the sandstone of Cape Hamilton, Baring island.’
Parry also describes Byam-Martin island as essentially composed of
sandstone, with some granitic and feldspathic rocks, these last being
probably erratics.
Respecting the coal seams which have been discovered in the Arctic
Archipelago, Professor Haughton further remarks:
‘If the different points where coal was found be laid down on a
map, we have, in order, proceeding from the southwest, Cape
Hamilton, Baring island; Cape Dundas, Melville island, south;
Bridgeport inlet and Skene bay, Melville island; Schomberg
point, Graham-Moore bay, Bathurst island; a line joining all
these points is the outcrop of the coal-beds of the south of
Melville island, and runs E.N.E. At all the localities above
mentioned, and indeed in every place where coal is found, it was
accompanied by the grayish-yellow and yellow sandstone, already
described, and by nodules of clay-ironstone, passing into brown
hematite, sometimes nodular and sometimes pisolitic in
structure.’
Dr. Armstrong, of the _Investigator_, referring to the northern part of
Banks island, states that outliers of Carboniferous limestone are found
at Cape Crozier and near Mercy bay, along with the sandstones and shales
with coaly streaks.
It is doubtful if the Carboniferous rocks occur on the northwest part of
North Devon, though placed there by De Rance and Dawson. Schei found
only Silurian and Devonian on the northern part of that island explored
by him, and the Carboniferous rocks do not show on the west coast of
Ellesmere until Store Bjornekap is reached. If a line were carried from
the outcrops of these rocks on Bathurst island northward to Store
Bjornekap it would cross the western part of Grinnell (island)
peninsula, but there is no reason to suppose that the outcrop would
follow such a line.
The Carboniferous rocks of western Ellesmere appear to be isolated areas
resting upon the underlying Devonian, and in turn covered by Mesozoic
rocks. Schei describes the area at Store Bjornekap as consisting in its
lowest part of beds of brownish-gray, hard, fossiliferous limestone;
higher up, of a white pure limestone, flinty limestone and pure flint
strata, richly fossiliferous, among the fossils being _Lithostrotion_
sp., _Fenestella_ sp., _Streptorhynchus crenistria_, _Rhynchonella
(Pugnax)_ sp., _Spirifer_ cfr. _ovalis_, _cuspidatus_, _mosquensis_,
_Productus_ cfr. _semireticulatus_, _costatus_, _punctatus_, _cora_, &c.
The extreme northeast part of Axel Heiberg island is marked as
Carboniferous by Schei, but there are no notes concerning this locality
in his geolocigal summary.
The Carboniferous sandstones have not been found in the northeast part
of Ellesmere island, but limestones of that age were found in several
localities to the west of Dana bay, and there is every likelihood that
rocks of this age extend across the northern part of the island to join
those of the western shore and the northern part of Axel Heiberg island.
MESOZOIC.
The discovery of the Sverdrup group of islands has greatly extended our
knowledge of the Mesozoic rocks of the Arctic basin. The Franklin search
parties discovered rocks of this age on the northern shores of the Parry
islands; at Point Wilkie, in Prince Patrick island; Rendezvous Hill,
near the northwestern extreme of Bathurst island and at Exmouth island
and places in the vicinity, near the northwest part of North Devon. The
explorations from the _Fram_ now show that these are but the southern
edge of a wide basin of these rocks which form the islands of King
Oscar, Ellef and Amund Ringes, while they constitute the lowlands of
Axel Heiberg and the western shores of Ellesmere along both sides of
Eureka sound. There they consist largely of sandstones with shales,
schists and limestones.
As before stated, Schei hints that their eastern extension to the shores
of Kennedy channel may be marked by the tilted and folded strata,
classed by De Rance as the Cape Rawson Series, of supposed Cambrian age.
TERTIARY.
Deposits containing fossil wood were discovered by M’Clintock, M’Clure
and Armstrong in the southwestern part of Prince Patrick island and on
the northwest side of Banks island.
‘At Ballast beach, on Banks land, large quantities of fossil and
sub-fossil wood occur, which Prof. Heer refers to the Miocene in
his Flora Fossilis Arctica, in which the following species are
described by Cramer: _Pinus MacClurii_, _Pinus Armstrongi_,
_Cupressinoxylon pulchrum_, _Cupressinoxylon polyommatum_,
_Cupressinoxylon dubium_, _Betula M’Clintockii_.
In many places along the western side of Ellesmere, in the
depressions between the mountains, thick deposits of sand with
embedded strata of lignite were found. Similar deposits were
found in the lowlands east of Blaamanden, and at the head of
Stenkulfjord in Baumann fjord. In addition to the lignite,
masses of slaty clay were found in the latter place, in which
were well preserved remains of _Sequoia Langsdorfii_, _Taxodium
distichum_ var. _miocenum_ and some others, well known witnesses
to a southern vegetation in these regions in a geologically late
period, i.e., the Miocene.’
The knowledge of the Tertiary deposits of the east side of Ellesmere is
summarized as follows by Dawson:
‘Small outlying areas of Tertiary (Miocene of Heer) are noted as
occurring at Water-course bay, at the entrance of Lady Franklin
sound, and in two places on the north shore of the sound. Coal
is found in these beds in association with black shales and
sandstones, and from collections made by Capt. Fielden and Dr.
Moss, Prof. Heer describes thirty species of plants closely
allied to the Spitzbergen Tertiary flora, and indicating rather
colder conditions than are expressed by the character of the
Disko island Tertiary plants. The coal appears to be an
excellent fuel, containing only 2·01 per cent of water.’
‘Capt. Greely’s expedition (1881 to 1884) though so important in
its results from a geographical point of view, has added
comparatively little to our geographical knowledge of Grinnell
land and the northern coast of Greenland, a fact due to the
absence of a geologist and the enforced abandonment of the
specimens collected. From a careful perusal of Capt. Greely’s
narrative ('Three Years of Arctic Service, 1886'), and from
information obligingly supplied by him and by Lieut. Brainard,
in answer to inquiries made by correspondence, some facts of
importance are, however, brought out. The Tertiary coal-bearing
formation is evidently much more widely spread in the part of
Grinnell land, in the vicinity of Lady Franklin sound, than the
previously quoted map of Messrs. Fielden and De Ranco would
indicate, though it may probably be regarded as forming detached
outliers (which I do not venture to outline) on the Cape Rawson
beds, shown by these authors to characterize the region
generally. Bituminous coal was found at Lincoln bay, half a
degree north of the mouth of Lady Franklin sound, on the east
Grinnell land coast, in different parts of the Bellows valley
(which runs inland to the north of the same sound) to the head,
and in the neighbourhood of Lake Hazen, to the westward, by
Capt. Greely. Lieut. Brainard also describes in an appendix a
fossil forest discovered by him in Archer fiord, a few miles
west of Cape Baird, which, with the associated rocks, is without
doubt referable to the Tertiary. Toward the head of Chandler
fiord (running west of Lady Franklin sound) Greely mentions high
cliffs of ‘schistose slate,’ and in Ruggles river, the outlet of
Lake Hazen, large slabs of ‘slate,’ which had been used by the
Eskimos in building their huts. Brainard speaks of the cliffs of
Beatrix bay as dark, those of Ella bay as very light, in colour.
These bays constitute the termination of Archer fiord. He
remembers the cliffs on Musk-ox valley to have been again of
dark colours. Respecting Greely fiord, on the west coast of
Grinnell land, he quotes from his diary: ‘On the north shore of
this fiord the line of cliffs presents a feature of marked
peculiarity; horizontal lines or strata of different colours run
uniformly for miles along their face.’ He adds: ‘The
predominating colours in these lines and of the cliffs was a
pale-yellow. On the south side, where we were camped, the cliffs
were of about the same colour as those spoken of above, but the
strata were not noticed. They were from 1,500 to 8,000 feet
above the sea-level, and presented a castellated appearance.
Fossils in great numbers were found here.’
To the west of the narrows of Ponds inlet, the high hills of crystalline
rock retreat from the southern shore of the inlet, leaving a wide plain
of stratified sand, gravel and clay, which extends far to the west and
southwest, and is penetrated by a number of deep bays on that side of
the inlet. This plain is indented by all the water-courses traversing
it, and in the beds of the principal streams broken lignite is found,
evidently fallen from beds of that mineral in the banks above. The
presence of lignite in these stratified deposits points to their being
Tertiary in age, and corresponding with the northern areas of this
formation already described as lying undisturbed in the wide valleys of
the older rocks. This area in the northern part of Baffin island is,
according to the natives, quite extensive, and probably extends in a
southwest direction to the lowlands of the northern and western sides of
Fox channel.
Capt. Adams, of the whaler _Diana_, said that lignite was to be found in
similar deposits near Cape Hay, on the east side of Bylot island, and
also at Durban island on the eastern coast of Baffin island. There is
little doubt that other areas of these Tertiary deposits occur on the
Arctic islands, but owing to no lignite or fossils having been found in
them they have not been separated from the drift and newer Post Tertiary
deposits of sand, gravel and clay of these coasts.
If Tertiary deposits were laid down on the lands of the western side of
Hudson bay, there is little chance of more than small protected areas
having escaped the intense glaciation to which the western shores of the
bay were subjected. Any such remaining areas are now probably hidden
beneath the mantle of drift so universal on the low lying portions of
this region.
POST TERTIARY.
Little or no attention was given by the earlier explorers to the
markings of ice-striae and other glacial phenomena, and the only records
of the movement of the glacial ice noted by them was the distribution of
erratic boulders. These observations have been summarized by Dawson as
follows:
‘Along the Arctic coast, and among the islands of the
archipelago, there is a considerable volume of evidence to show
that the main direction of movement of erratics was northward.
Thus, boulders of granite supposed by Prof. Haughton to be
derived from North Somerset are found 100 miles to the
northeastward, and pebbles of granite, identical with that of
Granite point, also in North Somerset, occur 135 miles to the
northwest. The east side of King-William land is also said to be
strewn with boulders like the gneiss of Montreal island, to the
southward. Prof. Haughton shows the direction and distance of
travel of some of these fragments by arrows on his geological
map of the Arctic archipelago, and reverts to the same subject
on pages 393-394, pointing out the general northward movement of
ice indicated, and referring the carriage of the boulders to
floating ice of the glacial period.’
‘Near Princess Royal island, in Prince of Wales strait, and also
on the coast of Prince of Wales island, the copper said to be
picked up in large masses by the Eskimos may be supposed to be
derived from the Cambrian rocks of the Coppermine river region
to the south, as it is not probable that it occurs in place
anywhere in the region of horizontal limestone where it is
found.’
‘Dr. Armstrong, previously quoted, notes the occurrence of
granitic and other crystalline rocks, not only on the south
shore of Baring land, but also on the hills inland. These, from
what is known of the region, can scarcely be supposed to have
come from elsewhere than the continental land to the southward.’
‘In an account of the scientific results of the _Polaris_
expedition, it is stated of the west coast of Smith sound, north
of the Humboldt glacier, that “wherever the locality was
favourable the land is covered by drift, sometimes containing
very characteristic lithological specimens, the identification
of which with rocks of South Greenland was a very easily
accomplished task. For instance, garnets of unusual large size
were found in latitude 81° 30´, having marked mineralogical
characters by which the identity of some garnets from
Tiskernaces was established. Drawing a conclusion from such
observations, it became evident that the main line of the drift,
indicating the direction of its motion, runs from south to
north.”’
Dr. Bell in his report on the geology of Hudson bay and Hudson strait,
1885, draws attention to the flow of the ice from the land on both sides
of the strait into that body of water, while the striæ on the islands in
the strait show that a great stream of ice passed eastward through the
strait from Hudson bay into the north Atlantic. These observations have
since been confirmed by observations of the striæ on other islands of
the strait.
Tyrrell’s observations on the glacial phenomena of the barren-land
region west of Hudson bay show that the country was intensely glaciated;
that the centre of glaciation was on a nearly level plain now elevated
some 400 or 500 feet above sea-level, there being no evidence to show
that it was much more elevated during the period of glaciation. The
centre of ice distribution was situated close to the western shores of
Hudson bay, and the moisture sufficient to allow of such an accumulation
of ice was probably derived from an open Arctic sea. The glacier moved
south and southwest from this centre up a gradual grade to Manitoba,
where morainic accumulations are found on the summits of the Duck
mountains at elevations from 1,800 to 2,400 feet above present
sea-level. Striæ evidently formed by moving ice from this centre have
been found by Dr. Barlow and the writer on the branches of the Moose
river to the south of James bay, where the movement was from the
northwest.
There is little doubt that the ice also moved northward from the centre
of glaciation, and that the evidence quoted above of the erratics found
in the western Arctic islands is proof of this.
From a study of the different sets of glacial striæ, Tyrrell concluded
that the centre of glaciation was, in the early part of the glacial
period, somewhere to the north and west of the head of Chesterfield
inlet; that later, when the ice increased in thickness, the centre of
dispersion moved to a position southwest of Baker lake; while as the
glacier diminished the centre moved nearer the seashore, and the final
stage was probably represented by the ice-cap breaking up into a number
of distinct glaciers, each with local movement of its own.
These conclusions of Tyrrell as to the southern movement of the centre
of glaciation are borne out by the writer’s observations of the striæ
along the shores of Roes Welcome, where as many as six sets of striæ
were found at Whale point, the usual number being three. The oldest set,
found only at Whale point, showed that the ice movement was from the
northwest. The next in age were from N. 50° E., or almost at right
angles to the oldest; following in order of age come striæ from N. 25°
E., N., N. 30° W., and N.W. The last three sets are found in a number of
places between Winchester inlet and Whale point; the others only at
Whale point. The direction of the above sets of striæ apparently shows
that the earliest accumulation of ice in the region north of the western
side of Hudson bay was somewhere to the northwest; this was followed by
an abrupt change in the ice-movement, which was next from almost
northeast, after which the centre of movement of the ice-cap gradually
shifted, by way of north, to northwest. It would also appear that the
centres of dispersion were much greater in area than the limits placed
upon them by Tyrrell.
This southern movement of the centre of dispersion of the ice is
diametrically opposite to what occurred in the case of the ice-cap of
Labrador, where the striæ along the east side of Hudson bay show that
the centre of ice-movement changed from a position near the central area
of the peninsula, a short distance north of the southern watershed, to
one some three hundred miles north, in the vicinity of the headwaters of
the Koaksoak river.
The glaciation of Labrador seems to have been later than that of the
western side of Hudson bay, as the striæ from the western glacier are
almost obliterated by those from the east and northeast along the rivers
south of James bay.
There is a marked difference in the evidence of the intensity of glacial
action between the southern regions and the eastern and northern
portions of the great area embraced in this report. On the shores and
islands of Hudson bay and Hudson strait the crystalline rocks have been
denuded of every trace of rotted surface material; they have been
smoothed, polished and intensely striated, and their present condition
is such that little or no change has taken place since the disappearance
of the ice, which once covered them deeply, the striæ being so fresh as
to appear of the formation of yesterday. When the eastern mouth of
Hudson strait is left, a change is soon seen in following the eastern
side of Baffin island northward. The hills are less rounded, and talus
lies on the slopes of the cliffs; about Cumberland gulf and Cyrus Field
bay there is evidence of a universal ice-cap having been present, but
the rounding, polishing and striation of the rocks are markedly less
than to the south and westward. In these places it is exceedingly
difficult to find striæ upon the rock surfaces, and these when found
show that the movement was local and from the highlands towards the open
sea. In the northern part of Baffin island the hills become more
serrated in outline, and many of the higher points appear to have never
been subjected to glaciation, the glaciers having only filled the
valleys; if an ice-cap existed the ice-movement to the coast was
determined by the course of the local valleys, and there is no evidence
of a movement not depending upon local conditions as is the case in the
region about Hudson bay. At Erik harbour, on the south side of the mouth
of Ponds inlet, there is evidence that the glacier which now terminates
at the head of the harbour once extended five miles farther seaward, and
filled the valley to a height of 400 feet above the present level of the
sea. Above that height the rocky walls of the harbour are not glaciated,
and are covered by slopes of disintegrated rock. Passing north of
Lancaster sound to the south of North Devon, there is little evidence to
show that the glaciation was ever much more severe than at present. At
Cuming creek, a narrow fiord cut some twelve miles into the limestone
cliffs, there is evidence that a glacier once covered its bottom, and
rose some two or three hundred feet above the present level of the sea;
but it was purely local, and the limestone cliffs everywhere show that
they have been long subjected to subaerial denudation, and that the
broken rock covering their sides has never been displaced by ice.
Very little time was given to the study of glaciation at Cape Sabine,
and the only evidence to show that it was more intense formerly was a
low moraine in the rear of Peary’s house at Payer harbour. Schei, who
devoted considerable attention to the glaciation of Ellesmere, is of the
opinion that the ice covering never greatly exceeded its present limits,
if it did so at all.
MARINE TERRACES.
Marine terraces are found along the coasts of the northern mainland and
islands wherever the conditions are suitable. Fronting the highlands
about Wager inlet and Repulse bay, on the western side of Hudson bay,
terraces are found cut into the drift deposits up to elevations varying
from 500 to 700 feet. The highest terrace seen by Dr. Bell on the north
side of Hudson strait had an elevation of 528 feet above the present
sea-level. At Cape Wolstenholme, on the south side of the western
entrance to Hudson strait the terraces rise to 800 feet above the sea.
At Douglas harbour on the same side and near the middle of the strait
the highest terraces noted were little over 400 feet. Along the eastern
shores of Baffin island terraces were constantly seen, which were
estimated to rise from 500 to 700 feet above the sea. Schei found
terraces with Post-Pliocene fossils at an elevation of 650 feet along
the shores of Ellesmere.
The foregoing evidence shows that at the close of the period of maximum
glaciation an uplift occurred to the land throughout the northeastern
Arctic region. This uplift is marked by the terraces existing on all the
shores, but they fail to agree with the theory that the uplift was
greatest where the accumulation of ice was greatest. There appears to be
no great difference in the height of the terraces in Ellesmere, where
the glaciation, never excessive, remains in nearly the same state as
when it was at its maximum thickness and of those about the shores of
Hudson bay, where an enormous thickness of ice once covered the land and
has now entirely disappeared.
The uplift, which took place in comparatively recent times, geologically
speaking, does not appear to be going on at present, as all the
historical evidence relating to the Hudson bay region points to a
remarkable stability in the coastal regions from the time of the first
records dating back to the voyage of Munck in 1619.
The present glacial conditions of the Arctic islands has been noted in
another part of this report, and it need only be here stated that the
lands fronting upon Hudson bay and Hudson strait are now free from
glaciers, the nearest approach being the occurrence of detached snow
banks in protected positions, which remain throughout the year. The most
southern glacier is the Grinnell glacier situated on the north side of
the high land separating Hudson strait from Frobisher bay, and plainly
seen crowning the summit of the north shore of Hudson strait for a
distance of more than fifty miles. This glacier is not very active, and
is said to discharge only a few small icebergs into one of the fiords on
the south side of Frobisher bay. Passing northward along the eastern
coast of Baffin island, the snow patches upon the hills become larger
and more numerous, but it is not until Cumberland gulf is passed that
real glaciers appear in the valleys leading down to the sea. These are
not very active, and seldom shed icebergs except on the northern part of
the island. Active glaciers are found along the southern side of North
Devon westward to the neighbourhood of Cuming creek, west of which the
ice-cap retreats, and the shores and cliffs are free of ice. The valleys
of the eastern and southeastern coasts of Ellesmere are filled with
active glaciers that discharge many large icebergs. In the southwestern
part the glaciers are not very active, and usually terminate at a
considerable distance from the sea.
ECONOMIC MINERALS.
With the exception of the area of iron-bearing rocks on the islands
along the east coast of Hudson bay, no systematic prospecting has been
done for minerals in the wide region covered by this report. Active
mining at the present is confined to a mine of mica, situated at Lake
harbour, on the north side of Hudson strait, a few miles east of Big
island. Earlier mining consisted of the extraction of small quantities
of coal from the outcrops of that mineral on Melville and Ellesmere
islands by expeditions wintering there. Our knowledge of the minerals
extends only to the chance observations of the earlier explorers, and to
the hurried examinations made by members of the staff of the Geological
Survey in the southern parts of the region under consideration.
The occurrence of Laurentian and Huronian rocks over large portions of
the area, both on the islands and mainland, leads to the belief that
important mineral deposits exist there in the same manner as in more
southern regions of similar rocks; in fact, specimens of the more
important minerals are reported from the north.
_Gold._—The occurrence of gold is reported only from the head of Wager
inlet, where specimens of free gold were found in the dark rocks of that
locality by Dr. Rae.
The presence of large areas of undisturbed Tertiary sands and clays in
the northern part of Baffin island and elsewhere are favourable to the
accumulation of placer gold deposits, if the precious metal occurs in
the underlying Laurentian and Huronian rocks. It would be well to test
the beds of the streams flowing through these deposits when they are
again visited.
_Silver._—A small quantity of silver is found in the galena, which
occurs in pockets in the limestone along the Whale river coast on the
east side of Hudson bay. The amount of galena is small, and so widely
scattered that it would probably be unprofitable to mine even in
favourable circumstances.
_Copper._—Tyrrell discovered large masses of Huronian rocks along the
western shores of Hudson bay, to the south of Marble island. In these
were many bands and masses of dark schists, all carrying quantities of
iron and copper sulphides. Of these deposits he reports as follows:
‘At a point northeast of Rabbit island the character of the
shore changes, and dark-green Huronian schists crop out from
beneath the boulders.’
‘North of Rabbit island is a high point, on which the Eskimos
are accustomed to camp while waiting for the traders from
Churchill. The point is composed of green calcareous, chloritic
schist, striking S. 55° W., and dipping N. 35° W. at an angle of
60°. The schist is cut by a dike seventy-five feet wide, of
massive green, highly altered diabase, containing a large amount
of mispickel. This diabase also outcrops along the shore, where
it incloses many bands of schists.’
‘The rock at the point south of Corbett inlet is a massive
green, fine or medium-grained diabase, which is now almost
entirely altered into a mass of chlorite, epidote, zoisite and
calcite.————This diabase is cut by many small veins of
quartz and calcite, which contain large quantities of pyrite,
arseno-pyrite and chalcopyrite.’
‘From Term point westward the shore is rocky, and the steep
rocky cliffs descend into rather deep water. The rock is a
dark-green diabase almost entirely altered to sausserite, and is
cut by many veins of quartz and calcite, holding
copper-pyrites.’
‘On the northern shore of Mistake bay, nine miles west of Term
point, is a long point of similar diabase. Seven miles further
southwest, about the middle of the west shore of Mistake bay, is
a high point of similar dark-green diabase, containing in many
places a large amount of copper-pyrites, and cut by small veins
of quartz studded with iron pyrites.’
‘Two miles south of Sir Biddy island is a prominent rocky point,
with a high rocky island lying a short distance off it. From
this prominent point the shore turns westward, and is bold and
rocky, being composed of dark-green fine-grained diabase,
studded with copper-pyrites.’
The above extracts from Tyrrell’s report show that on his hurried
journey southward from Chesterfield inlet he found Huronian rocks
occupying the shores of the bay for a distance of nearly a hundred
miles. At haphazard landings along this shore traces of copper deposits
were found in a number of places, and these would point to important
discoveries as likely to follow systematic search on this area.
A considerable amount of magnetic pyrites was found in the squeezed
diabase rocks along the east coast of Hudson bay, but careful analyses
failed to show any contained gold, nickel or copper in a number of
specimens from various localities on that coast, and it is highly
probable that no important deposits will be found in the basic rocks of
that side of the bay.
Small quantities of copper-pyrites were observed in the diabase schists
of the south side of Hudson strait, but never in sufficient amounts to
constitute mines of that mineral.
I was informed by Captain Adams, of the whaler _Diana_, that he had
picked up specimens of copper ore lying loose on the surface a few miles
in rear of Clyde river on the east coast of Baffin island.
Among the specimens brought home by Hall from Frobisher and Cyrus Field
bays, in the southeast part of Baffin island, were bornite and pyrite,
showing that copper ores also occur in that portion of the island.
_Iron._—Mention has been made of the iron ores on the west shores of
Ungava bay, on the north side of Payne river. The rocks in which these
ores are found have been altered by the intrusion of granites. They now
consist of quartzites, mica-hornblende schist and crystalline limestone,
and are the metamorphic representatives of the unaltered iron-bearing
rocks of the interior of Labrador peninsula and the east coast of Hudson
bay. In localities where the rocks are unaltered the iron ores occur
either as carbonates in a cherty rock, or as a mixture of magnetite and
hematite intimately associated with chert and jasper. At Payne river the
iron-bearing beds have a thickness of 420 feet. The upper 70 feet is a
light-yellow, fine granular quartzite containing patches of ankerite and
lime. Towards the top the rock shades to a dark bluish-gray, from the
presence of large quantities of magnetite in small flattened grains,
together with small scales of specular iron. These are usually mixed
with quartz with evidence of foliation, and at other places are in large
masses of nearly pure ore. Underlying these beds is 350 feet of
dark-bluish slaty quartzite holding considerable magnetite and hematite,
and shading upwards into a barren quartzite. Most of the ore of this
locality would probably require separation and concentration from the
admixed quartz before being of a grade sufficiently high for smelting.
The position of the deposits on the west side of Ungava bay, where the
tide rises and falls forty feet or more, is not very promising for
shipping.
More attention has been given to the iron deposits of the east side of
Hudson bay than to any other of the mineral deposits of the north. In
1877, Dr. Bell explored the east shore of Hudson bay as far north as
Cape Dufferin, and in his report on this exploration called attention to
the deposits of iron ore found in a bedded series of rocks, chiefly
sandstones, cherts and dolomites. These rocks he found forming the
islands along that coast from Cape Jones, at the mouth of James bay, to
Cape Dufferin, some 300 miles farther north. A strip of the same rocks
occupies the mainland from the vicinity of Great Whale river to beyond
the head of Richmond gulf, a distance of 120 miles.
The iron ores of value were found to be confined to the Nastapoka chain
of islands, which extend northward from Little Whale river for a
distance of 100 miles.
A further examination of these iron-bearing rocks was made by the writer
during the summers of 1898 and 1899, and more closely during the summers
of 1901 and 1902 when engaged in this work for a private company.
These iron-bearing rocks of the east side of Hudson bay have a close
resemblance to those of Lake Superior, so famous for the amount and
quality of their associated ores of iron. They consist of bedded
sandstones, cherts, shales, graywackes and dolomites, associated with
great outflows and sills of trap. The following general section of the
rocks of the Nastapoka islands will give a good idea of the rocks there,
while on the mainland other strata, free from or poor in iron, are
found.
Descending order:—
feet.
1. Rusty weathering, dark gray, siliceous
rock containing ankerite (carbonate of
iron and magnesia) and magnetite 20 to 100
2. Dark gray siliceous rock, containing
magnetite with small quantities of
ankerite 50 to 250
3. Red jaspilite rich in hematite ore 10 to 100
4. Red jaspilite poor in hematite ore 5 to 20
5. Purple or greenish weathering,
dark-green graywacke shales 10 to 70
6. Red jaspilite poor in hematite ore 0 to 5
7. Light greenish-gray sandstone and shale 10 to 300
8. Fine grained dolomite 0 to 50
The iron ores have a greater thickness and are richer on the islands in
the middle of the chain than elsewhere.
The rusty weathering, dark-gray siliceous rocks of division I. are found
on all the islands from Flint to McTavish, being wanting only on Cotter
island. The typical rock is a dark-gray chert made up of finely divided
silica showing under the microscope small grains of quartz filled in by
later accessions of that material in a finely divided state. It contains
minute crystals of magnetite scattered through the mass, and also
patches of crystalline carbonates. At the southern end of the chain it
is cherty and sometimes light-green in colour. These rocks are usually
in thin beds, the parting between the beds filled with brownish
ankerite, which also occurs in flat lenticular masses inclosed in the
cherts; many of these masses are several inches in thickness and several
square feet in area, so that the rock usually contains from twenty to
fifty per cent of ankerite. These ores are too much broken and too
intimately mixed with the cherts for profitable mining. The rusty
character of the rock is due to surface decomposition of ankerite to
limonite. The beds increase in thickness as the islands are followed
northward, and reach their maximum development on Davieau island and
northward to McTavish island, where they have a thickness of fifty feet.
These measures can be traced southward from the Nastapoka chain in the
outer islands lying along the coast for upward of 150 miles, being last
seen on Long island just north of Cape Jones, where they are overlaid by
a considerable thickness of trap.
The second division of the section is an arbitrary one, and was made to
embrace all the beds containing important deposits of magnetite. The
upper beds of the division grade into those of division I, while the
lower pass gradually into division III.
The typical rock of these measures is a dark-gray, fine-grained variety
of quartzite chert, containing considerable magnetite scattered through
it in minute crystals; it also contains small quantities of carbonates
of iron, magnesia and lime. The beds are usually thin (from one to
twelve inches) and the partings between them are filled with a mixture
of silica and magnetite with small quantities of ankerite. These
partings vary in thickness, but are generally thin between the upper
beds of the division, and quite thick (six inches to forty-eight inches)
towards the bottom, where they form important ores of iron; as the beds
of chert are often quite thin between two or more thick partings of ore,
they might easily be neglected in mining. The mixture of silica and
magnetite in the ore is an intimate one, with the silica usually in a
finely divided state.
The proportion of these substances is not constant, so that the ores
vary from a lean ferruginous chert to a rich ore containing upwards of
sixty per cent of iron. Large quantities of the better ores occur in the
lower beds of the division. The occurrence of these ores between the
beds of gray siliceous rock, and their intimate association with finely
divided silica, point to their deposition and enrichment from the
infiltrations of waters carrying solutions of iron and silica which were
deposited in the waters in cracks and between the bedding of the
already-formed siliceous rocks. This mode of formation has been
described by Van Hise for similar ores in the Lake Superior region.
On the three southern islands of the chain there is a gradual change in
the nature of these measures. They pass into a brownish-black siliceous
shale, rich in iron and containing considerable carbon as small scales
of graphite. This is the form in which they are found to the southward
on the islands as far as Long island. The thickness of the division is
very constant on the islands northward to McTavish, but it does not
occur on Cotter island.
The rocks belonging to the third division, as before stated, grade into
the division above them, and the line between them cannot be drawn
sharply.
The typical rock of the division is fine-grained and very siliceous,
with minute particles of silica coated with red oxide of iron, forming a
coarse impure red jasper.
These jasper rocks usually occur in thin broken bands, the partings
between them being filled with a finely-divided mixture of hematite,
magnetite and jasper. The hematite is greatly in excess of the
magnetite. The association of the iron ores and the jasper is intimate,
and they must have been deposited simultaneously from aqueous solutions
probably leached from the cherty carbonate measures above. Microscopic
sections from these rocks are almost identical with those of jaspilite
figured by Van Hise in his monograph on the iron-bearing rocks of the
Lake Superior region; and they must have had the same origin that he has
assigned to these rocks, namely, enrichments deposited by water
subsequent to the formation of the bedded rocks in which they are found
as partings, and filling the most minute cavities.
The amount of ore in this admixture of hematite and jasper varies
greatly. Where the ore is poor, the jaspery rock predominates and
incloses lenses of hematite, while where the hematite is most plentiful
it incloses similar lenses of jasper. The detailed description of these
rocks shows that the measures of this division contain an immense amount
of hematite. The rocks of the division do not occur on all the islands,
being wanting on Flint, Belanger and Ross. On Anderson they are
represented by a few thin beds not rich in ore, while on Clarke they
form the summit of the section with a thickness of eighty feet. They
reach their maximum development on Gillies and Taylor, where their ores
are richest and most concentrated. Farther northward they become thinner
and poorer in ore, being twenty feet thick on Davieau and only eight
feet thick on McTavish, where they die out. No trace of these measures
is found underlying the upper rocks on the islands south of the
Nastapoka group.
The fourth division, consisting of red jaspilites, is an arbitrary one,
of use only as a subdivision of the iron-bearing rocks. Wherever the
jaspilites are well developed the richer beds are underlain with leaner
measures, unfit for working, and these poorer ores constitute this
division. On Clarke island these beds are twenty feet thick; on Gillies
they vary from ten to twenty feet in thickness, on Taylor they are ten
feet, while to the northward they merge into the overlying division, all
poor in iron ores.
The richest ores are found in division III, where extensive beds several
feet in thickness are found containing ore practically free from jasper,
and ranging in iron values from thirty per cent to sixty per cent. Most
of these ores, however, would require separation from the bands and
lenses of jasper before becoming sufficiently rich to be economically
treated in the furnace. The position of the ores on the islands
separated from the mainland by a sound varying from a mile to four miles
in width, with excellent, almost tideless, harbours, constitute ideal
conditions for shipment. The mining of the ores would also be easy and
cheap, if advantage were taken of the great waterpower of the Nastapoka
river, which falls 160 feet into the sea within a few miles of the best
ore deposits, and from which electrical power might be generated easily
and cheaply. Owing to the distance of these ores from the nearest
furnaces, and the want of experience in the navigation of Hudson strait,
the shipment of them is at present out of the question. No coal is found
in Hudson bay, so that economical smelting near the mines cannot be
attempted, until electrical smelting becomes practicable some time in
the future.
In all the fields where extensive areas of iron-bearing rocks occur in
the Lake Superior region, the search by drilling has disclosed large
deposits of concentrated ore, and there is little doubt that such a
search in the Hudson bay region would lead to similar discoveries, as
the manner in which the ores occur is favourable for such
concentrations.
_Mica._—Active mining operations for mica are being carried on at Lake
harbour, on the north side of Hudson strait. This mine is being worked
in connection with the whaling steamer _Active_. A number of white men
are brought to the place from Scotland in the early summer, who, with
the assistance of the Eskimos, work the mine, and then return home in
the fall. Last summer thirteen tons of excellent mica were taken out in
this manner. Other deposits of this mineral will probably be found on
that coast to the westward in association with the crystalline
limestones so largely developed there. A mica mine was opened some years
ago on the west side of Cumberland gulf, but for some reason was shortly
after abandoned.
_Graphite._—Extensive bands, or veins, of this mineral were discovered
by Mr. Caldwell to the south of Port Burwell along the east shore of
Ungava bay. Graphite has also been found in the neighbourhood of Cape
Wolstenholme, and along the east side of Baffin island, but no attempt
has been made to develop any of the outcrops.
_Molybdenite._—Flattened crystals of molybdenite have been found in
many localities in the pegmatite veins penetrating the Laurentian rocks,
but in no place has the quantity been sufficient for mining.
There is no doubt that the combined areas of Carboniferous and Tertiary
coals are very extensive, and that they would form a valuable addition
to the mineral wealth of the Dominion if they were located in a more
accessible region. Situated as they are in the northern Arctic islands,
where navigation is at all times uncertain and unusually perilous, it is
very doubtful if they will ever prove of economic value.
_Lignite._—Attention has been drawn to the occurrence of lignite of an
excellent quality in the sand and clay deposits of Tertiary age along
the northern and eastern shores of Baffin island and on the east side of
Bylot island.
Little is known of these deposits, as the only information concerning
them is derived from small float specimens picked from the beds of the
streams that flow over these sands and clays. These lignites probably
correspond to the bituminous coal found in the folded Tertiary rocks of
the far north, and may prove to be quite extensive and of economic
value, as the localities at which they have been found, although within
the Arctic circle, are by no means so dangerous of access as the coal
beds of the north.
_Coal._—The presence of extensive deposits of coal on the island north
of Lancaster sound has already been mentioned in the discussion of the
Carboniferous and Tertiary formations of the northern islands. The
Carboniferous rocks cover all the western islands of the Parry group,
and extend northwesterly into the northwest part of Ellesmere. Parry
first discovered coal in the cliffs at Winter harbour on Melville
island, and used it for fuel on his ships. The Franklin search parties
later found outcrops of coal in other places along the southern and
eastern shores of that island and in the cliffs of Bathurst island.
These outcrops of coal indicate that the seams seen in the southern
cliffs will be found extending inland over the greater portion of the
islands, where they are covered by several hundred feet of newer rocks.
No coal has been found in the Carboniferous rocks of Ellesmere island.
The mineral occurs in thin beds along with sandstones and shales, and is
a good quality of bituminous coal.
In the folded Tertiary rocks found in the vicinity of Lady Franklin
sound on the west side of Kennedy channel several outcrops of excellent
bituminous coal have been discovered. The beds in the neighbourhood of
Fort Conger have been mined along the outcrop and used for fuel by the
Nares expedition and by Greely and Peary.
[Illustration: SCOTTISH WHALER ‘ECLIPSE.’]