III.--_The Carboniferous Rocks._
The Upper Silurian limestones already described are succeeded by a most remarkable series of close-grained white sandstones, containing numerous beds of highly bituminous coal, and but few marine fossils. In fact, the only fossil sh.e.l.l found in these beds, so 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 the marine sh.e.l.ls 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 Silurians 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.
The following lists contain the princ.i.p.al fossils and specimens presented to the Royal Dublin Society by Captain M"Clintock and by Captain Sir Robert M"Clure.
Coal, sandstone, clay ironstone, and brown hemat.i.te, were found along a line stretching E.N.E. from Baring Island, through the south of Melville Island, Byam Martin"s Island, and the whole of Bathurst Island. Carboniferous limestone, with characteristic fossils, was found along the north coast of Bathurst Island, and at Hillock Point, Melville Island.
I have marked on the map the coal-beds of the Parry Islands, which appear to be prolonged into Baring Island, as observed by Captain M"Clure. The discovery of coal in these islands is due to Parry, but the evidence of the extent and quant.i.ty in which it may be found was obtained during the expeditions of Austin and Belcher. In addition to the localities surveyed by himself, Captain M"Clintock has given me specimens of the coal found at other places by other explorers; and it is from a comparison of all these specimens that I have ventured to lay down the outcrop of the coal-beds, which agrees remarkably well with the boundary of the formations laid down from totally different data.
No. I. HILLOCK POINT, Melville Island (Lat 76 N.; Long. 111 45" W.).
_Productus sulcatus._ Journ. R. D. S., Vol. I. Pl. VII. Figs. 1, 2, 3, 4, 7.
_Spirifer Arcticus._ Journ. R. D. S., Vol. I. Pl. IX.
No. II. BATHURST ISLAND, North Coast, Cape Lady Franklin (?) (Lat. 76 40" N.; Long. 98 45" W.).
_Spirifer Arcticus._ Journ. R. D. S., Vol. I. Pl. IX. Fig. 1.
_Lithostrotion basaltiforme._
[34]No. III. BALLAST BEACH, Baring Island (Lat. 74 30" N.; Long. 121 W.).
1. Wood fossilized by brown hemat.i.te; structure quite distinct.
2. Cone of the spruce fir, fossilized by brown hemat.i.te.
No. IV. PRINCESS ROYAL ISLANDS, Prince of Wales" Strait, Baring Island (Lat. 72 45" N.; Long. 117 30" W.).
1. Nodules of clay ironstone, converted partially into brown hemat.i.te.
2. Native copper in large ma.s.ses, procured from the Esquimaux in Prince of Wales" Strait.
3. Brown hemat.i.te, pisolitic.
4. Greyish yellow sandstone, same as Cape Hamilton and Byam Martin"s Island.
5. _Terebratula aspera_ (Schlotheim). Journ. R. D. S., Vol. I. Pl.
IX. Fig. 4.
This interesting brachiopod was found in the limestone by Captain M"Clure, at the Princess Royal Islands, in the Prince of Wales" Strait, between Baring Island and Prince Albert Land. I have no hesitation in p.r.o.nouncing it to be identical with Schlotheim"s fossil, which is found in the greatest abundance at Gerolstein, in the Eifel. Banks Land, or Baring Island, is composed of sandstone, similar to that at Byam Martin"s Island, and at the Bay of Mercy. This sandstone contains beds of coal, apparently the continuation of the well-known coal-beds of Melville Island. It is a remarkable fact, that these carboniferous sandstones _underlie_ beds of undoubtedly the carboniferous limestone type, and that at Byam Martin"s Island, where fossils are found in this sandstone, they are allied to _Atrypa fallax_ and other forms characteristic of the lower sandstones of the carboniferous epoch. It is, therefore, highly 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, which rest on the summit of the carboniferous beds. It is interesting to find at Princess Royal Island, where, from the general strike of the beds, we should expect to find the Silurian limestone underlying the coal-bearing sandstones, that this limestone does occur, and contains a fossil, _T. aspera_, eminently characteristic of the Eifelian beds of Germany, which form, in that country, the Upper Silurian Strata.
No. V. CAPE HAMILTON, Baring Island (Lat. 74 15" N.; Long. 117 30"
W.).
1. Greyish-yellow sandstone, like that found _in situ_ in Byam Martin"s Island.
2. _Coal._--The coal found in the Arctic regions, excepting that brought from Disco Island, West Greenland, which is of tertiary origin, presents everywhere the same characters, which are somewhat remarkable. It is of a brownish color and ligneous texture, in fine layers of brown coal and jet-black glossy coal interstratified in delicate bands not thicker than paper. It has a woody ring under the hammer, recalling the peculiar clink of some of the valuable gas coals of Scotland. It burns with a dense smoke and brilliant flame, and would make an excellent gas coal; and, in fact, it resembles in many respects some varieties of the coal which has acquired such celebrity in the Scotch and Prussian law-courts, under the t.i.tle of the Torbane Hill mineral.
No. VI. CAPE DUNDAS, Melville Island (Lat. 74 30" N.; Long. 113 45"
W.).
Fine specimens of coal.
No. VII. CAPE SIR JAMES ROSS, Melville Island (Lat. 74 45" N.; Long.
114 30" W.).
Sandstone pa.s.sing into blue quartzite.
No. VIII. CAPE PROVIDENCE, Melville Island (Lat. 74 20" N.; Long. 112 30" W.).
A specimen of crinoidal limestone, apparently similar to that occurring in Griffith"s Island, from which, however, it could not have been brought by the present drift of the floating ice, as the set of the currents is constant from the west. If brought to its present position by ice, it must have been under circ.u.mstances differing considerably from those now prevailing in Barrow"s Strait.
Yellowish-grey sandstone.
Clay ironstone pa.s.sing into pisolitic hemat.i.te.
No. IX. WINTER HARBOR, Melville Island (Lat. 74 35" N.; Long. 110 45"
W.).
Fine yellow and grey sandstone.
No. X. BRIDPORT INLET, Melville Island (Lat. 75 N.;, Long. 109 W.).
Coal, with impressions of Sphenopteris.
Ferruginous spotted white sandstone.
Clay ironstone, pa.s.sing into brown hemat.i.te.
No. XI. SKENE BAY, Melville Island (Lat. 75 N.; Long. 108 W.).
Bituminous coal, with finely divided laminae, a.s.sociated with brown crystalline limestone, with cherty beds, and grey-yellowish sandstone, pa.s.sing into brownish-red sandstone.
No. XII. HOOPER ISLAND, Liddon"s Gulf, Melville Island (Lat. 75 5" N.; Long. 112 W.).
Nodules of clay ironstone, very pure and heavy, a.s.sociated with ferruginous fine sandstone and coal of the usual description.
The hill-tops and sides along the south sh.o.r.e of Liddon"s Gulf, and as far as Cape Dundas, are generally bare, composed of frozen mud, arising from the disintegration of shale, the annual dissolving snows washing them down and giving them a rounded form. The southern slopes generally support vegetation. Fragments of coal are very frequently met with, and at the mouth of a ravine on the south sh.o.r.e of Liddon"s Gulf there is abundance, of very good quality; it contains a considerable quant.i.ty of pyrites or bisulphuret of iron.
No. XIII. BYAM MARTIN"S ISLAND (Lat. 75 10" N.; Long. 104 15" W.).
Yellowish-grey sandstone, _in situ_, containing a ribbed _Atrypa_, allied to the _A. primipilaris_ of V. Buch, and the _A. fallax_ of the carboniferous rocks of Ireland.
Reddish limestone, with broken fragments of sh.e.l.ls, of the same description of brachiopod as the last.
Coal of the usual description.
Fine-grained red sandstone, pa.s.sing into red slate.