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Published online by Cambridge University Press: 01 May 2009
When we speak of Newfoundland, we speak of England's oldest and yet almost unknown Colony. When we look at its rocks, we shall find that they also are old, and from the metamorphisms and contortions they have suffered are almost unrecognizable. The first geologist who journeyed round the rugged shores which gird the island, and across the marshes and thickets which cover its interior, was the indefatigable Jukes.
page 252 note 1 I cannot see upon what grounds Prof. Judd founds this remark. The valley of the Great St. Lawrence, including the magnificent champaign regions of Western Canada, now called Ontario; is based upon Silurian rocks for the greater part, the highest formation being of Devonian age; the beautiful valley of Stratheam, in Perthshire, is upon Old Red Sandstone; the valley of the Forth, Stirlingshire, is Carboniferous; and a great part of Herefordshire, Monmouth, etc., is Lower Silurian. It seems to me, that the capabilities of a country, for the support of life, depend, not upon their actual position in the geological sequence; but upon the constituents of which they are composed, and the mineral character of the debris which is yielded by their ruins, and spread over the surface; and also in great measure to the degree of metamorphism and disturbance by which they have been affected.—A.M.
page 252 note 2 The crystalline limestone bands of Lower Laurentian age, so well known in Canada, have not been seen in place, in Newfoundland; but I have reason to think they exist to a partial extent in the valley of the great Cordroy River. About thirty miles up that valley I found large angular fragments of white crystalline limestone, with, graphite, which exactly resembled the Canadian rocks; and in front of the position they were supposed to occupy the hills are composed of labradorite, which I assume to be of Upper Laurentian age.—A.M.
page 253 note 1 These are in erratic blocks, more or less water-worn; their source is not known.—A.M.
page 253 note 2 I object to the term Cambrian, as applied to Huronian, and I introduced the name Intermediate, because the system is undoubtedly intermediate between the Laurentian and the lowest beds of Primordial strata, holding Paradoxides, Agraulus, Archœoeyathus, Iphidea, Agnoslus, Conocephatites, Obolella, and many other forms typical of the lowest Palœozoic fauna. I have shown that the Intermediate or Huronian system, must have been worn through by denudation to the very base, previous to the deposition of the beds holding the above-named fauna; as we find them occurring nearly undisturbed overlapping the Laurentian and lower beds of the Huronian. I pointed my evidences out to my old friend and colleague, Sir William Logan, on the ground, who was immediately convinced of the accuracy of my observations. I have also shown that there are some striking lithological resemblances between the Intermediate of Newfoundland and the typical Huronian of Canada.—A.M.
page 254 note 1 The type of the system in Newfoundland is in the peninsula of Avalon, where it occupies an enormous area. There are, besides the clay-slates spoken of here, a great mass of pale-green felsite slates, which weather of a dingy whitish colour, with occasional alternating beds of red slate. I have remarked that, except as intersecting veins, lime is very scarce throughout the series as seen in Avalon, and mica almost or altogether absent.—A.M.
page 254 note 2 The Aspidella terranovica and Arenicolites are found in the clay-slates, which are pretty high up in the series. They pass immediately below the sandstones and conglomerates of Signal Hill, which appear to be at the summit.—A.M.
page 254 note 3 Beautiful hand specimens of various ores of copper have been produced from many parts of the distribution, chiefly from quartz veins; but the extent and quantity of the ore, in no case I have ever known, seemed sufficient to warrant the requisite outlay for opening up a mine. Lead occurs in many localities, usually in calcareous veins. The occurrence so frequently of veins of calcite, in a non-calcareous rock, has induced me to speculate on their derivation; which I conceive possibly may have been from infiltration into the fissures of the older rock, from the calcareous overlying Primordial group, now denuded.
page 254 note 4 I have a very good collection of these fossils from many parts of the island. The formations are distributed in patches; one of the best developments being in Conception Bay, where the relations to the Laurentian and Huronian are most distinctly exhibited. There are also fine developments in Trinity Bay, in St. Mary's Bay, in Placentia Bay, in Fortune Bay, and on the island of Miguelon, from all which places I have made large collections of fossils. The series is recognized in Bonavista Bay, but not so well developed as at the places named above, and I have not hitherto been able to procure any organic remains from them. The base of the series is usually a conglomerate, passing upwards into a reddish sandstone, over which are a set of slates, which are admirably adapted for roofing slates. Mr. Milne's description applies especially to this latter locality.—A.M.
page 255 note 1 The passage upwards from the Paradoxides slates is very well displayed in Conception Bay, where there is no evidence of any want of stratigraphical conformity; but it is difficult to tell in what part of the section the Primordial ceases, and the Potsdam proper begins; a great mass of sandstone occurs at Kelly's Island, and there are alternating sandstones and black shales or slates, which form the largest island in the bay—Bell Island. The whole of these strata hold in greater or less abundance Cruziana similis, Billings, Eophyton Linnœanum, Torrell, several species of Lingula, and other forms which Mr. Billings was disposed to think were of Upper Potsdam type. These strata differ considerably from the beds Mr. Milne quotes, on the north and west sides of the island, which are probably higher measures.—A.M.
page 256 note 1 I made a very full report upon the Quebec Group in 1874, the result of my own observations in 1873, and of my assistant's survey by my direction in 1874; to which I beg to refer for my views of the structure. At page 52 of the said Report I have expressed myself thus: “The facts ascertained, as already represented in the description of the coast and river sections on the east side of Port-a-Port Bay, seem to point to the conclusion that the Silurian formations are arranged in a series of sharp anticlinal and synclinal folds, ranging generally about N. 22° E., S. 22° W.; the whole mass of strata having, towards the close of the later deposits or subsequently, been affected by vast igneous intrusion, and become much dislocated by great parallel or nearly parallel faults, the ground trend of which is N.E. and S. W. At the summit of the whole series is a great volume of igneous and magnesian rocks, consisting of various diorites, serpentines, and chlorites, which our evidences seem to indicate to be lapped over the inferior strata uneonformably, and to come in contact with different members at different places.” In Sir William Logan's investigations in Canada, the great mass of sandstone and conglomerate, displayed so largely at Sillery and other parts of the Gulf of St. Lawrence, were provisionally placed at the summit of the Quebec Group, and as overlying the metamorphic and igneous rocks with serpentines and metallic ores, etc.; but our evidences in Newfoundland seem to point to a somewhat different conclusion—unless, indeed, there may happen to be two great sandstone formations, one of which is absent in this island. The description of the rock of the St. Lawrence applies in nearly every particular to the rock here; but while we find it to succeed the Levis formation with perfect regularity, although with numerous folds and twists, in every case it seems to pass below the serpentines, wherever a contact has been seen; and moreover to pass below them unconformably. The Long Point of Port-a-Port Bay contains fossils recognized by the late Mr. Billings as not older than the Bird's Eye and Black River, and may be near the base of the Hudson River Group; and these strata are comparatively undisturbed; but they are brought down by a fault against older rocks, at the base of which the sandstones are displayed in great disturbance. Having weighed all the evidences with great care, I have come to the conclusion that the great igneous intrusion, of which mention is made in the above extract, must be nearly of the age of the Chazy, or perhaps later; that it has been the metamorphosing agent, and that the altered strata consisting of chloritic slates, serpentines, melaphyres, diorites, etc., belong to a horizon somewhere intermediate between the Chazy and the Hudson River Group.—A.M.
page 257 note 1 The confusion and disturbance manifested in Notre Dame Bay is such, that to obtain a structural section is almost impossible; while the total absence of organic remains in the group which contains the metallic ores adds to the difficulty of disentangling the complexities. Our evidences of horizon are therefore of a negative rather than a positive kind; hut the circumstance of these altered rocks being succeeded by a group containing fossils typical of a horizon ranging between the upper part of the Hudson's River Group and the Clinton is significant. These upper strata have been found in unconformable contact with the older and metal-bearing formations, and traced from the extreme eastern end of New World Island to the Exploits River. Near the base of the group there is a black shale or slate with Graptolithns ramosus, which was followed far up the Exploits River. These fossils Mr. Billings supposed to be types of Hudson River age. The higher beds of the formation were found to contain the following fossils, many of which indicate a period as late as the Clinton:—Orthis ruida; Rhynchonella; Stricklandinia lens; Modiolopsis; Atrypa reticularis; Strophomena rhomboidalis; Leptœna sericea; Orthis Dmidsoni (f); Heliophyllum; Zaphrentis bellisriata; Petraria; Fuvosites Gothlandica; Orthoceras Murchisonia; Brontcits; Encrinites; and Pentamerus.—A.M.
page 257 note 2 In my report for last year, 1876, I have shown reason for believing that the granites here spoken of are later in date, or contemporaneous with, the Quebec Group; and in my report upon the Exploits, 1871, I have shown that the porphyries and some of the basalts intersect the Middle Silurian. Felsites and diorites occur in strata in the Quebec Group; and also as intersecting veins.—A.M.
page 259 note 1 I have already alluded to the probable age of the igneous rocks, and to the geological position of the serpentines on the west coast of the island.—A.M.
page 259 note 2 This view is not improvable, but I am inclined to think, from the undisturbed state of the rocks already spoken of at Long Point, Port-a-Port Bay, tliat the time of greatest volcanic activity must have beeu at an earlier date, probably within the Cliazy or Trenton periods.—A.M.
page 260 note 1 In the note on page 256 I have already expressed my views regarding the stratigraphical position of these sandstones. I have visited St. Juliens myself, and Mr. James Richardson, of the Geological Survey of Canada, visited the place where the formation is largely displayed, at the north-eastern termination of the island; hut a contact with the serpentinous group was not seen in either case; and I hold to the opinion that it is in consequence of the later group being unconformably spread over the older rocks, that the sandstones are not seen at How Harbour or at Pistolet Bay.—A.M.
page 260 note 2 Rocks of Middle Silurian age have already been referred to, as having a wide spread in Exploits Bay and the southern parts of Notre Dame Bay. The lithological characters, and some few obscure fossils, also seem to indicate that the series, or a portion of it, extends far up the Exploits and the Gander Rivers.—A.M.
page 261 note 1 On the north side of St. George's Bay it rests against Calciferous and Potsdam.
page 261 note 2 I have tried to account for this phenomenon, which I have repeatedly observed, both in Canada and in Newfoundland, and a suggestion is offered at pp. 18 and 19 of my Eeport for 1873. The strata of Carboniferous age on the north side of St. George's Bay is almost perfectly flat.—A.M.
page 261 note 3 Neither have I seen any intrusions of trap in any part of the distribution of the Carboniferous; but the formation is very much disturbed and faulted, both on the south side of St. George's Bay and in the Grand Pond region.—A.M.
page 262 note 1 I refrain from more at present, than to make a few general remarks upon Mr. Milne's conclusions in regard to glacial action, and the rise of the land, as I shall probably have something to say upon these subjects at a future time. I think, however, there are evidences to show that there must have been enormous glacial action, probably intermittent; and that the rock-basins of many of the great lakes of the interior, and other phenomena at high elevations in the interior and on the coast, can only be accounted for as the result of such an agency. I also think that the evidences we have, of the rise of the land in very recent times, do not show an elevation of over a hundred feet at most over the present level of the sea.
My new Geological Map of Newfoundland will probably aid in illustrating both Mr. Milne's and my own remarks. It may be obtained at Mr. Edward Stanford's, 55. Chiiring Cross.—Alex. Mcheay.
