ONTARIO.

For a knowledge of the Pleistocene of Canada, the student ought first to read Dr. J. W. Dawson’s “Canadian Ice Age,” published in 1894. In this will be found references to the earlier literature of the subject. For the results of more recent studies the reports of the Canadian Geological Survey are to be consulted, as well as papers published in the scientific journals. For the more important of these papers the reader may consult the list published by Dr. H. L. Fairchild in 1918 (Bull. Geol. Soc. Amer., vol. XXIX, pp. 229).

To state the matter briefly, one may say that almost everywhere in Ontario are deposits of glacial drift of Wisconsin age. In a few localities have been discovered beds which belong to earlier glacial and interglacial epochs. On the other hand, around Hudson Bay, around the Gulf of St. Lawrence, along St. Lawrence and Ottawa Rivers, and the Bay of Fundy are marine deposits, laid down after the Wisconsin ice had retired from those localities and while the region which had been occupied by this ice-sheet was depressed so much that the sea could enter the basins named.

The most interesting locality in Canada for the student of vertebrate palæontology is doubtless Toronto, because of the presence there of Pleistocene deposits belonging to more than one stage, and because of the discovery of several species of extinct vertebrates and of many mollusks, insects, and plants. For an understanding of the geology of the region Coleman’s papers must be studied, as well as those of authors cited by him. On the interglacial deposits three of Coleman’s papers may be especially cited (Jour. Geol., vol. IX, 1901, pp. 285–310; 10th Internat. Cong. Geol., 1906, Mexico, pp. 1237–1258; Bull. Geol. Soc. Amer., vol. XXVI, 1915, pp. 243–254).

According to Coleman’s figure 1 of the first paper cited, the known interglacial deposits in that region extend from the mouth of Humber River eastward beyond the mouth of Rouge River, a distance of about 22 miles, and away from the lake a distance of about 8 miles. Deposits have been found even 14 miles north of Toronto (Coleman, 1915, p. 246). Coleman’s sketch map of the region, taken from his paper of 1901, is here reproduced (fig. 3).

According to Coleman (paper of 1915, p. 243) there are known at Toronto five well-defined sheets of boulder clay, with four sheets of interglacial sand and clay separating them. So far as the writer knows, only the lowest of these beds have been described with any particularity. These lowest beds constitute the Toronto formation, and it is these which have furnished nearly all the fossil animals and plants discovered in that region. This Toronto formation is divisible into two portions, and these have been designated as the Don beds and the Scarboro beds. They are regarded as having been deposited in the valley of an ancient river running from Georgian Bay to Scarboro. Of these the Don beds are the older. Sections of these are found in Toronto and outside, especially along Don River. They have been laid down usually on a boulder clay, 1 to 9 feet thick, which itself reposes on Hudson River shales. At one point along the Don an interglacial river had cut through both the boulder clay and the shale to a depth of 16 feet. The Don deposits consist of varying layers of sands, gravels, and clays. At one point the section obtained amounted to about 27 feet; but this, combined with another, made up about 44 feet. At one place trunks, 12 or 15 feet long, of trees have been found, which were flattened into the surface of the boulder till; also shells of unios, which are embedded in clay close to the boulder till.

Fig. 3.—Region about Toronto, Ontario, showing location of Toronto and Scarboro Heights Pleistocene beds. From Coleman.

In 1913 (Ontario Bur. Mines. Guide Book No. 6, pp. 15–18), Professor Coleman presented a list of the species found in the Don beds. Of the plants 32 species of trees had been secured, among them the pawpaw, the red cedar, and the osage orange; 41 species of fresh-water mollusks were listed, of which 12 were Unionidæ.

As bearing on the climate, it may be said that there are 12 species of the genus Unio listed, of which 4 species are now known only from localities south of the St. Lawrence drainage; while 3 other species live in Lake Erie, but not in Lake Ontario. The plants are mostly trees; and several species, as the osage orange and the pawpaw, are now found only considerably farther south. One species of maple no longer exists. Penhallow gave it as his opinion that the flora points conclusively to the existence of climatic conditions of a character more nearly like that of the middle United States to-day. The unios now missing from that region give evidence to the same fact. For these reasons the Don deposits are spoken of as the warm-climate beds.

The Scarboro beds are finely displayed at Scarboro heights, a few miles east of Toronto. The thickness of the clay here amounts to about 94 feet. In these deposits have been found possibly mammoth or mastodon and caribou, but there is some uncertainty about these. Only 14 species of plants have been secured and these are trees; but apparently no mollusks have been reported. As an offset there are great numbers of beetles. Of these there have been described 72 species, and all are extinct except 2.

The trees, according to Penhallow, indicate a climate somewhat cooler than that now prevailing in that region. The same conclusion was reached by Scudder from his study of the insects. In his paper of 1901, Coleman took the view that the Toronto formation had been laid down in the interval between the Iowan and the Wisconsin glacial stages, that is, during what is now known as the Peorian. In the address of 1906, page 44, he appears to have been inclined to accept Leverett’s view that at least the Don beds belonged to the Sangamon stage. By 1915 (paper cited, p. 252) he had about concluded that the Toronto beds were as old as the Aftonian stage.

Dr. G. F. Wright, in 1912 (Bull. Geol. Soc. Amer., vol. XXV, pp. 205–218), accounted for the deposits and fossil animals and plants found at Toronto in a different way. At a certain time in the Pleistocene the region about Toronto was occupied by some species of animals and plants now found only considerably further south. An ice-sheet from the Keewatin center extended thither and laid down the Don beds. Later the Labrador glacier pushed into that region and deposited the Scarboro beds. According to this view the whole succession of events would be much shortened.

The writer is disposed to accept Leverett’s estimate of the geological position of the interglacial beds at Toronto. The presence there of Elephas primigenius, Mammut americanum, and the probable Ursus americanus hardly counts in the determination of the geological age, for all these animals appear to have continued on from at least the Aftonian interglacial to the close of the Wisconsin. There are no specimens that show that either Rangifer or Cervalces existed during the Aftonian, although one can hardly doubt that they did then exist. In order to show that the Toronto formation belongs to the Aftonian, it would be necessary to produce satisfactory stratigraphical evidence or to find there genera and species of mammals which characterize the Aftonian, such as camels, Elephas imperator, and those horses which belong to the early Pleistocene. If the deposits belong to the Sangamon stage, such horses as Equus complicatus and E. leidyi ought in time to be discovered there.

Coleman has discussed the interglacial beds that occur elsewhere in Canada (10th Internat. Geol. Congr. 1906, Mexico, pp. 1237–1258; Bull. Geol. Soc. Amer., vol. XXVI, 1915, pp. 243–254). He refers to Chalmers’s account of interglacial deposits along Lake Erie; but so far as the writer has been able to determine, most of the deposits referred to are of Late Wisconsin age. However, as he says, Spencer found interglacial materials near Niagara Falls. Other beds have been discovered along Moose River, south of James Bay; but their geological position has not been definitely determined, and the fossils discovered there, mostly proboscideans, are not referred with certainty to the interglacial deposits.

Most of the vertebrate fossils found in Ontario, excepting many of those found at Toronto, belong to the Late Wisconsin stage; and in studying their geological relations one must, as in the States of New York, Ohio, Indiana, and Michigan, take into consideration the history of the Great Lakes after the Wisconsin ice-sheet began to retire. According to Leverett and Taylor’s maps (Monogr. LIII, U. S. Geol. Surv., plate XIV), as early as the time when the glacial ice had just begun to withdraw from Lakes Michigan and Erie, a considerable area of land had become cleared of ice in the peninsula bounded by Georgian Bay, Lakes Huron, Erie, and Ontario. We can hardly suppose, however, that any mastodons or any elephants, except possibly Elephas primigenius, could have made their way to that area. Even the last-mentioned species would have had to travel over many miles of glacial ice. Conditions were hardly more favorable when Lake Whittlesey had come into existence (op. cit., plate XVI). At a later stage (op. cit., plate XVII) the ice-free parts of the peninsula could have been reached only by crossing the lakes or over wide stretches of glacier. It is possible that some of the mastodons and elephants that have been found had crossed over into Ontario at about the stage represented by plate XIX of the work cited, but it is more probable that they lived there at a later time.

Brief mention is here made of the fossil vertebrates found in Ontario and their localities. More detailed statements will be found on the pages cited.

Beginning in the west, a mastodon has been found at Blythewood, Essex County (p. [45]). In Elgin County a mastodon has been met with at St. Thomas (p. [45]), and a mastodon (p. [45]) and an undetermined species of elephant at Highgate (p. [45]). A little farther back from the lake, at London, Middlesex County, has been found a mastodon (p. [45]). At Marburg, not far from the shore of Lake Erie, Dr. H. M. Ami exhumed a mastodon (p. [45]). The writer has not learned how this locality is related to the ancient beaches. At Dunnville, Haldimand County, a mastodon has been secured (p. [46]). It could hardly have lived there before the lake had assumed nearly its present level. The same remark will apply to the time when the mastodon (p. [46]), Elephas columbi (p. [147]), and possibly E. primigenius (p. [166]) lived at St. Catharines. From Hamilton, at the extreme western end of Lake Ontario, have been described remains of Elephas columbi (p. [147]), E. sp. indet. (p. [166]), elk, Cervus canadensis (p. [235]), and the beaver. Elephas primigenius has been found at Toronto, (p. [130]); also Cervalces, a bison (p. [256]), and a reindeer (p. [244]). The same elephant has been discovered at Amaranth, in Dufferin County (p. [130]). The elk, Cervus canadensis, has been reported from Strathroy, Middlesex County, and Kingston, Frontenac County (p. [235]). At Smith’s Falls, Lanark County, the humpback whale, Megaptera boöps, has been discovered (p. [17]). White whales, Delphinapterus leucas and D. vermontanus, have been found at Pakenham, Lanark County (p. [17]), at Cornwall, Stormont County (p. [18]), Nepean Township (p. [17]), Ottawa East, Carleton County, and Williamston, Glengarry County (p. [18]). At Ottawa has been discovered an assemblage of species, as listed on page [287].

The geology of the Hamilton locality has been described by Logan (Geol. Canada, 1863, p. 914), by Spencer (Canad. Naturalist, vol. X, 1883, pp. 222–230, 306–308), and by Coleman (Bull. Geol. Soc. Amer., vol. XV, 1904, p. 351). The remains mentioned were found in deposits forming what is called Burlington Heights. Here Dundas Valley opens into the extreme western end of Lake Ontario. The valley is about a half mile wide. Across this had been formed a bar, interrupted only at its northern end, with a height of 108 feet above the level of the lake and a width varying from a few hundred yards to less than a half mile. Its height is almost that of the Iroquois beach found on the south shore of the lake and continuing on the northern shore. Many years ago a canal was cut through the narrowest part of the bar, and it was in the construction of this that the elephant (p. [166]), elk (p. [235]), and beaver bones were found. It is evident that the bones were deposited there while the bar was being built and at a time when it lacked 38 feet of being as high as it now is. The elephant jaw is in good condition, and this indicates that the animal died near the spot.

Coleman (op. cit., p. 352) stated that afterwards a railroad cut had been made across the southern end of the bar, exposing 30 feet of coarse stratified gravel, followed below by 2 feet of brown clay (evidently an old soil) and 8 feet of blue till. In the old soil were found quantities of decayed wood, as well as bones of mammoth and other animals. About a mile farther west, pits were opened for clay, sand, and gravel. Coleman gives the following geological section at this place. The column at the right gives the heights above the lake level.

feet.feet.
Clay making red brick678
Gravel3072
White sand542
Hard pan437
White sand with mammoth tusks and bones 33
Covered to level of the bay 0

The mammoth tusks and bones were not water-worn. It will be observed that they were found 83 feet below the top of the Iroquois beach (116 feet above the present lake), while the jaw was only about 45 feet below the beach. Both Coleman, as cited, and Fairchild (Bull. Geol. Soc. Amer., vol. XXVII, p. 247) regard the formation of the bar at Hamilton as showing that during Iroquois times the lake became flooded to a height of about 82 feet.

Besides the interglacial species found at Toronto, which have already been mentioned, there may be noted a tooth of Elephas primigenius (p. 130), a cast of which was reported by Winchell. Whether this was derived from interglacial or late Wisconsin beds is not known. Coleman, as elsewhere cited, reported the finding of remains of one of the elephants on the Iroquois beach. On the same beach have been collected antlers of reindeer (p. [244]). These animals must have lived there not earlier than the time when that beach was forming, perhaps later.

Fig. 4.—Eastern Ontario, showing limit of fresh-water beaches and marine fossils. Redrawn from Coleman.

In a buried gorge extending in a northwestern direction from the whirlpool at Niagara to the Niagara escarpment, Dr. J. W. Spencer (Bull. Geol. Amer., vol. XXI, p. 433) has discovered what he regards as deposits equivalent to the Toronto formation, while older glacial and interglacial beds are found below and more recent ones above. No fossils were met with except wood. At Amaranth have been secured considerable parts of a skeleton of Elephas primigenius (p. [130]). This elephant must have existed rather late in the Wisconsin stage. About Kingston in Frontenac County, at two places, have been secured remains of the elk (p. [235]), but lack of details as to places and conditions precludes certainty as to their geological age. The fact that they were found in shell marl is favorable to the idea that they belonged to the Pleistocene. Here may be mentioned again the bison horn of uncertain geological age which was found on the north shore of Nipissing Lake (p. [266]). In Algoma County, on the banks of Moose River, was found a part of a skull of a mastodon, but there is uncertainty whether it had been buried in interglacial deposits or in marine Champlain beds. The region in the extreme eastern end of Ontario is interesting because it furnishes a considerable fauna belonging to the Champlain stage. During the last glacial stage the region on which the Wisconsin ice-sheet was resting became depressed to such an extent that when this ice retreated beyond the St. Lawrence River, marine waters occupied the basin nearly to the eastern end of Lake Ontario and Ottawa River as far as Lake Coulonge. Coleman’s figure of the region (Bull. Geol. Soc. Amer., vol. XII, pp. 129–146, fig. 1) is here reproduced (fig. 4) to show the western limits of the marine waters, so far as known, and the corresponding fresh-water beach along the north shore of Lake Ontario. Figure 5 from Coleman shows how the Champlain Sea was limited on the south. Marine fossils, especially mollusks, have been found along the upper St. Lawrence as far as Brockville, Quebec, and on the opposite side of the river, in New York. On Coleman’s map the present elevations of the old beaches at important localities are marked, that at Ottawa having an elevation of 450 feet and at Coulonge 370 feet. According to Johnston, who has described the Pleistocene geology in the vicinity of Ottawa (Mem. 101, Canad. Dept. Mines, 1917), there is a point about 8 miles northwest of the city where a marine terrace is found at a height of 690 feet above sea-level. The marine beds at Ottawa are divided into the Leda clays at the base and Saxicava sands above. The former have a maximum thickness of about 200 feet, the Saxicava sands, a thickness of about 40 feet. The fossils occur mostly in the Leda clays. In 1897, Dr. H. M. Ami (Ottawa Naturalist, vol. XI, pp. 20–26), and again in 1901 (Geol. Surv. Ann. Rep., XII, G, pp. 51–56), published lists of the fossils found in the Ottawa Valley, nearly all of them in the vicinity of Ottawa. There were listed 26 species of plants, about 13 species of marine mollusks, and the following vertebrates:

Fig. 5.—South shore-line of ancient Champlain sea. Redrawn from Coleman.

The aquatic forms are all species existing in the Gulf of St. Lawrence and along the northern Atlantic coast. The chipmunk lives at Ottawa. Specimens of feathers of birds also have been found in nodules, but the species have not been determined. The remains of the chipmunk were probably washed in by some fresh-water stream.

According to Johnston’s paper just cited, there are deposits of glacial drift underlying the marine Champlain beds, but they have furnished no fossils. The marine deposits extend up the Ottawa Valley at least as far as Coulonge Lake, and here has been found Mallotus villosus. At Welshe’s, 3 miles north of Smith’s Falls, Lanark County, have been found some remains of the humpback whale, Megaptera boöps (Dawson, Amer. Jour. Sci., vol. XXV, 1883, p. 200). It was met with (p. [17]) at an elevation of 440 feet above present sea-level. It appears to have been left there during the time when the Saxacava sands and gravels were being laid down (Coleman, Bull. Geol. Soc. Amer., vol. XII, p. 133).