JLJf^^ Reprinted from The Journal of Geology, Volume III, Number 6 September-October, 1 895 Glacial and Inter-Glacial Deposits Near Toronto By a. p. COLEMAN a. ■J ^ CHICAGO C|f «tiQ»cs(tp of ®t(Mgo pMi GLACIAL AND INTER-GLACIAL DEPOSITS NEAR TORONTO. A LONG line of yellowish white cliffs to t^^hc east of the city forms a striking feature of the voyage across Lake Ontario from Niagara to Toronto; and a closer examination of the Scarboro' Heights discloses a most interesting section of the drift. At the highest point the cliffs rise more than 300 feet above the lake, and the thickness of the deposits is probably considerably greater than this, for the solid rock nowhere crops out in a distance of twenty miles. Along many parts of the Heights, which are in all nine and a half miles long, reaching from a point three and a half miles east of the River Don to the mouth of Highland Creek, the undermining action of the lake provides for a constant series of fresh exposures; and at other points the deep V-shaped valleys of small streams, afford almost as good sections. From Scarboro' westwards to Toronto also, the cuttings for railroads and streets, and the ravines of thf> Don and its tributaries display more or less complete sections c the drift, some of them more than 150 feet in height. The Scarboro' Heights were an object of interest to engineers and geologists more than forty years ago as the source of the sand which, driving westwards along the lake shore, is arrested by the current of the River Don, thus forming the island which protects the harbor of Toronto;' Init no serious geological study appears to have been made of them except by Dr. George Jennings Hinde, who |)ublished an admirable account of them in 1878.' The results of his observations seem little known, probably from the fact of their having been published in a journal not very widely circulated and at a time when glacial studies did not 'Reports 011 the Iinprovenient and Preservation of Toronto Harbor, Prof. Henry Youle Hind, p. i; Sandford Fleming, p. 15; Appendix to Canadian Journal, 1854-5. "Glacial and Inter-glacial Strata of Scarboro' Heights, Can. journ., 1878, p. 388, etc. 022 62 3 TORONTO CLACIAI^ AND INTER-GLACIAL DEPOSITS. attract so much attention as they now do, since the rise of a body of able and ardent glacialists in America as well as the Oid World. The inter-glacial beds of the Don have been described briefly by the present writer'; but beyond these two papers little has appeared as to the drift in this part of Ontario. It seemed so difficult to correlate the results obtained from these two localities only a few miles apart, that it was decided to connect the two by a careful study of the whole ground. This has now been carried out with tolerable completeness, and it is proposed here to give a short account of the results. In doing the work great assistance has been received from the authorities of the Grand Trunk and Canadian Pacific Railways, who provided profiles of all the lines near Toronto; from the city engineer, who provided maps; ar.". from several specialists who have determined fossils obtained from inter-glacial beds; and I desire to express my heartiest thanks for their great kindness. It will be well to begin with an account of the Scarboro' Heights which afford the thickest and most complete section in the region. For this my own observations, which in general accord well with those of Dr. Hinde, will be made use of chiefly. The drift deposits show themselves first, after a long stretch of gravel beach, about three and a half miles east of the Don, as a low clit^ of stratified sand and sandy clay, below which blue till appears. The first outcrop is just west of Victoria Park, and the escarpment, which is only ten or fifteen feet high at the begin- ning, rises rapidly, after a break caused by the valley of a stream, to one hundred and sixty or eighty feet. About three and a half miles east of the Park the cliff suddenly rises to a height of more than 300 feet, but soon drops down to its old level, after v/hich it sinks gradually to a height of twenty or thirty feet, six miles farther east, where it is interrupted by the valley of Highland Creek. At its best exposures the escarpment displaj's, beginning at the level of the lake, about ninety feet of stratified clay, followed ' Inter-glacial fossils from the Don Valley, Am. (Jeol., Feb. 1894, P- *^5> etc. In this paper references are given to the literature on the subject, which is very scanty. THE JOURNAL OF GEOLOGY. 624 % by fifty feet of stratified sand, covered by a bed of \j till varying fr jm forty feet to nothing in thickness. e Three miles from Victoria Park this layer of till \ suddenly dips down to the lake, thickens to sixty ■^ or seventy feet, and rises as suddenly a quarter of a mile farther cast. The hollow left on its surface is filled with stratified clay to a depth of ninety feet, and this is followed, where the escarpment is high- "4 est, a half mile farther cast, by from seventy to one f hundred feet of stratified clay and sand, capped by ^ twenty or thirty feet of an upper till. About one O ° hundred feet of stratified sand overlying the western S end of the lower sheet of till, should perhaps be ^ correlated with this, though possibly of post-glacial ■^ aire. These sands thin out to nothing where the I ujjper stratified clay shows itself. The accomj^any- -N ing diagram, in which the heights are exaggerated i tenfold, will give a general idea of the section and ^ make a more elaborate description unnecessary. It 7" will be noticed that the lower bed of till dips down •g o to the lake at each end of the section ; while the ^ g ui)per till, forming the surface of a table land which -g -g comes out to the escarpment for a short distance "3 c Q .2 only, is cut off abrui)tly at each end. Examining the members of this section in ascend- ing order, we find at its base a series of bluish-gray clays rising out of the lake. They lie perfectly horizontal, arc often finely laminated with sandy partings, having sometimes twenty lamin;e to an inch, but at other times forming beds several feet in thickness. Narrow bands of flat green concretions of impure carbonate of iron occur at various levels ; and at others thin layers of peaty matter. Some beds of cla\- richer than others in plant food may be followed long distances by the eye as bands of rich, green vegetation, while other parts are bare. II 62 5 TORONTO GLACIAL AND INTER-GLACIAL DEPOSITS. The ])caty matter varies froin a mere film to a thickness rarely greater than half an inch, and is made up sometimes chiefly of mosses, but more commonly of fragments of bark, wood and twigs, waterworn and mingled with flakes of mica. Quite seldom one may find a larger knot or broken branch, but never trunks of any size. From these insignificant peaty layers Dr. Hinde obtained three species of diatoms, a chara, five mosses, Bryum, Fontinalis, Hypnum commutatum, II. revolvens (?) and another species of hypnum, spores of lycopodium, pieces of pine and cedar wood, portions of leaves of rush, etc., and seeds of various plants. Among animals he found two or three species of Cypris, a Planorbis and a Zonites (doubtful), as well as the elytra of beetles.' The insect remains v^^ere submitted to Dr. Scuddcr, who reports as follows :^ "Among the material was a considerable number of the elytra and other parts of beetles, an assemblage, indeed larger than has ever before been found in such a deposit in any part of the world, and they are mostly in excellent condition. Twenty nine species have been obtained, some of them in considerable numbers. Five families and fifteen genera are represented; they are largely carabid:e, there being six or seven species each of Platynus and Pterostichus and species also of Patrobus, Bembidium, Loricera, and Elaphrus. The next family in impor- tance is the StaphylinidK, of which there are five genera, Gcodro- micus, Arpedium, Bledius, Oxyporus, and Lathrobium, each with a single species. The Hydrophilida; arc represented by Hydrochus and Heloi)horus with each one si)ecies; and the Chrysomelidx by two species of Donacia. Finally a species of Scoiytidai must have made certain borings under the bark of juniper. " Looking at them as a whole and noting the distribution of the species to which they seem to be most nearly related, they arc plainly indigenous to the soil, but would perhaps be thought to have come from a somewhat more northern locality than that in ■ Can. Jour. 1878, p. 399- • 'Fossil Insects of North America, Vol. II., Teitiary, p. 40, THE JOURNAL OF GEOLOGY. 626 which they were found; not one of them can be referred to exist- ing species, but the nearest allies of not a few of them are to be sought in the Lake Superior and Hudson Bay region, while the larger part are inhabitants of Canada and the northern United States, or the general district in which the deposit occurs. In no single instance were any special affinities found with any characteristically southern forms, though several are most nearly allied to species found there as well as in the north. A few seem to be most nearly related to Pacific forms, such as the Elaphrus and one each of the species of Platynus and Pterostichus. On the whole, the fauna has a boreal asjiect, though by no means so decidedly boreal as one would anticipate under the circum- stances." It will be seen that this remarkable assemblage of insects is of great importance in coming to a conclusion as to the climate of the time when these deposits were laid down; and Dr. Scudder's wide experience in regard to the geographical range of North American insects gives special value to his views on the subject. By washing, drying, and examining with a lens peaty matter from Scarboro' the present writer has succeeded in obtaining a large amount of additional material, consisting of wing cases and other parts of the chitinous armor of insects, all of which has been submitted to Dr. Scudder, who has very kindly consented to determine them and thus add to the data available for judging of the climate. A considerable number of determinable parts of plants, such as leaves, seeds, mosses, etc., obtained in the same way, was sent to Dr. Macoun of Ottawa. The small collection of mosses was forwarded by him to Mrs. E. G. Britton of Columbia College, New York; and I am much indebted to both of them for the trouble they have bestowed on the determinations. Dr. Macoun gives the following list of the species determined by him in the material sent: Larix americana (?), Abies balsamea, Salix, alder, Carex aquatilis and C. utriculata, Equisetum, Oxycoccus vulgaris and vaccinium uliginosum. Of the last two he is quite certain. Mrs. Britton determines the mosses as follows: Limnobium t)27 TORONTO GLACIAL A A'/) L\'TKR-GLACL\L DEPOSITS. jKilustrc (?), L. montanum (?), llypniini lycopodioidcs (?), II. adunciim, H. tluitans (?). Professor I'cnhallow of Montreal has determined two specimens of wood from Scarboro' as probably Picea nigra. It will be noticed that the plants obtained by myself differ considerably from the list given by Dr. Ilinde, perhaps because taken from different levels in the clay. Doubtless the number of species could be greatly added to by careful search. Looking at the plants as a whole Dr. Macoun is of opinion that the climate was like that of the northern part of the Gulf of St. Lawrence or southern Labrador, cool and wet. He states that all the species are represented in the herbarium of the Geological Survey at Ottawa by specimens from the regions mentioned; and thinks that the deposit was formed in a pool surrounded by trees, such as we find in our northern woods today. Dr. Macoun's conclusions regarding the climate as determined from the plants correspond fairly well with those of Dr. Scudder; so that the (juestion may be looked upon as settled. There are, however, no evidences of the action of ice. Dr. Hinde remarks the comi)lete absence of i)ebbles or bowlders from these clay beds, a point which the present writer also has been struck with, suggesting no transport and dropjjing of materials by floating ice. One may infer from the uniform lamination and fineness of the clay that it was deposited in (|uiet water some distance from the shore. Leaves and bits of bark and mosses drifted in by the wind or brought down by a stream gradually waterlogged and sank along with the slowly settling flakes of mica and fragments of insects. It appears that forest fires raged in Ontario then as now, for fragments of charcoal or of chips charred on one edge are not infrequently found mixed with quite uncarbonized woody material. This, of course, does not necessarily imply the presence of man; for doubtless many fires have originated by natural causes, such as lightning. Resting conformably on the clay we find about fifty feet of fine, yellowish or grayish sand, sometimes having thin layers reddened with garnets or blackened with magnetite. Very THE JOURNAL OF GEOLOGY. 628 marked transverse beddinj; is often observed, indicalinj^^ more troubled water than during the deposit of the underlying clay. Some parts of these sands contain many nut-brown concretions of a much rounder form than those from the clay. A large number of these were broken, but only two or three contained traces of vegetable matter or |)ortions of insects as a nucleus. Peaty matter may be found in small amounts in the sand, and at a few points fresh-water shells were found along with the con- cretions, Sphicrium striatinum and Succinea obliqua, according to determination of Mr. C. T. Simpson. The Succineas seem almost too fresh and well preserved to be of inter-glacial age, but they are found nowhere except in the sand beds below the lower till, and the evidence of their age seems pretty conclusive. The beds just described were deposited in water having a level at least 140 feet above that of the present Lake Ontario; and they may have been considerably thicker than we find them now, for there is clear evidence that they were greatly eroded before the overlying till was spread out. At the Dutch Church not only the sands but the stratified clays also were cut through by a stream valley, for we find the bowlder clay filling a hollow that reaches below the level of the lake. Hindc supposes that the ice of the glacier ploughed out this deep valley; but there is no reason to suppose that this portion only should have been excavated by the ice front while the same materials were left untouched on each side. The bedding of the clay is scarcely distuibed right up to the contact with the till, which would be impossible if the snout of the glacier had ploughed its way through, but is intelligible if it simply filled a preexisting valley. The till which follows is of the usual description, a blue calcareous clay charged with polished and striated pebbles of lime- stone and black Utica shale, with p few Laurentian bowlders. This bed of till is continuous from end to end of the section except at a point about one mile and a half east of Victoria Park, where probably by subsequent erosion, it is thinned out to nothing for about 300 yards. There is a deep hollow in the till at the Dutch Church, where it dips down to the lake, jjerhajjs an 62g TORONTO GLACIAL AND INTER-GLACIAL DEPOSITS. oritT'inal ilcprcssion of its surface, now filled with ninety feet of stratified clay, very like the lower beils, but more calcareous and apjjarently free from fossils and concretions. At the jjoint where the ui)|)er terrace comes out to the shore these stratified clays are covered conformably by a series of stratified sands with some clay beds, in all seventy feet thick. Several of these beds at different levels are remarkably crum})led and contorted, while the beds immediately above and below a])])ear (juite undisturbed. They have perhaps been folded by Upi)er i)art of Section at Scailxiru' Heights, showini,' two upper layers of till ami tlie crumpled strata. After photograph by Dr. Ellis, the grounding of ice floes, and in ai)pearance they remind one of examples figured in Gci/cic's Gnat Ice Agc.^ No fossils have been obtained from these inter-glacial beds. The upper till, which overlies the country to the north of the Scarboro' Heights, forming a gently rolling table-land, describetl by Professor Chamberlin in conversation as a mild form of moraine, is seen at this section to consist of yellowish-brown clav with well striated j)ebbles and larger stones, fragments of black I'tica shales, often falling to pieces, limestones apparently of Trenton age, and archiean rocks, such as gneisses. It differs fiom the lower till in being somewhat more sandy, and esj)ecially in hav- ' 1'. 271-2. THE JOURNAL OF GEOLOGY. . 630 ing been greatly weathered, some i)arts at the bottom alone showing the original blue color of the clay. West of this highest part of the escarpment a series of rather coarse, cross-bedded, stratified sands and gravels, in which no fossils have been found, overlies the lower till, at first in a a thin layer, but rapidly thickening as the bed of till descends toward the lake near Victoria Park, where it ex[Kinds to a thick- ness of more than one hundred feet. Hinde looks on these sands and gravels as post-glacial, but similar deposits a few miles to the west and north are covered bv the upper till; and at a cutting on theScarboro' street railway a little north of the Park crumpled strata of the kind pre\iously referred to are well exposed, suggest- ing an inter-glacial age for these beds. However up to the present their position must be looked on as not [)ositivcly settled. A com|)aratively thin layer of coarse gravel and well-rountled stones, followed by loamv soil covers these sands and forms the surface of the Irocpiois terrace. From the descri})tion just given it will be seen that at the Scarboro' Heights there are two beds of till separated by a deposit of unfossilifcrous stratified clay and sand amounting in thickness, if we add the dejith of stratified clay at the Dutch Church to that of santl and clay at highest points a little farther east, of 160 feet. Below the lower till the fossiliferous sands and clays have a depth of at least 140 feet, their lower limit being covered by the lake. Dr. Hinde assumes a third till below the lower clay, nowhere exposed along the Scarboro' escarpment, but cropping twelve miles to the west at H umber Bay, where till overlies the Hudson River shales, and is covered by stratified clay not unlike that at Scarboro'. The Humber clays, so far as I have observed, do not contain peaty matter nor the i)late-like concretions of clay- iron stone; however, they arc so far separated that the conditions under which they were deposited may have differed greatly from those at Scarboro'. Whether the underlying till be found or not, there is every reason to think the lower Scarboro' sands and clays inter-glacial; for they contain a scries of minerals incUuling garnet, magnetite, » 6^1 TORONTO GLACIAL AND INTER-GLACIAL DEPO UTS. hornblende and biotitc, thoroughly characteristic of Laurentian rocks and not found in the adjacent Hudson River or Utica shales. The transport of these materials for a distance of not less than seventy miles is best accounted for by glacier ice. The extent of these deposits has not yet been worked out in detail, though the lower stratified clay was apjiarently wide- spread. Twenty feet of clav very like it, containing thin layers of peaty matter, may be seen on the shore of Lake Ontario four miles to the east of Highland Creek, here also covered by a bed of till. Exactly similar clay occurs about four miles to the north- west of Victoria Park in the brickyards of Messrs. Price and Logan. The exposures are excellent, one presenting a face of sixty feet; and the to|) of the clay, which rises about one hundred feet above Lake Ontario, is covered with a few feet of stratified sand. One finds the greenish plate-like concretions, and peaty matter containing mosses, pieces of bark and wood, elytra of beetles, flakes of mica, etc., just as at Scarboro'. The layer of till is wanting at these brickyards, but is found a few hundred yards farther north near the corner of Danforth avenue and Greenwood lane. If we include the Humbcr clay in the series, this lacustrine deposit has a length of twenty two miles, by a breadth of at least one and one half miles. Omitting the Humber beds, it has been traced for about sixteen miles. The upper, unfossiliferous clay from the Dutch Church seems also very widely distributed. It may be found as suggested by Dr. Hinde, in the north of Toronto (formerly Yorkville), where it is used to make gray brick. It seems to occur also at the Don Valley brickworks, and other points along the Don ravines. Similar stratifietl unfossiliferous clays making white or buff or gray brick occur at various j)oints a few miles to the north and west of Toronto ; and beds very like them underlying an upi)er till are well exj)osed on the lake shore between Newcastle and Newtonville, more than forty miles to the east. The u|)|)er unfossiliferous clays a|)pear then to be even more wiilely spread than the lower peaty clays, though one can hardly make sure THE JOURNAL OF GEOLOGY. 632 that the deposits at all the localities mentioned were laid down in the same body 01 water and at exactly the same time. The inter-glacial deposits on the Don, best shown at the brickworks owned by the Messrs. Taylor, were described a year ago,' but will be referr' I to again, giving the results of a careful reinvestigation under better conditions. When it was examined in the preparation of the paper referred to, the cjuarry consisted of two i)arts, a lower one showing about forty feet of drift, including nearly three feet of till resting on Hudson River shale, twenty-five feet of stratified sand with one or two clay beds, and, above this, ten feet of stratified clay making red brick. A slope of grass extended from tliis part of the cpiarry for about one hundred yards to the upper portion, where about forty feet of stratified clay making buff brick were •'o be seen, the top of the exposure reaching almost to the level of the plain formed by the Iroquois beach of Spencer. The part cov- ered with grass was stated by the men at work in the quarry to consist of the same clay as that worked for buff brick, i nd was included with the upper stratified clay in the section given. About a third of a mile northwest of the (piany the Davenport Ridge, a morainic tract of gently rolling highland, comjjosed of somewhat sandv till containing bowlders and striated stones, comes to a sudden .^lop and forms a cliff fifty to seventy feet high at the Iroquois beach. That the Davenport till stretched much farther south before the Irocjuois water had encroached upon it is clear, not alone from the steep cliff but from the immen;;e bowlders scattered over the terrace, evidently left behind when the finer materials were washed away by wave action. Such bowlders lay on the surface just above the cpiarry, until removed a year ago. The fact that the ui)[)er stratified clay of the cpiarry may be traced hero and there up the ravine to the north, until, about half a mile above the brickyard, it under- lies the till of the Davenport ridge, confirms the conclusion. The Daveniiort ridge is a continuation of the mild moraine ■ Inler-Klucial fossils In.m the Don ViUlev, Am. Clcol. \nl. Xlll., I'cl.niaiy 1894, p. 05-95. 633 TORONTO GLACIAL AND INTER-GLACIAL DEPOSITS. forming the upper plateau at Scarboro', the two being separated only by the deej) bay-like depression of the Don Valley ; and it seemed to me probable, last year, that the layer of till overlying the shale at the brickyard was a continuation of the lower Scar- boro' till, which :iinks beneath Lake Ontario near Victoria Park- three or four miles to the east. This implied that the fossilifer- ous beds at the Don, with the overlying stratified clay in which no fossils occur, were equivalent to the upper, unfossiliferous beds at Scarboro'. This spring, however, new excavations at the brickyard have completely overturned this theory by disclosing a thick bed of till in the slope formerly covered with grass. This overlies the fossil-bearing strata which correspond, therefore, to to the lower, fossiliferous bed at Scarboro', so far as position is concerned. At present the cpiarry presents the following sectio" as meas- ured by aneroid and steel tape : "'eet. Soil and stratified clay, making buff biick (unfossiliferuus) 43 Till (partly covered with f^rass) about - - - .35 Stratilied clay with peaty matter, making red brick - 13 Stratified sand with some clayey beds (fossiliferous) - 24 Till - - - "- - - - 2 Hudson River shales, about - - - - 60 The Hudson River shales rise about thirty-five feet above the level of Lake Ontario. At the Don Valley brickworks we have, then, a lowest till resting on the rock and overlaiil with fossilif- erous beds ; a second till corresponding to the lower Scarboro' till; but no uppermost till, though one probably existed before the formation of the Irocjuois beach, and the upper stratified clay passes beneath the upper till at the Davenport ridge a half-mile away. So far as I have observed the three tills are nowhere all disclosed in a single section ; but a shaft sunk through the Daven- port ridge or the highest part of the Scarboro' Heights would probably cut through all three. Since the [)aper on the Don fossils was published three new localities have been found in the same valley; one of them, which was opened to give employment to the convicts at the gaol THE JOURNAL OF GEOLOGY. 634 near by, j)roving especially intercstini^ ; since thin layers of mat- ted deciduous leaves occur in it. One of these localities is at the shore of a pond a mile above the brickyard, so that the fos- sil-bearint^ sands and clays have been shown to extend for three miles alouiT the valley of the Don. Judgint^ by the j)osition of these beds with reference to the lake, the stream in which they were formed had a much more rapid fall than the present slug- gish river. The lowest fossil bed in the up])er ])art of the valley Ijuaiiy 111 'I'liylor's brickyard, Don Valley, 'roronto. 'llic section .sliows tiie Hud- son River sliale ; llie lowest till resting on it (dark); the fossiliferous stratitied sand and clay ; the middle till just beneath the grass at the staging ; and the upper strati- fied unfossiliferous clay in the much foreshortened upper ipiarrv. The |)iiologra|)h is by Dr. Ellis, of the ScIkjoI of Practical Science, Toronto. is about forty feet above the lake ; at the Convict Cutting ten or fifteen feet ; while at the cutting for the Don improvements, near the mouth of the present river, fossils were found several feet below the level of Ontario. The localities most produeti\e in fossils are the brickyard and the Convict Cutting, and a brief description of them may be of 635 TORONTO GLACIAL AND INTER-GLACIAL DEPOSITS. interest. At the brickyard unios, retainiiiir their dark epidermis and havinj^ the valves united, are often found embedded in a few inches of blue clay immediately ovcrlving the till. The sands above this contain more or less waterworn unios, pleuroceras, sphieriunis, etc., while the overlying stratified clay beneath the middle till holds a little peatv matter, but nothing well enough preserved to be determinable. At the Convict Cutting, too, the unio bed is disclosed, but some stratified, sandv clav beils in the upj)cr part of the section have proved much more interesting, that patient collector, Mr. Townsend, having obtained from them a large number of leaves, among which he thinks are leaves of the oak, beech and willow. It is verv difficult to preserve these leaf fragments, since the clay dries up and the brown traces of the outline and veining shrivel up and become almost unrecognizable. Up to the present the unios have proved the most important finds along the Don. They include the Unio phaseolus, U. clavus, U. pustulosus, U. pustulosus, var. schoolcrafti, U. occidcns (?), U. luteolus, U. undulatus, U. rectus, U. trigonus, and U. solidus. The other shells obtained are .Sph;trium striatinum, Pleurocera subulare, P. elevatum, an undetermined species of the same genus and a single specimen which may be V. pallidum, I'livsa ancil- laria and Amnicola limosa. I am indebted to Dr. Dall and his assistant, Mr. C. T. .Simpson, for the determination of the above species, all of which occur at the brickyards and several of them at the other points. A few other fossils, including one or two species of ostracods, a number of elytra of beetles and one or two teeth, the latter found bv Mr. Townsend, have been obtained at the Convict Cutting with the leaves, but have not yet been deter- mined. The plants include fragments of tree trunks, leaves, a very few mosses and chara. The specimens of wood have been determined by Professor Penhallow of McGill to be P'raxinus (]uadrangulata, Quercus obtusiloba, Ulmus americana, Madura aurantiaca and Picea sitchensis (r). Some leaves sent from the Convict Cutting he considers to be of willows and poplars. Pro- THE JOURNAL OF GEOLOGY. 636 fessor Penhallow had previously found in material sent by Mr. Townscnd from the Don Improvements, Asimina triloba, Ulmus racemosa, Taxus baccata and a new maple leaf, which was named Acer pleistocenicum.' In respect to the woods, Professor Pen- hallow says that they are usually badly decayed, but that he has referred them to the nearest living species. If we compare the inter-glacial fossils of the Don with those of Scarboro' we find them surprisingly different. Up to the pres- ent only one species of animal, Sphiurium striatinum, a form having a wide range, has been shown to be common to both localities. It will be of great interest to learn if Dr. Scudder finds insects from the Convict Cutting the same as those from Scarboro' or not. No two trees are undoubtedly alike, though Picea nigra of Scarboro' is not far removed from Picea sitchensis of the Don ; and willow leaves of undetermined species have been found in both places. It will be remembered that both the insects and plant remains of Scarboro', in the opinion of such good authorities as Dr. Scud- der and Dr. Macoun, point to a cool climate like that of Lake Superior or Labrador ; while the Don fossils, on the other hand, point equally conclusively to a climate as warm as that of Toronto at present, if not considerably warmer. The numerous unios, some of them no longer found in our lakes, though common far- ther south in the Mississippi drainage system ; "' the forest trees including three sj)ecies (Asimiana triloba, the osagc orange and P>axinus c|uadrangulata) now belonging to the portions of Ontario along Lake Erie and the states to the south, 3 hint at a climate very far from glacial, probably comparable to that of Ohio at present. There seems no doubt also that both of these deposits are inter-glacial and included between the same sheets of till ; though the lowest till is out of sight below the lake at Scarboro'. These two series of beds can hardly have been formed contempora- ■ 15ull. Geol. Soc. .\ni., Vol. I., |>. .^28. ''C. T. SiMi'SON, I'roceedings U. S. National .Mus. Vol. .\VI., pj). S'H-S- 3Dr. Macoun, Forests of Canada, Trans. Royal Soc. Can., Sec. IV., 1894, p. 1 1, 637 TORON'^'O GLACIAL AND INTER-CLACIAL DEPOSITS. ncously; one must have preceded the other; but which came first is not easy to decide. One mi^ht assume that the Scarboro' clays were formed first, a cold climate continuing for a long [)eriod of time after the departure of the earliest ice sheet ; that the water was drained ofi or the land elevated afterwards, and the Don of those days exca- vated its comparatively wide and deep valley apparently not greatly different from the present one. Meantime the climate had become warm, and southern forms of life pushed their way northward and occupied the river and its shores until the second advance of ice destroyed them. This hypothesis seems to agree with many of the facts, particularly if Dr. Hinde is correct in his belief that the stratified clay resting on till near the mouth of the 1 lumber is a continuation of the fossiliferous Scarboro' beds. The quite similar cla^-s at Price's brickyard would then be a rem- nant of a wide sheet of such lacustrine deposits afterward eroded by the Don. There is an ai)pearance of interbedding of a thin layer of the peaty clay at the Taylors' brickyard with the bowl- der-clay above ; while the upper fossiliferous beds at Scarboro' were much eroded before this sheet of till was laid down, facts which perhaps point in the same direction. If this hypothesis be correct the Don beds, being much later than those of Scarboro', may somewhere be found resting unconformably on their eroded surface. Up to the present, however, no such section has been observed. On the other hand one might suppose that the Don beds are the older ; that after the till was laid down there was a sudden change of climate, and that southern forms of life quickly fol- lowed uj) the retreat of the ice-sheet as it vanished under the action of warm sun and winds. The fact that Mississipjii unios lived and died right on the unweathered surface of the blue till at the brickyard fits best with this assumption. If there had been a long period of erosion before they arrived, one would expect to find the till wcatnered brown and its enclosed pebbles of shale crumbled to pieces, instead of being fresh and sharply striated. Taking this view, the layer of peaty clay just beneath the middle THE JOURNAL OF GEOLOGY. 638 till at the Don is the equivalent of the ninety or more feet of peaty clay at Price's brickyard and Scarboro' ; and one niig-ht expect to find the iinio bed, or its equivalent as to climate, beneath the level of the lake at Scarboro'. It should, however, be observed that up to the present no species has been shown to be common to the peaty beds of the Don and those of Scarboro', except one ubiquitous shellfish. It may be that future excava- tions will settle which hypothesis is correct; if, indeed, some entirely different interi)retation may not be put ujjon the facts described. Two very interesting articles have appeared recently, one by Professor Chamberlin in the Journal of Geologv, the other by Mr. Warren Uphani in the American Geologist, referring to the succession of glacial deposits in America, and mentioning the Toronto inter-glacial beds in that connection. Professor Cham- berlin gives the "Toronto Formation" tentatively an independent position as the possible equivalent of Geikie's Neudeckian,' and places it in the interval between the lowan and Wisconsin sheets of till. Mr. Uj^ham places the Toronto inter-glacial beds in a somewhat similar position, but looks upon them as only in a limited sense inter-glacial, " since they lie between deposits of glacial drift ; but they seem better referred to moderate oscilla- tions of the ice boundary during its general retreat after the lowan stage, that is, to a time during the Wisconsin or moraine- forming stage rather than to distinct glacial epochs."* He sup- ports this view by a statement as to thinning out of the beds of till between Scarboro' and Toronto, suggesting the nearness of the ice border; and finds the deposits "quite inexplicable on the hypothesis that these till formations record great readvances of the ice, as either to the lowan stage or to the Wisconsin moraines. "3 In regard to the thickness of the sheets of till it may be mentioned that they vary greatly in this resjject within short 'JdURNAi, OK Gkoi.ogy, Vol. III., No. 3, pp. 273-275. "Am. Geol., Vol. XV., No. 5, p. 289, etc. 3 11)1(1., p. 200. 639 JONONJO GLACIAL AND INTER-C, I.ACLIL DEPOSITS. distances both at Scarboro' and along the Don, but by no means always in the sense of thinning out towards the west. For instance, the middle till, the lowest visible at Scarboro', is there generally less than thirty feet thick and for a mile or more scarcely averages five feet in thickness ; but at the Dutch Church, where the subglacial debris has been crowded into a deep valley, it reaches a maximum of seventy feet. The same bed of till at the Don brickworks is thirty-five feet thick, and a little farther south, between the Winchester street bridge and Danforth avenue, is apparently ninety feet thick. The upper till at Scarboro', so far as I have measured it, runs from twenty to thirty feet in thickness ; but at Moore Park Sta- tion, less than a mile north of Taylor's brickyard it is forty-five feet thick, and at V'ork Mills, three or four miles northwest, is nearly sixty feet in thickness. In reality the difference in thickness of the drift at Scarboro' and the Don is due rather to the greater or less development of the inter-glacial beds than to the thickness of the till. If these inter-glacial dejjosits were formed during slight oscil- lation of the ice margin, one would sui)posc that drifting ice floes or even bergs would have been active on the waters of the time, transporting bowlders and other materials, which should be imbedded in the clays and sands of the lake bottom ; but neither Dr. Hinde nor the present writer has been able to find stones of any kind in the 140 feet of fossiliferous beds at Scarboro'. The case of the Alaskan glaciers cited in the article men- tioned' is in reality not at all analogous to the conditions pre- vailing at Toronto during the earlier inter-glacial time. In Alaska the Japan current brings comparatively warm moist air right up to latitude 60°; while the highest mountains in North y\merica rise a few miles inland, their icy flanks intercepting the moisture- laden winds from the Pacific and causing a tremendous snowfall in a region where the snowline is only 2000 feet above sea level. If Mt. Fairweather, Mt. St. Elias and Mt. Logan were leveled, • Ibid., p. 278. ■////•; JOURNAL OF GEOLOGY. 640 how long would the Mahispina and other Alaskan glaciers hold their ground ? At Toronto during one part of this inter-glacial time we had a climate, judging bv the flora and fauna, far milder and drier than that of Alaska; and, nothing that can be called a mountain rises between this and Hudson liay. The inter-glacial time was long enough not only to allow of the deposit of the thick beds of sand and clay that have been described, but to allow the great body of water in which they were formed to be drained to a depth of one hundred and fifty feet, and the new land surface to be deeply eroded. At the Dutch Church, for instance, a valley was dug a mile in width from edge to edge and a cjuarter of a mile wide at the lowest level exposed by Lake Ontario.' All of this must have demanded time and plenty of it. J^an any one believe that meantime, while elms and oaks and mai)les, not to mention the papaw, were growing along the Don, the ice-field, with no loftv slopes to supj)lv gathering ground for neve, was lurking a few miles off, ready to advance and overwhelm the deciduous forests ? It has been pointed out in a previous paper that Toronto lies not more than 500 miles from Hudson Bay or 700 from the cen- ter of Labrador, with no mountains intervening.* There seems no more reason to assume that a great ice-field existed within those distances while the Don fossils were being buried than there is to assume it at the jjresent day. As a whole, then, the evidence at Toronto seems to support strongly the theory of Geikie, Cham- berlin and others as to the distinct ice ages separated by mild inter-glacial times. The unfossiliferous clays and sands lying between the mid- dle and upper sheets of till and having a thickness of at least one hundred and sixty feet at Scarboro', and of forty at Toronto, indicate a second recession of the ice. The absence of fossils, the presence, though rarely of angular striated pebbles in the clay, and the corrugated and crumpled beds here and there found among the upper sandy layers suggest a cold, perhaps ' See Suction of Scarboro' Heiglits. -Am. Geol., Vol. XIII., p. 92. 641 TORONTO GLACIAL AND LVTKR-GLACLIL DEPOSITS. Arctic climate, iiiiplyiiisj^ perhaps only a long recession of the ice, not its complete removal. The ujjper ])art, consisting of cross-bedded sand aiul clayey sand, seems (juite wiilespread, for similar beds lying between the rolling surface of till and a lower sheet of till have been found on a branch of the Don seven miles north of the city, at Pickering twenty miles northeast, and on the lake shore near Newcastle forty miles to the east. IL may be that fossils giving a hint as to the climate in this inter-glacial jjcriod will be fountl at some ♦^^ime. The tooth of a mammoth was found last summer on the Don eight miles north of the city at a point where the stream flows over the middle till and cuts away banks showing stratified sand and in some cases the uppe till also, but the fossil may be post-glacial rather than inter-glacia in age. The same holds of two mastodon teeth found several years ago, one on the Don, the other in a sand pit two or three miles east of the city. If Professor Chamberlin is correct in assigning the fossilifer- ous beds of Toronto and Scarboro' to the interval between the lowan and Wisconsin ice ages;' then the up[)er stratified beds imply a still later ice age, se})arated probably by a shorter and less genial inter-glacial time than the former one. It is however possible, as suggested by Professor Chamberlin, for the beetle- bearing beds of Scarboro' in case they should prove to belong to a lower horizon than the Don beds, that the fossiliferous beds near Toronto are of Aftonian age, i. e., belong between the Kansan and lowan sheets of till ; and that the upper beds repre- sent the interval between the lowan and Wisconsin ice sheets. The former supposition seems to me the more probable, since there is some likelihood that the mild morainic sheet forming the Davenport ridge and upper Scarboro' Heights runs out in the neighborhood of Toronto, and hence cannot be continuous with the Wisconsin sheet to the so ithwest. Until the till sheet lying to the north and east of Toronto has its western boundaries traced this point cannot be settled. A long halt in the retreat of the last glacier, if not a recru- " Journal Gkoldgy, Vol. III., No. 3, p. 273, etc. THE JOURNAL OF GEOLOGY. 642 (lesccncc of glacial conditions after another interval, is indicated by the great niorainic loops stretching from Trenton westwards to Lake Huron and passing (as the Oak ridges) about eighteen miles north of Toronto. The post-glacial history of the region near Toronto has not yet been satisfactorily worked out, though one episode, that of the Irocjuois water as described by Dr. Spencer, has left its mark very distinctly in the old beach to the north of the city, and must have had considerable importance as regards the formation of surface dejjosits. Much of the somewhat loess-like fine clayey sands of the Humber valley may turn out to be post-glacial ; and Dr. Hinde supposes that the upper hundred feet of sand and gravel at the west end of the Scarboro' cliffs are of the same age ; but my own observations incline towards an inter-glacial position for these thick and widespread but greatly eroded deposits. Similar sands occurring at York Mills and other points north of the city are undoubtedly covered by the upper till, which may simply have been removed from the more southern parts near the lake. Unprotected by a layer of till these sands are easily attacked by wind and water and superficially rearranged, so that their original structure and relationshij) becomes obscured. Of course the Don and Humber with their tributaries have formed in the lower sluggish parts of their courses alluvial deposits of clay and sand that arc evidently modern, and in some instances arc added to by every spring flood. The succession of events since Pliocene times in the vicinity of Toronto may now be reviewed in order to bring to a focus the results of the observations described in this paper. No Pliocene deposits have been found in this region, suppos- ing the earliest advance of the ice to indicate the end of the Pliocene; but the lowest till forms a carpet over the eroded surface of the Hudson River shales. At the time the earliest glacier advanced the Scarboro' region formed a valley whose hollow is now below the surface of Lake Ontario, and there were low hills where the Don and Humber valleys now exist, the 643 TORONTO GLACIAL AND LWTER-GLACIAL DEPOSITS. highest observed level of the shale being about eighty feet above the lake at Lambton Mills on the Humber. The retreat of the ice was followed by a rise in the water of the lake to a level at least 150 feet above the present lake, depositing that depth of clav and sand upon the unweathered till. The Scarboro' water, as it may perhaps be called, was then drained off to a point below the present lake level, and at some points erosion took place to a corresponding depth. It is possi- ble that the climate became warmer during this period of erosion and that the Don beds were deposited afterwards. At the time of the second glacial period the toiK)graj)hy of the region hatl greatly changed. The Scarboro' Heights already had an elevation of 150 feet, while valleys reaching the jiresent lake level had been cut bv Highland Creek and the Don, as well as by the Dutch Church stream, which now has no equivalent. The retreat of the second ice-sheet was followed bv a rise of the water to a height of 280 feet above the present lake, the water being cold and lifeless, and bearing ice floes. Once more the lake was drained, at least partiallv, and erosion went on, for the upper till is found at a sand j)it near the corner of Bloor and Christie streets in Toronto at a level of about 120 feet above the present lake. Either the period of dry land was short, giving no time for the cutting of deep valleys, or the level of the lake of those days was considerably above the present Lake Ontario, The contour of the land at the end of this inter- glacial period is more difficult to settle than in the former one ; but it is tolerably certain that the Scarboro' Heights had almost their present height, and that the Don valley was much shallower than at present, if it existed at all. The retreat of the third ice-sheet was followed as before by a rise of water. Lake Irocpiois reaching 160 feet above the present lake to the north of Toronto, and about I go at Scarboro'. After the draining of Lake Iroipiois it is [)robable that the surface of the country presented much the same rolling swells of till as are now found north and cast of Toronto; fo , in general, erosion has gone on to a moderate degree only, e.\ce|)t where the more ' . THE JOURNAL OF GEOLOGY. 644 powerful streams have cut out picturesque ravines, such c.s arc seen along the Don and H umber. It is probable that at the end of the first inter-giacial period the topograi)hy had almost as old an asjiect as at present, indicating as long a time for erosion as has elapsed since the last ice age ; but the dry land stage during the second inter-glacial period was apparently much shorter. The length of time during which high water lasted during the two mild periods must have been very great to allow the immense sedimentary beds to be deposited at Scarboro' and elsewhere, 150 feet thick in the earlier period and 160 in the later. The Irocpiois high water stage after the last ice age was probably much shorter, since it has left much smaller sedimentary deposits. It is a notable fact that each ice-sheet advanced api)arently during a time of low water, and was followed by a stage of high water ; whether this is to be accounted for by assuming an ice dam at the foot of the predecessors of Lake Ontario, or a change in the level of the land surface caused by the loading and unload- ing of its ice burden, it is very unlikely that the sea has extended inland so far as Toronto since glacial times. The numerous marine animals found as fossils lower down on the St. Lawrence and Ottawa would hardly have stopped short without reaching the Iroquois bay, if that had been a body of salt water, in communication with the Gulf of St. Lawrence.' However, no fresh water forms have been found on its beach, so that the evi- dence is only negative. The Scarboro' beds give very instructive evidence as to the comparatively slight erosive power of glaciers. Except near the east end of the section, where, as suggested to me some time ago by Mr. J. H. Tyrrell, the ice front began to rise upon the higher ground during the second advance and crumpled and con- torted the clay beds, there is no very striking disturbance even of the stratified sand, though here and there portions of the sand ' Two marine .shells have lieen picked up on the Iroquois beach, but, as suggested by Dr. Dall, to whom they were submitted, they have almost certainly reached tliat position by liuman agency. 645 rORONTO GLACIAL AND LXTER-GLACLIL DEPOSfTS. arc tilted out of place. The upi)er layer of till rests in some places on crumpled beds of sand, but more often one sees little trace of disturbance. One might almost describe the till as a lubricant allowing the ice-sheet to glide easily over the inequal- ities of the surface. A. P. Coleman.