IMAGE EVALUATION TEST TARGET (MT 3) fe // fe :A o h Va ^ V] <^ /a / c* ^^ ..-v ;> ^ .v> ">'.>^ <^/3' <^^ ^^ ^/ O;;^ ■M 1.0 lil — i;^iia ^ III 1.8 1.25 u a 1.6 6" Photographic Sciences Corporation ^^ \\ -?'-,. I\>' v^ (o &0 ,A [From The American (Seologisi, Vol. XIII. February, lH!)t.\ vi INTERGLACIAL FOSSILS FROM THE DON VALLEY, TORONTO. By A. P. ("OLEMAN, Ph. D., Prof. Met. nnllector.g In an appendix to the same pf.per Prof. Penhallow has figured a leaf found by Mr. Townsend, describing it as a new species under the name of Acer pleistocenicum, || He determined other specimens from the same locality as follows, — Asimina triloba, Ulmus race- mosa, and Taxus baccata. Mr. Wm. Spry, who was engineer in charge of the work during part of the time, informs me that there were tree trunks one or two feet through in the boulder-clay just above the underlying shale at Jail hill some- what north of the bridge. Since then a cutting on the Belt Line railway near the Win- chester street bridge, half a mile above the previous locality and the west side of the river, has afforded many very fragile specimens of Pleurocera, Valvata sincera and Sphterium *Geol. Sur. Can., 1863, p. 904. tCan. Jour., Vol. vi, p. 226. JCan. Nat. and Geol., Feb., 1861, p. 42. §Bull. Geol. Soc. Am., Vol. i, p. 315. Ijidem, p. 328. 1 ^*M.»%_1 fii/ci'lllocidi h'ossils. — ('(ilcHKiti . 87 sitriatinuni, as well as poarly Iraf^nientH of LJnio. Tlie I'ossil- it'erous bed is sandy and reaches about 25 to 35 feet above the Don. The most interestinff exposure of all has recently been opened at the Messrs. Taylors' l)rickyard, nearly a mile north of the Gerrard street bridge. Many specimens of Unio have been collected here by myself, Mr. Blue, Mr. Townsend and the workmen employed in the ([uarry. The majority of them are so fragile as to fall to pieces with even the most careful handling: and it was only after lollowing the advice of Dr. Dall, of the Smithsonian Institution, to soak the fossils in shellac varnish diluted with alcohol, that they could be at all satisfactorily preserved. My thanks are due to Dr. Dall and his aid, Mr. C. T. Simp- son, for the determination of the specimens, which include the following species , — Pleurocera sui)ulare, P. elevatum, an un- determined species of the same genus and a single specimen which may be P. pallidum ; Valvata sincera, Sphierium striati- num, Unio phaseolus, U. davus, U. pustulosus, U. pustulosus var. schoolcrafti, U.occidens ( V). l\ luteolus, U. undulatus, U. rectus, U. trigonus, U. solidus. Mr. Simpson has described thefte fossils in the Proceedings of the U. S. National Museum* and states that at least three of the species of Unio and one Pleurocera Jire n(» longer inhab- itants of the St. Lawrence drainage area, but belong to the waters draining into the Mississippi. A list of the species now living in the vicinity of Toronto, made out for nic h}- Dr. Hrodie, iieludes only four of the species obtainetl at the quarry, viz. V'alvata sincera, Sphterium striatinum, Unio luteolus and U. rectus. SpecinuMis of the two Unios which he has sent me are thinner-shelled than the fos- sils of the same species. Three specimens of wood obtained at the quarry just above the lower boulder-clay were forwarded to Prof. Penhallow, of McGill University, for examination. As his report is ap- pended to this paper, it is suHicient to state at this point that he refers the specimens, whicii he finds badly decayed and crushed, provisionally to the nearest living species, Fraxinus quadrangulata, Quercus obtusiloba, and Taxus baccata, var. *Vol. XVI, pp. 591-595. S^4-lo HH The American Oeoloyiitt. February, inw CHiiadL'nsis. The first two have not liitluTto been reported from the (!ana(lian tUil't. In order to show definitely the j?eo!ogieal horizon at whieii the fossils were found, the seetion exposed at Taylors' brick- yard has been measured, giving the following results: Feet. 1. Sandy boil followed by brownish grey clay with boulders ... 3 2. Stratified bluish grey clay (making buff brick) 69 3. Brownish or drab clay, much jointed (making red brick). ... 11 4. Brownish yellow stratified sand 4 5. Blue clay with peaty Hakes 3 (5. Brown sand and gravel (false bedding) with thin layers of blue or brown clay fossiliferous 18 7. Blue clay (till) with striated boulders 3 8. Hudson River shales 30 111 The Hudson River shales, which are (juarried to make dark red pressed brick, rise about 30 feet above the Don, here prac- tically at the level of lake Ontario; and are covered with a thin layer of ty|)ical boulder-clay containing finely polished and scratched fragments of the under-lying C^ambro Silurian rocks with a few stones of liaurentian origin. The residue of the clay after washing discloses particles of ((uartz, horn- blende, feldspar, etc., evidently derived from Archiean rocks. From the upper portion of the clay, which is indistinctly stratified, I have obtained Unios and the specimens of W(tod submitted to Prof. Penhallow. The Unios had evidently lived in the place where they were found, since they were not at all watcrworn, still preserved their dark epidermis and fre- quently had the two valves attached. The till fills up all in- equalities in the previously eroded surface and forms a floor with a gentle southward slope under the whole city. To the south it passes beneath the surface of the lake at some points. I am informed by Mr. B. E. Walker that in excavating for the foundations of the Board of Trade building a few years ago two shark's teeth, apparently of Tertiary age, were found in the till. One of them is now in his possession. It is hard to account for this find, since no Tertiary rocks are known to exist this side of Hudson's bay. Some small outlier may lie hidden under the drift or may have been completely swept away by ice action. 1^ Intet'liluoial Fi ^xila,— 'Coleman, m >^' Abovo the till we find IS feet of sniul with Homo firu' j?ravei and 11 few thin liiycrH of clny, a (IcpoHit formed in shallow water with Hhifting currents as shown by the false bedding. Well rounded pebbles of Laurentinn and Silurian roeks occur, and the sands contain fragments of most of the minerals be- longing to Arduean rocks. Some layers are brown from a deposit of hydrous sesquioxide of iron. Shells of Pleur(»cera and Spha-rium are common throughout the sand, and about eight feet above the till there is a layer containing many Unios, mostly separate valves more or less waterworn. Above the sand is a bed of blue calcareous clay with Hakes of peaty matter, then a bed of unfossiliferous sand, followed by a thick bed of distinctly Jointed brownish clay, making red brick, probably corresponding to the Erie clay described in the Geological Survey Report for 1863. This is succeeded b}^ 69 feet of finely stratified bluish grey clay too calcareous for brick-making in the lower portions but yielding a butf brick from the upper layers. Vtry few peb- bles or stones occur in it, the few that I have found being sub- angular with some faces polished and others rough. Under the microscope it appears to be a fine "rock flour" containing a few minute angular fragments of quartz, orthoclase, micro- cline, etc., as well as many indeterminable particles. Towards the top this clay merges into an unstratified brownish clay with many boulders of Silurian and Laurentian origin, some fairly well rounded, others subangular and more or less striated. The line between the brown clay and the overlying sandy soil also is not well marked. In the soil and on the surface are many large Archiean boulders, one mass of gneiss measuring nearly six feet in longest diameter. The top of the section, 140 feet above the Don, is at the level of the plain on which the northern part of Toronto is built, a plain extending several miles to the westward, but cut otf a quarter of a mile to the north by the Davenport ridge. Sev- eral other exposures along the Don and its tributaries or at railway cuttings in the neighborhood show similar sections of stratified sands and clays, but, as far as observed, without fos- sils. The upper boulder deposit is better displayed at the end of the C. P. R. trestle, a quarter of a mile to the south, than at the quarry itself. Here ten or fifteen feet of sandy uo The American Creoloyixt. Kcbraary, li<9* clay coiitainiiif^ iKUildci-H, cHpccially of liiiU'Htonc, htantifiilly polislii'd aiui Ktriatcd (»ii Komc racoK, f'i>rin tlu' uppcriiiost layer, and rest upon the saiiK; thick bed of lliicly HUalilifd bliiish- t^ray clay obwiTvcd at the (juarry. The DaviMiport ridge, really a plateau riwitig ;W> or 4a feet above the plain to the south, in found, where laid open by«Mit- tinj^s for roads or railways, to consist in its upper part of un- stratifled sand with numerous peiibles and boulders distinctly polished and scored, the whole evidently a f,'lacial deposit of somewhat diiferent nuiterials from iliose of the till at the bot- tom of the series. These f^rjacial sands once extended much far- ther to the south than now, |)erhaps reaching the present lake sliore, but wave action has washed them away, leaving l)ehind the large boulders once so thickly scatter^^d over the site of Toronto, though now mostly removed for road-making pur- poses.* Comparing tin- section just given with one kindly furnished by Dr. lirodie from a locality now buried from view, at the Win- chester street bridge, there are below the level of the lake, resting on Hudson River shulc, six feet of uncertain materials, five feet of a deposit containing leaves, wood and Cyclas goniobasis ( V),and five i'eet of till with boulders ditfering from th(>se found higher up. The upper part of this l)ed rises a little above the level of the lake. Upon this follow first a lacustrine deposit, say ftfteen feet, with wood, leaves, (Jydas and llnios; next, glacial clay with very large boulders of gneiss, etc.; and finally lake shore sand, not continuous. A somewhat ditferent account of the section is given by Mr. Townsend, as quoted by Sir Wm. Dawson. f Reversing the order in which Mr. Townsend arranges the series, we find blue till resting on the Hudson River beds; then sixteen feet of alternating sand and dark-colored clay with freshwater shells and wood; three feet of ferrugin(»us sand with argilla- ceous nodules (one containing a maple leaf) ; twenty-four feet of tough, stratified blue '-Erie clay;" and finally twenty-six feet of fine, light-colored sand, with layers of clay at bottom. The lowest fossilii'erou s deposit, mentioned by Dr. Brodie "Glacial Phenomepa of Canada, etc., Prof. Ramsey, Can. Nat. and Geo!., 1859, pp. 328. Ho gives a section of Toronto ririft. showing boul- ders. tBuU. Geol. Soc. Am., vol. i, p. ;!15. J fiiffryhirt'ti/ h'ltsxih. — Cohnnni. 01 \l but not hy 'wr Townscnd, Ih pi'i-hapH prcj^lacial. The fifteen or sixteen feet of liieiiHtrine deposit just aliove rhe ti'l, corre- spond to tile L'nio- and i'leiiroeera- hearing iieds of the brlek- yurd. The flection measured i)y Mr. (}. J. Hinde at Searboro' Hifjjiits differs more widely from the one deM(!ribed in tiie present pa- per, since tliere tlie iowi-st boulder clay is separated from tlu' secoj\il by UO feet of fonsiliferous clay and sand.* It is clear that our drift deposits vary greatly within comparatively short distances. In interpreting the facts observed in the Don vul'ey we have a first Ice age in wliich the glacier worked i; the Hud- son River shales into boulder clay, kiu ading in a few Arcluean boulders, and spreading a tough carpet of till in a gentle slope toward the hollow of lake v>ntario, and then withdrew; fol- lowed by the waters of the ake, which stood 40 or 50 feet above its present level, if we s ippose no change in the h;,,iit of land above sea at this point. Air. Simpson supposes that the lake was ice-dammed at this stage,f and drained into the Mississippi, making it possible fo- iiioUusks belonging to the Mississippi fauna to invade waters normally flowing into the St. Tjawrcnce. The supposition is a natural one, but seems contradicted by the fact thatat presentthe watershed between lake Ontario and the tributaries of the Mississippi is several hundred feet above the level of the lake. I have seen no re- ports of buried channels going low etutugh to drain lake On- tario into the Mississippi down to a level only .")() feet above the present, thoi.igh of course, the ])ossibility of finding one cannot be denied. There seems more evidence of an old channel leading past SynuHise through the Mohawk valley into the Hudson.}; which would not account for the ])resence of Mississippi forms in Ontario, however. In whatever way they were introdiiced, there is no ilo ibt that during intergla- cial time eight or ten species of Unio, several no longer found in our waters, lived at the mouth of the Don, first on the scarcely disturbed surfa<'e of the till, afterwards on beds of sarid and well rolled gravel brought down by the river and *Jour. Can. Inst., vol. xv, p. 392. tProc. Nut. Museum, No. 9r)2, p. 593. JWright, Man and the Glacial Period, p. 202. 92 The American Geoloyist, Febniary, 1894 spread in its sliiillow estuary. On the banks of the prehis- toric Don grew iret's such as now flourish in tlie same region, yews and cedars, maples, oaks and asiies; as weil as the papaw, now, I })elieve. not occurring north of the hike. .Judging by the flora and fauna the climate was 03' no means subarctic, but on the contrary fully as mild as at present, if not a little milder. The length (>f tlie interglacial time was sufficient for the deposit of 24 feet or more of sund and clay on the Don and liO feet of similar nuiterials at Scarboro" Hights, and for the growth of large forest trees. It is gencmlly supposed, from the direction of glacial stria- tions and of the transport of iioulders, that the center from which the ice ratliated was at the watershed between the St. Lawrence and Hudson bay or somewhat farther east in Lab- rador, at the fu" ^llest not uu)re than 700 miles from Toronto. At the present time in southern Hritish Columbia n6v6 is scarcely found on mountains rising less than 8,000 feet above sea level, and glaciers hardly come down to 5,000 feet. It is probable that a depression of the highest points to 7.000 or 8,000 feet would com[)leteIy wipe out all the glaciers of southern liritish Columbia. So far as T am aware, no point reaches 8,000 feet above sea level between Ontario and Hudson bay, and no point in Labrador rises much al)ove (5,000 feet. Unless the northern watershed stood very much higher above lake Ontario than at present, it is in.possible to imagine a wide spread sheet of ice existing there during interglacial time, when oaks and nuiples and papaws flourished on the land' and Mississippi Unios in the waters only 400 or ilOO miles to the southeast. I know of no evidence proving that the glacial center stood at that time 8.000 ur 4,000 feet higher above lake Ontario than at present, and hence conclude that th.e.ice fields \vere completely melted diuMng'the interglacial epoch, instead of merely receding a conij)aratively short distance before ad- vancing again. After the deposit of the fossiliferous beds the lake rose to at least 140 feet above its present level, perhaps dammed at its eastern end by the return of the ice during the second gla- cial period, and thick beds of day were laid down in quiet water. Probably the Don at this time was a glacial stream, Inteiujldcidl h'osslh. — Vole hum. 98 bringing down rock Hour from the not far distant ice front, us the upper waters of the Athabasca now do, and depositing it on the floor of a hike too muddy and cold for life. A further advance of the glacier buried the stratified clay beneath 30 or 40 feet of sandy clay and sand containing num- berless subangular, striated stones and some boulders of Lau- rentian and Silurian rack several tons in weight. These ma- terials show little or no stratification and are not waterworn 80 far as 1 have observed. The stria* on limestone pebbles are sharp, and there are flat pebbles of soft Utica shale here 20 miles from home, which would have been destroyed if trans- ported by wave action or by running water. The clays under this second glacial deposit appear to have been very little dis- turbed by the passage over them of the glacier. When the ice of the second glacial epoch retreated, the lakes, whether dammed by an eastern tongue of ice or lowered to the level *)f the sea, formeil a beach now 140 feet or more above the lake, Spencer's Iroquois beach.* Wave action re- moved the loose materials as far as the Davenport ridge, which forms so prominent a feature of the northern part of the city, the heavier stcuies being left where they rested as a boulder pavement. At the Iro(iuois stage the lake is cont-idered to have drained into the Hudson. Several of the Unios exterminated by the second advance of the ice did not re- turn when the ice retreated again. Was the continuously icy water unfavorable to the species which failed to return ? Mr. Simpson sup]K)ses that some change in the drainage system prevented them from reraining the lost ground. f The cliange from the Iroquois level to the present one miist have been rapid, leaving no time for the formation (^f intermediate beaches. Since the change of level the Don and its tributa- ries have had time to renu-ve the drift deposits tiown to base line for more than a mile nortli of Toronto l)iiy. NUTK ON lNTEH(iLA8, Prof. A. F. Coleman, of Toronto, sent me three e.\eellent specimens of interglaeial lignite for determination. They represented fragments of branches which must have been several inches in diameter when grow- ing. Outwardly the material api)eared well preserved, and after boiling in carbonate of potash for about two hours was found to be sufHciently soft and free from siliceous matter to section freely. It was therefore imbedded in parattine and sectioned on a microtome. Upon examination of the sections it was found that the struc- ture had been greatly altered by decay and compression, so that, with the exception of nuuiber two, reference to species could not be made with certainty. As, however, previous experience has shown the close iden- tity between the interglaeial vegetation and that of our own time in the same locality, it is probal)ly admissible to refer doubtful species to those modern species which they most nearly approach, and it may be that future material, more perfectly preserved, will enable us to decide more definitely as to the specific value of such provisional reference. There is, at any rate, the great advantage of avoiding the introduc- tion of new names which nujy hereafter require to be abolished. No. 1. FnAXINUSgUADBJANGULATA Michx. The specimen marked No. 1, was much altered by compression and decfiy, so that the tranEverso section was much disturbeil, while the longitudinal sections exhibited but poorly a very few of the characters upon which specific distinction is to be based. From the former, how- ever, it was at once clear that the plant was a Frfiximus, and as, of ex- isting speciee, it seems to approach most nearly to /". qmnlnuKjuhtia, I consider it proper to refer it, provisionally, to that species. So far as 1 am aware this is tl i first record we have of this genus in the intergla- eial of Canada. Fraxinus quadrangulata is at present found in Canada along the shores of lake Erie, and particularly about point Peter. {Ma- coun.) No. 2. Taxls haccata L., var. canaoknsis Gray. Specimen No. 2 showed the characteristic structure in cross section very clearly. In longitudinal section the u.sual markings of the tracheid walls were found to be largely obliterated, even to the bordered pits, Inter glacial Fossils. — Coleman. 95 but enough evidence remained to enable me to refer tho specimen with- out doubt to TaxuH haccata L.. var. canadensis Gray. This species has hitherto proved a somewhat common onis in the interglacial of Canada, particularly in the Don valley* No, 3. Qdercus obtusiloba Michx, Specimen No. 3 showed considerable alteration. While in transverse section the quorcic characters are well defined, in longitudinal sections the Btruciural markings were almost obliterated. The resemblance of this wood to modern oaks was found to be most marked in the case of Quercns obtusiloba Michx., to which I therefore refer it, provisionally. This is the first time an oak has buen found in the interglacial of Can- ada. Quercus obtusiloba is now found in southern Ontario, and particularly about the bay o f Quinte (Macoun). *The Pleistocene Flora of Canada, Bull. Geol. Soc. Am., i, 321. mm I . , "^'""mR- "'z. * w •" wm» Tt)e Americai> Geologist ^* J'®«55. '"^P*'^. *> J^ «nd 1»» be«n idued ttaaOUjr •inc« th«t date. It m iMrt; the olvaa of any institution, uOr of any wetion <« the eotuatn , ndr of any party. Its GdltQiiai ftosrd Is made ap of tfl^fe ac^TO Qeol.'>s!ets, whcsd plsees of j^idencB ►< se^twou train i^'^'*'*»**$i^f*?*'¥8 «»«''»'? *B? Iak08to the QuU. pn« i^ oonneoted wlffi the Uaaadlim 0^c^«al feirrey. «iiree luiTe beeta enq^a* ol the Cni<»d 9tat«» Se- olosrtcol PHttey. tjjo are SMte.GeologiBtg, fonraw pnidbsed mi State SnurertL flye are FrofiBMow ti Statu UnitMMtiea or otliBr iMite {Stations of learning antl all are actire paTtMiPimts in the development of Amenean Qeology. It Comtatot Orlgiiaa artloloa by AmerioaaOeologlttftandtnontlily reyieiws of current Geoloirioal literatw*. , It glyes personal «ad leiebttdd newt Itia oouttopoUtan in ite soientific scope and iO on to the fnoug^hifol and oaref ud oontribatioas of all Qeologiiits. SubttcHptton Is f 3»ft0 per Year ; and $4,00 td Foreign fieanf rleii. Bampl* OoplM. twesty orats. Baok avmbers o«a m ssfipUnA at ti.80 »«y ▼o)Qm*. Two Tolii)B|& yMvlr. «Mlt ef Bid}* tOiaa 4M »««•■■ ^ Address THE eEOLOfiiCAL inJB(.l$H(NG eOMPANI^ MlM»|||kl>*ou«, MINN.