IMAGE EVALUATION TEST TARGET (MT-3) // O (/u 1.0 I.I 1.25 IM 2.2 IM 111= \A ill 1.6 V <^ /: Photographic Sciences Corporation 33 WEST MAIN STREET WEBSTER, N.Y. 14580 (716) 877-4503 ^ L1>^ iV iV :\ \ ^Ar.-;v--_^- '^■_£^ ' ■ >k ^w ^^a S m ^ Ifc^^U '&^ M Jm' Mo ^ ■^^ ^^^ T' y^- -- ^^ss :. .1 EX UBRIS^^^ pi^ piP^v'iiiii"::yr''-v:| ^i0,y ^»^3 *l*l^ifSi^l!!ll«,lllllilffl iHi Shction IV., 1897. [107] Tkans. R. S. C. in. — The Bay of Fundy Trough in American Geoloyical IL'sfori/. By Professor Bailey. (Read June 23r(l, l.S'JT.) The fact that a northeastern or Aciuliaii basin, not only physio- graphically distinct from other regions of tho American continent, but to a considerable extent independent also as regards its biological pro- gress, was a feature of that continent even from the earliest Paheozoic times, was first brought prominently to notice by the late Prof. J. D. Dana, in the earliest edition (18(JG) of his Manual of (ieology. In that work the references to this sui)ject, under the heading of "The Kaslern Border Kegion," were for the most part of a very general character; but in the last edition of the same work, published thirty-one years later, the same idea is elaborated in much more detail, and several successive sketch- maps are presented, emboilying the autiiur's views as to the geographical evolution of the region to which they refer. As these views have reference to a most important subject, and are likely to be widely read and accepted, any facts which may tend to confirm or to modify them can hardly fail to be of value. It is the purpose of the present paper to discuss some of these conclusions, especially so far as they relate to New Brunswick and Xova Scotia, in view of such information as recent inves- tigations of the latter are calculated to atl'ord. Among the features which especially distinguish Prof. Dana's latest presentation of the subject is that of the recognition, among what he terms "areas of geological ])rogress," of an "Acadian channel," this being described as embracing the Bay of Fundy, and thence extending easterly to western Newfoundland, and in the opposite direction along and otf the New Englanil coast, probably as far as Narragansett bay. This Acadian trough is further described as persisting through Paheozoic time, and as being separated, at least during the earlier portion of that time, from another and more northerly trough — designated " the Gaspe- Worcester " or " Miiine-Worcester ' trough — by a i-ange of Ai'cluean rocks, possibly extending across the tiulf of St. Lawrence to Newfoundland ; while to the south it was delimitetl l)y another Arcluean range, termed the " Acadian protaxis," occu[)ying, in particular, central Nova Scotia, and thence extending westerly to Long Island. Finally, in the series of sketch-maps, to which reference has been made, rej)re8enting the sup- posed geographical conditions of eastern America in successive periods, various limits are assigned to the submerged and emerged areas, the Nova Scotian protaxis being retained in all. 108 llOYAL .SOCIETY OF ( ANAI>A ^ 'riic'^o views would, (licivlorc, make llu- oi'iii'iii nt llio Hiiy ol' l-'iiiidy ti'oiiii'h, as well us tlu' asMtciutud ridi^-c;s aiul (k'|»ressi()iis. coincidi'iit with and tiu' rcsidt of the very earliest oroifeine iiioveiiienfs of which we have aii\- kii<)wledi;'e. and to any oik- interested in the proliaMe history of tins j.oi'tioii of the eoiiiilry. must lie rei^'arded as of extreme iniportanee. Wo have now lo in(|niiT how far tluyare in aefordanee with our present knowlcdii;e. In tlir lii'.-t plaee il is lo he noliciMJ liiatin I'eeogni/.ini;' twolndtsonly dt' Aicliaan ro(d-reat central basin of Now Eriinswiek beiiii;' at the stimc tiim' made continuous with tlie l>ay of l-"und\ iroui;'li, from which tlie>i' l'rc-( 'ainlirian roidvs now coni|iletely seiiarale il. .\s to the ridii'es north of theeeiitrul basin, now occupied by the Coal measures, and dividing;- the latter from tlu; (ias|ie-\Voi'cestor tr(iUi;di. it is true that a portion of these have, in the reiiorls and nia]is of tln' (leoloii'ical Survey, been represented as Arcluean ; but even if this bo their aii'e of which there is as yet no delinite jiroof, the area which they occupv is not lara;e. and no evidence whatever is available to show that thev were eoniu'Cted citliei' on the one side with the rocks of New- foundland, or on the other with those of southern .Maine and .Massa- chusetts. It seems much moi'e probable that, if Arcluean at all, the rotdvs in (piestion rej)resenl one or more of several insular i^'roups in the Cam- lii-ian seas, of which others were to be found in nortiiern Maine, in soutli- ern New Brunswick and in eastern Nova Scotia. It' now we consider the facts connectt'd more particularly with tl:e Bav of i^undv trough, wi- tind dehiiite j)roof not only of the existence of terrestrial areas in this vicinity at the opening ot' the ("anibrian ei-a, but that these were so dis|)o.sed as to determine u northern border to the trou'i-h. not widely dilferent in position from that whicdi now limits it in the sanu' the west of the St. John river form one broad belt, being to the eastward of that stream divided into several, possibly insular, ridges, by intervening parallel troughs of Cambrian sediments. 4 4 'A [BAII.hv] THE BAY OF FUNDY TROUGH 109 i ■■;* Tlic iiortlifi'ii hortlc'i- of tlic liuy nl' Fundy tr()Ui;-li iK'iiii,^ tlms lixod fortlio early Piilu'ozuio witli soiuo dcf^rt'o of certainty, tlioui^li not in the poNilioti iis.sin'ued to it in the manual of Prof. Dana, we liavi' now to in(iiiire as lotlie corresixtndiny lioi'dei' on the south. At the pre.sent time ihi.s southern horder is, llii'oui;-hoiit its extent, marked by the truppeun range of the Nortli .Mountains, wliicli cannot possihly be okler than the Trias, and is probably .Jnras.sic. Kliininating this and the as.soeiated reel .sandstones, and uniting, us wouiil then i)e tlu^ case, the waters of the Minas basin. Annapolis basin and .St. Mary's bay with (hose of the Bay of J'undy. we lind the vuvU-^ whicii luwt border the trough on the south side to l)e of .Silurian or Eo-I)evonian age, rest- ing ior the greater part of their length ujion the granite ridge of the .South .Mountains, tlu: latter forming the backbone of the Xova Scotian peninsula. But is the backbone Areha'an ? It is .so represented in Pi-of. Dana's manual ; Itnt it is safe to say that, as regards all that portion at least of the })eninsula which now lies south ol'the present Buy of I'midv, it contains no Arclnean rocks \vhatever. The granites were loni;- since described by Sir Wm. Dawson as being intru.sive and of Devonian a<>'e. a conolu.sion wdiich all sul)se(|uent investigation has tended to conlirm ; and though both that author and Dr. Selwyn wei'e disjxwed to regard the liornblendicand ehloritic rocks of Varmouth as probably Jl;ironian. there is now no (jueslion that these too are really moi-e roceui, they being a member, and by no means the lowest member, of the same series as the gold-bearing nx'ks of the southei'n coast, usually regarded as ( 'aini)rian. Thus there are no rocks, at present disclosed to view, in the ])()riioii of Nova Scotia lying south ot the |)re.sent Bay of Fundy. which can ])roperly be pointed to as a portion of the "Acadian ])rota\is"; the only rocks ol' Areha'an age to be found in the pi'ovince being limited to the island of Cape Breton, and possibly to some poi-tions of {]\v ('oiic(£uid mountains. Before dismissing the Pre-Cambrian rocks it is interesting to note, in the case of tho.se of southern New Brunswick, the large amount of vol- canic matter which they contain, and which, m the rocks referral to the Huronian system alone, has been estimated to reach a thickness of at least 10,000 feet. So vast an accumulation of igneous matter aloiii"- lines parallel with the |)reseiit course of the Bay of Fundy troundi, not o liy strongly marks out the latter as a subsiding geosyncline as far back as Pi-e-Cambrian time, but as exhibiting, even then, conditions which, in later eras and in the same geosyncline, were rei)eated in the igneous extru.sions of the Silurian, the Devonian, the Lowei" Carboniferous and the Trias. We have now to consider more particularly the information to be obtained from the study of the Cambrian rocks. Sec. IV., isy?, fi. no ROYAL SOCIKTY OF CANADA The littoi'iil ()ri,i,nii of llit'si- fockw. ;is rcifui'ds 1 heir curlier iiioml)frs, is, in Nt'W 15niiis\vicU, sutHciontly attcsU'd liy the coiirsoness and l)iill< of till! coni^loinrra It' which constitute thesu meniliors; while their <)riifin is as cjcai'iv indicated in thi' tact tluit llioir contained peidiU's are identical with that ol' the Arclucan rid/^es near by. Kven higher in the aeries, thoni^h increasing- tineness indicates a dee)ienini;- of the waters in which the Iteds were deposited, the occurrence of wave-marks, ripple-inarks, mud-cracks and worn^ trails continue to atl'ord conclusive evidence of shallow water origin. And. frnall}', this conclusion tinds contirmation in the nature of the fossils, the well-known studies of which, hy Matthew, have I'lialiU'd him not only to determine, in ifreat detail, the successive changes in that fauna as affected by the varyinn" conditions under which it was develojK'd, but to draw probable conclusions as lo its relations with e(iuiv;dent faunas elsewhere, and possible migrations from one rey;ion tn another. Tlie most important ])oint in coimection witii the comparisons. .St) far as the subject under discussion is concerned, is that of the much closer resemblance of the Acadian ('ami)rian I'auna to that of l']uro|ie than to that ot interior America. I'\)llowini;- tlie su, regar.ls both their extension and their depth, is scarcely less remarkable; while their (diaracier is such as to indicate ( hat they could hardly have been depo.-iied in vei-y deep water or that their source was very fai' distant. It is true that, as compared with the ("ambrian rock of Xew lirun-e of the system, but apart from their ai'eiuiceous character, the oi/currence of rip])le-marks and t)ccasionally of pebble beds leaves little tloabt of their shallow water origin. And yet over the whole of southwcvstern Xova .Sc(jlia we liiul nothing to indicate the .souive from which they came. On i lu' contrary, it is now Icnown that, with the exception of the granite and sm;ill areas of lOo-Devonian and Trias, to be ])resently noticed, no other rocks than those of the ('ambrian system (so called) are to be t'ouicl over all this region. As, moreover, (here is reason to bL'lieve that the granite itself is but an excessively ni'Mamorphns ■(! condition ot' the ('amiu'ian ([uartzites (this metumorphism run occurring, however, until a much later period), we are I'orced to the conclusi')n that all the portion of Xova .Scotia under discussion was, during a large p>)rtion of t/'ambrian lime, in a con- dition of submergence, forming a iiorlion of a sul)sidin"- troU'Wi, whose southern aiul eastei'n limits cannot now be defined. As regards the slates which overlie the (puirtzites, it is evident that they indicate a .still deeper submergence, po-fsibly to considerable depths, Tiieir thickness has been variously estinuite(i at from 4,000 to lU.OOO ft., but if only 5.00U ft., this, if added to 10,000 fi., as a reasonable estimate foi- the quartzites, would indicate for the whole (,'ambriau .system in lYova ■Scotia a sub.sidence of nearly three miles. It may be that this sul)sidence will, in i)art. account for the remarkable absence of fossils in the Cam, brian rocks, the presence of cold currents traversing the submerged area being unfavourable to the growth or spread of organic forms. 1 112 UOYAL SOCIKTY OF CANADA ^ [f now wc iidviiiu'c ii stt'|i ii|i\v:iril in t lie ijjoolo^ioiil scaK'. we liiid tliiit tlio int'oi'inution tola' olii;iiiu'(l is still vi'iy scanty. No rocks of undoubted Canilifo Silurian atc^' luivc been idcntilicd in tbat part ol Nova Scotiu wliicli lies dirccth' south ot' tlic prr tMit Hav of l''uiidv, and tlicv occcur very sparini^ly on its noi'llici-u border. It is j)robablc, however, tbut extensive areas ol' such i-dcks liave been rontoved by di-nudatiou, the f)irti/iiitf)iu( hIuIcs found at llu' niouth of the St. Jolni rivei- show inir such relations to tlio C;anil)rian ro(!Us, on which they rest, as to indicate that ihey lit one time completely covered them. (.Nfatthew.) It is ]»roliable that tluy s])read over much of Nova Scotia as well, init of this nodetinite jiroid' has yet been obtained. In the LTp])cr Silurian the data ai"e more ample. In New Briuiswick the rocks of this ai^e ai-e widely disti'iltuted. but betwei'U those of the northern and those of the .«" that they were de[)osited in simllow bays and straits in and amoui;- the old lluronian hills, these latter then exi.stinu^ as islamls in the Silurian sea. There can be but little doubt that the source of these materials, so far as New Brunswiik is concerned, was still, as in the earlier Cambrian, to be found in the waste of the old Arclucan ridi^'cs iieai" by. and remnants of which, like islands, are seen projoctiiiii; tliroiigli them ; but while the northern edge of the trough now occu]iied by the Bay of Fundy thus con- tinues to be more or less clearlv indicated, we are still whollv witliout evidence as to its southern border. We do. indeed, tiud, all along the southern side of the Aniuipolis vnllcy. in the basins of Bear River,, Clements, Nictau and Torbrook, a great body of I'ocks, which are abun- dantly ibssiliferous and contain extensive iron ore deposits, both indicative of their marginal or shallow-water origin; but through much of their length the rocks with which they come into contact are granites, which at the same time show, b^- their peni'tration and alteration both ot' tlie fossil beds and tlie ore beds along their line of contact, thai they are of later origin. The fo.ssil- bearing strata being clearly of Ko-l)evonian age,, and the granites as clearly of later Devonian origin, while to the south no rocks more recent than those of the Cambrian ai'e to be found, we are again forced to the conclusion that, as in the earlier Paheozoic, so through the Silurian and Devonian eras, the Nova Scotia peninsula, in its western part at least, still lay below the sea level, the old protaxis, iT any, lying outside of and to the eastward of its present limits ; also, that ■I [nAll.KY] TIIK I'.AY OF MNDV TUoCdII 113 it \v!is to till' fdiitiiiucid sulwidciici! of tin- l!;iy of l''iiiiil\- iroiiLfli. nf which Novti Si'oijji may liiivo ivpi-cseiitcd the Jixial line, tiial we an' In asrriln^ the vast iminhoi- of ii^ncoiis dyivos hy wiiich. on lutth >i(lcs of the iiav, its st'diiiuMits ai-t' intiM'si'(.'lod, us well, prolial'ly. a-; the onyinalioii of iIh- ,i!;raiiitn whicli. a,i,Miii on lioth sides of the 1-ay, was t h(! closing cvi'iii n|' tiio hcvotiian aj^o. In thu distriliutioii. cliaractiM', and fo-ssils ol' the fiowor Carlioidfcroiis roclvs in tlic Acadiati rci^ion is allordcd jn'ctly satisfactory inforniation us to tiif condition oi' that vui,non at this hi" " ;>"-'i)d. At its opcninij the hind on cillicrsidc ol'tiic i!ay of JMindy t roui^di nndoubtcilly ntood somcwiiat above its |)Pesont level, the main dill'crcncc between its cotitonr at that tinu' and the jnvsent b(3iui,^ in the al)sence of tlieXorlli Moun- tains, wliich now mark its bordei-; but as the a^-e advanced, ditrereiitial inovd as a long island. ])arallel with tho axis of the trough. As in earlier periods, continued .subsidonco led to igneous extension.s, but these, instead of being, as heretofore, of granite, were now conlined to more liinitotl areas an,LCi/:i'>s. toii'i'tlior with theii- vory sparing occurronca to the westward on the Xew lirunswick sliorc and out iro absence on that oi' Nova .Si'otia. woiihl si'i-ni to indicate! citlicr that the conditions for their accuinniation were liero less tavoui-ahie. or that, if ever dejwsited, they liav'' iieen i-emoved by detiudation. Pi-of. Dana .seems to have regarded the coal-niaiting swatnjis of tlie (Inif of St. Lawrence as liaving been connected, tlwougli the Bay of Kiindy, with those oi'Ma.ssachusetts and Rliode Ishmd ; but the I'acts stated above seem rather to favour the idea lluit u bari'iei- of some lides of the latter as well as in the ishintl of Grand Manan. but nowherts at a distance I'rom the present limits of the bav. The strata are also faulted in the tlireclion of the axis of the bay. Of latei' .Me. large eiiibeibled blocks of such ti'ap. and hence that tlie^e sli'al;i. il' noi contemporaneous with, are moi'c recent than the latter. Ijut no li)s>ils have yet been fonnd by which their real age can be deternuned. and no satisfactory conclusions with ivgai'd to them are as yet pos>ible. li (inly I'eniains to consider bi'ielh !ln' possible condition of the Bay of l''undy trough in the (Quaternary era. As to the (ilacial or Ih'ift Period, the ([uestion here, as elsewhere, involves a decision between the rival t heories which would, on the one hand. pre>nppo.-e a gcnei'al npwai'd continc'ntal movement, with a corre- sjiondinu' enlargenieiil, liot b in ex ten i and (U'pth. of the polar ice-ca]>. and the conse(|uences incident thereto, and. on the other, would advocate a tleju'essiou ratliei' than elevation in the higher latitudes, with local glaci- ation only and a much wider well as by the tilling of the former b}' ice; in thi.' other view, though ivtaining its general position and form, the bay would have somewhat wider lindts. and. as in some earlier periods, would become a strait opeidng freely into the (iiilf of St. Lawrence, leav- ing Nova Scotia disconnected with the main land. The glacial pheno- mena of the latlei' would tlius be almo.'jt whollv local. ■m UMiiiMil [uailky] THE BAY Ol' FUNDY TROIKHI 118 4 i V I i While tlie sul)jefl is too icnt^lhy tor lull discussion her.;, the present writer leels eomi)elle.l to express his dissent from the views lately put forth upon this subjeet by Mr. Chuliiiers. of the (ieolo^'ieal Survey, as tavouriny- the seeond of the two hypotheses referred to. While fully admittiii!;- the faeta l.rouii'ht forward by that gentleman in sup]u)rt of his conclusions, the writer believes that these have all to do with the closing portion of the (llacial Period and that a far greater array of facts in favour of u ])revious condition id' general or continental glacialion can easily be brought forward. Thus, the vast numbers and the enormoiis size of the granite and Canibrian boulders strewed over the whole peiun- 8ula and upon its highest summits ; the fact that here, as elsewhere, the chief movement of the boulders has been in a southerly direction : that among the boulders occurring on bigby Neck and Hriar Island are some wholly nidike anything to be found in Nova Scotia, hut closely resembling thoscin so;ithern' New Brunswi(dv. while blocks of the characteristicN(. rib Momitaiii traps occiii' all along the south side of St. Mary's bay, as well as on the Atlantic shore oi' Yarmouth and Shelburne counties, show a general movement southward, such as could only be possible if the whole i)enin- sida were covered with a single icy mantle, and this a j.ortion of a still greater ice sheet coextensive with the northeastern ]»orlion of the conti- nent itself When to these evidences of continental glaciation we add the wonderfully ])erfect illustrations of moraines and kaiues. some of the latter thirty miles in length, with which the interior of the soutli western counties abound : the eimr.se and ])arallelism of the numenms tlord-liko indentations of the .southern coast, accompanied, as they frequently are, by evidences of glacial ploughing, which ;ire phenomenal in their char- acter ; the similar direction and parallelism of the transverse troughs, such as Dili-by (\\\{. Sandy Cove. Petite and (irand Passages, which more or less completely divide the North .Mountain range, and which again show evidence.- (d' glaciation to and below the present sea level ; iht; pheno- mena, as a whole, appear to be of such a character as to denumd some more general and some more energetic source than that of sudiiee as would gather around a few low islands, or even from the entire province. That evidences of a northward transfer of drift are to be found in the Aimaitolis valley, in the occurrence there of numeious boidders derive.l from the South >biuntain graiute. is, of course, not to be denied ; but. in the writer's opiinon. these boulders belong only to the closing era of the (ilacial i'eriod. their northward transfer being the natural result of the higher lands, sucdi as the South Mountains, being the last to become freed of their burden of ice, and, therefore, for a time left in the condi- tion of mers dc ijlaee. from which ice streams might descend in any direction. In partial contirmation of this view it may be of interest to note, that, according to the statements of farmei-s occupying the Anna- polis valley, the granite boulders in question are never met with at (h^pthf of more than ten oi- twelve feet below the present surface. 116 KOYAL SOCIETY OF CANADA Jii coiili'ust witli tlie HUppoaed elevations of the Glacial J'oriod. liio evidences of depression in the succeeding Champlain Period are clear and unuiistakalile. Not only do we find along the New Brunswick shore marine clays, us at St. John and St. Andrews, lilled with Post Tertiary- fossils, Init similar clays and associated sands also occu])}'. more or less completely, the Annaj)olis valley, indicating a lorinci- considerably greater depth to that valley. At St. John the height of the beds above the pre- sent sea k^vel is about 200 ft. ; in Nova Scotia the clays of Middlcton, holding marine shells and U()hiuraus, are not more than twenty or twenty-tive feet above the tide ; but it is probable that the total submerg- ence was much more than this, with the result of connecting Anna])oli8 basin eastward with the Basin of Miiias and westward with St. Mary's bay the North Mountains and their extension in Digby Neck being reduced to low-hing ritlges and islands. The evidences of modern subsidence in and about the Kay of Fundy, as shown by the submerged forests, eroded shell-heaps, etc, need not, of course, be here dwelt ujion. but are in accordance with the movements of earlier times, and sinularly point to this Bay of Fundy trough as u prob- able line of comparative instability in the earth's crust. In presenting the views advocated in this paper the write'/ is aware of the objection which may be urged against them as being too theoi-etical. But the facts of observation are only of interest and value as they are brought into correlation, and used in exphuiiition of the events or pro- cesses by which they have been determined ; and, as in every branch of scientitic incpiiry. the "scientiiic imagination,'" as it has been termed by Tyndall, must go hand in hand with observatioti and trial, he trusts that the ett'orts here made to discuss some of the probable phases in the development of an important portion of the continent may at least be suggestive of further lines of inquiry. I ' iMMuiiASKi)..^;;^.^^:i|k/