Compagnie Française Des Pétroles

COMPAGNIE FRANÇAISE DES PÉTROLES

NOTES ET MÉMOIRES

N° 1 : COLLOMB (G. R.)- — Etude géologique du Jebel Fezzan et de sa bordure paléozoïque. 36 pages, 3 figures, 1 carte géologique en couleurs hors texte. Mai 1962 (épuisé — out of print).

N° 2 : MENNIG (J. J.) et VITTIMBERGA (P.). — Application des méthodes pétrographiques à l'étude du Paléozoïque ancien du Fezzan. 64 pages, 54 figures. Juin 1962 (épuisé— out of print).

N° 3 : AYMÉ (J. M.), COUPPEY (C.) et MARQUIS (C.). — Stratigraphie du Massif de VAffolé (Mauritanie). 20 pages, 3 figures. Juin 1962 (épuisé — out of print).

N° 4 : AYNARD (C.). — Vers une rationalisation de la gravimétrie. 20 pages, 4 figures. Mai 1962 (épuisé — out of print).

N° 5 : JACQUÉ (M.). — Reconnaissance géologique du Fezzan oriental. 44 pages, 16 figures, 1 carte géologique en couleurs hors texte. Mars 1963.

N° 6 : SACAL (V.). — Microfaciés du Paléozoïque saharien. 30 pages, 100 microphotographies, 4 dépliants. Décembre 1963.

N° 7 : HOSSIN (A.). — Calcul de la porosité utile dans les grès argileux (Calculation of useful porosity in shaly sandstones). 96 pages, 31 figures. Avril 1964.

N° 8 : MASSA (D.), avec la collaboration de COMBAZ (A.) et MANDERSCHEID (G.). — Observations sur le Siluro-Dévonien des confins algéro-marocains. 188 pages, 18 figures, 2 hors-texte couleurs, 9 dépliants. Août 1965.

N° 9 : BUROLLET (P. F.), BYRAMJEE (R.) et COUPPEY (C.). — Contribution à Vétude sédimentologique des terrains dévoniens du Nord-Est de l'Écosse. 84 pages, 27 figures, 30 planches photographiques, 5 hors- texte, 1969.

N° 10 : MAURIN (A. F.) et RAASCH (G. O.). — Early-Frasnian stratigraphy, Kakwa-Cecilia Lakes, British Columbia, Canada. 80 pages, 53 références, 22 figures, 12 planches. Décembre 1972. AoW

A. F. MAURIN AND G. O. RAASCH

EARLY - FRASNIAN STRATIGRAPHY, KAKWA - CECIEIA LAOS

BRITISH COLUMBIA - CANADA

1972

A.F. Maurin : CFP - 39-43, Quai André Citroen 75739 PARIS CEDEX 15 - FRANCE G.O. Raasch : Raasch & Associates - Consulting Geologists Ltd - 3 - 1448 - 17 Av. S.W. CALGARY, ALBERTA. CANADA ABSTRACT

After 1968 field reconnaissance, a party spent three weeks of summer 1969 in the General Kakwa area (British Columbia). Northward shaling-out of Early Frasnian (Flume carbonates) was detailed both sedimen- tologically and paleontologically. Field involvment of these techniques secured appropriate faunal sampling which permitted later detailed study of faunal assemblages during winter 1969-1970. Strata herein studied cover this part of the Frasnian outcrop generally known as the Flume member and stratigraphically correlate with the Beaver Hill Lake — Waterways subsurface section, and northeastern Albert a expo sur es. The four studied sections exhibit the shaling-out of Southern carbonates deposited on a shallow open marine shelf. Tentative build-ups were erected at the margins of the shelf amidst biostromal banks. Stromatoporas were the major agents responsible for such reejïng. Northerly deepening conditions, or geographical changes in current regimes, hindered both frame builders' life and carbonate déposition, favoring shales accumulation. Marine conditions were almost the same along the horizontal slice of water for bottom dwellers such as Brachio- pods. An extremely rich Brachiopod fauna allows very detailed corrélations between sections spread over a 15 kilométré strip (coupled with classical cor al associations). Part II deals with paleontological breakdown of the Flume section into five main faunal assemblages. The quality of collected material is such that the three medial assemblages are of uppermost value for correlating eastward into the Alberta Plain subcrop, the well-described outcrop of Waterways, and subsurface of Northwest Territories. Corals and Brachiopods corrélations are extended to United States. With the help of published Conodont and Cephalopod evidence, relationship with European zones is tentatively established. A réévaluation of the full Frasnian biostratigraphic zonation is proposed in Appendix with emphasis on lower zones, namely DFR 2 Ladogioides pax zone, DFR 3 Atrypa scutiformis zone (gathering assemblages II and III), and DFR 4 Atrypa gregeri zone.

(80 Pages, 53 References, 22 Figures, 12 Plates)

RÉSUMÉ

L'affleurement étudié se trouve dans les Montagnes Rocheuses Canadiennes, en Colombie Britannique, près de la frontière avec F Alberta. Après des vols de reconnaissance effectués en 1968, une mission de terrain consacra trois semaines de l'été 1969 à étudier le Frasnien de la région du Lac Kakwa. Le passage latéral carbonates-argiles de la partie basale de ce Frasnien (formation Flume) fut l'objet de travaux sédimentologiques et paléontologiques très détaillés. La présence d'un paléontologiste dans l'équipe était un gage de qualité pour l'échantillonnage des faunes. L'étude de ces faunes fut effectuée à Calgary (Alberta) l'hiver suivant. Ce numéro des Notes et Mémoires traite donc de la partie inférieure du Frasnien affleurant en montagne, communément appelée formation Flume, équivalent stratigraphique des Formations BEAVER HILL LAKE ou WATERWAYS, bien connues en subsurface de la Prairie Canadienne (Alberta). Plus au Nord-est, le biseau d'érosion contre le Bouclier Canadien fait affleurer d'autres termes équivalents pour lesquels le nom WATER WA YS a été défini.

Cette formation Flume définie dès 1930 par RAYMOND dans la partie montagneuse de la vallée de la Rivière Bow est encadrée à la base par des couches Cambro-Ordoviciennes érodées, au-dessus par des argiles ou des carbonates Récifaux. Dans la région étudiée, en Colombie Britannique, cet affleurement marque la limite d'exposition vers le nord de ce Flume classique, sous un faciès connu en Alberta, vers le sud-est. La transgression Frasnienne au-dessus des terres émergées au Givetien et au Frasnien basai (la "Peace River Arch" et la "Ride d'Alberta") est particulièrement bien contrôlée vers le sud, depuis la région de Kakwa où le Frasnien inférieur (Flume) est plus complet par la base que son équivalent d'Alberta (région de Jasper- Banff, dans les parcs nationaux).

Le lecteur trouvera en fig 22 un résumé schématique de ces caractéristiques transgressées sur de vastes zones de l'Alberta et de Colombie Britannique Nord-occidentale. Il faut aussi noter que les argiles sus- jacentes peuvent contenir des accidents récifaux d'importance économique majeure : les récifs Frasniens du LEDUC en sont l'expression en subsurface.

Partie 1 Les quatre coupes présentées montrent le passage graduel des carbonates aux argiles à l'intérieur d'une plate-forme épicontinentale très peu profonde. L'envahissement argileux se fait progressivement depuis le nord, pour les termes inférieurs. Des tentatives de construction récifale, vite étouffées par la sédimentation argileuse, s'observent dans la partie externe de la plate-forme. D'une manière générale cependant, la présence d'organismes récifaux se traduit par l'accumulation de biostromes à Stromatopores. Une analyse de ces phénomènes récifaux aboutit d'abord à l'individualisation de communautés de Coelentérés : le nom de M. LECOMPTE est évoqué pour sa grande contribution à l'écologie de ces commu- nautés. Du côté canadien, retenons les travaux majeurs de FISCHBUCH (sur l'équivalent du Flume en subsurface) et d'EMBRY-KLOVAN (sur des phénomènes récifaux du Frasnien supérieur de l'Ile Banks en Arctique). Ces derniers peuvent s'appuyer sur l'exceptionnelle qualité de l'affleurement pour chiffrer les tranches d'eaux propres à chaque communauté. Les trois communautés majeures rencontrées à Kakwa-Cecilia sont : — A - Communauté à Amphipores et Stromatopores bulbeux — B - Communauté à Stromatopores bulbeux et Coraux rugueux — C - Communauté à Stromatopores lamellaires et Coraux rugueux Tous les termes de passage existent, ce qui rend l'interprétation écologique très délicate. Parmi la faune associée à la niche écologique des récifs, signalons la présence de Gastéropodes et Cépha- lopodes géants, à test très épais. Ce phénomène biologique est rapproché de celui de la Zone des Monstres de GOSSELET, en Belgique et en France.

Les phénomènes récifaux proprement dits sont discrets : si dans les coupes orientales Cecilia Nord et Sud (KW7 et 6) une masse blanche, dolomitisée, à fantômes d'organismes lamellaires, laisse soupçonner un développement biohermal, les pauvres conditions d'affleurement interdisent toute analyse. A Wallbridge au contraire, la dolomitisation sélective de petites masses anomaliques en permet la description : tous ces phénomènes sont peu étendus et séparés entre eux par d'épaisses couches biostromales bien litées (faisant elles-mêmes partie du cortège récifal). Citons de bas en haut, des têtes de Stromatopores, de taille respectable, des lentilles à Amphipores, de petites colonies isolés de Stromatopores bulbeux, lamellaires, et de Coraux, des galettes construites par des Bulbeux, des Coraux et des Stromatopores branchus (Stachyodes), et enfin des monticules à gros bulbeux roulés et accumulés sans ciment visible. Une tentative de différenciation écologique est amorcée mais il est certain que cette discrétion des phé- nomènes la rend discutable. La terminologie souffre elle aussi d'une telle discrétion, et des termes moins défi- nitifs que bioherm, biostrome sont proposés. (La figure 21 est un résumé de tous ces phénomènes.)

L'envahissement argileux, en conditions bathymétriques à peine plus profondes que celle présidant au dépôt des carbonates, paraît être plutôt causé par un régime de courants particuliers. Un affleurement excep- tionnel permet même de contrôler ce passage graduel mais rapide des carbonates purs aux carbonates argileux le long de lignes-temps dont la morphologie est contrôlée. La disposition de cette plate-forme épicontinentale avec des faciès récifaux épais, développés vers le Nord-Est (Alberta) est bien connue dans la littérature. Nos affleurements se trouveraient placés en position sous le vent ou tout au moins à l'abri de l'énergie maxi- male (Figure 3). En fait, les conditions marines semblent identiques pour la faune benthique, tout le long des 15 kilo- mètres de l'étude, et les communautés de Brachiopodes sont d'une exceptionnelle richesse tant dans les faciès argileux que dans les faciès carbonatés.

Partie II Cette richesse en Brachiopodes a permis des corrélations très fines entre ces coupes réparties sur un front de quinze kilomètres, avec toutefois l'appui d'observations sur les Coralliaires (Planche I). Aucun échantillonnage de Stromatopores n'a été effectué car il est estimé que leur valeur en stratigraphie de détail reste à démontrer. Une étude paléontologique peut difficilement se résumer et le lecteur est prié de se reporter à la Planche III pour apprécier le nombre de spécimens et d'espèces ainsi contrôlés, Planche qui devrait se passer de commen- taires.

Cinq assemblages faunistiques sont ainsi individualisés : — Assemblage I : transgressif, avec de nombreux restes de poissons — Assemblage II : à characées (Trocholiscus) et Spirorbis. Cet assemblage est désigné par l'association Atrypa aff. scutiformis — A. cf bremerensis — Assemblage III : ou assemblage à Atrypa scutiformis — Assemblage IV : ou assemblage à Atrypa gregeri — Assemblage V : peu caractéristique et problématique : deux espèces d'Atrypa seulement le dis- tinguent de l'assemblage IV.

Ces assemblages de valeur locale sont ensuite replacés à l'intérieur des grandes zones à Brachiopodes du Frasnien du Canada Occidental ("Relation of Local Assemblages to Biozones"). La zone DFR 3, la plus basse, rassemble les assemblages I, II et III, bien que les deux premiers soient peu caractéristiques ni de DFR 3 ni de la zone DFR 2, n'apparaissant que très loin au nord. La zone DFR 4, rassemble les assemblages IV et V et il faut noter qu'elle inclut la zone DFR 5 des précé- dentes classifications (appliquées aux Montagnes Rocheuses, car une zone DFR 5 se distingue en subsurface). Certaines formes de Coraux ou Brachiopodes permettent de rattacher ces observations à des sites bien datés des États-Unis. Grâce à certaines publications sur les Conodontes et les Céphalopodes, il est même possible d'établir un début de corrélation entre notre Frasnien inférieur d'Alberta et Colombie Britannique et celui d'Europe Occidentale. Appendice : Ce numéro des Notes et Mémoires a fourni l'occasion à l'un d'entre nous (G.R.) de publier une remise à jour de l'échelle biostratigraphique de tout le Frasnien du Canada Occidental, précédemment publiée en 1966 dans le rapport de Jasper DOOGE sur "The Stratigraphy of an Upper Devonian Carbonate-Shale Transition between the North and South Ram Rivers of the Canadian Rocky Mountains" (thèse de doctorat de l'Université de Leyde, Pays-Bas) :

Echelle Raasch 1972 : DFR 12, zone à Vandergrachtella scopulorum DFR 11, zone à Cyrtospirifer whitneyi DFR 10, zone à Cyrtospirifer placitus DFR 9, zone à Calvinaria albertensis DFR 8, zone à Eleutherokomma reidfordi DFR 7, zone à Monelasmina besti DFR 6, zone à Eleutherokomma leducensis DFR 5, zone à Warrenella catacosoma DFR 4, zone à Atrypa gregeri DFR 3, zone à Atrypa scutiformis DFR 2, zone à Ladogioides pax

Le statut de la zone DFR 1 est encore imprécis : il correspond à la partie supérieure de la formation Slave Point connue en subsurface, et terme de passage entre Givetien et Frasnien. D'autres travaux (G.R.) sont en cours, mais il est bon de signaler que les études conjointes de la Compagnie Française des Pétroles et du même paléontologiste, G. RAASCH, conduisent à en rejeter le Brachiopode Ladjia caligatae, jusqu'alors considéré comme appartenant à cette zone. Ladjia caligatae appartient à la "zone à Cyrtina panda", immédia- tement antérieure et dont les Conodontes indiquent déjà un âge Frasnien au sens européen.

(80 Pages, 53 Références, 22 Figures, 12 planches) TABLE OF CONTENTS

Page LIST OF FIGURES 9

LIST OF PLATES 10 FOREWORD — AVANT-PROPOS H INTRODUCTION — FLUME FORMATION 13 Nomenclature 13 Scope of this paper — Définitions 14 Underlying Strata 15 Overlying Strata 15 Aknowledgements 15

PART 1 : A SHORT SEDIMENTOLOGIC ANALYSIS OF FLUME OUTCROP 19 TECTONIC FRAME — FACILITIES — LOCATION OF SECTIONS 19 DESCRIPTION OF SECTIONS 22 KW 3 Kakwa Lake North 22 KW 3bis Kakwa Lake South 23 KW 4bis Wapiti Mountain 23 KW 4 Wallbridge Mountain 24 Sections around KW 4 26 KW 6 Cecilia Lake South 26 KW 7 Cecilia Lake North 27 PETROGRAPHIC CONTROL FOR LOWER ASSEMBLAGES 28 CARBONATE-SHALE TRANSITION FRONTS 31 Major steps 31 Direct control for shaling-out 32 REEFING 35 Introductory remarks on petrology and ecology 35 Some thoughts on reefing terminology 36 Builders 37 Builders communities 37 Faunas - Floras associated to reef-biotas 38 Reefal features 40 — Upper Dolomite at Cecilia 40 — Subsidiary reefing at Wallbridge 40 D1AGENESIS PROBLEMS 48 Dolomite 48 Silica 49 SUMMARY 51

PART II : LOWER FRASN1AN FAUNAL SUCCESSION : CECILIA-KAKWA AREA ... 57 GENERAL CONSIDERATION 57 FRASNIAN OF CANADIAN ROCKY MOUNTAINS 59 Gross Faciès succession 59 Upper well-aerated succession 59 Medial poorly-aerated succession 60 Revision of zones of medial poorly-aerated succession 60 Lower well-aerated succession 61 ASSEMBLAGE ZONES : CECILIA-KAKWA AREA 63 Assemblage 1 63 Assemblage II 63 Assemblage III 64 — Bank-cum-reef carbonates 65 — Open-marine faciès 65 Assemblage IV 65 Assemblage V 66 Revision of zones of the lower well-aerated succession 66 Relation of local assemblages to biozones 67 APPENDIX : SUMMARY OF FRASNIAN FAUNAL-ZONE ZONATION WESTERN CANADA 69 DFR 12, Vandergrachtella scopulorum zone 69 DFR 11, Cyrtospirifer whitneyi zone 69 DFR 10, Cyrtospirifer placitus zone 70 DFR 9, Calvinaria albertensis zone 71 DFR 8, Eleutherokomma reidfordi zone 71 DFR 7, Monelasmina besti zone 71 DFR 6, Eleutherokomma leducensis zone 72 DFR 5, Warrenella catacosoma zone 73 DFR 4, Atrypa gregeri zone 73 DFR 3, Atrypa scutiformis zone 75 DFR 2, Ladogioides pax zone 76 REFERENCES CITED 77 ADDENDUM 80 LIST OF FIGURES

Page Fig. 1. Major physiography of Western Canada 16 Fig. 2. Air view of main Wallbridge Mountain section 16 Fig. 3. Location of studied area compared to major carbonate faciès of Alberta 17 Fig. 4. Location of sections and main tectonic features 20 Fig. 5. Wallbridge Mountain. Basai transgressive Devonian 24 Fig. 6. Air view of south part, Wallbridge Mountain outcrop 25 Fig. 7. Cecilia Lake South. Laminar Stromatoporoid bindstone overlain by rugose Coral bafflestone 27 Fig. 8. Some typical microscopic figures of lower Assemblage II at Wallbridge and Kakwa 29 A-B : Chamosite ooids. C-D : Girvanella envelopes around skeletal grains. E : Pseudo-ooid. F : Bryoza (?) fragment. Fig. 9. Shaling-out of Biostrome 470 at Wallbridge Mountain 33 Fig. 10. Close-up of right part of Fig. 9 33 Fig. 11. Wallbridge Mountain. Bulbous Stromatoporoid-^wp/!/>ora community 39 Fig. 12. Wallbridge Mountain. Stromatoporoid-Coral community 39 Fig. 13. Wallbridge Mountain. Laminar Stromatoporoid encrusting Poterioceras (?) and a gastropod 39 Fig. 14. Wallbridge Mountain, Stromatoporoid head 41 Fig. 15-16. Wallbridge Mountain, Labechiid-laminar Stromatoporoid-Coral balls 42 Fig. 17. Wallbridge Mountain. Close-up of right part of Fig. 18 43 Fig. 18. Wallbridge Mountain, Amphipora-lense at A A 464 45 Fig. 19. Wallbridge Mountain. Part of large bulbous-dendroid pancake reef. 45 Fig. 20. Wallbridge Mountain, bulbous-stroms cobble-mounds 46 Fig. 21. Reefing phenomena along Wallbridge outcrop 52 Fig. 22. Formations nomenclature and biostratigraphy, early Frasnian of Alberta and Northeastern British Columbia 55 LIST OF PLATES

Page PLATE I — GROSS LITHOLOGIES AND CORRELATIONS OF FLUME FAUNAL ZONES 24

PLATE II — A: PANORAMIC VIEW OF WALLBRIDGE MOUNTAIN OUTCROP B-C : SPECIMENS OF POTERIOCERAS 56

PLATE III — EARLY FRASNIAN FAUNAL DISTRIBUTION 66

PLATE IV — ATRYPIDS : ASSEMBLAGE TWO End of volume

PLATE V — ATRYPIDS, ATHYRIDS : ASSEMBLAGES TWO, THREE ....

PLATE VI — ATRYPIDS : ASSEMBLAGE THREE

PLATE VII — ATRYPIDS : ASSEMBLAGE FOUR

PLATE VIII — ATRYPIDS : ASSEMBLAGE FOUR

PLATE IX — SPIRIFERIDS

PLATE X — RHYNCHONELLIDS : ASSEMBLAGE FOUR

PLATE XI — ORTHIDS — STROPHOMENIDS : ASSEMBLAGE FOUR ....

PLATE XII — ATRYPIDAE AVANT-PROPOS

Ce numéro des Notes et Mémoires C.F.P. est écrit en Anglais et nous devons quelques explications à nos lecteurs de langue française : Tous les travaux de terrain au Canada Occidental furent exécutés par des équipes mixtes de géologues pétroliers. De plus, un des co-auteurs (G.R.), paléontologiste, dirigea les collectes de faune, puis présenta ses conclusions dans des rapports internes rédigés dans cette langue. Nous pensons que l'aspect particulier de notre présentation pourrait l'emporter sur l'aspect général et que, de prime abord, son intérêt principal réside dans l'application en Alberta d'observations sur une série bien connue comme réservoir pétrolier.

Notre intention étant d'ouvrir la discussion, non de présenter des conclusions définitives, aucune description d'espèces nouvelles n'a été faite. Les collections de faune ont été déposées au Service Géologique du Canada, Calgary, et sont à la disposition de chercheurs éventuels.

FOREWORD

The present issue of Notes et Mémoires C.F.P. is the first to be written in English, and we owe some explanations to our French readers : Fieldwork in Western Canada was carried out by a team including both English and French speaking geologists, and our arguments and discussions were in English. Moreover one of us, (G.R.), a paleontologist, lead fauna collecting and presented his observations in this language. It is believed that in this présentation, the particular may outweight the général, and should any interest arise, it would primarily be in the régional aspect of Alberta subsurface, of observations on strata équivalent to well-known petroleum reservoirs.

Since the main purpose of the present paper is to open a discussion, and not to make definite stratigraphical statements, no descriptions of possible new species are given. Ail C.F.P.'s collections are placed in the repository of the Geological Survey of Canada, Calgary, for potential investigations. INTRODUCTION-FLUME FORMATION

The present report deals with Lower-Frasnian lithostratigraphy and biostratigraphy of a rather small area located in British Columbia, Canada, near the Alberta border, between latitudes 53°00- 54°00 North and longitudes 12°00-12°10 West. (Fig. 1-3.)* Altitude range from 2 000 to 2 300 métrés (Fig. 4) and it has been experienced in 1968 that summer-snow conditions in this part of the Rocky Mountains were extremely unfavorable to stratigraphie surveys. Limited reconnaissance wasconduct- ed the same year and fieldwork restricted to lower outerops for général Devonian stratigraphy. Fortunately, 1969 has known a rather snow-free summer, at least for fourteen out of twenty days spent in the field. Again, latter flights in 1970-1971 proved very disappointing for complementary work. Moreover, the key section KW 4, although bare of végétation, is very close to and slightly higher than a regressing icefield. Ice patches remain in some depressions. This type of terrain is illustrated on Plate II and on Fig. 2. Close-up photography of outerops is a problem with this contrasting ice or snow and results in poor quality pictures. Base camp was set up at Two Lakes (Alberta), for logistic facilities, and wind conditions were at their worst through some passes such as Stinking Creek Pass (over 80 miles per hour). These difficultés have to be mentioned in order to increase the efficiency and safety of future field parties.

Nomenclature :

Since RAYMOND (1930) defined the Flume formation in the Jasper vicinity (Fig. 4) a considérable amount of more précisé data has been acquired on the stratigraphy of basal-Devonian strata in Rocky Mountains of Alberta and adjacent zones of British Columbia.

Aftera period of stimulating discussions (BELYEA-MC LAREN 1957 a, b, TAYLOR 1957-1958, etc.), time relationship between cropping out Flume in the Mountains, Beaver Hill Lake in the Alberta subsurface, and Northeastern Alberta Waterways outerops, is rather well documented in recent literature (MOYER et al, 1964, DOLPHIN-KLOVAN, 1970, NOBLE, 1970,FISCHBUCH, 1971,etc.).Updated and complété compilation on Frasnian nomenclature is found in WILSON (1968). RAYMOND'S définition of Flume included those strata overlying pre-Devonian rocks and overlain by shales of the Perdrix formation, a term he also defined himself. Unfortunately he omitted to include into basai Devonian the lowermost transgressive clastic sequence. Latter complications occured when new names were proposed both for the base and the top of the section. Formation nomenclature has to be rejected for the lower transgressive sequence which is, in essence, diachronous within very short distances. If understood as designating a latéral shaly équivalent of upper Flume carbonates, the naine Maligne could be very satisfactory. Better faunal evidences presented in Part II agree with DE WITT - Me LAREN (1950) about their first stratigraphical assignment for the Maligne. Once the faciès change is recognized, this shale section, consequently, should not be upgraded to Formation status. (Fig. 22).

Scope of this paper - Définitions

Two parts are devoted to the Flume section at Kakwa-Cecilia Lakes : — Part II deals with brachiopod and coral primary zonations into 5 major assemblages. Then these assemblages are gathered within two lower-Frasnian zones, namely DFR 3 and DFR 4 of the "Raasch Scale". This "scale" is itself revised in Appendix. — Part I has to be considered as a support to paleontology on grounds of lithologies, thicknesses, carbonate faciès, and anomalies such as reefing.

When comparing with eastward correlating beds (biostratigraphically), it should be noted that a third zone DFR 2 appears in the Waterways succession. By progressive onlap, the transgressive Frasnian begins later around land-masses such as the Peace River Arch and a broad Alberta Ridge (see MOYER et al 1964). At the close of DFR 2 time it is reasonable to imagine that these two land- masses were coalescing. On Conodont evidence, UYENO (1967) demonstrates this lowest Frasnian DFR 2 to be équivalent to the Waterways' Firebag, and to be still present inside the subsurface carbonate platform (Fig. 3). Note : some well known localities such as Roche Miette, Roche à Perdrix, etc., not represented on Fig. 3, fall within the DFR 3 remnant of Alberta Ridge, emersive.

DFR 1 zone is not mentioned in this review of basal-Frasnian strata. Its status is tentative and subject presently to an investigation of one of us (G.R.). Gross corrélations would give such a time- stratigraphic position to the Slave Point Formation of Northern Alberta and Northeastern British Columbia. Beaver Hill Lake is thus fully separated from Slave Point although far-ranging corrélations are vigorously discussed in Western Canada. Beaver Hill Lake is here used in its strictest sense.

The général transgressive character of Frasnian strata produces a typical pattern on Fig. 3 for the repartition of gross faciès. Basinal shaly faciès change shoreward into reef-supporting carbonates, then shoal carbonates and evaporites. This pattern is classical for every major phase of Fras- nian déposition, DFR 12 excluded (Winterburn time, cf. Appendix). Progressive overlap of previously emerged areas is a true transgressive character, and results in the disappearance of the Alberta Ridge, then of the Peace River Arch (where full immersion occurred during Famennian time). On the contrary, reefing inside or at the borders of a carbonate platform introduces false régres- sive characters in the same slices. Barrier reefs for example are bathymétrie anomalies strong enough to move "backwards", i.e. basinward, the most confined faciès, namely those faciès referred to in the literature as "intertidal", "supratidal", etc. One may discuss these attributions mainly in the case of reefs creating another cause for depositional confinement, thus offering différent environmental explanations. Underlying strata :

In the Rocky Mountains South of KLakwa Lake and in part of Alberta subsurface, the Flume Formation overlies a vast array of Paleozoic strata ranging frorn Cambrian to Ordovician.

In the Cecilia-Kakwa Lakes area, HARKER et al(1954)(dealing also with Flume faciès), and later, SLIND and PERKINS(1966) assign an Ordovician âge to a thick section of grey silty dolomites,strongly eroded under early-Frasnian transgressive clastics. (Fig. 5.) To the North West,i.e. deeper in the Rocky Mountains,TAYLOR( 1971, and 1971, personal communication) has evidenced Middle Devonian strata with typical Stringocephalus faunas. Unfortunately the Middle-Upper Devonian contact is only exposed north of the Peace River, more than 300 kilométrés northward from the area of study. Flume faciès overlying Middle Devonian, will not be debated in this paper, neither will be DFR 1 (Slave Point équivalent), strata of doubtful stratigraphie status.

Overlying strata :

As defined in the "Nomenclature" paragraph, the Flume Formation underlies CAIRN carbonates or their équivalent, the PERDRIX shales. A gross relationship does exist between Flume and Cairn faciès : Cairn carbonates generally overlie Flume carbonates while Perdrix shales overlie Maligne shales. Transgressive influences are such that these upper carbonates are slightly displaced shorewarcl from the lower carbonate front. In subsurface, such a pattern is an outstanding feature of considérable interest in exploration. Most of Leduc reefs (Cairn équivalent for their base) are found behind the major Beaver Hill Lake carbonate edge, acting as an appropriately thick sole. (Shoreward is understood for this complex basin in its broadest sense : towards environmental/y highest zones.) Cairn-Perdrix (DFR 5 up) faciès follows the rule in the Cecilia-Kakwa Lakes area, and although a fringe of Flume carbonates is exposed, overlying strata belong to the shaly faciès. Dark green shales form a conspicuous marker over the whole area (Plate II).

Aknowledgements

Publication of this paper has been authorized by TOTAL PETROLEUM NORTH AMERICA, formerly FRENCH PETROLEUM OF CANADA and its partner in the venture, GULF OIL OF CANADA. B. DESBORDES, C.F.P., participated in fieldwork and helped in early stratigraphie corré- lations. His contribution is gratefully aknowledged. P. LEHMANN, C.F.P., contributed to fauna collecting. Spécial thanks are due to B. PATRICK, assistant, L. MUTCHESON, draftsman, both from TOPNA. Calgary, and to J. LEROY and C. MESPLE draftsmen, C.F.P. for their considérable material help. We are indebted with D. HARVEY, University of Calgary, and L. SOLER, C.F.P., for the quality of photographie illustrations. Our work has been greatly facilitated by the skills of our pilot, A. PORSILD, Associated Helicopters, Edmonton.

We thank Dr P.F. BUROLLET, P.J. SWEENEY, C.F.P., for kindly reviewing the final draft of the manuscript. MAJOR PHYSIOGRAPHY OF WESTERN CANADA ® Location of study 0 1000 Km.

FIG. 2. - Air view of main Wallbridge Mountain section. Base of Flume is visible in lower right corner. Saddle on top with basai dip-slope of Wapiti Mountain in upper right. Snow-cover was at its minimum for full surnmer 1969. laterways

RIVER

son Creek

S/V/PE LAKE

FOX CREEK

AREA OF STÙDY

EDMONTON

Anc/e

EARLIEST FRASN.AN (DFR 3) REMNANT |Hf_jALBERTA RIOGE MNot reconstrûctëdT"

^ALGARY^ LOCATION OF STUDIED AREA COMPARED TO MAJOR VRBONATE FACIES OF ALBERTA

(BEAVER HILL LAKE EQUIVALENT)

Reef - supporting Carbonate Platform

after MOYER et al 1964 PART I

A SHORT SEDIMENTOLOGIC ANALYSIS OF FLUME OUTCROP

TECTONIC FRAME-FACILITIES — LOCATION OF SECTIONS

Early-Frasnian strata crop out along two major trends. Mapping of faults on Fig. 4 is minimal, and these accidents have been selected for their influence on stratigraphical corrélations. Studied Devonian and earlier strata form an outcrop bounded eastwards by the Cecilia Thrust. Steep-angle thrusts, or reverse faults, delineate a second trend (East Kakwa, East Wallbridge Faults). The général Devonian outcrop in this area is bounded westwards by the Alexander Thrust, and appropriate mapping is available from MOUNTJOY (1970). Extra observations can be made in the Mount Buchanan vicinity (Fig. 4) where Early Frasnian strata are exposed. This last exposure, however, has been neglected during our fieldwork because of difficultés in helicopter access, heavy minor faulting, and lack of major faciès changes from the Wallbridge area.

Ail outcrops are located on the East flank of the continental divide. This is the reason why flight and driving facilities are located in Alberta. Since 1969 these facilities have been greatly improved for coal mining research, and new roads have been built. For example good road access is now possible from Sherman Meadows — Two Lakes (Alberta) to Kakwa Lake. The southern part of Devonian outcrops is also accessible through the Sheep Creek Forestry air strip.

Out of the seven sections, six are located above the tree and grass lines. The last one, KW 6, exhibits however perfect exposure of Devonian strata along the cliffy banks of a creek (Fig. 4). Thrusting Devonian strata are quite well preserved from tectonics. Northward, in the shaly faciès, section KW 3 was apparently faulted, but section KW 3-bis was measured and sampled for control on the south side of the saddle, on an undisturbed outcrop. Results proved to be roughly the same as for KW 3. The key section, KW 4, has been selected along a 3 kilométré strip in the north part of Flume exposure (Plate II — A, Fig. 2, Fig. 6). The southern part is mostly grass-covered while northwards, snow-conditions hamper correct appraisal of latéral corrélations, and sometimes cause thick obser- CECILIA — KAKWA LAKES AREA

NORTHWARD PLUNGE",'. OF LOWER FRASNIAN - ( FLUME ) OUTCROP^j" -—— 5500 . ^V/ /\ LOCATION OF SECTIONS AND MAIN TECTONIC FEATU R ES

MT S! ANDREWS

EAST WALLBRIDGE FAULT \ ( TH RUST fi i

WAPITI MOUNTAIN

jr»'

WALLBRIDGE MOUNTAIN

BASTILLE VV MOUNTAIN

SOUTHWARD' PLUNGE Olç? FRASNIAN OUTCROP;/

3500 6000 5500

<7/ INTERSECTIOti / /MOUNTAIN ( vation gaps. Section KW 4 was chosen in order to minimize these gaps (reduced to few métrés below sample 473 on Plate I). This section is located inside a faulted block bound northwards and southwards by vertical faults readily mapped from air photos. Figure 2 illustrâtes such pattern. Notice that some latéral observations have been completed without major difficultés for the adjustement of both sides of the faulted block.

Sections presenteu are part of long-ranging stratigraphical work including the full Frasnian stage. This is the reason why sample numbers are not in continuity. For further references, letters AA are to be added before the number. A little over one hundred samples corne from the lower strata (this paper). Thirty six of them have been sampled in détail for paleontological use.

It has been mentioned in the Introduction that Part I was a sedimentologic support to Part II, a purely paleontological dissertation. This is why corrélations on the lithology chart, Plate I, do already include faunal evidences for assemblages. As a conséquence, little will be said of lithostratigraphy except where discrepancies exist between the two methods. As Assemblage I is bare of fossils with biostratigraphic value, and the base of Assemblage II itself is also considered more as a lithostratigraphic unit, some pétrographie and sedimentologic markers are illustrated. We do believe these extra remarks provide supporting evidences for our corré- lations.

Some earlier references to this spécifié area of British Columbia deserve spécial aknowledge- ment : — HARKER et al (1954) for Ordovician and lower Flume at Kakwa Lake and Wallbridge Moun- tain. Their Fig. 3 (p. 60) represents Wapiti Mountain, from recent topomaps (previously called Northeastern flank of Wallbridge Mountain).

— Me LAREN (1954) for Flume fauna at Kakwa Lake.

— JORDAN (1966) for faunal study, on material coming pro-parte from Wallbridge Mountain and Kakwa Lake (SHELL collections). DESCRIPTION OF SECTIONS

The Flume Formation, as previously defined with faunal evidences, will be briefly described for each of the sections. It is understood that information from Part II and Plate III are profusely used for this purpose.

KW 3 — KAKWA LAKE NORTH

Thicknesses

Assemblage V. . 12 métrés

Assemblage IV metres Assemblage III 20 metres Assemblage II 23 metres Assemblage I (transgressive) 4 metres

Total thickness (Flume) 95 metres

Liîhologies :

— The basai transgressive sandstone of little stratigraphie interest is a mixture of dominant quartz and few feldspars. Fish remains of small size (2 mm) are scattered throughout. Few lenticular layers of green shales are interbedded.

— Assemblage II is characterized by dark grey shaly limestones with quartz very abundant near the base and gradually disappearing upward. Major fossil content : Brachiopods, Crinoids.

— Small bulbous Stromatoporoids appear in Assemblage III, along with Crinoids, Brachiopods, Gastropods and mainly Corals. Shaly limestones are the dominant rock type and, although Stroma- toporoids may be present in fair numbers, no real biostromal layer has been recorded. — Assemblage IV and V are represented by the deepest faciès with considérable proportion of shales. Fauna follows this deep character with Brachiopods, Crinoids and Eopteropods (,styliolinas).

Note Assemblage V is tentatively defined at Cecilia Lake South. Possible boundaries have been drawn on the corrélation chart (Plate I) from faint lithological evidences. Thus biostratigraphical certainty about the upper boundary of the Flume Formation is not warranted much higher than sample AA 504.

Locality 504 opens also the discussion about Ladogioides kakwaensis : its occurrence is debated in Part II but it has to be stressed that MAC LAREN found his specimen between 61 and 66 métrés above the base of Devonian at Kakwa, within the present Assemblage IV zone. In the WALLBRIDGE vicinity (Wapiti Mountain ?) his specimen are 69 métrés above Ordovician strata. Our Assemblage IV occupies there the 62 to 117 metre interval. No discrepancy in sampling is noted between pioneer work by Me LAREN and ours, but for the scarcity or the lack of Ladogioides kakwaensis in our case. L. kakwaensis + Spinatrypa albertensis community has been reported from upper Flume at Roche à Perdrix (Alberta) by PATTERSON (1955), above the DFR 3 - emersive remnant of Alberta Ridge (cf page 14, Fig. 3). Heavy sampling, by earlier field parties, of this beautiful and large Brachiopod is suspected to be the reason (experienced elsewhere) for its absence on the Wallbridge outcrop. Weather conditions during lithological description and faunal sampling have been at their worst and, regrettably, no photographs of this section can be presented.

KW 3bis KAKWA LAKE SOUTH

Careful description and corrélations with KW 3 were made at KW 3bis in order to check for possible tectonic complications. Some of these corrélations were simply made by walking from one section to the other on prominent limestone beds (beds 488-489 for example). If tectonics do affect KW 3, it is in a minor way, with a slight réduction of few métrés out a thirty metre interval. However, faciès changes are readily noted within this 500 metre span : hard weathering sandstones appear thinner southwardly while in the same direction, Plate I shows decrease in shale content for some limy intervais. This phenomenon of rapid faciès change is better illustrated at KW 4, Wallbridge section.

KW 4bis WAPITI MOUNTAIN

Heavily silicified biostromes can be traced on air photos and were observed from the helicopter along the smooth crest of Wapiti Mountain, which represents a 2,5 km morphological surface. Unfor- tunately, little observation can be made, both for the lower-Flume section exposed on the Eastern clifF of Wapiti Mountain and for morphological patterns : stratigraphie dips are stronger than the dip-slope facing west and a biostromal limestone below sample 548 (bulbous stromatoporoids) crops out along a strip only 10 to 20 métrés in width. This is obviously not enough for transverse observations. Brachiopods and Corals are the main faunal elements of the overlying, slightly argil- laceous limestones. These beds belong to Assemblage IV and offer a good stratigraphical control for the continuity of the underlying biostrome (stromatoporoids). KW 4 — WALLBRIDGE MOUNTAIN

From binocular observations on the Eastern cliff of Wapiti Mountain, dolomite at KW 4bis is estimated to disappear near the boundary of Assemblage II and III. Wallbridge Mountain exhibits a slight dolomitization higher in the section, up to the top of Assemblage III. This limit also fits with a major lithological break between biostromes with anomalous surfaces and deeper shaly limestones. Good accessibility and, at the time of observation, almost snow-free outcrops allowed a very dense sampling and well-correlated latéral observations. For these reasons, KW 4 is considered as the key section, with its central position and exhi- bition of partial reefing and shaling-out.

Major cuestas of outcrop are on strike with strata, and very gentle west-dip (2° to 5°) allows perfect observation of sedimentological phenomena. Most of photographs are from this area.

Thicknesses

Assemblage V H metres

Assemblage IV 55 metres Assemblage III 32 metres Assemblage II 22 metres Assemblage I 8 metres

Total Thickness (Flume) 128 metres

FIG. 5. - Wallbridge Mountain. Basai transgressive Devonian. Quartzitic sand resting uncomformably on strongly eroded ordovician dolomites. CECILIA KAKWA LAKES AREA K W 4 KW 7 KW 6 CECILIA LAKE SOUTH GROSS LITHOLOGIES ANO CORRELATIONS METRES CECILIA LAKE NORTH OF FLUME FAUNAL ZONES

Sa mple with f a un a . ( # A A ... ) (4vi Skeletal ( limestone , dolomite ) o Chert as a major diagenetic element A

À A

0,5km 15km Q k m i T»L / NORTH SOUTH WEST EAST Lithologies — Tentative Assemblage I is well individualized by a thick bed of quartzitic sandstone (Fig. 5), where plants and fish remains are of larger dimensions than at Kakwa Lake. Well-preserved rostra and armour plates may be found in great numbers inside some pockets. Our sampling (AA 451) has been offered to the Geological Survey of Canada, Calgary, for possible détermination at the genus level. Therefore, further data on these specimens are to be found at the G.S.C. Ostracods, spore cases and a few minute gastropods preclude an environment somewhat similar to the sedimentary conditions prevailing for Assemblage II. — The presence of overlying hard-weathering carbonates (As. III) make the following sériés, fitting with Faunal Assemblage II, very conspicuous along the three kilométrés of Wallbridge exposure, and at Cecilia Lake locations. A broad recessive section of shales (Fig. 6) is a very good marker both for reconnaissance at a distance and for corrélations accross faulting.

FIG. 6. - Air view of south part, Wallbridge Mountain outcrop. White, hard-weathering beds are ordovician dolomites. Shales and shaly limestones of lower Assemblage II form the conspicuous recessive slope. Harder beds of dark carbonates near the top represent upper part of As. II. Above, the frontal moraine of icefield.

— Quartz content remains important, with some thin beds of sandstones and scattered quartz grains. The section is enriched in carbonate towards the top. Carbonate is first represented as grains by shells, spore cases, micritic envelopes, then as cernent in truly limy beds of marlstone, then as pure limestone. The burst of Spirorbis and Trocholiscus, easily observed on hand specimens, is an outstanding feature of considérable help for rough stratigraphy on the field. In the upper part of strata fitting with Assemblage II, fauna is represented by few Corals, Crinoids, and mostly Brachiopods (cf. "Atrypa beds" of HARKER et al. 1954). — Assemblage III corresponds with an explosion of Coelenterate communities producing thick biostromes. It should be noticed that the same succession is present at Cecilia Lake, where shaly limestones (As. II) are overlain by biostromal dolomites.

At Wallbridge, dolomitization is incomplète and this partial diagenesis enhances sedimentological observations (example on Plate II, Fig. C). Tentative reefing will be illustrated later. Out- side Coelenterate représentatives, Stromatoporoids of various kinds (bulbous, laminar, dendroid or branching, cylindrical) and rugose Corals, a very rich and diversified Brachiopod fauna is associated to every rock-type. Shaling-out of the whole succession of As. III is not exposed and occurs northwards (between Wapiti Mountain and Kakwa Lake), but for the highest part of the biostromal mass where direct observations of this phenomenon are of enough interest to be discussed apart.

— Overlying the biostromes, Assemblages IV and V occupy a sériés of shaly beds ranging from thin shaly limestone layers to dark grey shales. Accordingly, like at Kakwa Lake, fauna follows this vertical faciès change and Brachiopods, Crinoids and Corals were the only animais living in such a deeper muddy environment.

SECTIONS AROUND KW 4

The full exposure of Flume carbonates at Wallbridge have been investigated, firstly for a reconnaissance of the best possible section (KW 4), secondly for faciès changes of sedimentologic importance. For example, Assemblage I — II have been described and sampled at locality shown on Fig. 6. This section is not recorded in the present report due to the perfect similarity with lower zones of section KW 4. More important are the short traverses (few métrés) aimed at shaling out or reefing phenomena. On Plate I the lone 470-471 traverse is illustrated but Fig. 21 at the end of PART I represents a synthetic review of ail these anomalous features of little stratigraphie value.

KW 6 CECILIA LAKE SOUTH

After rapid description of underlying strata, this section was aimed at detailing a higher step in the carbonate front (As. IV). Fauna sampling was started at the postulated base of this unit.

Assemblage V 6 métrés Assemblage IV 51 métrés Assemblage III \ Assemblage II 70 métrés Assemblage I *

Total thickness (Flume) 127 métrés

Lithologie

— If Assemblage I and II have been noted under a similar faciès to Wallbridge Mountain, we have to mention, for Assemblage III : 1) The decrease in bulbous Stromatoporoids from KW 4 and the greater abundance of laminar Stromatoporoids associated with Corals. 2) The lack of dolomitization in the last 12 metres of this part of the section (As. III). It appears as if the upper biostromes of KW 4 were replaced by shaly limestones where fossils (Brachiopods and Corals) have been the object of intense silicification. — The base of strata gathered into Assemblage IV consist of a thick massive association of laminar Stromatoporoid-bindstone and rugose Corals-bafflestone (Fig. 7). Bindstone and Bafflestone are understood according to EMBRY-KLOVAN (1972). The matrix ofboundand baffled material is very light-colored. The remainder of Assemblage IV and Assemblage V in toto, are represented by the now classical shaly limestones with Brachiopods and Gastropods. The two upper samples, AA 544, AA 545 bear the three anomalous Brachiopod species associated with two forms belonging to Assemblage IV. Reasons for, and weaknesses of the tentative faunal breakdown will be found in PART II.

FIG. 7. - Cecilia Lake South. Laminar stromatoporoid bindstone overlain by rugose coral bafflestone. Note light eolor, and silicification of coelenterates. Knife is 8 cm long.

KW 7 CECILIA LAKE NORTH

Two beds of thick light-grey dolomite crop out at this location. They are associated with shaly limestones, and this succession correlates easily with strata of Assemblage IV at Cecilia South, with a similar thickness. Assemblage V can be traced rather easily by walking on this part of outcrop bare of végétation. The base of the dolomite is as well conspicuous and forms a little cliff protruding out of alpine meadows in the lower slope. Lowermost beds of dolomite show ghosts of laminar organisms (Stromatoporoids ?). After a few metres of shaly limestones, a white dolomitic faciès reappears with well-distinguished Corals and Stromatoporoids. Faciès is similar to the faciès of lowermost Assemblage IV at Cecilia Lake South. The remainder of the section consists dominantly of beds of limestone or shaly limestone with Crinoids and Brachiopods. PETROGRAPHIC CONTROL FOR LOWER ASSEMBLAGES

Data presented for Assemblage 1 and lower Assemblage 11 are rather scant from a paleontological standpoint. Fortunately, between KW 3 Kakwa Lake and KW 4 Wallbridge Mountain, thin sections reveal an almost perfect identity in faciès distribution.

A major correlative faciès is noted with Chamosite ooids (Fig. 8 A, B) for two samples at KW 4 (AA. 486-487) and one at KW 3 (AA. 453). Such ooids range in size between 200 and 600 microns, and most of them are spherical. Elongate forms are created by the morphology of the original nucleus. Very few have a nucleus, generally a quartz grain. A typical feature is the presence, either in the center or within layers, of chamosite crystals (Fig. 8 B). Their close association with spore cases indicate a rather well-aerated and agitated environment where every particle was able to roll back and forth. However, as some Trocholiscus spore cases are surrounded by such ooids, we have to remember that : 1° These cases may have been rather sticky and possibly covered with some mucilage, at least for a short period after their release. 2° Energy level was low enough to allow such a mucilage to glue previously rolled-over particles. FIG. 8. - Some typical microscopic figures of lower Assemblage II at Wallbridge and Kakwa. A - B : Chamosite ooids. Arrows in B point towards typical chamosite crystals, also in B the ooid is stuck to a Trocho- liscus spore case affected by spar overgrowth. C - D : Girvanella envelopes around skeletal grains. Boring eflfect shown by arrows in D. In C, particle is in lower left corner, separated from Girvanella tubes by an opaque dust. E - Pseudo-ooid. Radial outer layer of possible algal origin. Notice parallel faces for crystals, suggesting blade-like pattern. F - Bryoza (?) fragment. Blue green Algae, for their part, are another good environmental indicator : apart from micritic envelopes of discrète Algal origin, Tubular algae (Girvanella, Fig. 8 C, D) show a remarkable tendency to stick around skeletal particles. In some cases where tubes are flattened during compaction of sediment, it is obviously impossible to distinguish between true micritic envelopes and "Girvanella envelopes". By comparison with modem Scytonema, one can reach a better compréhension of the phenomenon. Observations on Andros Island by BLACK (1933) and MONTY( 1967) show a calcification of Scytonema's sheaths. This calcification is not always completed, with différent stages. Whatever the biochemical process, the resuit is a micritic tube and a micritic cernent. It is reasonable to think that during the early process of compaction, either incomplète calcification of tubes or incomplète lithification can produce micritic films around particles. These films should look similar to the micritic envelopes of BATHURST (1966).

Boring effect of Girvanella also is similar to the process described by BATHURST and, in fact, represents the main criterion for distinguishing the type of envelope. Fig. 8 D illustrâtes such a nesting effect, early stage for boring process on a skeletal grain. Change in the pH at the contact of living

Algae is enough to mobilize CaC03 from aragonitic particles. This rôle of Girvanella has been fully debated by KLEMENT and TOOMEY (1967) for Ordovician examples. Other crusts of possible algal origin are noted in the sandy (quartz) limestones below preceding examples, mixed with Bryozoa (?) chunks (Fig. 8 F). Some nodules seem to develop around organic nuclei (fish bones for example) and after an inner phosphatic encrustation (mosaic) a blade-like arrangement may be observed in the outer envelopes (Fig. 8 E). This ooidic arrangement should be studied more carefully, but is reminiscent of Nuia-like crusts around particles from Cambrian bioherms of Texas. On material from these last strata, progressive changes, from the classical tubular form into a possible encrusting new form, have been noticed. This information is provided with caution by the senior author who would favor (in both cases) the concept of radial pseudo-ooidic growth origi- nating from algal activity. Although a brackish tidal environment is suggested in PART II from observations on spore cases and Pelecypods, sedimentologic control from thin sections would indicate a slightly deeper environment. Skeletal grains of marine fossils, activity of nesting (if not boring) green Algae around the full surface of grains, and Chamosite ooids are strong enough indicators of a subtidal energetic faciès, within the photic limit. A near-shore, shallow zone (not deeper than few tens of métrés) is suggested and fits with the transgressive pattern for DFR 3 over remnant of Alberta Ridge (Fig. 3 and discussion in PART II). Should this interprétation be right, then one would have to reconsider the morphology of such an emerged land mass. Its surface would have to be far smoother than the word Ridge, admitted in literature, is implying. In fact, some authors use Arch for describing this feature. CARBONATE-SHALE TRANSITION FRONTS

A — MAJOR STEPS :

These steps are readily observed on Plate I, "Gross lithologies and corrélations of Flume faunal zones."

Assemblages I-II slice

A sensible decrease in shale content has already been noticed between the two Kakwa Lake sections. This tendency continues southwards to Wallbridge Mountain, then eastwards to Cecilia Lake south. Although some prominent beds were walked along at Kakwa Lake, the phenomenon is rather discrète and appears very progressive and gentle, hindering possible direct observations. Moreover, this time slice remains shaly over the whole area and shaling-out will bear its full meaning in higher assemblages represented by true carbonate sheets, disappearing northwards into shale.

Assemblage III slice

More or less dolomitized biostromes of Cecilia Lake, Wallbridge and Wapiti Mountains are replaced by a full shaly section at Kakwa Lake. There, few Stromatoporoids are scattered inside a rather homogeneous sériés of shaly limestones or marlstones.

The presence of Corals, Crinoids in association with small forms of bulbous Stromatoporoids has to be compared with the same type of association detailed at Wallbridge. If bathymétrie changes cannot be refuted, they have to be minimal in order to allow, at Kakwa Lake section, a bottom shallow enough to accomodate the needs for stromatoporoidal growth.

Another due for reducing bathymétrie importance of one faciès compared to the other is the striking similarities between Brachiopods communities at species level (see Plate III). Channelling on top of some biostromes illustrated in the next chapter, is also a rather good approximation for possible increase in water depth : at Wallbridge Mountain shaly limestones, with faciès similar to those observed at Kakwa, plaster channels never deeper than two meters. It is inferred that sea floor between Wallbridge and Kakwa was rather flat (excluding possible channels) and nearly horizontal, with a depth-increase of only few métrés over a distance of 15 kilométrés.

Assemblage IV slice

Two phenomena are observed : I. — At Wallbridge, where gross faciès is roughly similar to the faciès noted at Kakwa Lake, tentative buildups (Stromatoporoid cobble mounds Fig. 20) introduce a peculiar shaling-out. This type of carbonate — vs — shale faciès has been misleading in cases where control was scant and true contact between carbonate and shale sections was covered or poorly exposed. Isolated biohermal islands, or prominent barrier edges, have strongly dipping depositional surfaces and exhibit a laterally-corresponding shale-slice, indicator of an encasing environment of definite posteriority. Once again it is believed that bathymétrie individuality for each faciès might be very faint : Increase in depth for such a shaly environment may be as low as the différence of level directly measured on a stratigraphie marker.

II. — Between Wallbridge Mountain and Cecilia Lake South a drastic change of carbonate content is readily noticed in the section. Faunal communities remain identical, with dominant Corals and Brachiopods. However, the base of Assemblage IV initiâtes a major faciès and faunal change with a northward paroxysmal development at Cecilia Lake North : dolomitization affects a reefal faciès dominated by laminar Stromatoporoids (Fig. 7). Once again, reefing introduces another anomaly within shaling-out pattern. In this easterly trend, however, shaling-out occurs southwards while the main component was northwards for the remainder of studied outerops.

Assemblage V slice

As for the lower slices (As. I-II), this tentative zone remains shaly over the whole area. Compared with the previous As. IV slice, this open-marine character may give some merit to the stratigraphical validity of such a breakdown. Subsurface controls show such a constancy over very large areas ; this extent is rather appropriate when séparation between Flume = Beaver Hill Lake, and Cairn = Cooking Lake-up is hampered by identity of faciès. At any rate, it seems advisable to define, at the limits of a stratigraphie formation, if not a conti- nuous open-marine marker, at least beds with a faciès spread over the greatest surface possible.

B. DIRECT CONTROL FOR SHALING-OUT

On topmost parts of some patch-reefs it is possible to discern laterally-changing faciès. On Fig. 18 hollow surface of buildup is plastered with well-bedded shaly limestones changing depositionally updip into Stromatoporoid rudstones, on the highest parts of the reefal topography. FIG. 9. - Shaling-out of Biostrome 470 at Wallbridge Mountain. Depositional dips on the left and center of photograph. Upper well-bedded shaly carbonates abut upon biostrome slope.

FIG. 10. - Close-up of right part of FIG. 9. Progressive shaling-out of separate beds disappearing into the true biostromal mass. Hammer for scale. North on right. In the field, this phenomenon is readily discerned and well described in the literature. Bathy- métrie changes are there directly involved but the process may not account for shaling-out on a broad and flat shelf. The 15 kilométré span is comparable to other epicontinental platforms with carbonate- shale transitions, both in subsurface (Beaver Hill Lake) and in exposures of the Rocky Mountains (North Ram River in DOOGE 1966 for example).

A zone of rapid carbonate shale transition has been delineated at Wallbridge Mountain, at the top of Assemblage III slice (Fig. 21). Bulbous Stromatoporoid biostromes are affected by channelling. Both the growth habit of Stromatoporoids and these erosional features help conclude to a rather shallow depositional environment : a depth of few metres is suggested, within the range of tidal currents action. Northwards, the biostrome is abruptly interbedded with shalesand its remaining beds gradually loose their biostromal character. Bulbous stromatoporoids decrease in size and number while the matrix of skeletal mud becomes increasingly shaly (Fig. 9-10). Within 25 metres, shaling- out is completed and on the right side of illustrations the biostrome is replaced by a 1,5 metre-thick section of alternating well-bedded limestones and thin shale layers. No noticeable change of bathymetry can be recorded from depositional pattern on Fig. 10. Ecological and environmental inter- prétations have to be adjusted to a realistic model : current action seems to be the most suitable factor to explain this carbonate-to-shale gradation, and ecological différences along apparent horizontal bottoms. REEFING

INTRODUCTORY REMARKS ON PETROLOGY AND ECOLOGY

The classification proposed by EMBRY-KLOVAN (1971)*, used elsewhere in this text, is noteworthy : it fulfils the needs of field geologists and reef students for a carbonate terminology adapted to the presence of rock builders. Outcrop or core descriptions are more easily performed and, provided followers will comply with the original meaning of each term, macroscopic studies of organic features will be enhanced by such a suitable tool.

Another positive point is the proposed addition (p. 737) of DUNHAM'S (1962) classification for matrix description. Thus, both macroscopic and microscopic features may be introduced into a short and clear-cut sentence applied to the type of depositional texture. The 2 millimétré cut-off is obviously arbitrary, and one may discuss the validity of parameters from terrigenous clastics classification applied to biological elements. For example, even if clasticity is one character of Amphipora or rugose Coral-floatstones, depositional interprétation may be drastically différent from quartz- pebbles muddy conglomérâtes. Important transportation may be implied in the last case while simple death and partial decay of stick-like organisms are enough to produce the same type of rock in the first case.

This is why the proposed association of macro- and microscopic terms (EMBRY-KLOVAN and DUNHAM pro-parte) appears of great value : as far as depositional energy is concerned, Dunham's classification allows more conclusive observations, from matrix characters. On the contrary, at the other side of the Allochtonous limestones scale, lack of matrix could be an energy-indicator of some interest. A complementary term correlative to Dunham's grainstone would be of some merit for field geologists.

* A similar paper by EMBRY-KLOVAN is to be found in European literature (of better availability for some libraries) : EMBRY, A.F. and KLOVAN, J.E. 1972. Absolute Water Depth Limits of Late Devonian Paleoecological Zones. Geol. Rundschau Band 61 Heft 2, pp. 672-686. Stromatoporoid taxonomy and ecology are a controversial subject. In some cases, changes in growth habit can be observed directly along cropping-out beds at Wallbridge Mountain. Generally, specific déterminations are thought to be irrelevant to detailed zonations such as those allowed by Corals, Brachiopods, microfossils studies. Our information and sampling on Stromatoporoids is considered too scant for further discussion but on some photographie examples. It has been the privilege of the senior author to work with M. LECOMPTE and his informai lessons on Coelenterate ecology will be long remembered. His pioneering studies and publications are considered as classics and available in every text dealing with Devonian Reefing. This is the reason why, instead of referring to any of his papers, we rather acknowledge his teaching and his influence over this chapter. Stromatoporoid ecology remains a critical problem and hinders a reasonable view of environmental conditions. An excellent summary of this problem applied to the same Early-Frasnian strata, and well-documented evolutionary distribution charts will be found in FISCHBUCH (1968, pp.500 - 517). It is obvious that conclusions from our 14 days field trip could not compete with his work and his synthetic présentation of faunal distribution within 6 densely-cored subsurface reefs, correlative of the presently studied strata. DOLPHIN-KLOVAN (1970) have discussed Coelenterate ecology applied to reefing of younger Frasnian âge. From their data on Banks Island (NWT) EMBRY-KLOVAN (1971, 1972 op. cit) are able to quantify their ecological conclusions ("absolute water depth limits").

SOME THOUGHTS ON REEFING TERMINOLOGY

The reader is reminded that Part I is a sedimentologic support to Paleontology. Our purpose is to illustrate where and why prolific faunas of stratigraphie value (Brachiopods-Corals) are found. Since CUMINGS and SHROCK (1928) then CUMINGS (1932) defined the terms bioherm, biostrome, a great deal of new définitions for the same words have been proposed by numerous workers. Later on, LOWENSTAM'S (1950) magistral study on Silurian reefs and their depositional aspect introduced his own terminology, based on Silurian biota, paleogeography, and their sedimentologic conséquences. Once again a bloom of remarks, altérations, changes was initiated by this paper from workers hastily transferring Silurian facts to their own problem in another part of the geological column. For example, if the word biostrome has not too much sulfered from such a semantic activity, bioherm, unfortunately, needs to be redefined by each author. Lowenstam's concepts, incorrectly applied, have become a source for misleading environmental assertions, such as the wave resisting, and mostly the binding characters. A new school of workers has apprehended the danger of misunderstanding between reef students. References to the recent, with simple words, appear fruitful. Insight looks to modem carbonate platforms and reefs have brought-up discovery of early lithification, sophisticated research on diagenesis, and downgrade some other sedimentologic or ecological aspects applied to fossil structures unproperly called reefs, bioherms, etc. (DUNHAM, 1970, has summarized these discrepancies). This is why, in the following Unes, little use will be made of "classical" terms. As often as possible, references to modem reef features will be made. Instead of bioherm, and sometimes of biostrome, we shall use adjectives from these words, biohermal, biostromal, implying, in our sense, less préci- sions about the peculiar. Sedimentologic conclusions too, will follow the same careful approach, and rather than solving depositional problems, this chapter will add more puzzles into the complex "Reefal Sedimentology".

BUILDERS Ail major kinds of Coelenterates* are noticed to participate in rock-accretion at Wallbridge and Cecilia Lake. As expected, Stromatoporoids with bulbous growth-habit have the best building-potential, along with laminar (encrusting) forms in one well-delineated zone. Dendroid forms (Stachyodes), rugose Corals, Amphiporas, and fragments of tabulate Corals contribute to a noticeable percentage of the bulk of clastic carbonates (Floatstones, Rudstones). None of these forms has been observed in position of growth, in contrast to bulbous and laminar Stromatoporoids. An arbitrary séparation is made for branching forms of Stromatoporoids : only Stachyodes are retained in this group while branching Amphiporas are put apart : Stachyodes may have other growth forms (massive) while Amphiporas keep their delicate branching or tubular pattern, are easily recognized on the field, and belong to a family différent from the classical STROMATOPORIDAE. It should be noted that some flat forms (.Euryamphipora, etc.) are denied the status of "Amphiporidae" by some authors (M. LECOMPTE, 1967, Personal communication). Labechiid Stromatoporoids benefit also of spécial attention in this présentation. Observations on some European and Canadian forms, and typical weathering figures allow the parting of this interesting family. They range from Silurian to Carboniferous without marked evolutionary change and represent the lone "Coelenterate" chancing to survive through Famennian stage in Canada. A last mention should be made about the little rôle of Algae. Surprisingly, none of the Rho- dophytes known in subsurface (Swan Hills = Beaver Hill Lake, for bibliography, see FISCHBUCH, 1968, p. 521) have been recorded. The only algal remains are abundant micritic envelopes and two kinds (or species ?) of Girvanellas (Fig. 8, C-D). The largest form (illustrated) occurs in the lower part of the section (Assemblage II) while thinner tubes accumulate in the lime muds of Assem- blages III-IV. Once reefal patterns are analyzed, a possible explanation for the lack of crustose ancestral Coral- lines or Solenopores will be proposed in conclusion. However, blue-green algae appear as anecessary component of buildups, where gluing and binding of soft sediments between standing Coelenterate- patches is achieved by these underrated algal-threads.

BUILDERS COMMUNITIES In some rare cases a single species is involved in the building, or the accretion of sedimentary anomalous figures (Fig. 14, 17, 19, 20). However, Coelenterates generally follow a more conceptual pattern for reef biology. Numerous types of associations, fitting with différent ecological conditions, i.e. différent needs for living assemblages, have long been recognized, both in recent and fossil reefs. The three major communities at Wallbridge and Cecilia are respectively :

* Phyllum Coelenterata, classes Hydrozoa (Stromatoporoids), Anthozoa (Corals). Uncertainty about the phylogenesis of Stromatoporoids is discarded here, keeping in minci they could be related to the Poriferas. A — Amphiporas-Bulbous community (Fig. 11) Bulbous Stromatoporoids of large size (up to 40 centimetres in diameter), generally in growth position, form the bulk of floatstones, while Amphiporas are rather scarce, floating in a black lime- mud matrix.

B — Bulbous-Rugose Corals community (Fig. 12) Bulbous are smaller than in the previous community. Some of them show a tendency to flatten towards the laminar habit. The matrix of dark grey to black lime-mud is less abundant and both Corals and Stromatoporoids are overturned or even broken. The rock, skeleton-supported, is a rudstone. This community présents the greatest variations and ail kinds of gradational faciès towards the Amphipora-Bu\bous community or the next, laminar-rugose Coral community. Stachyodes are present as an important constituant, apparently without polarity in any direction. In a few cases, Amphipora-Stachyodes accumulations have been noticed as well as Rugose- Stachyodes assemblages. The Wallbridge outcrop is interesting in the sense that strike pattern allows direct observations of such gradations by walking along one single biostromal bed.

C — Laminar-Rugose Coral community (Fig. 7) The perfect type has only been observed at Cecilia Lake, within Assemblage IV. Here a puzzling problem will arise about the color of matrix (white) compared with other biostromes or mounds accumulations at Wallbridge Mountain, within Assemblage III. Gradational faciès are represented at Wallbridge Mountain, towards the bulbous (Labechiid) — rugose Coral faciès (Fig. 15-16).

FAUNAS-FLORAS ASSOCIATED TO REEF-BIOTAS

Major faunas have been described in the chapter DESCRIPTION OF SECTIONS. Brachiopods, Crinoids and, to a smaller extent, Gastropods are associated to biostromes and some biohermal lenses (pancake reefs). Microorganisms present in the matrix are mainly Foraminiferas, blue-green Algae (Girvanella) and radiosphaerid Calcispheres. An interesting phenomenon occurs at the close of Assemblage III-time and near the base of Assemblage IV. Thick-shelled, and/or giant sized Gastropods (up to 15 cm diameter) and Cepha- lopods. They are either associated to muddy biostromes (Fig. 13*) or to well-bedded lime-muds deposited in channels (PI II, B. C).

* Remarks on Fig. 13 : Notice polarity for calcite fill of Cephalopod cavity, associated with Stromatoporoid growth. After death of the animal, the shell must have been stuck vertically in the mud, with gas in the upper part, then Stro- matoporoid growth was initiated on the top of the protubérance. When weight reached a critical value, both shell and Stromatoporoid warped down, sinking into the unlithified mud. Another interprétation would be that Stroma- toporoid growth was parasitic duringlifetime of Cephalopod. Bryozoa incrustations are known on coiled cephalopods. This would imply a vertical habit for Poterioceras (?) with a benthic life. Buoyancy necessary for supporting such a thick parasite appears improbable. FIG. 11. - Wallbridge Mountain. Bulbous Stromato- poroid - A mph ipora community.

FIG. 12. - Wallbridge Mountain. Stromatoporoid- Coral community. Stachyodes, small bulbous (notice change in size with FIG. 11 ), some showing a tendency towards the laminar habit.

FIG. 13. - Wallbridge Mountain. Laminar Stroma- toporoid encrusting Poterioceras (?) and a Gastropod (left). M ud matrix is slightly dolomitized, some pockets are filled with pure dolomite (insidecephalopod shell).* FISCHBUCH (1968, p. 502) also points out thick-shelled Gastropods in the platform phases of his Swan Hills reefs. Both Gastropods (mud or mats feeders) and Cephalopods seem adapted (?) to a rather turbulent life in shallow muddy bottoms, where their weight could possibly balance wave energy.

REEFAL FEATURES

A. — Upper dolomite at Cecilia Lake

Two thick beds of light grey to whitish dolomite with remains of thin tabular organisms crop out at Cecilia North Section. The base of these anomalous beds correlate with the base of a rather thin bed of limy mudstone — framestone (Fig. 7) at Cecilia Lake South. Unfortunately, outcrop conditions are such that direct observations between the two sections are only possible near this lower marker and an upper limy layer interbedded with shales (see page 26). However, air photos suggest, within this 0,6 km strip, a full section invaded by the white dolomitic faciès (smooth scree slope). The two sections are tentatively interpreted as located on both sides of a possible build-up (laminar-bulbous community ?) standing in high energy conditions, above correlating shaly bioclastic limestones (Brachiopods, rugose Corals, Crinoids) deposited in a somewhat deeper environment.

B. — Subsidiary reefing at Wallbridge

Numerous features of small extent are present on both sides of section KW 4. Their shapes, sizes and sedimentological patterns appear to be related to the types of community contributing to their accretion.

Stromatoporoid head (Fig. 14)

A perfectly spherical colony of stromatoporoid, in growth position, is trapped inside well- bedded Amphipora muds (floatstones). Direct control on relationship between this light-colored colony and surrounding dark brown mud, show diachronism between faciès. Sagging aflfecting underlying strata, and finally draping of overlapping layers indicate this stromatoporoid colony first grew faster than mud deposited, then was caught-up and killed by these micritic conditions.

The height of living stromatoporoid above muddy bottom was in the range of few tens of centi- mètre, and contrasting colors between matrix and head suggest two separate environments. The higher, fitting with biological needs of a rather healthy stromatoporoid had to be well oxygenated and provided a wealth of nutrients (planktonic ?). This biological fact may be correlative with the destruction or organic matter resulting in the white color of the fossil. The lower environment, muddy and rather unfit for life but for specialized forms, such as Amphi- poras, could mark a critical limit for reducing conditions (preserving black organic matter).

The complété encasing of the head by dark Amphipora muds helps in refuting latter differen- tiation by diagenesis (preferential circulation through porosity anomalies). On the contrary, one gets the feeling that the process was completed at the same time as burial by the first overlying beds. This example of "reefing" on a very reduced scale is important in some aspects : it is impossible FIG. 14. - Wallbridge Mountain, Stromatoporoid head. This colony is made ot'one specimen of Stromatoporoid which results into a giant bulbous form. Notice compaction and sagging of underlying beds on lower left. Encasing strata are made of Amphipora floatstones.

to find any clue about energy, and conclusions about bathymetry are scant : the best that can be said of depth is that critical conditions between two chemical média (pH, Eh) were fulfilled : these conditions are met in numerous cases of discrète origin. Wave action limit, surface currents, deep currents, seepage of fluids through underlying unconsolidated ooze are some of the naturalistic explanations. For example, facts begin to accumulate from deep-sea observations in the Atlantic, the Mediterranean Sea, etc. and they concern, for example, drastic évolution of our concepts on modem corals. The following examples on other subspherical reefal bodies bear more conclusive character of sedimentological interest.

Labechiid — Laminar Stromatoporoids— Corals patch-reefs {Fig. 15, 16).

These patches appear inside well-bedded mudstones and shaly coral-floatstones. Scarce bulbous Stromatoporoids (Labechiid) initiate the anomaly. They are either in growth position, inside the patch-reef or isolated as a single colony of small size (15 cm horizontally or vertically). Bound material is constituted of floatstones-rudstones with a great variety of Corals (few rugose, numerous tabulate Thamnoporids) and fragments of laminar Stromatoporoids. The binding agents are laminar Stromatoporoids, some of them being torn off and furnishing the clastic fragments. FIG. 15-16. - Wallbridge Mountain, Labechiid-laminar Stromatoporoid-Coral balls. These balls are patch-reefs produced by the binging effect of laminar Stroms over Cord\-Stachyodes rubble. Some massive forms (Labechia ?) are still in growth position, some are boulders inside the laminar Bindstone. Encasing strata are either mudstones or poor Coral-floatstones. The overall impression of this rock type is that of a bindstone although framework (Labechiid) or rubble are present (Corals, laminars clasts). This mixing of ail kinds of reefal rocks is, in our sense, a very good indicator of a true reef, although under a miniature size. It is admitted our concept of reef is as large as possible and even in the original "sailor" concept, no need for such a structure to reach the surface of water is necessary to make it "hazardous" for a boat. Factually, those structures of Fig. 15-16 fit with the BALLSTONES of CUMINGS (1932 p. 345).

As for the previous exapple, these balls appear lighter than the surrounding sediments. The matrix of bound material is by itself lighter than the outer muds of floatstones. Geometrical relationships are also identical to the example of Fig. 14. However, the clasticity of floatstones and rudstones, the type of rubble, may increase our précision about energy level. Noticeable energy was needed to tear these laminar organisms which are supposed to have been strong crusty binders.

Amphipora — lense (Fig. 17-18) This lense is made of a light colored massive rudstone with spaghetti-like Amphipora closely packed (matrix is scarce). It is flanked on both sides (Fig. 18) by prograding scales, definitely posterior, where down-sloping change of faciès is observed. Matrix (wackestone) becomes gradationally more abundant towards the base of each scale which agglutinate altogether into thinly bedded Amphipora floatstones. Correlatively the color gets darker and undiscernable from the dark brown of underlying strata.

FIG. 17. - Wallbridge Mountain. Close-up of right part of FIG. 18. Dark brown bulbous-Coral floatstones matrix. Détail of prograding scales on fianks of lense. On a miniature scale, this structure, a truebioherm as defined by CUMINGS and SHROCK (1928), provides a wealth of informations on sedimentology : Correlative changes of faciès and colors along dipping time-lines show clearly the rôle of bathymetry changes around a critical value (Fig. 7). Such rudstones may resuit from the in situ accumulation of broken Amphipora-sticks. Death, basai decay of possible algal origin and little energy, can create such an accretion on the location of a thick Amphipora meadow. One can vizualize such a living circular community, baffling sediments (original bafflestone) in little quantities, and acquiring a smooth domal shape over a quiet bottom. It is believed no lithification of such a bafflestone was in process before oxygénation of organic matter, then breakdown of dead Amphiporas. Later récurrences of growth-then-accretion may have occured on the periphery of such a resulting dead spot, at the same depth. We would like to compare this phenomenon to some modem dead patches of Pontes with a circular live festoon, sort of under- water "fairy ring". This phenomenon of bafflestone to rudstone (or floatstone) transition is perfectly exposed in quarry-cuts of Middle Frasnian at Tailfer, Belgium. There, it is obvious the later faciès derived from disaggregation (biological, mecanical) ofbushesofrugose Corals (disphyllids), someofthem preserved few métrés avay at rigorously the same paleo-level.

Identical faciès occurs immediately above the lense, but at a far larger scale. Its natural extent is unknown and although it is felt to have proceeded from the same biological phenomenon, possibly resulting into a broad and extremely smooth lense, exposure conditions oblige one to consider this bed as biostromal. (Fig. 18)

Pancake reef (Fig. 19)

This structure is also lens-like but differs from the preceding lense by its size, the type of rock builders (Bulbous, Stachyodes, Corals) and latéral relationship with surrounding strata. Extending over approximately 80 métrés, this body is 1,80 metre thick and pinches out on both sides of exposure (southern left part illustrated on Fig. 19) in roughly the same way than thq Amphipora lense of Fig. 18. However, the surface of this reef was rather irregular and undulating. Some dépres- sions are filled with younger bioclastic muds, well-bedded, while some others are the expression of latéral change of faciès on gently downwarping planes correlating with the reef masses. This phenomenon of biostromal beds (rudstones) getting more matrix downwards (floatstones) is sketched on Fig. 21 and is similar to shaling-out of biostromal beds of Fig. 10.

Our terminology may be discussed : in fact this structure is a flat patch-reef, lense-like, but resulting from the coalescing of discrète mounds. However, its reefal and biohermal characters are rather similar to those debated for previous reefal bodies : morphology, matrix slightly lighter than surrounding floatstones, abundance of stromatoporoids. High depositional energy is indicated by the clasticity of Stromatoporoid fragments. The tendency of Stromatoporoids to develop into the bulbous, dendroid and episodic laminar forms would favor a very diversified and complex environment with upper reaches within agitated waters. Corals (rugose) contribute also to the complexity of such an assemblage. Fie. 18. - Wallbridge Mountain, Amphipora-\ense at AA 464. Shallower episode with anomalous outer-slopes, above layers of bulbous-amphipora rudstones. A second high-energy episode, biostromal, overlies the lense (see FIG. 17 for closeup). Hammer for scale.

FIG. 19. - Wallbridge Mountain. Part of large bulbous-dendroid pancake reef. Background : cliff of Wallbridge Mountain with upper siope of icefïeld. Cobble mounds (Fig. 20)

The uppermost of reefal anomalies lie within Assemblage IV; therefore, they are correlative of reefing at Cecilia Lake. These mounds are made exclusively of overturned and rounded fragments of Stromatoporoids. No matrix is present and cobbles are packed together; sparry calcite of suspected diagenetic origin fills the original porosity of this "rudstone".

FIG- 20. - Wallbridge Mountain, bulbous-stroms cobble-mounds. Shaly limestones drape over and between the mounds. Geologist stands at beginning of saddle.

The whole mass is light-grey, white-weathering, and contrast strongly with younger encasing strata (Coral-Crinoids floatstones). Some patches of bulbous-laminar Stromatoporoid are themselves encased inside flanking beds (right part of Fig. 20) and appear to be reefal sheets of small extent growing over the muds, on the slopes of bottom anomalies.

Ail required conditions for true reef or bioherm attribution seem present. However, it is hard to imagine such piles of uncemented detrital material withstanding any kind of energy. Two solution are proposed : a) Early cementation (of algal origin?), later destroyed by diagenesis, was providing strong enough binding to initiate mound topography. b) These structures, lacking any mud matrix, may be, on the contrary, the resuit of "hyper- energy" provided by storms. From an initial flat area, crowded with bulbous colonies, only a storm would be able to tear and break-off Coelenterate heads, then transport and accumulate them on a spécifié and areally restricted spot. Such storm deposits are known in the recent, both offshore (flat open lagoons) and onshore Grand Cayman Island (B.W.I.) for example. From différent morphologies of these modem sedimentary features, and considered the poor quality of exposure at Wallbridge, both the mound — or the ridge-shapes can be present. Biostromes

These beds, the reefal nature of which is debated by CUMINGS (1932), justify two scales for observation :

1. — The whole section of Assemblage III at Wallbridge (Fig. 21) has to be considered as a biostrome, some 32 metre thick. In the détail, minute anomalies, as those described earlier, are interbedded with indivi- dually biostromal beds. This fact fits perfectly with the picture offered by Cumings for his examples, and with reef flats of modem seas, where isolated patches of living communities are scattered over skeletal or muddy bottoms.

2. — Early cementation followed by erosional channelling has been evidenced for biostrome 470. Bulbous-Stromatoporoid rudstones are eroded on top of the biostrome and directly overlain by muddy beds (wedging illustrated in Fig. 9). Such an erosional process could create, if acting deeper, a false biohermal lens-like mass where none of the bioherm characters (but for the presence of Coelenterates) would be detected. This misleading aspect on morphologies created by conséquences of early cementation should be given some thought by reef students. DIAGENESIS PROBLEMS

The present account would not be complété if little was said of the dolomitization and silicification problems. Neither would our purpose of opening discussions be fulfilled.

DOLOMITE

Dolomitization affects most of carbonate faciès at Wallbridge Mountain and Cecilia Lakes, while the Kakwa Lake sections, considered deeper in the shaling-out concept, remain unaffected. Once this first point is stated, in-depth analysis of dolomitization is rather confusing. The following lines summarize observations reported on Plate II : diagenesis, complété for the supposed reef between Cecilia South and North and for the two longues at Cecilia North, disappears southward, where a somewhat similar reefal faciès is not afifected. (Porosity is correlative to this dolomitization). Morphology and depositional dips can be suspected for creating this differential phenomenon. At Wallbridge, the biostrome of Assemblage III, the mounds inside Assemblage IV are partially dolomitized; ail other biohermal anomalies are fully dolomitized as well as their surrounding strata. (These last beds are less dolomitized at a distance from the bulging anomalies). Within the biostromes, dolomitized bulbous stromatoporoids appear inside lime-muds. Matrix is attacked only in those cases where higher energy can be suspected (torn-out fragments of laminar stroms, broken Corals). The initial stage of these sediments prior to burial seem to offer an answer for such a diversity. For example biostrome 470, lithified early before channel fill, is not dolomitized. A last remark may give some crédit to this proposai : Bioturbation is correlative of dolomitization in mudstones : (Plate II, C), dolomitized burrows, excretion or protective-mounds are outstanding sedimentary features within lime muds. From the shape and size of burrows and mounds, and from the lack of fossilized remains of burrowing animais, one can reasonably assume they were worms. No lithification took place before these soft bodied agents churned their way into sketetal or peloidal wackestones. Increased porosity inside this new bioturbated sediment, appears to be the key for the dolomite story. This theory fits also with preferential dolomitization of animal framework inside com- pact sequences unaffected themselves. A very early stage for magnésium fixation, during burial (or even anterior) is suggested from these remarks.

SILICA Occurrences of cherts (organic) have been reported on Plate I. At first glance, this repartition chart is puzzling : silica appears randomly within every carbonate faciès. Every type of macrofossil may be affected as summarized by the foliowing table (silicified organisms are individualized by heavy lettering, out of most common communities) :

Cecilia North Laminars (?, inside flat voids)

Cecilia South Laminars Corals Brachiopods

Wallbridge Amphiporas Corals Bulbous Stachyodes Corals Bulbous Stachyodes Corals Bulbous (rare)

Wapiti Corals Bulbous

Kakwa Corals Bulbous

At our present stage of knowledge, it does not appear appropriate to make tentative corrélations between type of fossil, faciès and silicification. The least that can be said is the early stage when this diagenesis took place : no isolated inorganic cherts have been noticed and the concentration of SiO2 within organic structures only, would favor the concept of silica mobilization in semi-plastic sediments during phases of lowering pH of interstitial water (plasticity is needed to explain shapes of collapsed sediments around some cherts).

Dolomitization appears even earlier, as deduced, at Cecilia, from lamellae of silica obviously filling preferentially leached calcitic patches inside the dolomite. SUMMARY

Sections in the Kakwa-Cecilia Lakes area are interesting both on sedimentological and paleontological grounds for two related reasons :

— Compared with classical examples of Flume or Beaver Hill Lake, every phenomenon under- went half development in this area : reefing is sporadic and of limited sizes. Extremely mixed faunas, well specialized elsewhere and limited to their proper environment, hinder possible energetic and bathymétrie attributions. Dolomitization is uncomplete. Shaling-out occurs without apparent bathymétrie variations.

— An exceptional Brachiopod fauna, associated to reasonable numbers of corals, allows detailed assemblage-studies presented in Part II.

The model

Before stressing on some interesting aspects of exposure, we shall briefly analyse why ail these peculiar characters occur at the same place : flat, broad, and relatively shallow platforms seem to accomodate the facts : — Evidences for flatness of the bottom over large distances are provided by the depositional morphologies and direct observations on shaling-out. They are enhanced by the similarities between Brachiopods populations. — Evidences for little depth are provided by Stromatoporoid reefing. Apart from the cobble mounds, energy evidences are rather scant so that depth limit should fit with the maximal tolerance of Coelenterates. However, it is admitted that wave energy dissipâtes over broad shoals, thus minimizing the water slice (provided an appropriate oxygen content).

A kind of critical value for depth is suggested by drastic faciès changes along gently sloping beds : decrease in animal health, increase in the préservation of organic matter, rapid décliné of skeletal constituants fit with a theoritical boundary for Eh conditions. Interstitial waters, initiating early diagenesis after burial, would follow this morphological pattern, with a boundary in pH conditions both for silica and possible dolomite mobilization.

Looking back to Fig. 3, map of areal extent for Beaver Hill Lake and Flume carbonates, such a platform is readily conceived, on the leeward side of a broad epicontinental shelf, open towards the North and North East. More than bathymetry, currents were the cause for shaling-out and, in the supposed absence of wave energy, the conveyors for oxygen and food to reefal communities.

Topics of interest : a) Reefing : In the Alberta-British Columbia Rocky Mountains, exposures of biohermal reefing at Flume level are so scarce that our modest features should not be overlooked. Comparisons between Beaver Hill Lake reefs and classical Flume biostromes cannot lead to fruitful concepts for subsurface exploration. Moreover, one may wonder if these separated little reefal bodies would not provide perfect examples of how a reef is actually built? Is it a permanent phenomenon producing vertically the same faciès over great thicknesses, or rather a of slightly différent faciès mov'mg laterally during reef growth? Such an irregularity is favoured by observation on modem phenomena and by difficult- ies any reef student has experienced at least once when trying to get a synthetic picture of fossil complexes. On Fig. 21 it is easy to conceive that, should lenses, mounds, patches and irregular biostromes be three times thicker or more numerous, then a reef-complex would develop, and compare with Swan Hills reefs as detailed by FISCHBUCH (1968) and other workers.

b) Uncompleted dolomitization : Enough limestone remains for recognizing major faciès and faunas, often destroyed in the more classical Leduc reefs and their outcrop équivalents (completely dolomitized). On the other hand, selectivity of diagenesis (reef vs encasing strata, bioturbated figures vs mud layers) enhances some sedimentological features (burrows) and may improve our knowledge of the dolomite problem in its early stages.

c) Shaling-out : From direct observation this phenomenon may be related to other causes than bathymetry (currents?) in some particular cases.

d) The Algae problem : A very good topic for open discussion would be the lack of red Algae in the platform faciès at Wallbridge. Corallines and Solenopores have been reported from correlative reefs in Alberta subsurface. For one possible cause, we would favour the weakness of energy as guessed from reefing analysis. Most of reef examples studies in the fossil and modem models indicate red algae to live preferentially in the most agitated waters i.e. near the end of reefal cycles, towards emersion phase. Another puzzling fact is their latéral repartition, from modest représentation along some parts of reef, to their abrupt explosion in some other spots. Health of animal colonies seems related to such a bloom, where, in the most exposed parts of an animal edifice of poor potential, Rhodophytes suddenly replace and encrust the dead protubérances of Coelenterates, but for few deeper bulbous forms. Such a biological anomaly has been observed in the North Part of Six Men's Bay, Barbados Island : there, the red algae-bloom occurs between two reef spurs, over a distance less than 25 métrés.

e) The shell-thickening and size-increase phenomenon :

Giant-sized Gastropods, thick-shelled Cephalopods appear abruptly near the boundary of Assemblages III, IV, and disappear as suddenly. Other Devonian occurences (Givetian) will be debated in Part II. Environmental conditions within reefal shelves explain a great deal of these biological particu- larises. Parasitism (ex. boring Fungi), and other kinds of "sickness" could be the original cause for this possibly false adaptation to agitated biota.

On a more academic basis, it should be kept in mind that basai Frasnian has been an anomalous period where giant faunas (Brachiopods, Gastropods, etc.) are remarkable. Western Europe is the best example with the "Zone des Monstres" of Gosselet (1871) belonging to F 2 a (Europe), "Cyrtospi- rifer orbelianus Zone", where two species of Orthoceras are also reported. Other occurences of giant forms are reported around the world, from European Siegenian, African Mississippian. The Cretaceous Rudistid appearance could be similar and we propose the burst of Givetian Stringocephalus as another example. It appears appropriate to suggest a compilation of this phenomenon on paleontological and biological grounds.

Brachiopods

The preceding sedimentologic picture of the Kakwa-Cecilia Lakes carbonate-shelf now explains the richness and stratigraphie value of Brachiopods communities spread over différent faciès. Part II will deal with their stratigraphie exploitation. As a conclusion to Part I and as an introduction to Part II, a nomenclature-biostratigraphic chart (Fig. 22) illustrâtes tentative faciès and time relationships inside lower Frasnian strata of Alberta and British Columbia. SL: Slave Point. I I Terrigenous Clastics I J Carbonate Platform Reefal m Shaly

FIG. 22. - Formations nomenclature and biostratigraphy, early Frasnian of Alberta and Northeastern British Columbia. Time relationships of main faciès are tentative (see Part II).

Remark : Since striking lithological similarities can be established between KW 4 and some nearby Beaver-Hill Lake sections, drilled in Alberta-subsurface, it is reminded that our 1/600 scale for Plate 1 and Fig. 21 fits with the "7 inch to 50 feet" scale of North American standards. PLATE II

A. PANORAMIC VIEW OF WALLBRIDGE MOUNTAIN OUTCROP. Cliff on right is made of silty dolomites (Ordovician). Recessive shaly beds of As. II crop out in the middle of grass-covered area, then extend obliquely upwards to the right. Above, the first cliff-forming limestone belong to the "Atrypa beds" of HARKER et al. Top left, icefield and summit of Wallbridge Mountain.

B and C. SPECIMENS OF POTERIOCERAS. Dark grey matrix of skeletal limestone. Light brown patches are made of skeletal dolomite and correspond to bioturbated material. Notice in C, middle right and upper right, cone-shaped mounds with central chamber. hS1- PART II

LOWER FRASNIAN FAUNAL SUCCESSION, CECILIA-KAKWA AREA

GENERAL CONSIDERATION

In the summer of 1969, detailed stratigraphie and biostratigraphie studies by French Petroleum Company Ltd., in the area of Kakwa and Cecilia Lakes, British Columbia, furnished valuable stratigraphie data which made possible a progressive revision of biostratigraphic zonation for the lower and middle parts of the Frasnian succession.

The previous Frasnian zonation by the junior author appeared in Jasper Dooge's report on "The Stratigraphy of an Upper Devonian Carbonate — Shale Transition between the North and South Ram Rivers of the Canadian Rocky Mountains" (University of Leiden doctoral thesis, N.V. DRUK- KERIJ, J.J. GROEN en ZOON, Leiden). The zonation, which appears on p. 12 (op.cit.) is based in part on original studies by RAASCH and in part on data extracted from other published works.*

A major difficulty in establishing a général zonation for the Frasnian Sériés in Western Canada arises from the fact that the working out of the succession depends on a compilation of data from three widely separated areas, namely, (1) the Canadian Rocky Mountains of Western Alberta and Eastern British Columbia ; (2) the Waterways area of Northeastern Alberta ; and (3) the Hay River area in the southern part of the District of Mackenzie. The succession of benthonic macrofaunas, therefore, involves a considérable degree of interpolation between the three areas.

* Warren and Stelck, 1950, 1956 ; D.J. Me Laren, 1954 ; A.E.H. Pedder, in House and Pedder, 1963 ; and C. Crickmay, 1966. FRASNIAN OF THE CANADIAN ROCKY MOUNTAINS

In the case of the Canadian Rocky Mountains, the section is deficient at two horizons : (1) the earliest Frasnian zones (DFR 1 and 2) are absent by non-deposition ; and (2) the middle part of the succession (DFR 6 through DFR 9) is mainly in paleontologically inhospital faciès.

Gross Faciès Succession

In this région, the Frasnian Sériés is divisible, in the grossest sense, into three successive major lithofacies. These are : (1) a lower unit of shallow, well-aerated, open-marine deposits (Flume) ; (2) a medial relatively poorly-aerated unit, presumably a deeper water, offshore faciès (Perdrix) ; and (3) a terminal shallower and better-aerated open-marine faciès (Mt. Hawk/Southesk).

The megafaunas of the medial, poorly-aerated faciès are impoverished as to species. Moreover, the organisms adapted to this relatively hostile environment tend to have longer ranges (biochrons) than do those that occur in the shallow, well-aerated faciès. Finally, as more précisé field data continue to accrue, it becomes increasingly apparent that the lithic boundaries separating these gross facies- units are diachronic.

Upper Well-Aerated Succession Because of the varied and abundant faunas, it has been possible to firmly establish the presence in the Southesk/Mount Hawk Unit of three successive faunal zones, designated (Raasch in Dooge, 1966) in descending order : DFR 12 Vandergrachtella scopulorum Zone DFR 11 Cyrtospirifer whitneyi Zone DFR 10 Cyrtospirifer placitus Zone. Medial Poorly-Aerated Succession

In the Dooge paper of 1966, the faunal zone succession for the medial, poorly-aerated succession is presented as follows : DFR 9 Leiorhynchus albertense Zone DFR 8 Leiorhynchus carya Zone DFR 7 Receptaculites Zone DFR 6 Leiorhynchus insculptum Zone.

Revision of Zones of the Médical Poorly-Aerated Succession

Subséquent data from other areas, plus some discoveries arising from the 1969 French Petroleum study, indicate that this nomenclature must be seriously revised. Of the four Zones indicated above, only DFR 7, Receptaculites Zone, is adequately characterized faunally to permit tracing away from the Rocky Mountain région. In the Hay River area of the District of Mackenzie a similar and contem- poraneous fauna occurs. Both the Rocky Mountain and the Hay River assemblages bear the diagnostic brachiopod Monelasmina besti Pedder, plus a number of other species held in common.

Since the Receptaculites has not been found outside the mountain région, whereas the genus Monelasmina, although limited to a narrow horizon, not only is widespread in Western Canada, but also occurs, low in the type Frasnian, in northwestern Europe (see PEDDER, 1960 a), it seems desi- rable to change the name of DFR 7 from Receptaculites Zone to Monelasmina besti Zone.

In the Hay River area, above the M. besti Zone, beds in a shallow, well-aerated, open marine faciès bear a rich fauna, notably of brachiopods. For this zone, DFR 8 of the succession, we retain Crickmay's (1966) name Eleutherokomma reidfordi.

Between the E. reidfordi-bearing beds of the Hay River Formation and the base of the Escarp- ment Member at its top, is an unfossiliferous gap of considérable magnitude. The lower part of the Escarpment Member bears a rich fauna correlative with that we have designated as DFR 10 Cyrtos- pirifer placitus Zone in the Rockies.

The unfossiliferous interval on Hay River may be équivalent to our DFR 9 Zone of the mountains which corresponds to Me LAREN'S (1954) Calvinaria albertensis Zone. It remains to be firmly established whether DFR 9 Calvinaria albertensis Zone is in fact a biochronic zone or a faciès assemblage in a transitional environment between the Southesk/Mt Kawk upper well-aerated faciès and the Perdrix medial poorly-aerated faciès.

In the Hay River région, beneath the horizon of DFR 7, the beds are on a presumably deeper water offshore faciès as are their équivalents in the Rockies. Fossils are rare and local in occurrence.

Accordingly, we must turn for diagnostic fauna to the sub-surface area of Alberta where core studies by CRICKMAY (1966) have discriminated two zonal assemblages,the Eleutherokomma leducensis Zone and the Warrenella catacosoma Zone, to which we would add the désignation DFR 6 and DFR 5 respectively. (Our proposed DFR 5 Warrenella catacosoma Zone is not to be confused with the "zone" we designate in Dooge, 1966, as DFR 5 Leiorhynchus athabascense Zone. This is a distinct and older faunal assemblage we currently merge with Zone DFR 4, as will be discussed below).

In summary then, we propose the following succession for those Frasnian beds which in the Canadian Rocky Mountains, comprise the Medial, Poorly-Aerated Unit : DFR 9 Calvinaria albertense Zone DFR 8 Eleutherokomma reidfordi Zone DFR 7 Monelasmina besti Zone DFR 6 Eleutherokomma leducensis Zone DFR 5 Warrenella catacosoma Zone

Lower Well-Aerated Succession

The lower well-aerated faciès, expressed in the Canadian Rockies as the Flume and Maligne Formations, was divided by RAASCH in 1966 (op. cit.) into the following zones : DFR 5 Leiorhynchus athabascense Zone DFR 4 Allanaria allani Zone DFR 3 Leiorhynchus kakwaense Zone

A fuller early Frasnian zonation developed in the Waterways area of northeastern Alberta, where a fourth and oldest Zone DFR 2 is represented in the Firebag Member of the Waterways For- mation. This, the author (in Dooge, 1966) designated as the Ladogioides pax Zone.

As a resuit of sub-Frasnian on-lap relations, this zone does not reach the Canadian Rocky Moun- tains, and in fact, the succeeding DFR 3 Zone is likewise absent over large areas of the mountain région.

The divisions of the Lower Well-Aerated Faciès, as published by RAASCH in Dooge, were derived partly from original study of collections and stratigraphie sections by Shell Canada Limited, abetted by whatever additional information was available in published literature. This material was of a semi- reconnaissance quality involving the Rocky Mountain belt from North Saskatchewan River to Cecilia Lake. Although data was obtained from 40 sections, it was, nevertheless, relatively haphazard as in this stage of exploration structural and lithostratigraphic considérations tended to dominate the biostratigraphic. By contrast, the French Petroleum exploration party of 1969 concentrated on a small area geographically in a limited stratigraphie span, in which the collecting of faunal information was on at par with other lines of investigation. The results when completed, as expressed in the faunal assemblage distribution chart (Plate III), upset certain not illogical preconceptions of the faunal zonation for this part of the Frasnian, and consequently, the évaluation of certain lithographie unit boundaries as well.. ASSEMBLAGE ZONES : CECILIA-KAKWA AREA

In considering the relations of the several faunal assemblages present in the Cecilia-Kakwa area, we will examine the succession first from a purely local standpoint, that is, in terms of the local teilchrons of species present. These local teilchron units will be referred to as assemblages. Subse- quently, these assemblages will be evaluated in terms of latéral persistence on a régional scale, and will also give a truer picture of the biochronal range of the faunal components. As may be observed from the accompanying distribution chart (Plate III), the faunal succession in the Early Frasnian of the Kakwa-Cecilia area appears to break down into five faunal assemblages. In addition to the vertical succession, interesting latéral fauni-facies relationships are demonstrated.

Assemblage I

The initial deposits, relatively well-sorted sandstones of limited but irregular thickness, bear little other than fish remains. Absence of associated marine fauna suggests that the sediments accumu- lated in marginal, probably freshwater ponds and lagoons. These beds and their fauna are designated Assemblage I, a faciès zone that may or may not be a time zone as well.

Assemblage II

The succeeding limited thickness of calcareous mudstones and marlstones, as expressed both on Wallbridge Mountain and at Kakwa Lake, bear an unusual fossil assemblage, namely a great abundance of characeous spore cases (Trocholiscus) and of a tiny coiled annelid (Spirorbis). Spirorbis normally occurs as a sessile organism attached to shells or to the base of compound corals, usually in small numbers. Yet here it is unattached and in overwhelming numbers. The abundant spore cases suggest kelp-like algal masses, and the Spirorbis may have been attached to the leafy fronds from which they were liberated on decay of the latter. With the exception of the odd fish bone or scale, the only other fossils noted were thin layers of closely packed pelecypods, the paper thin shells of which were not preserved in the soft, marly matrix. Mud-bottomed brackish tidal lagoons would seem to satisfy the observed biotal conditions. Available calcium carbonate may have been limited, as suggested by the thinness of the pelecypod shells.

The higher portion of the succession comprising Assemblage II consists of regularly bedded thin limestones, commonly coquinoid, and marly shales with an abundance of brachiopods. At Wall- bridge Mountain, the initial brachiopod coquinas are made up almost exclusively of two species of the small brachiopod genus Cyrtina*. The Cyrtina beds seem to be absent at Kakwa Lake (or possibly unexposed) and the Trocholiscus-Spirobis muds are succeeded by beds jammed with several species of the brachiopod Atrypa, which dominâtes the remainder of the assemblage. At Wallbridge Mountain a similar situation prevails from immediately above the Cyrtina* beds to the top of the assemblage. On the basis of similar species assemblages, beds 458 and 460 at Wall- bridge appear to correlate with beds 488 and 490 at Kakwa, respectively (see faunal assemblage distribution chart Plate III).

The only other abundant fossil in the assemblage is the brachiopod Schizophoria, which appears in the upper third and continues to the top of the Flume/Maligne section. Schizophoria species are generally long-ranging, and therefore of little value for finer biostratigraphic subdivision. The remaining fossils in the assemblage occur only in small numbers.

Most of the Atrypa, Cyrtina, Athyris, and Schizophoria species are similar to those which occur in the early Frasnian Cedar Valley Formation and its corrélatives in the Upper Mississippi Valley and Upper Great Lakes régions. The lone coral compares with a species of similar age-relations in Nevada. To what extent our fossils are conspecific with those from the northern United States would require careful taxonomic comparison. Suffice it to say here that they are, in toto, sufficiently close to indicate a generally similar âge.

With the unremarkable exception of the Schizophoria, most of the fossils do not range above the upper limit of the assemblage. Abundant at both localities and restricted to the assemblage are Atrypa aff. scutiformis Stainbrook and Atrypa cf. bremerensis Stainbrook. It may, accordingly, be designated the A. aff. scutiformis-A cf. bremerensis Assemblage. The nature of the fauna as well as the physical characteristics of the beds indicate a shallow, well- aerated open-marine ("open-shelf") environment for both localities.

Assemblage III

Assemblage III is interesting in being in a stromatoporoidal reef-cum-bank carbonate faciès on Wallbridge Mountain and in dominantly a shallow, well-aerated open marine faciès at Kakwa Lake.

* The reader is referred to Addendum, p. 80. Bank-cum-reef Carbonates

The stromatoporoidal limestones on Wallbridge Mountain include a shelly fauna which is difficult to collect from the massive carbonate but is, nevertheless, of value for diagnostic purposes. Heavy-shelled molluscs include a commonly occuring heavy-shelled large gastropod (" Trochonemop- sis n. sp. giant") and a cephalopod ("Poterioceras? sp. 471", PI II and Fig. 13) ranging upwards into assemblage IV, the eroded sections of which produce bizarre patterns on the rock surface. In addition to the molluscs, there occur in the upper part of the assemblage, a few thin coquinoid bands of a species of Atrypa (A. sp. 458) which already makes its appearance in the upper part of assemblage II. The général characteristic of the biota of the bank-cum-reef carbonate faciès here recalls that of the older, Upper Elk Point carbonates, which, while composed dominantly of branching and/or cabbage stromatoporoids, include significant numbers of thick-shelled and "giant"-sized organisms, notably large gastropods. A high availability of calcium carbonate is predicated, for both assemblages III and IV.

Open-marine Faciès

In contrast to the biota at Wallbridge Mountain, that at Kakwa Lake is of the shallow, well- aerated open marine faciès, and assemblages are similar in character (but not in species) to those prevailing in Assemblage II below. The brachiopods here weather out of marly shales and cover the slopes. The dominant elements are three species of Atrypa and a new genus of atrypid having a super- ficial external resemblance to the Hamilton genus Tropidoleptus. Among these the only described species is Atrypa scutiformis Stainbrook of the middle member of the Cedar Valley Formation (Iowa), but also occurring abundantly in the Calmut Member of the Waterways Formation in northeastern Alberta. The Atrypa is, moreover, probably the lineal descendant of the "Atrypa aff. scutiformis" so abundant in the beds of Assemblage II. A. scutiformis may be taken as the designate fossil of the assemblage.

The similarity in thickness of the beds comprising the assemblage at the two localities, the absence of any indication in the sediments of strong wave or current action, plus the intercalation of beds with stromatoporoids and the dominantly open-marine faciès at Kakwa Lake suggests that the accumulation of stromatoporoidal carbonates at Wallbridge Mountain was in the nature of a biostromal buildup of no more than slight relief with respect to the surrounding sediments, and that it was probably not emergent.

Assemblage IV

Assemblage IV yields brachiopod faunas that are far richer in variety than those of the underlying zones. The faunifacies at Kakwa Lake is entirely in the realm of well-aerated, shallow, open marine environment. That on Wallbridge Mountain is dominantly so, but patch reefs occur up to within a few métrés of the top of the zone. The lower half of the assemblage-zone at Wallbridge was largely snow-covered at the time of our visit and no collections were made. Among brachiopods, the assemblage holds a considérable number of forms that can be identified with species described elsewhere, either from Western Canada or from the Mississippi Valley. Generic variety is greater than in Assemblage III. In addition to the ubiquitous Atrypa, Schizophoria, and Cyrtina*, the spiriferids Allanella and Eleutherokomma, along with Strophodonta, productids, leio- rhynchids, and Athyris are present. A prominent additional element is supplied by rugose corals of the généra : Phacellophyllum, Tabulophyllum, and Ptychophyllum. Since a coral fauna has not previously been collected from this part of the section in Western Canada, the species are as yet undescribed. Since the distinctive Atrypa gregeri Rowley (synonym A. clarkei Warren) ranges throughout Assemblage IV and occurs widely along the Rocky Mountain front as well as in eastern Alberta, we choose it as the designate zone fossil. Many of the brachiopods occurring in Assemblage IV, like those in Assemblages II and III, are close to if not identical with species occurring in the Cedar Valley and Snyder Creek formations of Iowa and Missouri. In Assemblage IV, however, the number of Late Cedar Valley plus Snyder Creek forms is much larger than in the underlying assemblages.

Assemblage V

Assemblage V yielded a limited fauna and its status is therefore tentative. Of the five brachiopods present, two are species of Atrypa distinct from those below. The presence of Assemblage V at Cecilia Lake is probably a resuit of the persistence there of well-aerated conditions for a somewhat longer period than at the other three localities in the area. This local persistence of well-aerated waters in an area which, as a whole, is poorly-aerated, could have been the resuit of shoaling over biostromal or biohermal reefs.

Revision of Zones of the Lower Well-Aerated Succession

Data derived from the detailed studies of the Early Frasnian beds in the Cecilia-Kakwa area revealed that the relative positions of a number of the described brachiopod species was other than that assumed by their authors and other biostratigraphers, the junior author included. This was the natural resuit of the fact that no extensive detailed biostratigraphic studies had been published for the Rocky Mountain région.

Our study, for example, shows that the three zones, 14 through 16 of CRICKMAY, 1966 (his "jasperensis", "allant", and "killeri" zones), and two zones of RAASCH (DFR 4 and 5), fall within a single assemblage zone. Moreover, the species used by RAASCH for the DFR 3 Zone, L. kakwaensis (and which Me Laren originally established as the designate for the "Lower Flume") actually occurs much higher, namely at or near the top of the "Upper Flume", that is, at the top of our Zone IV.

* The reader is referred to Addendum, p. 80. PL.M

CECI LIA KAKWA LAKES AREA

EARLY FRASNIAN FAUNAL DISTRIBUTION

NOTE : Horizontal Lines Are Isochronous And Do Not Necessarily Reflect True Stratigraphie Thickness

No Specimens Collected But Observed In Field

X Indicates Organisms That Are Not Specificaliy Identified And Hence Of Little Value For Zonal Discrimination

ASSEMBLAGE JE ASSEMBLAGE JJL ASSEMBLAGE J5L

WALLBRIDGE MN > o M n > CECILIA LAKE >

WAPITI MN

KAKWA LAKE o

Spirorbis sp. undet. CO RECORDED OCCURRENCES : Trochiliscus sp. undet. t>o Fish remains X Pelecypods undet. X Cyrtina cf. missouriensis Calîaway ( Mo.) ; M. Cedor Valley Cyrtina cf. robusta M.Cedor Valley { lowa ) Schizodus sp. undet. Athyris cf. buffaloensis o M. Cedor Valley Atrypa aff. randalia o U. Cedor Valley Atrypa cf. rustica t> M. Cedar Valley Atrypa blockhawkensis CO > > . U. Cedar Valley > Co Atrypa aff. scutiformis >o oo. M. Cedar Valley ) Atrypa cf. bremerensis > DO > . L. Cedar Valley > Straparollus sp. 458 >CO o . Ascinophyllum cf. fasciculum M Devil's Gâte ( Nev.) Atrypa sp. 468 > o Schizophoria meeki/iowensis o* o» o > o o M. Cedor Valley Crinoid ossicles X X XXX X Spirorbis sp. X X

Atrypa scutiformis M. Cedar Valley ; Calmut Atrypa n. sp. Kakwa * vars. __ o Coenites sp. 493 >I Actinostroma sp. I— Aulopora sp. 493 o Atr. ( Desquamatia ) sp. 493 $ Stromatoporoids undet. _ Trochonemopsis ? sp. giant Pelecypods , Orthodesma - like > Thamnopora sp. CO Stachyoides sp. DiversophyHum ? sp. 4 66 Atrypa sp. 496 I Atrypid , Tlopidoleptus - like > H Hederella sp Michelinoceras ? sp. Platyostoma sp. Amphi pora SHALLOW , WELL - AERATED OPEN - MARINE

Cyrtina billingsi Firebag , Moberly ; Flume > I U. Cedor Valley Atrypa cf. rotunda o WALLBRIDGE MT. : H Strophodonta cf. Iinderi Ô M Cedar Valley -D STROMATOPOROtDAl Cyrtina triquetra nn > € m M.&U. Cedar Valley Z BIOSTROMAL BUILD - UPS OR BANKS > ^ Strophodonta costato K> L. Cedar Valley Eleutherokomma killeri KAKWA LAKE : > Mildred S > ^ ">D Phocellophyllum sp Wallbridge __ > WELL- AERATED , SHALLOW, • • O > O Atrypa gregeri OPEN - MARINE. o o O -o M• 2O IO r2n oii cg Snyder Cr. (Mo.); Christina-Moberly Atrypid genus 548 • Z r Platyostoma sp 548 O o ~ -i Ladogioides sp, new o o o S ' Z. m c Eleutherokomma jasperensis o• o o t> . *> £ Maligne ; Christina-Moberly o o U. Cedor Valley ; Moberly Athyris randalia s = 8 Atrypa sp 473 • O 0* x> - > S O > m 7a Spinatrypa sp. 548 -< Z m Allanella minutilla o Maligne + > Poterioceras ? sp 471 Coenites sp. O o Tabulophyllum sp. 474 >t Atrypa cf. devoniana minor M. Cedar Valley Allanella allani o Moberly Rhipidomella ? sp. Kakwa o t> î> Spinatrypa albertensis O co Calmut , Moberly ; Flume. Echinoid ossicles X Bellerophon sp. O Phacellophyllum ? densum c>> I Grumbler ) Ptychophyllum sp. 473 Atrypa sp. undet. > Strophodonta cf. iowensis t> M. Cedar Valley . Leiorhynchus carya t•> Maligne , Perdrix Devonoproductus secundus Maligne , Perdrix Atrypa sp. discoid . Leiorhynchus cf. russelli Peace Pl.- Firebag ; Flume Tentaculites sp. . Cranaena ? sp.

. Atrypa sp. 476 co __ Flume . ladogioides kakwaensis o

. Atrypa sp. 544 Moberly . Eostrophalosia pedderi M. Cedar Valley - Atrypa pronis

WALLBRIDGE MN > # CECILIA LAKE > > WAPITI MN S O KAKWA LAKE os rr°, In stratigraphie terms, the current study indicates that the Flume and Maligne formations are diachronic faciès expressions and are not constant in time-stratigraphic value. This is most especially true of the thin and discontinuous Maligne Formation. It is absent from most sections, and where present, is a short transitional faciès between the well-aerated Flume beds below and poorly-aerated Perdrix beds above.

In the Waterways area, Crickmay's Christina, Moberly, and Mildred members are based on minor lithologie différences, and their faunas are faciès controlled. They tend to merge when traced over a wider area than that of their local occurrence in eastern Alberta.

Relation of Local Assemblages to Biozones

Assemblage I, being in a freshwater lagoonal faciès, cannot be directly related to the shallow open-marine succession on which the zonal breakdown is based. It is either a faciès — équivalent of DFR 3 Atripa scutiformis Zone or immediately older.

Assemblage III is the local analogue of Zone DFR 3, as developed in the Calmut Member of the Waterways Formation of northeastern Alberta as well as in the lower part of the Flume Formation in the Eastern Ranges of the Rockies as far south as the northern part of Jasper National Park. Beyond this, it disappears southward by depositional onlap and overlap.

Assemblage II is regarded tentatively as a part of Zone DFR 3 also, since it is genetically close to Assemblage III, and has nothing significantly in common with the DFR 2 Ladogioides pax Zone. This latter does not reach the Canadian Rockies but is typically developed in northeastern Alberta in the Firebag and Peace Point members of the Waterways Formation.

Zone DFR 3 is based on its biotal assemblage rather than on the range of any single index fossil. The faunal designate term published in the Dooge paper as "Leiorhynchus kakwaensis" is a mis- nomer. The 1969 work in the Cecilia-Kakwa area showed this species to occur not within but well above the assemblage it was intended to designate. In its place, we propose to substitute "Atrypa scutiformis" which occurs conspicuously at the horizon of Zone III not only in the Rockies and in northeastern Alberta, but also in the middle (Rapid) member of the Cedar Valley Formation in lowa, whence it was originally described.

The discovery, as stated above, that Zones DFR 4 and 5 of RAASCH (1966) and the équivalent "jasperensis", "allant", and "killeri" zones of CRICKMAY (1966) are no more than local teilzones of a single zone, requires the merging of these into a single biozone. This we propose to designate DFR 4 Atrypa gregeri Zone. The designate species is not only widespread in Western Canada, but southward as far as the north flank of the Ozark Mountains (Snyder Creek Formation in Missouri), whence it was originally described.

Assemblage V of the Cecilia-Kakwa area is currently too weakly characterized to permit conclu- sse assignment to one of the régional zones, but may tentatively be considered as part of Zone DFR 4. In summary, we propose the following faunal zone succession for the Early Frasnian : DFR 4 Atrypa gregeri Zone DFR 3 Atrypa scutiformis Zone DFR 2 Ladogioides pax Zone The désignation Zone DFR 1 is reserved for strata constituting a part of the Slave Point For- mation, the faunal and âge relationships of which are currently under investigation by the junior author. APPENDIX

SUMMARY OF FRASNIAN FAUNAL-ZONE ZONATION WESTERN CANADA

DFR 12, "Vandergrachtella" scopulorum Zone

Zone DFR 12 is known from the southern part of the District of Mackenzie and from those parts of the Canadian Rocky Mountains where it has not been removed by pre-Famennian érosion.

Except for some random descriptions by C.H. CRICKMAY (1950, 1957), the fauna is largely undescribed. In addition to the diagnostic "l/ande^i-ac-hte/la"* scopulorum Crickmay", V. keeniCrickmay, and Cyrtospirifer owenensis Fenton and Fenton, there are undescribed species of Athyris, Atrypa, Cyrtina, Devonoproductus, Gypidula, Producte/la, Schuchertel/a, and Tenticospirifer. Additional généra present include Chonetes, Cranaena, Nervostrophia, Schizophoria, and Spinatrypa. Most of the corals range downward, but the following species may be confïned to the zone : Hexagonaria schucherti (Fenton & Fenton), Metriophyllum bouchardi M. Edwards & Haime, Phillip- saslraea cincta Smith, as well as undescribed species of Alveolites, Aulocystis, and Chaetetes.

We know of no corrélatives of the DFR 12 Zone in North America, with the probable exception of the Owen Formation of the Hackberry Group in Iowa.

DFR 11, Cyrtospirifer whitneyi Zone

The Cyrtospirifer populations of the Frasnian show a large degree of individual variation. This is especially true of the "Spirifer" whitneyi group, as typically developed in the Cerro Gordo Forma- tion of the Hackberry group in Iowa and elsewhere, including Western Canada. Here C. charitopes Crickmay (1952) is interpreted as a junior synonym of C. whitneyi productus (Fenton and Fenton).

* Vandergrachtella Crickmay is probably a junior synonym of Theodossia. Brachiopods diagnostic of the zone include Cyrtospirifer whitneyi (Hall, s.s.), C.w. gradatus (Fenton & Fenton), C.w. productus (F. & F.), Atrypa rubromitra Crickmay, Cyrtina navicel/a (Hall), Devonoproductus walcotti (F. & F.), Indospirifer kobayashii (Crickmay), Nervostrophia maclareni (Pedder), Producte/la thomasi (Stainbrook), Spinatrypa planosulcata minor (F. & F.), Tenticospirifer cyrtiniformis (Hall & Whitfield).

In contrast to the case in Zone DFR 12, much of the brachiopod fauna of DFR 11 has been described, either locally or from the correlative Cerro Gordo and Chemung formations of lowa and New York, respectively. In addition, are undescribed représentatives of some of the above généra, plus Chonetes, Douvillina, Gypidula, Hypothyridina, Stenoscisma, Strophodonta, Strophonelloides and Theodossia.

The large coral fauna consists mainly of species which range through more than one zone or that tentatively are identified or undescribed. Exceptions are Macgeea proteus (Smith) and Phace/lo- phy/lum densum (Smith). The coral fauna is dominated by species of Acinophyllum, Alvéolites. Hexa- gonaria, Phacellophyllum, Spongophyllum, Tabulophyllum, and Thamnopora.

This zone commonly lies at the top of the Southesk-Mt. Hawk succession, as the succeeding Zone DFR 12 has been removed over large areas by pre-Famennian érosion. On Hay River, Zone DFR 11 is represented by the Grumbler, Alexandra, and the upper beds of the Escarpment Member of the Hay River Formation.

DFR 10, Cyrtospirifer placitus Zone

This zone coincides with the lower part of the Southesk-Mt. Hawk succession. On Hay River, it comprises the bulk of the Escarpment Member of the Hay River Formation.

Where pre-Famennian valleys eut deeply into the Frasnian suberop, Zones DFR 11 and DFR 10 may be entirely removed. This is of rare and local occurrence. Remarks relative to the plasticity of Cyrtospirifer populations set down in connection with Zone DFR 11 also apply here. Thus, Cyrtospirifer tha/attadoxa Crickmay (1952), itself a variable form, is interpreted as a population variant of the lowa Amana/Independence species C. placitus Stainbrook, which is accordingly taken as the zonal designate.

Other brachiopods diagnostic of the zone include Cyrtospirifer occidentalis (Whiteaves), C.cf.syringothyriforn1is(P^ecke\ma.nn),l^Pugnoides,, subacuminatus(Webster). Most of the brachiopods which dominate the zone also occur in the underlying DFR 9 Zone. These are Atrypa varicostata (STAINBROOK), Devonoproductus vulgaris (STAINBROOK), "Gruenewaldtia" americana (STAINBROOK), Ca/vinaria a/bertense (WARREN), Producte/la rugatula (STAINBROOK), Schizophoria amanaensis Stain- brook, and Thomasaria rockymontana (WARREN) (senior synonym for T. a/tumbonata, STAINBROOK, 1945). In addition, are représentatives of the généra "Camarotoechia", Chonetes, Gypidula, Hypothy- ridina, Nervostrophia, Schuchertella, Spinatrypa, Strophodonta, Tenticospirifer, Theodossia, etc. Whereas a large proportion of the brachiopod species are shared by the underlying Zone DFR 9, DFR 10 contrasts with the latter in having a rich coral fauna (thus the différences between the "zones" may be faciès controlled, in which case they are teilzones belonging to the same biozone). The coral fauna ranges upward and compares closely with that of Zone DFR 11.

DFR 9, Calvinaria albertensis Zone

DFR 9 is genetically related to Zone DFR 10 and may be a latéral équivalent of the lower part of that zone and of the Southesk and/or Mt. Hawk formations. It is characterized by the virtual absence of corals and a brachiopod fauna similar to that of DFR 10 but greatly reduced in variety. In many localities the fauna consists principally of an abundance of C. albertensis (WARREN), "Gruenewaldtia" americana (STAINBROOK), and Thomasaria rockymontana (Warren). It occurs only locally in the Canadian Rockies in sediments intermediate in character (and position) between the Upper Wellaerated Southesk/Mt. Hawk Faciès, and the Medial Poorly-aerated Cairn/Perdrix Faciès.

Zones DFR 9 and DFR 10 bear a fauna correlative with that of the Independence (equals Amana) Formation of lowa, the Sly Gap Formation of New Mexico, and the Nunda ("High Point") Sand- stone in the lower part of the Chemung Group of New York.

On goniatite evidence, Pedder (in House & Pedder, 1963) places the Calvinaria albertensis Zone at the top of the Manticoceras cordatum Zone of the European standard section.

DFR 8, Eleutherokomma reidfordi Zone

Zone DFR 8 as developed in the Hay River area of the District of Mackenzie is in a well-aerated shallow open marine faciès. It is équivalent to the upper part of the Medial, Poorly-aerated Faciès Unit of the Canadian Rocky Mountains. Brachiopods diagnostic of the zone, in addition to E. reidfordi (Crickmay), are Atrypa cosmeta (Crickmay), and Tenticospirifer aff. shellrockensis (Belanski), as well as undescribed species of Schi- zophoria, Nervostrophia, Strophodonta, and Cranaena. Cyrtospirifer glaucus (CRICKMAY), Cyrtina lapidea (PEDDER), and Nervostrophia borealis (PEDDER) range upward from the underlying DFR 7 Zone. The fauna is provincial in that few, if any, species are present in Frasnian équivalents in the United States. These, chiefly on stratigraphie evidence, are presumably such units as the Shellrock Formation of lowa, and the upper part of the Naples Group of New York.

DFR 7, Monelasmina besti Zone

On Hay River, this zone coïncides with the lowest fossiliferous beds exposed. Doubtless as a resuit of inadéquate field data, CRICKMAY (1952, 1966) does not successfully discriminate this from the overlying. In the Rockies, the zone and faciès intertongue with the Perdrix-Cairn poorly-aerated faciès as far south at Twp. 48, Rge. 3, W6. Northward in the mountains, I have identified it as a narrow tongue on Gas Keg Ridge, north of the Peace River, British Columbia.

On Hay River, in addition to the zone fossil, Nervostrophia borealis (PEDDER), Cyrtina lapidea (Hall), Cyrtospirifer glaucus (CRICKMAY), Eleutherokomma killeri (CRICKMAY), and Athyrus occidentalis (WHITEAVES) have been identified. In addition, there are undescribed species of Schizophoria, Strophodonta, Produetella, Atrypa and probably Allanella. The undescribed species are limited to the zone, but most of the named species range somewhat higher, whereas A. occidentalis and E. killeri range as low as Zone DFR 4.

While corals are absent from the zone in the Hay River area, in the Rocky Mountain occurrence of the zone these are a prominent part of the fauna. Since no taxonomic studies have been published on these mid-Frasnian corals, they remain undescribed, except for a few long-ranging types, such as Phacellophyllum tructense Me LAREN, which extends downward from the Upper Frasnian. Généra include Mictophyllum, Ptychophyllum ?, and Spongophyllum.

Except for the zone fossil, M. besti, which ties the Rocky Mountain and Hay River occurrences, most of the brachiopod species in the mountains also are local and undescribed. Généra represented include "Ambocoelia" (s.l.), Athyris, Atrypa, Chonetes, Cyrtina, Cyrtospirifer?, Eleutherokomma, Gypidula, Hypothyridina, (cf. emmonsi Hall & Whitfield), Leiorhynchus, Nervostrophia, Produetella, "Pugnoides", Spinatrypa, Schizophoria, Schuchertella, and Tenticospirifer. Described species include Spinatrypa planosulcata (WEBSTER) and Warrenella nevadensis (WALCOTT).

In addition, Receptaculites is conspicuous in the mountain assemblages.

There is little in the faunas to permit précisé corrélation with mid-Frasnian units in the United States. Affinities appear to be closer to Old World faunas. For example, Pedder (1960a) remarks : "The horizon at which Monelasmina occurs in the Northwest Territories of Canada is almost identical with its type horizon in northwest France. In both localities, it occurs with Cyrtospirifer and species presently referred to as Eleutherokomma by many Canadians. Both occurrences are several hundred feet above beds with Stringocephalus and both are about 200 feet below the main occurrence of the Cyrtospirifer verneuili (sensu stricto) and C. thalattadoxa species group of brachiopods" ; i.e. our DFR 11, Cyrtospirifer whitneyi Zone.

DFR 6, Eleutherokomma leducensis Zone

So far as is known, this portion of the Frasnian succession does not appear in outcrop in the Shallow, Well-aerated, Open Marine Faciès, but is most probaly represented in some portion of the relatively unfossiliferous portion of the Perdrix/Cairn formations in the mountains, and of the lower part of the Hay River Shale in the southern part of the District of Mackenzie.

Its discrimination as a viable faunal zone depends on core studies made by Crickmay (1966 and earlier) from the Alberta Structural Basin. Thus, from the California Standard Winterburn Province N° I well, 5420'-5550' (immediately above the Cooking Lake Formation), he lists (1966, p. 24) : Leiorhynchus albertense Warren Leiorhynchus inelegans Me Laren E/eutherokomma leducensis Crickmay Warrenella apodecta Crickmay plus some additional brachiopods not identified as to species. Of these, L. albertense normally occurs higher (DFR 9), but the remainder are indigenous and diagnostic.

Since the fauna is unknown outside the région, wider corrélation can only be estimated on the basis of général stratigraphie position as somewhere in the Naples Group of New York and its Ame- rican équivalents.

DFR 5, Warrenella catacosoma Zone

This zone, like the preceding, is known only from the "subsurface" of the Alberta Basin, and again C.H. CRICKMAY is to be credited with its discrimination.

The fauna of this zone, corresponding to the important Cooking Lake marker horizon, was originally presented by C.H. CRICKMAY in 1961 and recapitulated in 1966 (pp. 18, 24, 25). Ithas little to characterize it other than the zone fossil, Warrenella catacosoma Crickmay. The remainder of the zonal assemblages appear to have affinities with corals and brachiopods which occur in some cases in lower zones, in other in higher. Accordingly, DFR 5 récognition as a viable biozone must for the time being be regarded as highly tentative.

DFR 4, Atrypa gregeri Zone

The Atrypa gregeri Fauna in the Canadian Rocky Mountains occurs in the Flume Formation from as far north as the Sikanni Chief River headwaters, B.C.*, to as far south as the McColl-Fron- tenac Moose Dome # 1 well in the "Foothills" and to the Wardner area in the Western Ranges of the Rockies. From the Great Wall area of Jasper National Park and the Skokie area in Banff National Park southward, it rests on older Paleozoic rocks, except for local intervention of some non- marine fish- and plant-bearing beds. The faunal elements characterizing the DFR 4 Zone in the Rocky Mountain région have been presented in preceding sections of this report. In addition to the species listed from Assemblage Zone IV in the Cecilia-Kakwa area, the following brachiopods may be regarded as significant : "Atrypa" multicostellata Kottlowski, Eleutherokomma hamiltonae Crickmay and Leiorhynchus athabascense Kindle. The latter fossil appears to be limited to the transitional faciès, commonly referred to as the Maligne Formation, shown by the 1969 French Petroleum field studies to be a latéral faciès équivalent of Zone DFR 4, of the Flume Formation.

* The reader is referred to Addendum, p. 80. Many of the species recorded in Zone DFR 4 in the Rockies are also present in the Waterways area of northeastern Alberta, where they occur in Crickmay's (1957) Christina, Moberly, and Mildred Members of the Waterways Formation. In addition to the brachiopods already recorded from the Rocky Mountain région, we may add, on the basis of our own studies as well as those of Crickmay and Warren, the following : Atrypa clarkei Warren (equals A. gregeri) Maclarenella maculosa Stehli Athyris cedarensis Stainbrook Athyris occidentalis Whiteaves Chonopectoides catomorphus Crickmay Eostrophalosia pedderi Crickmay Lorangerella phaulomorpha Crickmay Lorangerella sulciplicata Crickmay Schizophoria athabascensis Warren (also in DFR 3)

From the Hay River Région in the southern part of the District of Mackenzie, the junior author has identified the following from cores of the Frobisher 5B well on the Hay River, from the interval 170'to 340' : Rhyssochonetes aurora Hall Allanaria allani (Warren) Lingula spatulata (Vanuxem) (ranging as low as DFR 2) Nervostrophia tulliensis (Hall) (ranging as low as DFR 1) Eleutherokomma hamiltonae Crickmay Atrypa bentonensis Stainbrook Tentaculites mackenziensis Kindle Buchiola retriostriata V. Buch Lunulicardium cf. finitum Clarke Bactrites sp. cf. gracilior Clarke Styliolina fissure!la Hall Ontario clarkei Beushausen

The pelecypods in particular indicate affinities with the Naples Group of the New York standard section.

Studies by UYENO (G.S.C. Paper 67-30, pp. 8-9) on conodont evidence, show the Christina, Moberly and Mildred Members of the Waterways Formation of northeastern British Columbia to comprise the Middle Division of the Polygnathus asymmetrica Conodont Zone of Early Frasnian Age. In the Rocky Mountains, more specifically at the type locality of the "Maligne Formation" at White Sulphur Spring, CLARK and ETHINGTON (1965) also find a lower to middle P. asymmetrica assemblage, thus confirming the brachiopod and goniatite evidence cited by us. (The authors also recognize several additional standard conodont zones from the Perdrix and Mount Hawk formations, but it is not possible to relate them specifically to our megafaunal zones for this interval). On theother hand, we find CLARK and ETHINGTON'S inclusion of the lower part of the Flume at White Sulphur Spring in the "varca" zone and "Sparganophllumkalk" and therefore Givetian untenable in the face of other catégories of evidence. This may be attributed to the meagre character of the conodont évi- dence from their CSS-16 and CSS-17 samples (see op. cit., p. 385).

The occurrence in the "Maligne Formation" at White Sulphur Spring of the goniatite Timanites (WARREN and STELCK, 1956, p. 8; House, in HOUSE and PEDDER, 1963) indicates an équivalent corrélation, namely with the Oberdevon Stufe N° 1 gamma of the goniatite zonation of northwestren Europe, with equivalencies in the Naples Group of New York.

The brachiopod fauna has its closest affinities with the Snyder Creek Formation of Missouri, and probably also the upper, or Coralville Member of the Cedar Valley Formation in lowa.

Johnson, 1970, regards the genus Rhyssochonetes as having a narrow range within the Taghanic Stage of late Givetian Age. However, in Western Canada, we fînd it occurring from mid-Givetian (Hare Indian, Middle Pine Point) through Upper Givetian (Dawson Bay) into Early Frasnian (Zone DFR 4, Moberly).

Relative to the local Assemblage Zone V of the present report, two of its three brachiopod species, Atrypa pronis Stainbrook and Eostrophalosia pedderi Crickmay also occur in the Upper Waterways of northeastern Alberta, within the DFR 4 Faunal Zone.

DFR 3, Atrypa scutiformis Zone

In the Rocky Mountains, Zone DFR 3 occupies the position of the lower part of the Flume Formation as far south as the Great Wall in the north part of Jasper National Park in the Front Ranges. In the Interior Ranges, it extends farther south to Mt. Devon and Fossil Mountain in the Skokie Area of Banff National Park. In ail of these places it rests upon Early Paleozoic strata. Its southward disappearance is a conséquence of progressive overlap. As has been stated above, the DFR 3 Zone in the Cecilia-Kakwa Lakes Area is typically developed in Assemblage Zone III. It seems probable that Assemblage Zones II and I also fall within the span of the biozone. The fauna of DFR 3 has not received the same degree of published taxonomic attention as is the case of some of the later Frasnian zones. Fortunately, many of the species are the same as, or close to, named forms from the Cedar Valley Formation of lowa. As a resuit, there is not much to be added as significant from localities in the Rockies other than that shown for the Cecilia-Kakwa Area. The fauna is more richly developed in northeastern Alberta where it occupies the Middle Water- ways, Calmut interval. The following significant forms have been identified by the junior author and/or C.H. CRICKMAY : Atrypa cf. randalia Stainbrook Athabaschia asmenista Crickmay Devonoproductus tertius Crickmay Producte/la aff. belanskii Stainbrook Spinatrypa albertensis (WARREN) (also in DFR 4) Strophodonta costata Owen (in basai DFR 4 at Cecilia Lake) Strophodonta cf. cedarensis Stainbrook Strophodonta cf. dorsata Stainbrook Strophodonta halli Cleland Tylothyris annae (Swallow) In the Hay River area, in the Frobisher well cores mentioned above, the interval in which the DFR 3 Zone might be expected to occur is devoid of significant fossils, although both the DFR 4 Zone above and the DFR 2 Zone below have well-developed faunas. Therefore, diagnostic faunas of the DFR 3 Zone are yet to be discovered in the southern part of the District of Mackenzie.

Affinities of the DFR 3 faunas are clearly with the middle, Rapid Member of the Cedar Valley Formation of Iowa and its corrélatives in Missouri (Callaway) and Wisconsin (Milwaukee). On conodont evidence, Uyeno (op. cit.) places the Calmut ("Calumet") Member in the lower P. asymmetrica Zone, and, therefore, in the Early Frasnian in both the European (Ziegler) and United States (Clapper) sense.

DFR 2, Ladogioides pax Zone

The Ladogioides pax Zone is currently known only from the plains, from the Waterways area of northeastern Alberta northward and westward to the lower Peace River valley, Great Slave Lake area and Hay River area. In the Alberta Rockies, including the Cecilia-Kakwa Lake area, its absence is clearly a resuit of transgressive overlap.

The fauna of the DFR 2 Zone merits further megafaunal study. At present, the following significant species are known from northeastern Alberta : Atrypa cf. littletonensis Stainbrook A trypa cf. independensis Webster Eleutherokomma impennis Crickmay Eleutherokomma aechmophora Crickmay Ladogioides pax Me Laren Leiorhynchus russelli Me Laren (also in DFR 4) Lingula spatulata Vanuxem

From the core of the Frobisher well near Hay River, the junior author has identified Lingula spatulata Vanuxem, Styliolina fissurella Hall, Nervostrophia tulliensis (Hall) (also occurring lower and higher), Eleutherokomma impennis Crickmay, Devonoproductus sp., Atrypa gigantea Webster.

CRICKMAY mentions Ladogioides cf. pax from the well core of N.W.T. Deep Bay N° 3 north of the west end of Great Slave Lake. A.W. NORRIS (1965) lists an assemblag including Ladogioides pax "from basai limestone beds of Hay River Formation exposed north of Sulphur Bay".

The DFR 2 Ladogioides pax fauna is unknown outside of its limited area of occurrence in West- ern Canada. Uyeno's conodont studies show that it falls within the Early Frasnian, Lower P. asymmetrica Zone. REFERENCES CITED

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Bulletin of Canadian Petroleum Geology, Vol. 14, N°4, pp. 442-468. SMITH, S., 1945. Upper Devonian Corals of the Mackenzie River Région, Canada. Geol. Soc. America, Spécial Paper N° 59. STAINBROOK, M.A., 1943a. Spiriferacea of the Cedar Valley Limestone of lowa. Jour. Pal., Vol. 17, N° 5, pp. 417-50. (for additiona! papers on Cedar Valley and Amana/Independence brachiopod faunas related to Western Cana- dian faunas see also Stainbrook, 1938, 1940, 1942, 1943b, 1945 ; and Fenton, C.L. and Fenton, M.A., 1924). TAYLOR, G.C., 1971. Devonian and Earlier Stratigraphy and Structure of Monkman Pass and Wapiti Map-areas (British Columbia and Alberta) in Report of Activities, Part A : April to October 1970, Geological Survey of Canada, Paper 71-1, Part A, pp. 234-235. TAYLOR, P.W., 1957. Revision of Devonian Nomenclature in the Rocky Mountains. Journal Alberta Society of Petro- leum Geologists, Vol. 5, N° 8, pp. 183-195. TAYLOR, P.W., 1958. Further Data on Devonian Corrélations. Journal Alberta Society of Petroleum Geologists, Vol. 6, N° 1, pp. 13-19. UYENO, T.T., 1967. Conodont Zonation, Waterways Formation (Upper Devonian) Northeastern and Central Alberta. Geological Survey of Canada, Paper 67-30. WARREN, P.S. AND STECK, C.R., 1950. Succession of Devonian Faunas in Western Canada. Royal Soc. Canada, trans., Vol. 43, ser. 3, sec. 4. WARREN, P.S. AND STELCK, C.R., 1956. Devonian Faunas of Western Canada. Geol. Assoc. Canada, Spécial Paper N° 1. WILSON, G. A., 1968. A Brief Description of Devonian Strata between the Valleys of the Bow and Athabaska rivers. Alberta Society of Petroleum Geologists, 16th Annual Field Conférence guidebook, pp. 29-41. ADDENDUM

Part II was written in early 1972 before the transfer of one of us to France. Before the text was sent to press a very interesting paper by JOHNSON and NORRIS was made available : Tectnocyrtina, a new Genus of Devonian Brachiopods — Journal of Paleontology, Vol. 46, N° 4, pp. 565-572, July 1972. Two species of this new Cyrtinid, in relation with this issue of Notes et Mémoires, are dealt with, pages 566 to 570 : T. billingsi and T. missouriensis. References to new localities in British Columbia (Nabesche River, GSC loc. C. 3144 and Sikanni Chief River GSC loc. 51557) complément northwestwards our published information on Brachiopod Assemblages and extend their possible value from local to régional (their Brachiopods associations are very close, pro-parte, to ours, cf p. 73) We feel confident that our Cyrtina cf missouriensis of samples AA 454, 459 at Wallbridge will open a new discussion either for a stratigraphie revision of Assemblage II or for the evolutionary aspect of a possibly new Cyrtinid. The presence of C.F.P. faunas at the G.S.C., Calgary, is thus amply jus- tified. (A.M.) PLATES IV to XII ATRYPIDS : ASSEMBLAGE TWO

1-4 Atrypa aff. scutiformis Stainbrook 1938 Close to this mid-Cedar Valley (Iowa) species, characterized by its concavo-convex pedicle valve. Anterior, pedicle, brachial, and latéral views, x 1 ; from Wallbridge Mn. (455) B.C.

5-12 Atrypa sp. 468 Distinguished from the preceding by its biconvex profile and level anterior commissure. Compare also "A. independensis" of other Canadian authors. Anterior, pedicle, brachial, and latéral views of two specimens, xl, showing range of variation within the suite. Both specimens from Assemblage Two (458) at Wallbridge Mn., B.C. [(Possibly the same species as that shown by D.L. Jordan (University of Saskatchewan, 1966, pl. 7) as Atrypa (Rhinatrypa) multicostellata (Kottlowski)].

13-16 Atrypa blackhawkensis Stainbrook Much more coarsely plicated than A. aff. scutiformis and blunter anteriorly. The species recurs at the top of Assemblage Four. Anterior, pedicle, brachial, and latéral views, X 1, of aspecimen from Assemblage Two at Wallbridge Mn. (455), B.C., from the same bed as that which yielded A. aff. scutiformis. Compare also Atrypa nevadana Merriam of D.L. Jordan'sthesis,pl. 7, pp. 11-15.

17-24 Atrypa cf. rustica Stainbrook Distinguished by a highly convex brachial valve, plus relatively coarse plications and a narrow shell. The Iowa-type of the species occurs low in the Middle (Rapid) Member of the Cedar Valley Formation. Anterior, pedicle, brachial, and latéral views, xl, of two specimens showing range of variation in the species population ; from Assemblage Two at Kakwa Lake (488), B.C.

ATRYPIDS : ASSEMBLAGE TWO

Fig. 1-8 Atrypa bremerensis Stainbrook 1938 Anterior, pedicle, brachial and latéral views, xl, of two specimens showing range within the species population; from Assemblage Two at Kakwa Lake, B.C. In lowa, the species occurs in the Lower (Solon) Member (Cedar Valley) which is Givetian in âge.

ATHYR1DS : ASSEMBLAGE TWO

Fig. 9 Athyris cf. buffaloensis Stainbrook Pedicle view, x2, from (486) Kakwa Lake, B.C. The species occurs typically in the Middle Cedar Valley (Rapid Member) in lowa.

ATRYPIDS : ASSEMBLAGE THREE

Fig. 10-20 Atrypide genus undet. Presumably an undescribed atrypid genus with général proportions recalling the orthoid Tro- pidoleptus. This appears to be the same fossil as that referred to by D.L. Jordan (op. cit) as "Ana- trypa kakwaensis Norris Ms". Anterior, pedicle, brachial, and latéral views of two specimens and anterior, pedicle, and latéral views of a third ; ail x2 ; from Assemblage Three at Kakwa Lake (497), B.C.

ATRYPIDS : ASSEMBLAGE THREE

Fig. 1-4 Atrypa scutiformis Stainbrook 1938 Anterior, pedicle, brachial, and latéral views of a specimen, x 1, from the top of Assemblage Three, Kakwa Lake (497), B.C. This, the zone fossil of DFR 3, occurs prominently in the Calmut Member, Waterways Formation of Alberta and in équivalent beds in the Flume of the Canadian Rockies.

Fig. 5-12 Atrypa n. sp. "KAKWA" Anterior, pedicle, brachial, and latéral views of two specimens, x 1, showing range of species — population variation ; from lower part of the assemblage at Kakwa Lake (492), B.C. Although this specimen is close to A. scutiformis, plications are much coarser and valves more swollen.

Fig. 13-16 Atrypa n. sp. "KAKWA", var. 497. A population variant of the preceding, distinguished by the highly inflated profile. Anterior, pedicle, brachial, and latéral views, x 1 ; from the upper part of the assemblage, at Kakwa Lake (497), B.C.

Fig. 17-20 Atrypa n. sp. "KAKWA" var. An undesignated variety : pedicle view x 1.5, brachial, latéral, and anterior views x 1 ; from (496) Kakwa Lake, B.C.

Fig. 21-24 Atrypa sp. nov. 496. A small species close to the associated A. scutiformis but having a much lower postero-brachial profile. Pedicle and brachial views, x 2, and anterior and latéral views, X 1 ; specimen from (496) at Kakwa Lake, B.C.

PLATE VII

ATRYPIDS : ASSEMBLAGE FOUR

1-8 Atrypa sp. nov. 473, var. A The fine plications recall A. gregeri Rowley, A. clarkei Warren (probably a junior synonym of the preceding), and A. cosmeta Crickmay, from which it dilTers : (1) in the regular distant concen- tric lamellations, and (2) in the inaequivalve character with a shallow pedicle valve. Anterior, pedicle, brachial, and latéral views, X 1, of specimens showing limitations of the species- population variation : from middle of Assemblage Four at (473) Wallbridge Mn., B.C.

9-20 Atrypa sp. nov. 473, var. B A variant of the above which is smaller at maturity and has a more convex pedicle valve. Pedicle, brachial, latéral, and anterior views, xl, of three individuals from mid-portion of the Assemblage at Wapiti Mn. (549), Wallbridge Mn. (473), and Kakwa Lake (502), respectively.

21-24 Atrypa sp. nov. 473, var. C A small variant with aequiconvex valves. Pedicle, brachial, anterior, and latéral views of a specimen, x 1, from middle of Assemblage at (473) Wallbridge Mn., B.C.

ATRYPIDS : ASSEMBLAGE FOUR

Fig. 1-4 Atrypa cf. rotunda Stainbrook Pedicle, brachial, anterior, and latéral views, xl, of an exfoliated specimen from base of the assemblage at Kakwa Lake (498), B.C.

Fig. 5-11 Atrypa gregeri Rowley A pedicle, brachial and latéral view; and an anterior, pedicle, brachial, and profile view of two specimens, x2, from the mid-portion of the assemblage at (500) Kakwa Lake. The species is widespread in North America, from the Snyder Creek Formation in Missouri, through the Upper Waterways and Flume in Alberta, to northwestern Canada.

Fig. 12-15 Atrypid genus undet. (548) Pedicle, brachial, latéral and anterior views, x2, of a specimen from the lower part of the assemblage at Wapiti Mn. (548), B.C. Possibly a Spinatrypa but plications rnuch finer and rasp-like rather than spinulose.

Fig. 16-19 Spinatrypa sp. 548 A species which may fall within the range of variation of S. albertensis Warren, but which has finer and more freely dividing plications. Pedicle, brachial, anterior, and latéral views, x2, of a specimen from (548) at Wapiti Mn., B.C.

Fig. 20-23 Spinatrypa albertensis (Warren) Anterior, pedicle and brachial valves, x2, and latéral, xl, views of a specimen from top of Assem- blage Four at (504) Kakwa Lake, B.C. Described originally from the Waterways Formation of eastern Alberta.

Fig. 24-27 Atrypa devoniana var. minor Stainbrook 1938 Anterior, pedicle, brachial, and latéral views, xl, of a specimen from the mid-portion of the assemblage at (473) Wallbridge Mn., B.C. Typical of the variety (which might be regarded as a species) that occurs in the base of the Middle Member (Rapid) of the Cedar Valley Formation of Iowa.

SPIR1FERIDS

Fig. 1-4 Cyrtina billingsi Meek Anterior, pedicle, brachial, and latéral views, x 2, of a specimen from (497) top of Assemblage Three at Kakwa Lake, B.C. Elsewhere the species occurs in the Early Frasnian Waterways and Flume Formations of Alberta.

Fig. 5-7 Cyrtina cf. triquetra Hall Anterior, pedicle, and brachial views, x 4, of a specimen from base of Assemblage Four at (498) Kakwa Lake, B.C.

Fig. 8-15 Eleutherokomma jasperensis (Warren) Latéral, pedicle, brachial, and anterior views of two individuals ( x 2, X 4, respectively) from Assem- blage Four at Kakwa Lake (499, 500), B.C.

Fig. 16 Eleutherokomma jasperensis (Warren) Brachial interior, x2, from middle of Assemblage Four at (473) Wallbridge Mn., B.C.

Fig. 17 Eleutherokomma cf. killeri Crickmay Pedicle valve, x2, resembling Crickmay's species but lacking the diagnostic extended mucrones. Same locality and horizon as preceding.

Fig. 18 Eleutherokomma killeri Crickmay Pedicle valve, x2; extended mucron preserved on right side of shell, but does notshoweffectively in the photograph. Same locality and horizon as the preceding.

Fig. 19-20 Allanella minutilla Crickmay Pedicle valve ; latéral and pedicle views, X 6, from mid-uortion of Assemblage Four at (537) Cecilia Lake, B.C.

Fig. 21-22 Cyrtina cf. umbonata Hall Brachial and latéral views, X 2, of a specimen from (500B) middle of Assemblage Four at Kakwa Lake, B.C.

RHYNCHONELLIDS : ASSEMBLAGE FOUR

Fig. 1-4 Ladogioides sp. nov. Posterior, anterior, brachial, and pedicle views, x 2, from about middle of the Assemblage at Kakwa Lake (500B), B.C.

Fig. 5-7 Athyris randalia Stainbrook Vertical, dorsal, and latéral views, x2, of a specimen from (500B) Kakwa Lake. Originally described from the Upper Cedar Valley (Coralville Member) of Iowa.

Fig. 8-15 Leiorhynchus cary a Crickmay Anterior, pedicle, brachial, and latéral views showing degree of species-population variation. Fig. 8-11 (502) from Kakwa Lake, and 12-15 (473) from an équivalent horizon at Wallbridge Mn., B.C. Ail figures x 2.

Fig. 16-19 Ladogioides kakwaensis (Mc Laren) Anterior, pedicle, brachial, and latéral views, natural size, of a specimen close to McLaren's (1954) holotype. From (504) topmost beds of Assemblage Four at Kakwa Lake, B.C.

ORTHIDS — STROPHOMENIDS : ASSEMBLAGE FOUR

Fig. 1-12 Rhipidomella ? sp. "KAKWA" Anterior, brachial, pedicle, and latéral views of three specimens, x4, from mid-portion of Assem- blage Four (500 B), Kakwa Lake, B.C.

Fig. 13-15 A fourth individual, ventral, dorsal, and profile views, x 4, from Kakwa Lake (500 B).

Fig. 16-17 Strophodonta cf. iowensis Owen Pedicle and brachial views of a specimen, xl.5, from (474) mid-portion of Assemblage Four at Wallbridge Mn., B.C.

Fig. 18 Strophodonta costata Owen Pedicle valve, x2, from mid-portion of Assemblage Four at Wallbridge Mn., B.C. (473).

Fig. 19 Strophodonta, cf. subdemissa Hall A pedicle valve, x 1, from the same locality and horizon as the preceding. 5 6 7 8

19 ATRYPIDAE

Fig. 1-3 Atrypa sp. "DISCOID" Pedicle view, x2, brachial viewxl.5, and anterior view x I, of a specimen of this subcircular, very flat species from (502) upper part of Assemblage Four at Kakwa Lake, B.C.

Fig. 4-7 Another example of the same species, pedicle view xl.5, brachial view x2, latéral and anterior views natural size ; same locality and horizon.

Fig. 8-11 Atrypa sp. 544 Pedicle (x 1.5) and brachial, latéral and anterior views (x 1 ) from (544) Assemblage Five at Cecilia Lake, B.C. A species with plications as in A. gregeri from which it differs in proportions, especially in the somewhat extended trail.

Fig. 12-15 Atrypa pronis Fenton & Fenton Pedicle, brachial, latéral, and anterior views of an exemple, natural size, from Assemblage Five (545) at Cecilia Lake, B.C. Described originally from the Middle (Rapid) Member of the Cedar Valley Formation, Iowa.

Fig. 16-19 Atrypa blackhawkensis Stainbrook Pedicle, brachial, latéral and anterior views of a specimen (x 1) from the top of Assemblage Four at (504) Kakwa Lake, B.C. The species occurs in the Upper (Coralville) Member og the Cedar Valley Formation.

Fig. 20-22 Spinatrypa albertensis (Warren) Brachial (x 1.5), latéral and anterior views (x 1) of a specimen from top of Assemblage Fourat (504) Kakwa Lake, B.C. mam