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LA,TE ORDOVICIÆ{ SOLITARY RUGOSE CORATS oF TIIE BEAVERFOOT FORMATTON, SOUTIIERN ROCKY UOI'NTATNS, BRITISH COLI]MBIÀ AND ALBERTA. Caroline J. Knapp A thesis presented to the Unlversfty of ManÍtoba in partíal fulfill¡tent of the requírements for the degree of I'iaster of Scíence ln Departmeût of Earth Sclences Ilinnipeg, Manítoba 1985 LATE ORDOVICIAN SOLITARY RUCOSE CORALS OF THE BEAVERFOOT FORMATION, SoUTHERN ROCKY MOUNTAINS, BRTTTSH COLUI'ÍBrA AND ALBERTA BY CAROLINE J. KNAPP A thesis submitted to the Faculty of Graduate Studies of the University of Manitoba in partial fulfillment of the requirements of the degree of MASTER OF SCIENCE ,-/@ '1985 Permissio¡r has been granted to the LIBRARY OF THE UNIVER- SITY OF MANITOBA to lend or sell copies of this thesis. to the NATIONAL LIBRARY OF CANADA to microfilnr this thesis a¡rd to lend or sell copies of the film, and UNMRSITY MICROFILMS to publish an abstract of this thesis. The author reserves other publication rights, a¡rd neither the thesis nor extensive extracts from it may be printed or other- wise reproduced without the author's writte¡r permission. a Contents Abstract 1 Introduction . 3 Abbrevlations 3 Explanatíon of figures 4 General geologY 7 History of stratígraphlc nomenclature 7 Llthos tratigraPhY 9 BiostratigraPhY 11 DeposiEíonal- envíronments . 13 Solitary rugose corals l4 Previous work . T4 Present material 15 Preservation . 15 Identification and rel-ative abundance of taxa ' 22 Geographic and stïatigraphíc distributíon 24 Taphonoury and Paleoecologr 26 Abrasion 26 Attachment structures . 28 OrientaËiot¡ . 30 Pal-eo ecolo gi c assocíatÍons 34 Paleoenvironments and pal-eobathymeÈry 36 Close bíotic associates . .. 38 Objeets within corall-a 38 Epizoans and boríngs .. 40 Distributl-on and evolutlon 42 t_1 Sal 42 Blghornla 44 Grewingkía .. ... 46 Deíracorat-1ir¡m 48 Pal-eobiogeography 49 Bíostratigraphy 5l Sys temaÈic pal-eontol-ogy s4 Genus Salvadorea Nelson ,1981 54 S. disÈineta dlstlgcta (!ütlson, L926) 55 Salvadorea sp. 2 of. Nelson, 1981 68 Genus Bíghornia Duncan, L957 . 70 B. patel-l-a (ltíLson, 1926) 75 'and B. wilsgnae Knapp Elias' n. sp. 89 B. sp. cf. B. botteÍ Nelson,'1963 . 92 Genus Grer¡ingkia Dybowski, 1873 . 95 g. haysit haysii (Meek, 1865) 95 Genus -_-----Deiracoralliun Nelson, 1963 . 109 D. prolongatum (trIilson, 1926') 109 Acknowledgments 119 References cíted L20 Appendix 1. Distribution and frequency of coral-s r29 Appendix 2. Identifícation of speclmens 136 Appendix 3. Bíometríc data . r52 Appendix 4. Additional- data on S. distínq.lEq ¡listlncga t67 Appendix 5. Length of cardinal septum 169 iti Table 1. Features of sol-itary corals 27 Figures 1. Geologic map of southern Rocky Ìtountaíns 5 2. Topographic nap showing Localities Nl2, &!!\, K12B . 16 3. Photograph of l-ocal-itíes K124, ElgE 18 4. Stratlgraphíc section, localiÈíes Elä' K12B . 20 5. G. haysii haysii- and S. distlncta distincta 32 6. S. digtincta distincta and Salvadorea sp. 2 64 7. Number of maJor septa ln S. distincta disÈincta and Salvadorea sp. 2 66 8. Coral hefght and cross-sectional dimension ln BLghornia 73 9. B. patel-la, B. wílsonae, and B. sp. cf . B. botteí 83 10. Cross-sectional dÍmensions in Bighornfa 85 11. Nunber of major septa in B1 87 L2. G, haysti havsíi 103 13. Cross-sectional dimensions in Grenringkia and Deiracoral-I-iun 10s 14. Nr¡mber of major septa ín G. haysil haysii 107 15. D. prolongatum 115 16. Number of major septa l-n D. prolongatum ..... LL7 1 Late Ordovician sol-ltary rugose corals of the Beaverfoot Fotmation' southern Rocky Mountainst Britlsh Col-unbfa and Alberta Caroline J. Knapp Department of Earth Sciences . University of Manítoba' llÍnnf Man Canada 2N2 The following Late ordovician solitary Rugosa are Present wíthin the Beaverfoot Fornation (Upper Ordovicl-an-Lower Silurian) in the southern Rocky Mountains of Brftlsh Col-unbia and Alberta: Salvadorea dístÍncta distincta (I,Iilson, L926) , Bighornía patel"l-a (I{íLson , 1926) , B. sp. cf. B. bortei Nelson, L963, Grewingkia haysii haysii (Meek' 1865), Deiracoralliun prolongatum (ÏIlLson, 1926), and Salvadorea sp.2 of Nelson, 1981. Corals of this Salvadorea-dominated assemblage are most comtron and widespread ín the l-ower parÈ of the Beaverfoot above the basal WhískeY Trail Member. Analyses of coral abrasion, curvature, and life orientatíon suggest that G. havsii havsii inhabited hígher energy environments than S. distincta disÈíncta and B. patel-la. All taxa probably lived fn close proxin:ity, and the coralla were transPorted during severe storms. The presence of so1ítary corals fn particular intervals within the Beaverfoot Formation coul-d indicate shallow hrater maxima and/or relatível-y oPen' nor:mal marine condítions. The area of Beaverfoot sedimentation r¡as situated wiÈhín the Red River-Stony Mountain SoLitary Coral Province, which oecupíed'most of North America during Late Ordovician tfme. The six species in thís 2 formation comprise an ttepicontlnentaltt assemblage, and all occur in the Hudson Bay Basin. The absence of "continental marginrr Èaxa could reflect envíronmental faetors or geographic barríersr or could indicate that the Beaverfoot Formation r{tas deposlted some distance from the edge of the conÈínenL. The base of the Bigh ornia-Thaerodonta zone in the Beaverfoot Formation is hereín placed at Èhe lowest occurrence of solitary corals withín the lühiskey Traíl Member. El-ser¿here' this Salvadorea-domlnated assemblage fírst appears in Maysvillian to niddle Richmondían strata. The Bíehornia-Thaerodonta zone is exÈended upward to ínclude coral-bearing beds thought to be near the Ordovician-Silurian boundary. The uppermost portion may be Ganachian' No evolutÍonary changes are recognízed ín solitary rugosan specíes I^ríthín the Beaverfoot Form¿tÍon. B. wilsonae Knapp and Elias' n. sp.r the ancestor of B. patell-a, ís known from the second value Dolomite of the Montoya Group in New Mexico and Texas, and Èhe Selkirk Member of the Red River Formation in southern Manltoba' 3 Introduction The Beaverfoot Formatíon of Late OrdovicÍan to Early Silurían age is exposed in the southern Rocky Mountains of British col-umbia and Al-berta (Fie. 1). trIiÈhín this area, the original depositional stríke as well as trends of thrust sheets, mountain ranges, and outcrops are all approximately paral1e1 in a northwesf-southeasÈ direction. The formation represents predominantly carbonate deposítion on a broad platform along the early Paleozoic continental margin of western NorÈh America. Varfous faunal- zones have been recognízed r¿ithin the Beaverfoot, but the only descríptive paleontologícal r¡rork l^7as by I'lilson (1926) . The purposes of this study are to describe, using modern techni-ques, the LaÈe Ordovician solítary Rugosa of the Beaverfoot Formation, to document their straËÍgraphíc and geographíc distríbutions, and provide paleoecologic inÈerpretations. The evolutíonary, paleobiogeographic, and biostratigraphíc sÍgnificance of these fossíls is consídered using comparÍsons l¡íth corals descrÍbed from elsewhere in North America (Nelson,1963, 1981; Elias,1981, 1982a, 1983a, 1983b' 1985; Elias and Potter,1984), and a chronostratígraphic framework based prinaríly on conodont data (Sweet, 1979i McCracken and Barnes, 1981; Elias, 1985). Canada, Ottawa, Ontario) Abbreviations--€SC (Geologícal Survey of ',MMH (l"luseurn mineralogicum hafniensis, Geologisk Museum, Copenhagen' Denmark), PMO (Paleontologisk Museum, os1o, Norway)' usNM (NaÈional Museum of NaÈural History, Smithsonlan Institutíon, l'lashington, D'C')' 4 Explanatíon of figures-For photographs of coral exteriors' specimens TÍere coated wlth amonium chloride. Al-L transverse and l-ongitudinal secÈions nrere prepared using thin sections as negatives !n a photographic enlarger. Transverse sectlons are oriented as they appear l-ookíng down from the caLice toward the tLp of the eoral, ¡¡ith the cardinal- síde faeing th.e botÈon of the page. A.l-1 1-ongftudinal sections are orfented with the cal-ice faclng the top of the page. 5 Flgure l. Geologlc map of part of the southern Roeky l.(ountains from Norford, 1969, f'LE. 6). Late Ordovician solitary rugose corals fron the Beaverfoot Fornatlon were coll-ected at the local-itles named below. IÞshed line geologic boundary Short dash-dot l-lne feather edge of stratigr¿phlc lnterval- beneath sub-Devonlan unconfornity Long dash-dot llne structural- dLscontfnuity along Rocky l'fountaín Trench Solid l1ne truncation due to recent eroslon sr Tegart Formatlon (Sllurl.ao) osb Beaverfoot Formåtlon (Upper Ordovicl'an to Lo!úer Silurian) 0rûr{ Mount l{ilson Quartzite (l{lddle to Uppel Ordovfcian) lnO upper Lower to MlddLe ordovlcfan (owen creek Formatlon, skokl Iornatfon' TLpperary quartzlte, Glenogl-e shales, upper pårt of outra¡r Fornatlon) llP Palllser Pass I{sl Irllndermere Creek t'6P between Spray Rlver and Palliser Pass r Faírmont Spríngs & llhite Knight }iountaln -NÀ Mount Wll-son -NC Tipperar5¡ Pass ND Pedley Pass NE. ìbunt SincLair NE Carbonate Creek ¡¡4 IndLanhead lfountain N7 Pinnacle Creek N9 Itatch Creek N10 Pagliaro Creek Nr1 Ilorse Creek N12 Bl-ackfoot Creek N14 Shatch Mountain uu lbunt Onslo¡'r N31 Pípestone River N40 Clrrus Mountain Kt2 Akutlak Creek Lq 51. Radum osb+J BRITISH tr. r s. st COLUMBIA osb Cfanbrook¡ o 21 {km t--l-g c^xA u 7 General geoLogy Hístory of stratigr aphie nomenclature-strata in the Beaverfoot Range of southwestern BriLish CoLumbia were first studied by McConnell (1887). He identified a sequence of quartzÍtes succeeded by dolomites as the t'Ilalysítes beds ," and assigned it to Ëhe Silurian. Burling (1922, p. 452) proposed the name BeaverfooÈ FormatÍon for Èhe "I1alysÍtes beds," and consídered Ít to be Late OrdovicÍan (Richmondian) in age. The type section ís at Carbonate Creek. The quartzite interval tras separated from Èhe BeaverfooË and named tr{onah Quartzite by tlalcott (1924¡ P. 48-50). He also proposed the term Brisco Formatlon for a Silurian dolomítíc and argil-laceous unit above the Beaverfoot (Italcott, 1924, P. 47, 48). fne type sections of his units are at Mount Sinclair in the Brisco Range. Lat.er workers could not differentiate the Beaverfoot and Brisco on lithologic grounds, and used Èhe term Beaverfoot-Brísco Formation (references cÍted in Norfordr1969, p.