Short Notes

BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA VOL 70. PP. 107-110. 1 FIG. JANUARY 1959

FAl.'LTEl) KINDLE (MISSISSIPPIAX) SECTION AT , , CAXADA

BY SAMUEL J. NELSON

The abnormally thick carbonate section of that complex folding was the cause of the ex- the at Crowsnest Pass, Alberta, traordinary thickness. Warren (1928; 1933) and has interested geologists for many years. The McKay (1932) thought that their measured Rundle here attains an apparent thickness of thicknesses of between 5000 and 5300 feet were more than 5000 feet in contrast to near-by sec- caused by deposition and not structural com- tions most of which are less than 3000 feet. plications. Cundill (1955) concluded, from Although no obvious faults occur in this sec- lithologic studies, that the succession was re- tion, some geologists attribute the thickness to peated by three faults and possibly a fourth, repetition, while others consider basinal deposi- and indicated that the true stratigraphic thick- tion as the answer. J. R. Cundill (1955) out- ness is about 2700 feet.1 The section was lined stratigraphic evidence illustrating fault- recently briefly referred to by Bostock, Mulli- ing in the section, and the writer here presents gan, and Douglas (1957), who stated that the paleontologic evidence in support of Cundill's maximum thickness is 3900 feet. Faulting was interpretation. not mentioned. The section discussed is exposed on the north In 1955 the writer with J. R. Cundill and side of Crowsnest Lake at Crowsnest Pass in two assistants spent 10 days making detailed the southern immediately fossil collections from the section. A study of east of the Alberta- boundary. faunas has shown that Cundill's three main The Rundle here is a westward-dipping, super- faults are probably correct, and that the fourth ficially undisturbed sequence of carbonates which he tentatively proposed is also present. underlain on the east by the Banff and overlain Faunal evidence indicates that the stratigraphic on the west by the Rocky Mountain formation. thickness of the Rundle is between 2900 and The Rundle group at Crowsnest Pass, as in 3000 feet (Fig. 1). Thus Cundill's excellent most areas of the southern Canadian Rockies, stratigraphic analysis is confirmed by paleon- can be divided into three formations which, tology. in ascending order, are the Livingstone, Mount The writer wishes to express his gratitude to Head, and Etherington. In other areas these officials of The British American Oil Company, three formations generally aggregate between Ltd., Calgary, for financial backing of this 2000 and 3000 feet: the Livingstone (1000- project. Dr. P. S. Warren, of the University of 1500 feet), of resistant light-colored crinoidal and interbeddedfiner-graine d car- 1 bonates, of Osagean age; the Mount Head Cundill placed only the Livingstone and Mount Head formations in the Rundle group and stated (600 feet), a recessive unit of Meramecian age that their combined stratigraphic thickness was consisting of dark , dolomite, and about 2100 feet. If the Etherington (his Tunnel shaly beds; and the Chesterian Etherington Mountain formation) is included in the group formation (700 feet or less) of resistant light- then the above figure of 2700 feet is obtained. Some confusion has been caused by the fact that weathering dolomites and limestones. The his diagram shows a total thickness of 2750 feet reader is referred to Warren (1927), Beales for the Livingstone and Mount Head in contrast (1950), Douglas (1953), Xorris (1957), and to the stated figure of 2100 feet. Cundill (Personal Bostock, Mulligan, and Douglas (1957) for communication) mentioned that the latter figure was derived by assuming an arbitrary value for details of Rundle . repetition on the fourth fault. Faunal evidence Dawson (1886), who made the first reference (Fig. 1) suggests that the figure is closer to 2300 to the Rundle of Crowsnest Pass, considered feet. 107

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TUNNEL MOUNTAIN MOUNT RAE CROW5NEST PASS SECTION MI Volley Ar*a HionwoodPasS Approxirri_ahe Sj-raHjrapliie PosiHon lanff Alb«rhi Hiqhwood River Area Fault Slice

Fault ^ic« 4. E. 1415.16 1713

. ^oo |_j^^^.

^gul^ Slke I. Foull-5!i«2

-B I,M.S.6.7 Foulf Slice 5 18 Q:lfracl0,futpa'Mf(Mt*tl) 17 tinop'oJuttulovafal (Mall) E 16 OrHcfftejleaikaifrerw'f MtChoney a 15. Sf Wfe /./oj-/1 NomogJ ( P.oHtn. t- Cjwollow) w

D 15. Littorfrohonan-tefum (CMckmay)

II12. Dtc/ytx/oifurFchmocanchu* f-enuicostus histi-ia^s (Hall!) C. 10 Producfel/a indioneniis (Hall) I Rocky Mountain. 6. Gitfye//a lutgifJo (Hall)

r~7^7| f^erin^on

53 Mounf- Head T Expo^ursi pot j or lacking formafio

Banff -3 formation

FIGURE 1.—CORRELATION OF THK RUNDLE GROUP () OF CROWSNEST PASS, ALBERTA

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Alberta, has guided the writer through most useful for local mapping. The stratigraphic phases of this study. position of the Crowsnest Pass L. arizelum with Figure 1 shows the stratigraphic correlation respect to assemblage C suggests that the of the fault slices diagnosed for the Rundle containing strata probably correlate with limestone of Crowsnest Lake with two well- uppermost rather than lowermost Mount Head. known sections in Alberta—Mount Rae (Storm An interval of about 500 feet separates assem- Creek), about 65 miles north of the Pass, and blages D and E, while in other nearby sections , 45 miles farther northwest. this interval is 140-200 feet. Thus the enlarged Footages for the last section are those of Beales interval suggests repetition by faulting. No (1950); those of Mount Rae are the writer's. diagnostic fossils occur above assemblage E, Portions of sections not pertinent to this dis- but the 400-foot section between K and the cussion are omitted; their deletion is indicated base ol the Rocky Mountain formation is simi- by jagged lines on columnar sections in the lar to that of normal sections and suggests that figure. faulting is absent. Lithologic divisions and footages of the Crowsnest Pass Rundle (Fig. 1) are those of Cundill (1955). The base of the Mount Head REFERENCES CITED formation in this paper has been raised 200 feet Beales, F. VV., 1950, The Late Palaeozoic forma- above that of Cundill so that the lithologies tions of southwestern Alberta: Geol. Survey conform more closely with the formation at Paper 50-27. 72 p. Tunnel Mountain and Mount Rae. Cundill's Bostock, H. S., Mulligan, R., and Douglas, R. J. \V., 1957, The Cordilleran region: p. 283-392, "Tunnel Mountain formation" is here called Pis. 30-36, Figs. 61-78; in Geology and eco- the Etherington formation (sec Norris, 1957; nomic minerals of Canada: Geol. Survey Bostock, Mulligan, and Douglas, 1957) to Canada, Econ. Geology, ser. 1, 4th ed., 517 p. conform with more recent nomenclature. Crickmay. C. H., 1955, The Minnewanka section of the Mississippian: published by the author, Five diagnostic fossil assemblages are recog- Imperial Oil Co., Calgary, Alberta, 15 p. 2 nized in sections portrayed on Figure 1 and pis., 3 charts are designated as assemblages A to E, respec- Cundill, J. R., 1955, Notes on faulted Mississip- tively. Spinfer banffensis Warren is the only pian section at Crowsnest Pass: Alberta Soc. Petroleum Geologists Jour., v. 3, no. 8, p. fossil present in assemblage A. This easily 138-139 recognizable species occurs 585 feet above the Dawson, G. M., 1886, Preliminary report on the base of the Livingstone on Tunnel Mountain, physical and geological features of that por- suggesting a middle Livingstone correlation tion of the between lati- tudes 49° and 51° 30': Geol. Nat. History for assemblage A in fault slices 1 and 3. Species Survey Canada, pt. B, Ann. Rept. 1885, p. of assemblage B, geographically widespread in 1B-169B the Canadian Rockies, are characteristic of Douglas, R. J. VV.. 1953, stratig- lower Mount Head strata. Cundill's (1955) raphy in the southern Foothills of Alberta: Alberta Soc. Petroleum Geologists Third Ann. lithologic evidence has been used in determining Field Conf. and Symp., p. 68-88, Figs. 1-9, the fault position at the top of fault slice 1, for 9A the stratigraphic interval between assemblage B McKay, B. R., 1932, The Mesozoic-Palaeozoic in this slice and in superjacent slice 2 could contact and associated sediments, Crowsnest district, Alberta and British Columbia: Geol. represent the fossil assemblage range rather Survey Canada Summ. Rept. 1931, pt. B, p. than repetition by faulting. Assemblage C is 1B-25'B, Figs. 1-2 characteristic of the lower part of middle Norris, D. K., 1957, The Rocky Mountain suc- Mount Head although Echinoconchus biseriatus cession at Beehive Pass, Alberta: Alberta Soc. Petroleum Geologists Jour., v. 5, no. 10, (Hall) and Dictyoclostus tenuicoslus (Hall) are p. 248-254. Figs. 1-2 known to range some distance higher. Assem- Warren, P. S., 1927, Banff area, Alberta: Geol. blage D consists of Lithostrotion arizelum Survey Canada Mem. 153, 94 p., 7 pis. (Crickmay). The holotype of this species is 1928, The Palaeozoics of the Crowsnest Pass, Alberta: Roy. Soc. Canada Trans., v. 22, from basal Mount Head strata at Lake Minne- sec. 4, p. 109-119, 1 PI. wanka (Crickmay, 1955). Specimens almost 1933, Geological section in Crowsnest Pass, identical with the type are abundant in upper- Rocky Mountains, Canada: Roy. Canadian most Mount Head at Mount Rae. The writer Inst. "Trans., v. 19, pt. 2, p. 145-160 considers that these stratigraphically higher DEPT. GEOLOGY. UNIVERSITY OF ALBERTA, ED- specimens are either homeomorphs developing MONTON, ALBERTA, CANADA out of L. whitwyi Meek of middle Mount MANUSCRIPT RECEIVED BY THE SECRETARY OF THE Head, or an expression of a reintroduced zonule SOCIETY, MAY 13, 1958

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