(Middle
Cambrian, Yoho National Park, Canadian Rocky Mountains)
There have been many problems in the past with designating and correlating units within the Stephen Formation, Burgess Shale Formation, and the Cathedral Formation. Much of the controversy and problems arise from faulting in the area and especially from environmental (facies) differences between the stratigraphic units. There are shelf platform sequences that include shallow water inner detrital belt, middle carbonate belt, and carbonate shelf edge facies, as well as deeper water (basinal) outer detrital belt facies. These all have posed problems in correlation and descriptions of the formations in the area.
What used to be known as the Stephen Formation is now restricted to what was known as the "thin" Stephen Formation. The Stephen Formation now includes the Narao and Wapituk Members. What was formerly the "thick" Stephen Formation (basinal Stephen) is now called the Burgess Shale Formation. This formation comprises units that include the classic Burgess Shale localities (Walcott Quarry (including the "phyllopod bed"), Raymond Quarry), the Mt. Stephen Trilobite Beds, as well as most of the soft-bodied faunas (Collins Quarry, S7, Ehmaniella Zone faunas, etc.).
The Burgess Shale and Stephen Formations outcrop mainly in Banff and Yoho National Parks in the Alberta-British Columbia border area. All known outcrops are in Canada's Rocky Mountain Parks, so collecting is strictly forbidden. The Burgess Shale is a UNESCO World Heritage site.
Please note that we are still unsure which trilobites occur in the newly restricted "thin" Stephen Formation. The list below may include species which only occur in the "thick" Stephen (Burgess Shale Formation).
Bathyuriscus sp.
Chancia palliseri (Walcott, 1908b)
Ehmaniella burgessensis Rasetti, 1951
Ehmaniella waptaensis Rasetti, 1951
Elrathia permulta (Walcott, 1918b)
Elrathina cf. E. brevifrons Rasetti, 1951
Elrathina cordillerae (Rominger, 1887)
Glossopleura sp.
Hanburia gloriosa Walcott, 1916b
Kootenia burgessensis Resser, 1942
Ogygopsis klotzi
Olenoides serratus (Rominger, 1887) [=Nathorstia transitans Walcott, 1912a]
Oryctocephalus burgessensis Resser, 1938
Oryctocephalus matthewi Rasetti, 1951
Oryctocephalus reynoldsi Reed, 1899
Oryctocephalus sp. indet.
Pagetia bootes Walcott, 1916b
Parkaspis decamera Rasetti, 1951
Peronopsis montis (Matthew, 1899)
Ptychagnostus praecurrens (Westergaard, 1936) [=Triplagnostus burgessensis Rasetti, 1951]
Spencella sp.
Selected References:
Aitken, J.D. and McIlreath, I.A., 1984 The Cathedral Reef Escarpment. A Cambrian great wall with humble origins. Geos, 13: 17-19
Aitken, J.D. and McIlreath, I.A., 1990. Comments and Reply on "The Burgess Shale: Not in the shadow of the Cathedral Escarpment". Comment: In defense of the escarpment near the Burgess Shale fossil locality. Geoscience Canada, v.17, no.2, p.111-116.
Burgess Shale - First Glimpse of the Cambrian Explosion
Fletcher, T. P. & Collins, D. H. (1998) The Middle Cambrian Burgess Shale and its relationship to the Stephen Formation in the southern Canadian Rocky Mountains. Canadian Journal of Earth Sciences 35: 413-436.
Fletcher, T. P. & Collins, D. H. (2003) The Burgess Shale and associated Cambrian formations west of the Fossil Gully Fault Zone on Mount Stephen, British Columbia. Canadian Journal of Earth Sciences 40: 1823-1838.
Fritz, W. H., 1990. Comments and Reply on "The Burgess Shale: Not in the shadow of the Cathedral Escarpment". Comment: In defense of the escarpment near the Burgess Shale fossil locality. Geoscience Canada, v.17, no.2, p.106-110.
Fritz (1971) Geological setting of the Burgess Shale. Proc. North American Paleontological Convention: 1155-1170, 1969, Part 1.
Rasetti, F. (1951) Middle Cambrian stratigraphy and faunas of the Canadian Rocky Mountains. Smithsonian Miscellaneous Collections, Volume 116, No. 5, 277 pp.
Whittington, H. B. (1985) The Burgess Shale, 1985, Yale University Press. QE770.W6
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