Archaeocyathids and the Lower Cambrian Continental Shelf of the Canadian Cordillera

1975 ◽  
Vol 12 (12) ◽  
pp. 2014-2020 ◽  
Author(s):  
C. R. Stelck ◽  
A. S. Hedinger
Keyword(s):  
British Columbia ◽  
Continental Shelf ◽  
Lower Cambrian ◽  
Rocky Mountain ◽  
Canadian Cordillera ◽  
Western Canada ◽  
Early Cambrian ◽  
Structural Trend ◽  
East And West

The geographic occurrences of archaeocyathids are plotted for the Cordilleran region of western Canada. The archaeocyathids are found both east and west of, and within the Rocky Mountain Trench in British Columbia and are found east and west of the Tintina Trench in the southern Yukon. The overall pattern of the occurrences indicates that the shallow neritic portion of the continental shelf in Early Cambrian time traces a pattern widely diverse from that of the later, superimposed, Laramide structural trend. Portions of the continental shelf were already in existence west of the Rocky Mountain Trench by Early Cambrian time.

A Review of Geophysical Studies in the Canadian Cordillera

1971 ◽  
Vol 8 (7) ◽  
pp. 788-801 ◽  
Author(s):  
M. J. Berry ◽  
W. R. Jacoby ◽  
E. R. Niblett ◽  
R. A. Stacey
Keyword(s):  
British Columbia ◽  
Heat Flow ◽  
Rocky Mountain ◽  
The United States ◽  
Vancouver Island ◽  
Geophysical Data ◽  
Fault System ◽  
Canadian Cordillera ◽  
Crust And Upper Mantle ◽  
Juan De Fuca

Geophysical studies of the crust and upper mantle have been conducted in the Canadian Cordillera for over two decades, but only recently have sufficient data been collected to permit a synthesis and a correlation with the major geological units. The studies have included gravity, heat flow, and magnetotelluric observations, geomagnetic depth sounding, and high level aeromagnetics as well as both small and large scale refraction and reflection seismic surveys.It now appears that major crustal units may be recognized geophysically:(i) Seismic and gravity data suggest that the Plains and Rocky Mountains are underlain by two units of the North American craton with a crustal section 45–50 km thick. The northern unit appears to terminate at the Rocky Mountain Trench while the southern unit may extend to the Omineca Geanticline.(ii) The combined geological and geophysical data suggest that the Rocky Mountain Trench and possibly the Kootenay Arc near the 49th parallel mark the edge of the Precambrian continental margin and that the western Cordillera was formed by a complex succession of plate interactions with repeated reactivation of block boundaries.(iii) A combination of magnetic and heat flow data suggest that the region between the Rocky Mountain Trench and the Fraser Lineament is part of the Cordilleran Thermal Anomaly Zone recognized by Blackwell in the United States.(iv) Seismic data in Central British Columbia suggest that the Pinchi Fault system is a boundary between two crustal blocks.(v) The crustal thickness of the Coast Geanticline appears to increase gradually to the west to approximately 40 km and, at least in southern British Columbia, does not have a root zone below the mountains.(vi) The crustal section beneath Vancouver Island is abnormally thick and there is some paleomagnetic data which suggest that the Island may not have been formed in its present position, contiguous to the Cordillera. The crustal section for the northern part of the Insular Trough is significantly thinner.(vii) The active spreading of the Juan de Fuca Rise – Explorer Trench is now well documented. The geophysical data suggest active subduction of the Juan de Fuca plate beneath Oregon, Washing-ton, and southern Vancouver Island. However, further north there is no evidence for subduction.

Coccidia of Rocky Mountain bighorn sheep in Western Canada

1971 ◽  
Vol 49 (11) ◽  
pp. 1461-1464 ◽  
Author(s):  
Leslie S. Uhazy ◽  
Jerome L. Mahrt ◽  
John C. Holmes
Keyword(s):  
British Columbia ◽  
National Park ◽  
Rocky Mountain ◽  
Bighorn Sheep ◽  
Western Canada ◽  
Fecal Samples

A survey of coccidia in the Rocky Mountain bighorn sheep (Ovis. c. canadensis) in Alberta and Kootenay National Park, British Columbia, was conducted from the winter of 1967 to the spring of 1969. Ninety percent of 510 fecal samples examined were positive for coccidia. The species recovered, in order of prevalence, were Eimeria ovina (syn., E. arloingi) (56%), E. parva (35%), E. crandallis (34%), E. ahsata (33%), E. ninakohlyakimovae (19%), E. faurei (6%), E. intricata (5%) and E. granulosa (1%). Coccidiosis was not encountered in the field; however, evidence which suggests the magnitude of pathogenic infections is presented.

Imbricated terranes of the Cariboo gold belt with correlations and implications for tectonics in southeastern British Columbia

1986 ◽  
Vol 23 (8) ◽  
pp. 1047-1061 ◽  
Author(s):  
L. C. Struik
Keyword(s):  
British Columbia ◽  
Continental Shelf ◽  
Rocky Mountains ◽  
Rocky Mountain ◽  
East Central ◽  
Pillow Basalt ◽  
Shelf Sediments ◽  
Kootenay Lake ◽  
Southern Rocky Mountain ◽  
Bounded Sequences

The Cariboo gold belt of east-central British Columbia is divided into four fault-bounded sequences of distinct stratigraphy. They are, from east to west, the Cariboo (continental-shelf sediments), Barkerville (continental-shelf sediments and intercalated volcanics), Slide Mountain (rift-related submarine pillow basalt, chert, and diorite) and Quesnel (island-arc sediments and subaqueous volcanics) terranes. Each is separated from others by thrust faults. Grit, phyllite, limestone, and volcanics of the Barkerville terrane may be correlative with the Eagle Bay Formation near Adams Lake and the Lardeau Group near Kootenay Lake. Barkerville terrane may be part of a more regional rock package, Selkirk terrane, which is defined to include Kootenay terrane, Badshot Formation, and Horsethief Creek and Hamill groups. Selkirk terrane is (i) separated everywhere by a low-angle fault from the overlying age-equivalent but stratigraphically and structurally different Cariboo terrane and (ii) separated by a system of faults in the general location of the Southern Rocky Mountain Trench from the age-equivalent but stratigraphically and structurally different North American terrane of the Rocky Mountains.

Jurassic location of the Yukon-Tanana Terrane from paleomagnetism of the folded Mississippian Tatlmain Batholith and Ragged Stock

2019 ◽  
Author(s):  
D T A Symons ◽  
K Kawasaki
Keyword(s):  
British Columbia ◽  
North America ◽  
Fault Zone ◽  
Early Cretaceous ◽  
Rocky Mountain ◽  
Early Jurassic ◽  
Canadian Cordillera ◽  
Clockwise Rotation ◽  
Thrust Faulting ◽  
Host Rocks

Summary The extensive Yukon-Tanana terrane of the northern Canadian Cordillera has been considered controversially to be part of the allochthonous ‘Baja B.C.’ microcontinent or of the para-autochthonous North American cratonic margin during the Mesozoic. Paleomagnetic methods have isolated a very-stable Early Jurassic thermochemical remanent remagnetization in the terrane's felsic Tatlmain batholith and mafic Ragged stock after correction for: 1) rotation from northeast-plunging anticlinal deformation; 2) northerly dipping tectonic tilt of the host rocks; and, 3) northwestward regional translation on the adjacent Tintina transcurrent fault zone. The resulting 196 ± 6 Ma Tatlmain and Ragged paleopoles are 64.9° N, 44.8° E (A95 = 5.9°) and 64.2° N, 58.5° E (A95 = 7.7°), respectively. The YTT paleopoles support para-autochthonous tectonic models that have the YTT: 1) accreting to North America by the Early Jurassic; 2) undergoing non-significant orogen-perpendicular shortening by mid-Early Cretaceous from thrust-faulting; and, then 3) undergoing significant orogen-parallel northward translation of ∼500 km from mid-Early Cretaceous to the Eocene. In contrast, the paleopoles for Stikinia and Quesnellia of the Intermontane Belt show progressive northwestward translation relative to North America by ∼1000 km and a rotation of ∼55° cw since mid-Early Cretaceous. We speculate that ∼500 km of the northward translation is related to dextral motion on the Tintina and Northern Rocky Mountain Trench fault in British Columbia, and that the clockwise rotation is related to upper crustal tectonics in both Yukon and southern British Columbia.

Westerly derived Early Cretaceous gold paleoplacers in the Western Canada foreland basin, southwestern Alberta: tectonic and economic implications

1995 ◽  
Vol 32 (8) ◽  
pp. 1079-1092 ◽  
Author(s):  
Dale A. Leckie ◽  
David Craw
Keyword(s):  
British Columbia ◽  
Early Cretaceous ◽  
Foreland Basin ◽  
Rocky Mountain ◽  
Low Grade ◽  
Western Canada ◽  
Gold Content ◽  
Economic Implications ◽  
Quartz Veins ◽  
Sedimentary Succession

Albian-aged (Early Cretaceous) igneous pebble to cobble conglomerates fill multiple, northeast–southwest-oriented, subparallel channels in the upper Blairmore Group (upper Beaver Mines and Mill Creek formations) of the Rocky Mountain foreland basin, southwestern Alberta and southeastern British Columbia. Paleocurrent data show that the conglomerate was derived from the west. Clast petrography implies a provenance that includes granitoids, mafic volcanics, low-grade metamorphic rocks, and shallow-level (ca. 7 km depth) postmetamorphic quartz veins formed from meteoric fluids. The conglomerate was probably derived from the southern Omineca Belt of British Columbia prior to the rise of the Rocky Mountains. The conglomerate contains detrital gold grains up to 150 μm in diameter, and chemical analyses indicate widespread anomalous gold concentrations (up to 910 ppb Au) in conglomerate matrix. Gold content in these igneous-clast conglomerates excèdes that reported from the richest modern placers in Alberta. Less pronounced but persistent As anomalies (up to 260 ppm) occur also. Postdepositional alteration of conglomerate matrix chemically mobilized Au and As from their detrital source grains and redistributed these elements. Gold enrichment in the igneous-clast conglomerate contrasts strongly with background gold concentrations in the underlying conglomeratic Cadomin Formation. The gold concentrations in the igneous-clast conglomerate demonstrate that paleoplacers derived from the Canadian Cordillera have accumulated in the Western Canada foreland basin, a sedimentary succession previously dismissed as a host for detrital gold.

Stratigraphy, facies changes, and correlations in the northern Selkirk Mountains, southern Canadian Cordillera

1978 ◽  
Vol 15 (7) ◽  
pp. 1129-1140 ◽  
Author(s):  
Richard L. Brown ◽  
Clinton R. Tippett ◽  
Larry S. Lane
Keyword(s):  
Continental Shelf ◽  
Lower Cambrian ◽  
Canadian Cordillera ◽  
Early Paleozoic ◽  
The West ◽  
Late Proterozoic ◽  
Selkirk Mountains

The Hadrynian Horsethief Creek Group that underlies much of the northern Selkirk Mountains is divided into three members. The upper pelitic member is overlain by latest Hadrynian to Lower Cambrian rocks of the Hamill Group and is correlated with the Yankee Belle Formation of the Cariboo Group in the Cariboo Mountains to the northwest. The underlying middle marble member is correlated with the Cunningham Formation, and the lowest exposed lower pelitic member with the Isaac Formation.Westward thickening of the Horsethief Creek Group is paralleled by a gradational change in the upper pelitic member from a predominantly clastic sequence to the east to a predominantly calcareous sequence to the west. The overlying Hamill Group also changes in character, becoming more pelitic and interdigitating with basaltic metavolcanics toward the west. These facies changes are compatible with results from adjacent areas that point to deposition on a continental shelf in late Proterozoic to early Paleozoic time.

Early Cambrian coral-like fossils from the Northern Cordillera of Western Canada

1969 ◽  
Vol 6 (4) ◽  
pp. 782-785 ◽  
Author(s):  
Robert C. Handfield
Keyword(s):  
British Columbia ◽  
Western Canada ◽  
Early Cambrian ◽  
Conical Shells ◽  
External Wall ◽  
The Family ◽  
Mackenzie Mountains

Tabulaconus kordeae, n. gen., n. sp., is a coral-like fossil found in the Sekwi Formation, Mackenzie Mountains, District of Mackenzie and the Atan Group, Cassiar Mountains, British Columbia. The species consists of small, conical shells with a layered external wall and abundant tabulae. It is placed in the family Gastroconidae, previously known only from Siberia. Associated Archaeocyatha and Trilobita prove its Early Cambrian age.

scholarly journals A second glimpse of Early Cambrian life: new collections from Sirius Passet, North Greenland

1992 ◽  
Vol 155 ◽  
pp. 48-50
Author(s):  
J.S Peel ◽  
S.C Morris ◽  
J.R Ineson
Keyword(s):  
Lower Cambrian ◽  
Lower Devonian ◽  
Western Canada ◽  
Early Cambrian ◽  
Economic Interest ◽  
Burgess Shale ◽  
Southern Sweden ◽  
Hunsrück Slate ◽  
Middle Cambrian ◽  
North Greenland

The German mining term lagerstatten, referring to a rock of any composition containing constituents of economic interest, has been widely applied to occurrences of abundant or unusually well preserved fossils (cf. Seilacher et al., 1985). The Middle Cambrian Burgess Shale of western Canada is perhaps the most famous of all fossil-lagerstatt, with many of the approximately 140 known species preserving exquisite details of the soft anatomy of members of a community of organisms that was fossilised more than 500 million years ago (Whittington, 1985: Conway Morris, 1979, 1986; Gould, 1989). Other well known examples include the Upper Cambrian 'Orsten' of southern Sweden, the Lower Devonian Hunsruck Slate and the Jurassic Solnhofen Limestone of Germany (Stürmer et al.. 1980; Muller, 1985; Barthel et al. 1990; summary in Briggs & Crowther, 1990, pp. 266–297). The term can be applied aptly to the Sirius Passet fauna of central North Greenland, where a wealth of exceptionally preserved fossils (e.g. Fig. 1) from tile Lower Cambrian Buen Formation has been recorded from a small locality in western Peary Land, near the south-western end of the broad valley known as Sirius Passet (Fig. 2). The locality yielding the Sirius

The Occurrence of Cuterebra (Diptera, Oestridae) in Western Canada

Parasitology ◽  
1926 ◽  
Vol 18 (4) ◽  
pp. 430-435 ◽  
Author(s):  
Alfred E. Cameron
Keyword(s):  
British Columbia ◽  
Spotted Fever ◽  
Rocky Mountain ◽  
Careful Examination ◽  
Western Canada ◽  
Rocky Mountain Spotted Fever ◽  
Tamias Striatus ◽  
North West ◽  
North West Territories ◽  
Prevalent Species

Reference to the National Insect Collection at Ottawa shows that species of the genus Cuterebra have been collected in various localities of Western Canada at different times. Of these Cuterebra grisea Coq. is distributed throughout Manitoba, Saskatchewan, Alberta, North-West Territories and British Columbia. There is one record each of C. emasculator Fitch (determined by Aldrich as C. fontinella Clark), of which the locality is unknown, and of C. fasciata Swenk, from Peachland, British Columbia. The specimen of C. emasculator bears a note that it had been reared from a chipmunk, Tamias striatus lysteri Richardson. The remaining species, C. americana var. polita Coq., C. similis Johnson and C. tenebrosa Coq. have all been collected in British Columbia. There is but a single record from the Eastern Provinces and that a specimen of C. fasciata from Bathurst, New Brunswick, dated August, 1900. Altogether there are 22 specimens in the National Collection belonging to six species. Of these there are 11 specimens of C. grisea, which would thus appear to be the most prevalent species in Western Canada. The comparative paucity of specimens may be correctly attributed to the peculiarly shy habits of the species, the adults of which, according to information furnished me by Criddle, prefer rather dark situations, such as outbuildings, summer kitchens and the ground burrows of rodents. They occur on the wing from June to September and are probably to be found closely attendant upon the haunts of their rodent hosts. That the percentage of parasitism is not high is concluded from the fact that Parker and Wells (1919), in a careful examination of over a thousand rodents in Montana for possible infestation by the Rocky Mountain spotted fever tick, Dermacentor venustus Banks, found but two that were parasitised, each with one larva of C. tenebrosa.

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