scholarly journals The Ca. 162 Ma Galena Bay Stock and Its Relationship To the Columbia River Fault Zone, Southeast British Columbia

1987 ◽  
Author(s):  
R R Parrish ◽  
R L Armstrong
Keyword(s):  
British Columbia ◽  
Fault Zone ◽  
Columbia River

Kinematic interpretation of mylonitic rocks in part of the Columbia River fault zone, Shuswap terrane, British Columbia

1982 ◽  
Vol 19 (3) ◽  
pp. 456-465 ◽  
Author(s):  
Richard L. Brown ◽  
Donald C. Murphy
Keyword(s):  
British Columbia ◽  
Fault Zone ◽  
Hanging Wall ◽  
Regional Metamorphism ◽  
Columbia River ◽  
Coarse Grained ◽  
Thick Section ◽  
Mylonite Zone ◽  
Relationship Of ◽  
Igneous Texture

Mylonitic rocks of the Columbia River fault zone have been examined in a 600 m thick section, 20 km north of Revelstoke, British Columbia. At this locality coarse-grained granite with well-preserved igneous texture lies in the hanging wall of the fault zone. Adjacent to the boundary of the mylonite zone the granite is foliated and mineral segregation gives rise to well-defined compositional layering. The foliation (Sf) is defined by oriented mineral grains and flattened porphyroclasts. In areas of intense strain compositional layering (Sc) is parallel to Sf. At the boundary of the mylonite zone and in weakly deformed areas within the mylonite zone Sc and Sf are inclined at angles up to 30°. Sf is taken to be a plane of flattening, and Sc appears to parallel a plane of shear. After correction for effects of late-stage flexural slip folding the angular relationship of Sc to Sf may be used to determine sense of shear in the mylonitc zone; the hanging-wall rocks have been displaced toward the east relative to the footwall. Formation of mylonitic fabrics and associated displacement of the Selkirk allochthon eastward relative to the underlying Monashee Complex occurred after the Middle Jurassic peak of regional metamorphism and before brittle reactivation and uplift in the Tertiary.

Downie Slide, Columbia River, British Columbia, Canada

1978 ◽  
pp. 365-392 ◽  
Author(s):  
D.R. PITEAU ◽  
F.H. MYLREA ◽  
I.G. BLOWN
Keyword(s):  
British Columbia ◽  
Columbia River

scholarly journals Conservation Evaluation of the Small-flowered Tonella, Tonella tenella, in Canada

2006 ◽  
Vol 120 (2) ◽  
pp. 179
Author(s):  
George W. Douglas ◽  
Jenifer L. Penny
Keyword(s):  
British Columbia ◽  
Private Property ◽  
Columbia River ◽  
The West ◽  
Rock Outcrops ◽  
West Side ◽  
Central California ◽  
Gulf Islands ◽  
Talus Slopes ◽  
Conservation Evaluation

In Canada, the Small-flowered Tonella, Tonella tenella, is restricted to the west side of Saltspring Island in the Gulf Islands of southwestern British Columbia. This population represents the northern limits of the species which is disjunct from its main range in southern Washington (Columbia River gorge), through Oregon to central California. In British Columbia, Tonella tenella is associated with rock outcrops and dry, steep, sparsely forested talus slopes at elevations of 50 to 300 m. The population on Saltspring Island is on private property and not directly imperilled at this time. There is, however, a potential for housing development in the future on this waterfront site, thus the authors consider the species endangered.

scholarly journals Surveys for terrestrial gastropods in the Kootenay region of British Columbia, with new records and range extensions

2020 ◽  
Vol 133 (3) ◽  
pp. 221-234
Author(s):  
Kristiina Ovaska ◽  
Lennart Sopuck ◽  
Jennifer Heron
Keyword(s):  
British Columbia ◽  
New Records ◽  
Columbia River ◽  
Columbia River Basin ◽  
Coastal Forests ◽  
Terrestrial Gastropods ◽  
Coeur D'alene ◽  
Northwestern Montana ◽  
Single Category ◽  
Conservation Concern

The northern Columbia River basin, extending from the Kootenay region in British Columbia southward to the Idaho panhandle and northwestern Montana, contains a unique terrestrial gastropod fauna, but in Canada few surveys have specifically targetted this group. Here we report on terrestrial gastropods detected during surveys of 314 sites distributed in five biogeoclimatic zones across the Kootenay region. The surveys occurred on 65 days over seven years from 2007 to 2015, usually in September–October. We detected 45 taxa identified to species, belonging to 33 genera; micro-snails of the genus Vertigo (apart from Vertigo ovata) were combined into a single category, and snails belonging to Succineidae were not identified further. Regionally endemic species previously reported from the region included Western Banded Tigersnail (Anguispira kochi occidentalis), Coeur d’Alene Oregonian (Cryptomastix mullani), Rocky Mountainsnail (Oreohelix strigosa), Subalpine Mountainsnail (Oreohelix subrudis), and Pale Jumping-slug (Hemphillia camelus), which was widespread across the region. Magnum Mantleslug (Magnipelta mycophaga), the distribution of which extends beyond the Kootenay region, was detected at several widely spaced sites. Two species new to Canada were detected, Pygmy Slug (Kootenaia burkei) and Sheathed Slug (Zacoleus idahoensis), both of which were subsequently assessed to be of conservation concern both provincially and nationally. Other notable observations included the detection of Fir Pinwheel (Radiodiscus abietum), a regional endemic, which has been previously reported only once, and three species common in coastal forests but not previously reported from the region: Pacific Banana Slug (Ariolimax columbianus), Robust Lancetooth (Haplotrema vancouverense), and Northwest Hesperian (Vespericola columbianus). Further surveys, especially at higher elevations, may reveal other additional or unusual species.

Hydraulic and sedimentary processes causing anastomosing morphology of the upper Columbia River, British Columbia, Canada

Geomorphology ◽  
2009 ◽  
Vol 111 (3-4) ◽  
pp. 194-205 ◽  
Author(s):  
Bart Makaske ◽  
Derald G. Smith ◽  
Henk J.A. Berendsen ◽  
Arjan G. de Boer ◽  
Marinka F. van Nielen-Kiezebrink ◽  
...  
Keyword(s):  
British Columbia ◽  
Columbia River ◽  
Sedimentary Processes

MAGNETIC AND TECTONIC REGIONALIZATION ON TEXADA ISLAND, BRITISH COLUMBIA

Geophysics ◽  
1964 ◽  
Vol 29 (4) ◽  
pp. 565-581 ◽  
Author(s):  
D. H. Hall
Keyword(s):  
British Columbia ◽  
Fault Zone ◽  
Coastal Area ◽  
Magnetic Anomalies ◽  
Tectonic Pattern

A significant correlation exists between direction patterns in magnetic and tectonic trends on the northern two thirds of Texada Island, British Columbia, Canada. The patterns were analyzed in further detail by dividing the area into regions based on amplitudes of magnetic anomalies and on patterns in the magnetic trends. A technique involving smoothing and crosscorrelation was applied in the examination of the relationships between the patterns. The regions established on a magnetic basis also are distinct on the basis of tectonic pattern. However, correlation between the magnetic and tectonic patterns varies from region to region within the area. The directions N 50° W, N-S, and E-W, common throughout the coastal area of British Columbia, are the most widespread in the patterns studied on Texada Island. A distinctive zone, identified as a fault zone cutting across the island with a trend of N 20°W stands out in the patterns.

Morphologically distinct populations of the shorthead sculpin, Cottus confusus, and mottled sculpin, Cottus bairdi (Pisces, Cottidae), near the western border of Canada and the United States

1989 ◽  
Vol 67 (11) ◽  
pp. 2711-2720 ◽  
Author(s):  
Alex E. Peden ◽  
Grant W. Hughes ◽  
W. E. Roberts
Keyword(s):  
United States ◽  
British Columbia ◽  
Columbia River ◽  
Missouri River ◽  
The United States ◽  
Fin Ray ◽  
Cottus Bairdi ◽  
Mottled Sculpin ◽  
Western Border ◽  
Flathead River

Previously known within Canada from the Flathead River, nominal Cottus confusus also occur in the Kettle, Columbia, and Slocan rivers of British Columbia. The latter populations are similar to those from Washington, and possess a post-maxillary pore, lower numbers of pectoral rays, prickles behind the pectoral fin, and a smooth head. They are sympatric with nominal Cottus bairdi, with some individuals morphologically intermediate between the two species. Flathead River samples of nominal C. confusus differ from Columbia River populations in absence of the pore and prickles, higher fin ray counts, and larger head papillae. Specimens of nominal C. bairdi previously reported from the St. Mary River (Saskatchewan and Nelson drainages) and Milk River (Missouri River drainage) of Alberta are similar to Flathead River C. confusus, with others intermediate between Flathead River C. confusus and Columbia River populations of C. bairdi and C. confusus. Differences between Flathead River and Columbia River samples suggest that these populations require separate status in Canada. Similkameen River samples of C. bairdi are morphologically variable, individuals from upstream populations having some characters similar to those of C. confusus. A thorough study of C. bairdi and C. confusus in the United States is needed to redefine species limits.

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