scholarly journals Five surficial geological maps of the Canoe river valley from the Columbia river to Valemount, British Columbia

1973 ◽  
Author(s):  
R A Achard
Keyword(s):  
British Columbia ◽  
Columbia River ◽  
River Valley ◽  
Geological Maps

Structural and stratigraphic setting of the Downie slide, Columbia River valley, British Columbia

1980 ◽  
Vol 17 (6) ◽  
pp. 698-709 ◽  
Author(s):  
Richard L. Brown ◽  
John F. Psutka
Keyword(s):  
British Columbia ◽  
Shear Zone ◽  
Columbia River ◽  
River Valley ◽  
Axial Plane ◽  
Western Slope ◽  
Second Phase ◽  
Main Body ◽  
The North ◽  
Slide Mass

The Downie slide is a late to postglacial rockslide situated on the western slope of the Columbia River valley about 70 km north of Revelstoke, British Columbia. It attains a maximum thickness of 270 m and is estimated to involve 1.5 × 109 m3 of rock and debris. The head of the slide is bounded by a nearly vertical escarpment reaching heights of more than 125 m; its lateral boundaries are defined by a prominent east–west trending scarp on the south and a more subdued linear northeast trending ridge on the north. The toe forms the west bank of the Columbia River in this area.The slide occurs within a compositionally anisotropic formation of high-grade pelitic and semipelitic schists and psammites. The main shear zone at the base of the slide is located in pelitic schists. Minerals in the rock of the shear zone have been mechanically crushed and locally reduced to a fine-grained gouge.Three distinct phases of deformation are recognized in the Downie slide region. The location and attitude of the second and third fold phases and their associated fabrics controlled the external geometry of the slide.Along the western slopes of this part of the Columbia River valley the second phase of deformation has been dominant. Within the formation that contains the slide, bedding is extensively deformed by tight to isoclinal second phase minor folds that exhibit a penetrative axial plane foliation. At Downie slide this foliation dips approximately 20° eastward towards the Columbia River, and nearly parallels the slope of the hillside; the basal shear zone of the slide developed parallel to the axial plane foliation.West of the slide, third phase major and minor folds have been superimposed on the second phase geometry, but they die out eastward, and are of only minor significance within the main body of the slide. The eastern limit of major superposition coincides with the head scarp of the slide. The slide mass broke away along the hinge zone of the first major monoclinal flexure fold associated with this front of phase 3 folding.Late fracturing probably influenced the position of the northern and southern lateral boundaries of the slide.

Geology and paleoecology of early Holocene lacustrine deposits in the Columbia River valley near Fauquier, southern British Columbia

1989 ◽  
Vol 26 (2) ◽  
pp. 257-265 ◽  
Author(s):  
Robert J. Fulton ◽  
Barry G. Warner ◽  
Helen J. Kubiw ◽  
René A. Achard
Keyword(s):  
British Columbia ◽  
Organic Material ◽  
Columbia River ◽  
River Valley ◽  
Early Holocene ◽  
East Side ◽  
Lacustrine Deposits ◽  
Subalpine Zone ◽  
Plant Remains ◽  
The Last Glacial

Early Holocene lake sediments are exposed near Fauquier, on the east side of the Arrow lakes in the Columbia River valley of British Columbia. A glacial lake occupied the valley at the time of deglaciation, but by 10 ka BP this had been replaced by a nonglacial lake that was at least 250 km long and as much as 5 km wide.Comparison of pollen and macroscopic plant remains in these nearshore and littoral deposits with modern vegetation indicates that many of the plants present between 9 and 10 ka BP are found in the area today, either along the valley floor or at higher elevations in the subalpine zone nearby. Some of the organic material may be allochthonous; this complicates paleoecological and paleoclimatological interpretations. It appears that the climate in the Columbia River valley between 9 and 10 ka BP was as wet or wetter than at present. The presence of many of these species in the southern Columbia River valley of British Columbia during early Holocene time suggests that elements of the modern vegetation had migrated rapidly northward from southern refugia, probably within 1500 years of the end of the last glacial episode.

scholarly journals Landslides in weakly cemented glaciolacustrine sediments, Morkill River valley, British Columbia

2001 ◽  
Vol 38 (4) ◽  
pp. 889-900 ◽  
Author(s):  
Corey R Froese ◽  
David M Cruden
Keyword(s):  
British Columbia ◽  
River Valley ◽  
Carbonate Content ◽  
Canadian Rocky Mountains ◽  
Density Profiles ◽  
Frost Action ◽  
Dominant Component ◽  
Freeze And Thaw ◽  
Calcite Cement ◽  
The Relationship

Slopes in weakly cemented glaciolacustrine sediments in the Morkill River valley in the Canadian Rocky Mountains stand at up to 70°. Based on field and laboratory observations it appears that a contributing factor to instability is the softening of the soils by frost action and the leaching of calcite cement. Field density profiles demonstrated increased density and carbonate content with an increase in depth. Laboratory tests of carbonate content indicated a positive correlation between calcium carbonate and density in the glaciolacustrine sediments. The relationship was strongest in sands, in which leaching and dissolution were important components of softening. In clays, frost action was the dominant component of softening. Freeze-thaw tests showed a 50% decrease in strength after one cycle of freeze and thaw in the silts and clays.Key words: landslide, cemented, glaciolacustrine sediments, British Columbia.

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