scholarly journals Sedimentary processes and surficial geology of the Pacific margin of the Queen Charlotte Islands, British Columbia

1996 ◽  
Author(s):  
J V Barrie ◽  
K W Conway
2002 ◽  
Vol 39 (2) ◽  
pp. 189-205 ◽  
Author(s):  
Yvonne Martin ◽  
Kenneth Rood ◽  
James W Schwab ◽  
Michael Church

Despite the importance of landsliding in routing sediment through mountainous drainage basins, few studies have documented landsliding rates over extended time and space scales. We have investigated landsliding in surficial material in the Queen Charlotte Islands using a large inventory of events, derived from aerial photography, covering an area of 166.7 km2. The mean erosion rate for shallow landsliding is 0.10 mm·a–1, which is at the upper end of shallow landsliding rates observed in the Pacific Northwest and coastal British Columbia, but several orders of magnitude lower than rock-based landsliding rates reported in the literature. Probability distributions for landslide area and volume are somewhat convex in form. Flattening of the curve found at low magnitudes may be due to sampling bias or physical mechanisms inhibiting failure, and the steepening for high values may exist because the sampling period is not long enough to adequately represent large events. Landslides generally initiate on hillslope gradients greater than 0.50–0.60. The largest numbers of landslides occur on south- to southwest-facing slopes and east- to northeast-facing slopes. Most events occur on concave and straight hillslopes in upper-slope positions. Landsliding rates were found not to be affected by rock type. Hillslopes in the Queen Charlotte Islands are often mantled by weathered Quaternary deposits and, hence, landsliding events are not directly controlled by weathering of bedrock. About 31% of landslides identified in this study deposited material in stream reaches, with about 83% of these landslides deposited in reaches with gradients between 3% and 10%.


1981 ◽  
Vol 18 (12) ◽  
pp. 1900-1903 ◽  
Author(s):  
N. Champigny ◽  
C. M. Henderson ◽  
G. E. Rouse

Recent palynological, megafaunal, and intrusive evidence from a section low in the Skonun Formation in the Cinola deposit on Graham Island indicates that it was deposited in the late Early Miocene, and that the age of the Skonun ranges up to the early Middle Miocene in outcrop sections on northeastern Graham Island. Correlations are made with several Miocene series of the Pacific Northwest and Alaska.


Botany ◽  
2010 ◽  
Vol 88 (4) ◽  
pp. 352-358 ◽  
Author(s):  
Irwin M. Brodo

A species of Lecanora in the L. dispersa group, with a well-developed pale thallus and a granular epihymenium, resembling L. albescens , is found exclusively on shoreline rocks and appears to be new. It is described as Lecanora schofieldii  sp. nov., found mainly in the Pacific Northwest, but also rarely on the northeast coast. Its distinctions from similar species on shoreline rocks are given, together with a key for their identification. The first western record of L. xylophila from rocks is given.


1961 ◽  
Vol 18 (5) ◽  
pp. 873-891 ◽  
Author(s):  
T. H. Butler

Of 2,820 early post-larval unsexed crabs collected by small-meshed trawl in two regions of the Queen Charlotte Islands, 1,175 were measured and the 1st and 2nd post-larval instars were identified as modes at 6.9 and 10.0 mm, respectively. Increments of 5 unsexed moulted crabs, carapace widths 6.80 to 9.96 mm, were from 36.3 to 46.5%. A total of 284 males, from 83 to 186 mm, moulted in crab traps, live-wells, and while at large as tagged specimens; 44 females, from 88 to 145 mm, moulted in traps. Using equations of regression of new carapace width on old width for both sexes and starting at the 2nd instar, average carapace widths were calculated for instars 3 to 15. In the width-frequency distributions of 8,145 crabs, separation of stages was sufficient for identification of age-groups. It is estimated that a year after hatching, males reach stage 5 or 6 (24.2 or 31.1 mm); after 2 years stage 11 or 12 (96.6 or 119.5 mm) is attained; after 3 years stage 13 (146.9 mm); after 4 years most males are in the 14th stage (176.2 mm) and above the British Columbia legal size of 165 mm; and generally after 5 years males are in stage 15 (207.5 mm). Growth of females is similar for 2 years, but afterwards is slower.


1936 ◽  
Vol 68 (4) ◽  
pp. 71-79 ◽  
Author(s):  
Geo. R. Hopping ◽  
H. B. Leech

The western hemlock sawfly, Neodiprion tsugae Middleron, first came to our notice from the Queen Charlotte Islands, British Columbia. In 1931, reports of the dying of hemlocks over large areas came from rangers and timber operators of this region. A survey conducted by Mr. W. G. Mathers of the Dominion Entomological Branch, in September and October of that year, indicated that the injury extended over approximately forty square miles. In 1932, the outbreak showed definite signs of subsiding, and had practically disappeared by 1933, although many trees were killed during the peak year of 1931, indicating that this is a primary enemy of western hemlock, and that outbreaks may be expected from time to time in the Pacific Northwest.


2001 ◽  
Vol 38 (5) ◽  
pp. 825-838 ◽  
Author(s):  
T S Hamilton ◽  
J Dostal

Voluminous basalts dominate a middle Tertiary bimodal volcanic assemblage in the Queen Charlotte Islands, British Columbia, Canada. These moderately enriched mid-ocean-ridge basalt (MORB-)like magmas were associated with significant crustal extension related to the subduction of the Pacific–Farallon ridge and the initiation of a slab window environment, which persisted for 35 Ma. These asthenospheric melts were derived from a low degree of melting of a heterogeneous peridotite source mainly in the spinel stability field, as inferred from fractional melting inversion calculations. The basaltic magmas in turn gave rise to both tholeiitic and calc-alkaline volcanic strata up to 3.5 km thick in local grabens. The tholeiitic basalts resemble MORB, with rare-earth element (REE) patterns ranging from slightly depleted to enriched in light REE (LREE). The calc-alkaline basaltic andesites are enriched in LREE, but are not strongly depleted in Nb. The rocks have overlapping Nd, Sr, and Pb isotopic compositions, similar to those of intraplate basalts from the adjacent northeast Pacific seamounts and Cordillera. The difference between the tholeiitic and calc-alkaline rocks is, in part, attributed to polybaric fractional crystallization of different proportions of plagioclase to mafic minerals from a similar tholeiitic magma. This marginal-basin subalkaline volcanic sequence and its genesis describe the slab window environment for the Tertiary tectonics of the western Canadian continental margin and provide a model for older combined tholeiitic and calc-alkaline volcanic successions.


1957 ◽  
Vol 89 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. D. Gregson

Tick paralysis continues to be one of the most baffling and fascinating tickborne diseases in Canada. It was first reported in this country by Todd in 1912. Since then about 250 human cases, including 28 deaths, have been recorded from British Columbia. Outbreaks in cattle have affected up to 400 animals at a time, with losses in a herd as high as 65 head. Although the disease is most common in the Pacific northwest, where it is caused by the Rocky Mountain wood tick, Dermacentor andersoni Stiles, it has lately been reported as far south as Florida and has been produced by Dermacentor variabilis Say, Amblyomma maculatum Koch, and A. americanum (L.) (Gregson, 1953). The symptoms include a gradual ascending symmetrical flaccid paralysis. Apparently only man, sheep, cattle, dogs, and buffalo (one known instance) are susceptible, but even these may not necessarily be paralysed.


2006 ◽  
Vol 120 (2) ◽  
pp. 163
Author(s):  
George W. Douglas ◽  
Jenifer L. Penny ◽  
Ksenia Barton

In Canada, Dwarf Woolly-heads, Psilocarphus brevissimus var. brevissimus, is restricted to the Similkameen River valley, south of Princeton in southwestern British Columbia and the extreme southeast and southwest corners of Alberta and Saskatchewan, respectively. This paper deals with the three British Columbia populations which represent the northwestern limit of the species which ranges from south-central British Columbia, southward in the western United States to Montana, Idaho, Washington, Oregon, Nevada, Utah, Wyoming, California and Baja California, Mexico. In British Columbia, P. brevissimus is associated with calcareous vernal pools and ephemeral pond edges in large forest openings. This habitat is rare in the area the few existing populations could easily be extirpated or degraded through slight changes in groundwater levels, coalbed methane gas drilling, housing development or recreational vehicles.


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