Geological sketch map of Vancouver Island and Gulf Islands

1967 ◽  
Author(s):  
J E Muller
1974 ◽  
Vol 11 (2) ◽  
pp. 280-284 ◽  
Author(s):  
Richard J. Stewart ◽  
Richard J. Page

Laumontite and heulandite are extensively developed as metamorphic minerals in sandstones of the Late Cretaceous Nanaimo Group, Vancouver Island and Gulf Islands, British Columbia. Major post-depositional changes in the sandstones also include widespread carbonate cementation and replacement, alteration of plagioclase and biotite, and development of a phyllosilicate matrix. The sequence apparently is depth-zoned, with heulandite present only in the upper 1000 m of section, and laumontite developed in the upper 2500 m. The zeolite assemblages probably were developed during burial metamorphism, as subject to controls of permeability and suppression by a high chemical potential of CO2. Comparable assemblages should be expected in similar clastic sequences found in other portions of the Cordillera, particularly the thick Mesozoic successions of the Intermontane and Insular Fold Belts.


2020 ◽  
Vol 639 ◽  
pp. 185-197 ◽  
Author(s):  
MJ Malick ◽  
ME Hunsicker ◽  
MA Haltuch ◽  
SL Parker-Stetter ◽  
AM Berger ◽  
...  

Environmental conditions can have spatially complex effects on the dynamics of marine fish stocks that change across life-history stages. Yet the potential for non-stationary environmental effects across multiple dimensions, e.g. space and ontogeny, are rarely considered. In this study, we examined the evidence for spatial and ontogenetic non-stationary temperature effects on Pacific hake Merluccius productus biomass along the west coast of North America. Specifically, we used Bayesian additive models to estimate the effects of temperature on Pacific hake biomass distribution and whether the effects change across space or life-history stage. We found latitudinal differences in the effects of temperature on mature Pacific hake distribution (i.e. age 3 and older); warmer than average subsurface temperatures were associated with higher biomass north of Vancouver Island, but lower biomass offshore of Washington and southern Vancouver Island. In contrast, immature Pacific hake distribution (i.e. age 2) was better explained by a nonlinear temperature effect; cooler than average temperatures were associated with higher biomass coastwide. Together, our results suggest that Pacific hake distribution is driven by interactions between age composition and environmental conditions and highlight the importance of accounting for varying environmental effects across multiple dimensions.


2018 ◽  
Vol 603 ◽  
pp. 189-200 ◽  
Author(s):  
WD Halliday ◽  
MK Pine ◽  
APH Bose ◽  
S Balshine ◽  
F Juanes

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