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PACIFIC SCIENCE, Vol. XV, October 1961 
12 
II 
10 
M 
MONTHS 
M J J 
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o 
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(T 
TEMPERATURE (°C.) 
MALCOLM I. (PULTENEY POINT) 
AUG. 1954- DEC. 1955 
(MONTHLY) 
MAXIMA 
MEAN MAXIMA 
— GRAND MEAN 
MEAN MINIMA 
X — x- — x MINIMA 
Fig. 19. Monthly temperatures of seawater at Pulteney Point, Malcolm Island, for the period 1954-55. 
two ranges lies the Coastal Trough, part of a 
great depression extending intermittently north- 
westward from the Gulf of California through 
the Puget Sound- W illiamette lowland and on 
into Alaska. In British Columbia this great val- 
ley is largely submerged and comprises the ex- 
tensive areas of the Strait of Georgia, Queen 
Charlotte Strait, Queen Charlotte Sound, and 
Hecate Strait ( Fig. 1 ) . 
The Coast Mountains consist largely of Mes- 
ozoic rocks ranging from Triassic to early Ter- 
tiary and are composed of principally granitic 
rocks with some included masses of Mesozoic 
and Palaeozoic strata. The rocks of the Van- 
couver I. Ranges are composed conspicuously 
of masses of Triassic and Jurassic lava and vol- 
canic products, lesser contemporaneous sedi- 
ments with subordinate amounts of later granitic 
rocks, and marine and continental Cretaceous 
TEMPERATURE (C°) 
10 10 10 10 10 10 10 
Fig. 20. Temperature profiles at station 19 (1953) 
near Malcolm Island from bathythermograph traces. 
