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Figure 1. Magmatic flux rates for the northern
Coast Mountains in British Columbia, Canada.
Flux rates are from Gehrels et al. (2009). Photo
by H. Stowell.
Figure 2. Pressure and temperature estimates
for metamorphism during garnet growth in
the Mount Waddington area of the Coast
Mountains, British Columbia, Canada. Data are
from Elizabeth Bollen (unpublished). Photo by
H. Stowell.
The Moho is ~35 km deep near Vancouver, and significant oro- melting during the Late Cretaceous. Batholith growth continued
genic collapse is not apparent there, also indicating along-strike during dextral transpression, potentially with large latitudinal
variation in the batholith. translation. In the Prince Rupert area, crustal extension marked
the end of batholith growth during the Eocene. Metamorphic
Structural and metamorphic studies show that the batholith P-T-t paths indicate rapid exhumation of granulite during this
formed in a dynamic and variable tectonic regime that differed extension. Although this event was pronounced in the Prince
along its length. Understanding of the tectonics is complicated Rupert and Ketchikan map-areas, it did not significantly affect
by Early Cretaceous sinistral transpression that altered the the southern part of the batholith; it is not known if Eocene
Jurassic to Early Cretaceous magmatic patterns. Subsequently, extension occurred north of Ketchikan.
a large pulse of Late Cretaceous magma intruded during doubly
vergent thrust faulting and dextral transpression. Metamorphic In spite of the large datasets available for parts of the batholith,
pressure-temperature-time (P-T-t) data linked with structural significant gaps in data limit understanding of the processes
analysis indicate significant crustal thickening and local partial responsible for batholith growth. Most particularly, the apparent
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