scholarly journals U - Pb Ages of Jurassic - Eocene Plutonic Rocks in the Vicinity of Valhalla Complex, Southeast British Columbia

1992 ◽  
Author(s):  
R R Parrish
Keyword(s):  
British Columbia ◽  
Plutonic Rocks

Nd isotopic characteristics of metamorphic and plutonic rocks of the Coast Mountains near Prince Rupert, British Columbia

1998 ◽  
Vol 35 (5) ◽  
pp. 556-561 ◽  
Author(s):  
P J Patchett ◽  
G E Gehrels ◽  
C E Isachsen
Keyword(s):  
British Columbia ◽  
Volcanic Rocks ◽  
Metamorphic Rocks ◽  
Published Data ◽  
Isotopic Data ◽  
Crustal Component ◽  
Coast Mountains ◽  
Crustal Rocks ◽  
Metasedimentary Rocks ◽  
Plutonic Rocks

Nd isotopic data are presented for a suite of metamorphic and plutonic rocks from a traverse across the Coast Mountains between Terrace and Prince Rupert, British Columbia, and for three contrasting batholiths in the Omineca Belt of southern Yukon. A presumed metamorphic equivalent of Jurassic volcanic rocks of the Stikine terrane gives epsilon Nd = +6, and a number of other metaigneous and metasedimentary rocks in the core of the Coast Mountains give epsilon Nd values from +3 to +7. A single metasedimentary rock approximately 3 km east of the Work Channel shear zone gives a epsilon Nd value of -9. Coast Belt plutons in the traverse yield epsilon Nd from -1 to +2. The Omineca Belt plutons give epsilon Nd from -10 to -17. All results are consistent with published data in demonstrating that (i) juvenile origins for both igneous and metamorphic rocks are common in the Coast Belt; (ii) representatives of a continental-margin sedimentary sequence with Precambrian crustal Nd are tectonically interleaved in the Coast Mountains; (iii) Coast Mountains plutons can be interpreted as derived from a blend of metamorphic rocks like those seen at the surface, or as arc-type melts contaminated with the older crustal component; and (iv) Omineca Belt plutons are dominated by remelted Precambrian crustal rocks.

Metamorphic framework and plutonic styles in the Prince Rupert region of the Central Coast Mountains, British Columbia

1970 ◽  
Vol 7 (2) ◽  
pp. 376-405 ◽  
Author(s):  
W. W. Hutchison
Keyword(s):  
British Columbia ◽  
Regional Metamorphism ◽  
Plutonic Rock ◽  
Oscillatory Zoning ◽  
Metamorphic Belt ◽  
Coast Mountains ◽  
Eastern Zone ◽  
Median Zone ◽  
Metamorphic Zone ◽  
Plutonic Rocks

The metamorphic framework in Prince Rupert – Skeena region of the Coast Mountains of British Columbia comprises schist, gneiss, and migmatite displaying progressive regional metamorphism that overlaps the Barrovian and Idahoan Facies Series. Although part of the circum-Pacific metamorphic zone, the Coast Mountain metamorphic belt is apparently not paired. Plutonic rocks, which were probably an integral part of the early metamorphic framework, have apparently been mobilized during metamorphism and continued to move out of their original environment while metamorphism waned, some even deforming the pre-existing fabric.Within the framework, four main plutonic styles have been recognized:1) Autochthonous, migmatitic, plutonic complexes.2) Para-autochthonous, steep-walled (tadpole) plutons.3) Para-autochthonous, tongue-shaped, recumbent plutons.4) Allochthonous, intrusive plutons.Quartz diorite and granodiorite are the most common plutonic rocks. Diorite and quartz monzonite are less common: gabbro and especially granite are rare.In the course of moving from the sites of generation to the zones of emplacement, the plutonic rock became:1) more homogeneous.2) less migmatitic and impoverished in inclusions.3) less foliated.4) more acidic, more biotite-rich.5) a rock containing plagioclase of lower average anorthite content and more complex oscillatory zoned crystals.The complex oscillatory zoning appears in a gross way to reflect the variable history accompanying (pulsative ?) movement during crystallization.Time of emplacement of most of the plutonic rock is not known. The potassium–argon age dates (between 53° N and 55° N) display a consistent pattern, with a westerly zone yielding the oldest dates (84 to 140 m.y.), a median zone, intermediate dates (64 to 79 m.y.) and the eastern zone, youngest dates (chiefly 40 to 50 m.y.). These dates may reflect sequential emplacement from west to east but some evidence also suggests that they may reflect sequential uplift and unroofing from west to east.

The distribution of skarns in British Columbia and the chemistry and ages of their related plutonic rocks

1995 ◽  
Vol 90 (4) ◽  
pp. 920-937 ◽  
Author(s):  
G. E. Ray ◽  
I. C. L. Webster ◽  
A. D. Ettlinger
Keyword(s):  
British Columbia ◽  
Plutonic Rocks

The Geochemistry of Three Tin-Bearing Skarns and TheirRelated Plutonic Rocks, Atlin, Northern British Columbia

2000 ◽  
Vol 95 (6) ◽  
pp. 1349-1365 ◽  
Author(s):  
G. E. Ray ◽  
I. C. L. Webster ◽  
S. B. Ballantyne ◽  
C. E. Kilby ◽  
S. B. Cornelius
Keyword(s):  
British Columbia ◽  
Plutonic Rocks
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