Abstract
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 ε(Nd)=+6, and a number of other metaigneous and metasedimentary rocks in the core of the Coast Mountains give ε(Nd) values from +3 to +7. A single metasedimentary rock approximately 3 km east of the Work Channel shear zone gives a ε(Nd) value of -9. Coast Belt plutons in the traverse yield ε(Nd) from -1 to +2. The Omineca Belt plutons give ε(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.
Original language | English (US) |
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Pages (from-to) | 556-561 |
Number of pages | 6 |
Journal | Canadian Journal of Earth Sciences |
Volume | 35 |
Issue number | 5 |
DOIs | |
State | Published - 1998 |
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)