Corundum genesis at the Blue Jay Sapphire occurrence (British Columbia, Canada) as a record of metamorphism and partial melting in the Monashee Complex
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F23%3A00130188" target="_blank" >RIV/00216224:14310/23:00130188 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.1016/j.lithos.2022.106992" target="_blank" >https://doi.org/10.1016/j.lithos.2022.106992</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.lithos.2022.106992" target="_blank" >10.1016/j.lithos.2022.106992</a>
Alternative languages
Result language
angličtina
Original language name
Corundum genesis at the Blue Jay Sapphire occurrence (British Columbia, Canada) as a record of metamorphism and partial melting in the Monashee Complex
Original language description
The sapphire (corundum) occurrence near Revelstoke, British Columbia, Canada, occurs in the Monashee Complex of the Omineca Belt of the Canadian Cordillera. Corundum occurs in boudins or pod-like zones of restite within a garnet-bearing leucosome. Both zones are peraluminous and contain plagioclase, K-feldspar, and biotite and muscovite as the dominant mineral phases. Relative to the leucosome, the corundum-pods are slightly depleted in SiO2 (55.28 wt% in corundum-pods vs. 62.7 wt% in leucosome) and K2O (4.74/7.05 wt%) and enriched in Al2O3 (22.57/21.97 wt%), Fe2O3 (5.96/2.11 wt%), TiO2 (0.71/0.21 wt%), CaO (0.68/0.60 wt%), and MgO (0.59/0.28 wt%). The peraluminous nature of the corundum-bearing pods is consistent with partial melting of a metapelitic protolith. Similar chemical compositions between the corundum-pods and garnet-leucosome are interpreted to infer a single, in situ partial melting event. Coinciding melt-compatible and incompatible elements suggest a closed system. Igneous textures in thin section (coarse-grained, euhedral corundum; twinning in plagioclase; small cuspate-shaped biotite, and myrmekitic intergrowths of feldspars) confirm a partial melt origin. Petrography and thermodynamic models reveal that corundum growth and partial melting was fueled by the breakdown of muscovite along the prograde P-T path. Whole-rock geochemistry of the leucosome groundmass devoid of garnet shows high Sr/Y and La/Yb ratios indicative of garnet fractionation, and garnet mineral chemistry are Ca-poor indicating garnets crystallized from the peraluminous partial melts at peak P-T conditions. 206Pb/238U ages of garnet-equilibrated zircon indicate that peak metamorphic conditions occurred at or before ∼60.69 Ma. Continued zircon growth until 50.22 Ma tracks the presence of continued partial melt following peak metamorphism during nearly-isothermal decompression. A resulting P-T-t path for basement rocks form the Thor-Odin dome constrains the timing of peak metamorphism and ensuing partial melting events during Cordilleran orogenesis.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10504 - Mineralogy
Result continuities
Project
—
Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2023
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Lithos
ISSN
0024-4937
e-ISSN
1872-6143
Volume of the periodical
438-439
Issue of the periodical within the volume
February
Country of publishing house
NL - THE KINGDOM OF THE NETHERLANDS
Number of pages
23
Pages from-to
1-23
UT code for WoS article
001012193500001
EID of the result in the Scopus database
2-s2.0-85146132001