Bibliographische Detailangaben
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Personen und Körperschaften:
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Petts, D C (VerfasserIn); Moser, D E (VerfasserIn); Longstaffe, F J (VerfasserIn); Davis, W J (VerfasserIn); Stern, R A (VerfasserIn) |
| Format: |
Elektronische Zeitschrift
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| Sprache: |
English
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| veröffentlicht: |
Elsevier BV, 2014 |
| Gesamtaufnahme: |
GEM: Geo-mapping for Energy and Minerals
, Lithos issue 192-195, 2014 p. 259-270, Earth Sciences Sector, Contribution Series
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| Schlagwörter: |
Cumberland Batholith;
Chesterfield Block;
Central Heearne Supracrustal Belt;
Athabasca Mylonite Zone;
Pehnryn Group;
Piling Group;
Snowbird Tectonic;
Wathaman Batholith;
British Columbia;
Northwest Territories;
Nunavut;
Manitoba;
Saskatchewan;
Wollaston;
Zeitschrift;
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| Quelle: |
GEOSCAN
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| Zusammenfassung: |
The western Churchill Province of the Canadian Shield experienced a prolong...
The western Churchill Province of the Canadian Shield experienced a prolonged and complex formation history (ca. 4.04 to 1.70 Ga), with evidence for multiple episodes of orogenesis and regional magmatic activity. Here we report on the oxygen isotopic compositions of garnet and zircon recovered from lower crustal xenoliths, which have U-Pb ages between ca. 3.5 to 1.7 Ga. Zircons from four metabasite xenoliths from the Rankin Inlet sample suite have ?18O values ranging from +5.7 to +8.6 ¿. Zircon from three metatonalite/anorthosite xenoliths and five metabasite xenoliths from the Repulse Bay sample suite have ?18O values of +5.6 to +8.3 ¿. High ?18O values (> +6.0¿) measured for the oldest igneous zircon cores (ca. 3.5 Ga and 3.0-2.6 Ga) from three metatonalite/anorthosite xenoliths indicate zircon crystallization from evolved metatonalite/anorthosite protolith magmas that were generated from or had assimilated supracrustal rocks, which interacted previously with surface-derived fluids. Mantle-like ?18O values of ca. 2.9-2.6 Ga igneous zircon cores from one metabasite xenolith suggest formation from a juvenile basaltic/gabbroic magma. The mantle-like ?18O values of ca. 2.0-1.9 Ga metamorphic cores from one metabasite xenolith indicate a basalt/gabbro protolith and localized reworking of the lower crust caused by regional-scale plate convergence. The wide range of ?18O values for ca. 1.75-1.70 Ga metamorphic rims (identified in all xenoliths) indicates regional transient heating and reworking of juvenile and evolved, supracrustal-derived crust, induced by magmatic underplating along the crust-mantle boundary.
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