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Article
No evidence for Hadean continental crust within Earth’s oldest evolved rock unit
Little is known about the character of the Hadean crust. Geochemical analyses of the 4-billion-year-old Acasta Gneiss from Canada suggest Earth’s earliest crust formed from a mafic reservoir, similar to the fo...
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A Comparison of Chronometers Applied to Monastery Kimberlite and the Feasibility of U-Pb Ilmenite Geochronology
The Monastery kimberlite in South Africa is one of the most extensively studied kimberlites in the world and offers an ideal natural laboratory for investigating new geochronometers. Many kimberlites do not co...
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Article
The Mesoproterozoic Zig-Zag Dal basalts and associated intrusions of eastern North Greenland: mantle plume–lithosphere interaction
The lavas of the Zig-Zag Dal Formation of eastern North Greenland constitute a Mesoproterozoic tholeiitic flood basalt succession up to 1,350 m thick, extending >10,000 km2, and underlain by a sill complex. U–Pb ...
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Article
Proterozoic zircon growth in Archean lower crustal xenoliths, southern Superior craton – a consequence of Matachewan ocean opening
Granulite-grade, anorthositic and mafic xenoliths recovered from a Jurassic kimberlite pipe near Kirkland Lake, Ontario are fragments of the lower crust that underlies the ca. 2.7 Ga Abitibi greenstone belt o...
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Article
Polymetamorphic evolution of the Lewisian complex, NW Scotland, as recorded by U-Pb isotopic compositions of zircon, titanite and rutile
U-Pb isotopic relations in zircon and titanite of granulite and amphibolite gneisses in the Lewisian complex and bordering Laxford Front reveal complex discordance patterns indicating multiple Late Archean and...
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Article
Geochronological constraints on the emplacement history of an anorthosite — rapakivi granite suite: U−Pb zircon and baddeleyite study of the Korosten complex, Ukraine
U−Pb zircon/baddeleyite ages obtained for the Korosten anorthosite-rapakivi granite complex, Ukrainian shield, suggest that different magmatic phases were emplaced during a period of ca. 30 million years as a ...
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Article
Timing and origin of midcontinent rift alkaline magmatism, North America: evidence from the Coldwell Complex
The Coldwell Complex represents the largest alkaline intrusion associated with the Midcontinent Rift System in North America. This complex contains a plethora of rock types that have previously been subdivided...
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Article
U–Pb baddeleyite ages for the Scourie dyke swarm, Scotland: evidence for two distinct intrusion events
PRECISE and accurate radiometric ages for continental mafic dyke swarms are a prerequisite for global correlation of mafic magmatic events, calibration of apparent polar-wander paths and deciphering mechanisms...
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Article
A 1,800-million-year-old Proterozoic gneiss terrane in Islay with implications for the crustal structure and evolution of Britain
A basement gneiss terrane is exposed in the western part of Islay, an island south of Mull in Scotland. This gneiss terrane has been inferred previously1–5 to be part of the Lewisian complex (that is, Archean in ...
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Article
Precise U-Pb zircon ages for the Molson dyke swarm and the Fox River sill: Constraints for Early Proterozoic crustal evolution in northeastern Manitoba, Canada
Precise U-Pb zircon ages have been obtained for samples from the Molson dyke swarm and the Fox River sill in NE Manitoba, Canada. The ages determined for the Cross Lake and Cuthbert Lake dykes are 1,883.7 ...
