Timing of the magmatism of the paleo-Pacific border of Gondwana: U-Pb geochronology of Late Paleozoic to Early Mesozoic igneous rocks of the north Chilean Andes between 20° and 31°S

摘要: U-Pb zircon geochronological data provide record of about 130 Ma igneous activity in the Andes northern Chile, which extended episodically from latest Early Carboniferous to Jurassic (328-194 Ma). The overall show that volcanism and plutonism were essentially synchronous major episodes developed during Late Mid-Permian (310 260 Ma) Permian Triassic (255-205 Ma), with less prominent mid-Carboniferous (330 320 (200-190 Thus, dominantly silicic magmatism along Chilean segment southwestern border Gondwana supercontinent. Further Mid-Late (250-194 was bimodal rift-related, continental and/or marine sedimentary strata related early stages break-up Gondwana. Most volcanic rocks Precordillera Domeyko Cordillera Chile (21°30’ 25°30’S) are older than assigned Choiyoi succession Argentina, being instead equivalent age sequences present eastern Argentinean foreland. On other hand, successions exposed easternmost part San Rafael Block Argentina. An eastward expansion or migration is inferred, interpretation consistent at time timing Paleozoic coincident Peru western Argentina according available data, revealing a rather evolution southwestern, paleo-Pacific