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Probing the lithosphere and geochemical boundaries in the pre-Mesozoic crust of Peru through geochronology and isotope geology of Paleozoic to Tertiary rocks

English title Probing the lithosphere and geochemical boundaries in the pre-Mesozoic crust of Peru through geochronology and isotope geology of Paleozoic to Tertiary rocks
Applicant Schaltegger Urs
Number 107470
Funding scheme Project funding
Research institution Département des sciences de la Terre Université de Genève
Institution of higher education University of Geneva - GE
Main discipline Geochronology
Start/End 01.04.2005 - 31.03.2007
Approved amount 313'167.00
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Keywords (7)

geochronology; isotope geochemisry; continental margin; basement; magmatism; terrane; Peru

Lay Summary (English)

Lead
Lay summary
The Neoproterozoic - Early Paleozoic evolution of the Gondwanan margin of the north-central Andes has been investigated by a U-Pb zircon geochronology study from a 1000 km transect in the Eastern Cordilleras of Peru and Ecuador. This part of South American continental li-thosphere has been formed during Famatinian/Pampean (0.45-0.55 Ga) and Grenville/Sunsas (0.9-1.1 Ga) orogenies, which are interpreted to be either buried underneath the present-day Andean chain or adjacent foreland sediments to the east. The existence of an Ordovician-Silurian subduction-related magmatic belt (474 - 442 Ma) and Ordovician high-grade meta-morphism in the Eastern Cordillera of Peru is documented for the the first time. The Carbonife-rous to Jurassic magmatism in the Eastern Cordillera of Peru shows a temporal and geochemical evolution from north to south, which is explained by progressing back-arc extension due to very oblique subduction. Our working model implies accretion of oceanic crust or terranes to the Andean margin in the Carboniferous (responsible for cessation of arc magmatism, uplift and gold mineralization), continuing crustal thinning in the back-arc and restart of active margin magmatism in the early Jurassic.
Direct link to Lay Summary Last update: 21.02.2013

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Associated projects

Number Title Start Funding scheme
116572 Probing lithosphere processes thtough geochemical and geochronological studies - Permian / Triassic intracontinental rifting and Jurassic subduction-related magmatisme in Southern Peru 01.04.2007 Project funding
100286 Probing the lithosphere and geochemical boundaries in the pre-Mesozoic crust of Peru through geochronology and isotope geochemistry of Paleozoic to Tertiary magmatic rocks 01.04.2003 Project funding

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