Artigo Revisado por pares

Tectonomagmatic evolution of Western Amazonia: Geochemical characterization and zircon U-Pb geochronologic constraints from the Peruvian Eastern Cordilleran granitoids

2009; Geological Society of America; Volume: 121; Issue: 9-10 Linguagem: Inglês

10.1130/b26488.1

ISSN

1943-2674

Autores

Aleksandar Mišković, Richard Spikings, David Chew, Jan Košler, Alexey Ulianov, Urs Schaltegger,

Tópico(s)

Geochemistry and Elemental Analysis

Resumo

Research Article| September 01, 2009 Tectonomagmatic evolution of Western Amazonia: Geochemical characterization and zircon U-Pb geochronologic constraints from the Peruvian Eastern Cordilleran granitoids Aleksandar Mišković; Aleksandar Mišković † 1Department of Mineralogy, Earth Sciences Section, University of Geneva, 13 rue des Maraîchers, CH-1205 Geneva, Switzerland *Current address: Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue (54-1224), Cambridge, Massachusetts 02139, USA. †E-mail: miskovic@mit.edu Search for other works by this author on: GSW Google Scholar Richard A. Spikings; Richard A. Spikings 1Department of Mineralogy, Earth Sciences Section, University of Geneva, 13 rue des Maraîchers, CH-1205 Geneva, Switzerland Search for other works by this author on: GSW Google Scholar David M. Chew; David M. Chew 2Department of Geology, Trinity College Dublin, College Green, Dublin 2, Ireland Search for other works by this author on: GSW Google Scholar Jan Košler; Jan Košler 3Department of Earth Sciences, University of Bergen, Allegaten 41, N 5007 Bergen, Norway Search for other works by this author on: GSW Google Scholar Alexey Ulianov; Alexey Ulianov 4Institute of Mineralogy and Petrography, University of Lausanne, BFSH 2, CH-1015 Lausanne, Switzerland Search for other works by this author on: GSW Google Scholar Urs Schaltegger Urs Schaltegger 1Department of Mineralogy, Earth Sciences Section, University of Geneva, 13 rue des Maraîchers, CH-1205 Geneva, Switzerland Search for other works by this author on: GSW Google Scholar Author and Article Information Aleksandar Mišković *Current address: Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue (54-1224), Cambridge, Massachusetts 02139, USA. † 1Department of Mineralogy, Earth Sciences Section, University of Geneva, 13 rue des Maraîchers, CH-1205 Geneva, Switzerland Richard A. Spikings 1Department of Mineralogy, Earth Sciences Section, University of Geneva, 13 rue des Maraîchers, CH-1205 Geneva, Switzerland David M. Chew 2Department of Geology, Trinity College Dublin, College Green, Dublin 2, Ireland Jan Košler 3Department of Earth Sciences, University of Bergen, Allegaten 41, N 5007 Bergen, Norway Alexey Ulianov 4Institute of Mineralogy and Petrography, University of Lausanne, BFSH 2, CH-1015 Lausanne, Switzerland Urs Schaltegger 1Department of Mineralogy, Earth Sciences Section, University of Geneva, 13 rue des Maraîchers, CH-1205 Geneva, Switzerland †E-mail: miskovic@mit.edu Publisher: Geological Society of America Received: 17 Jun 2008 Revision Received: 10 Nov 2008 Accepted: 12 Nov 2008 First Online: 02 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2009 Geological Society of America GSA Bulletin (2009) 121 (9-10): 1298–1324. https://doi.org/10.1130/B26488.1 Article history Received: 17 Jun 2008 Revision Received: 10 Nov 2008 Accepted: 12 Nov 2008 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Aleksandar Mišković, Richard A. Spikings, David M. Chew, Jan Košler, Alexey Ulianov, Urs Schaltegger; Tectonomagmatic evolution of Western Amazonia: Geochemical characterization and zircon U-Pb geochronologic constraints from the Peruvian Eastern Cordilleran granitoids. GSA Bulletin 2009;; 121 (9-10): 1298–1324. doi: https://doi.org/10.1130/B26488.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract The results of a coupled, in situ laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) U-Pb study on zircon and geochemical characterization of the Eastern Cordilleran intrusives of Peru reveal 1.15 Ga of intermittent magmatism along central Western Amazonia, the Earth's oldest active open continental margin. The eastern Peruvian batholiths are volumetrically dominated by plutonism related to the assembly and breakup of Pangea during the Paleozoic-Mesozoic transition. A Carboniferous-Permian (340–285 Ma) continental arc is identified along the regional orogenic strike from the Ecuadorian border (6°S) to the inferred inboard extension of the Arequipa-Antofalla terrane in southern Peru (14°S). Widespread crustal extension and thinning, which affected western Gondwana throughout the Permian and Triassic resulted in the intrusion of the late- to post-tectonic La Merced–San Ramón-type anatectites dated between 275 and 220 Ma, while the emplacement of the southern Cordillera de Carabaya peraluminous granitoids in the Late Triassic to Early Jurassic (220–190 Ma) represents, temporally and regionally, a separate tectonomagmatic event likely related to resuturing of the Arequipa-Antofalla block. Volcano-plutonic complexes and stocks associated with the onset of the present Andean cycle define a compositionally bimodal alkaline suite and cluster between 180 and 170 Ma. A volumetrically minor intrusive pulse of Oligocene age (ca. 30 Ma) is detected near the southwestern Cordilleran border with the Altiplano. Both post-Gondwanide (30–170 Ma), and Precambrian plutonism (691–1123 Ma) are restricted to isolated occurrences spatially comprising less than 15% of the Eastern Cordillera intrusives. Only one remnant of a Late Ordovician intrusive belt is recognized in the Cuzco batholith (446.5 ± 9.7 Ma) indicating that the Famatinian arc system previously identified in Peru along the north-central Eastern Cordillera and the coastal Arequipa-Antofalla terrane also existed inboard of this parautochthonous crustal fragment. Hitherto unknown occurrences of late Mesoproterozoic and middle Neoproterozoic granitoids from the south-central cordilleran segment define magmatic events at 691 ± 13 Ma, 751 ± 8 Ma, 985 ± 14 Ma, and 1071–1123 ± 23 Ma that are broadly coeval with the Braziliano and Grenville-Sunsás orogenies, respectively. Our data suggest the existence of a continuous orogenic belt in excess of 3500 km along Western Amazonia during the formation of Rodinia, its "early" fragmentation prior to 690 Ma, and support a model of reaccretion of the Paracas-Arequipa-Antofalla terrane to western Gondwana in the Early Ordovician with subsequent detachment of the Paracas segment in form of the Mexican Oaxaquia microcontinent in Middle Ordovician. A tectonomagmatic model involving slab detachment, followed by underplating of cratonic margin by asthenospheric mantle is proposed for the genesis of the volumetrically dominant Late Paleozoic to early Mesozoic Peruvian Cordilleran batholiths. 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