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The Mejillonia suspect terrane (Northern Chile): Late Triassic fast burial and metamorphism of sediments in a magmatic arc environment extending into the Early Jurassic

Casquet, Cesar; Herve, Francisco; Pankhurst, Robert J; Baldo, Edgardo; Calderon, M.; Fanning, Christopher; Rapela, Carlos W; Dahlquist, Juan A.

Description

The Mejillonia terrane, named after the Mejillones Peninsula (northern Chile), has been traditionally considered an early Paleozoic block of metamorphic and igneous rocks displaced along the northern Andean margin in the Mesozoic. However, U-Pb SHRIMP zircon dating of metasedimentary and igneous rocks shows that the sedimentary protoliths were Triassic, and that metamorphism and magmatism took place in the Late Triassic (Norian). Field evidence combined with zircon dating (detrital and...[Show more]

dc.contributor.authorCasquet, Cesar
dc.contributor.authorHerve, Francisco
dc.contributor.authorPankhurst, Robert J
dc.contributor.authorBaldo, Edgardo
dc.contributor.authorCalderon, M.
dc.contributor.authorFanning, Christopher
dc.contributor.authorRapela, Carlos W
dc.contributor.authorDahlquist, Juan A.
dc.date.accessioned2015-12-10T22:24:13Z
dc.identifier.issn1342-937X
dc.identifier.urihttp://hdl.handle.net/1885/53155
dc.description.abstractThe Mejillonia terrane, named after the Mejillones Peninsula (northern Chile), has been traditionally considered an early Paleozoic block of metamorphic and igneous rocks displaced along the northern Andean margin in the Mesozoic. However, U-Pb SHRIMP zircon dating of metasedimentary and igneous rocks shows that the sedimentary protoliths were Triassic, and that metamorphism and magmatism took place in the Late Triassic (Norian). Field evidence combined with zircon dating (detrital and metamorphic) further suggests that the sedimentary protoliths were buried, deformed (foliated and folded) and metamorphosed very rapidly, probably within few million years, at ca. 210. Ma. The metasedimentary wedge was then uplifted and intruded by a late arc-related tonalite body (Morro Mejillones) at 208 ± 2. Ma, only a short time after the peak of metamorphism. The Mejillones metamorphic and igneous basement represents an accretionary wedge or marginal basin that underwent contractional deformation and metamorphism at the end of a Late Permian to Late Triassic anorogenic episode that is well known in Chile and Argentina. Renewal of subduction along the pre-Andean continental margin in the Late Triassic and the development of new subduction-related magmatism are probably represented by the Early Jurassic Bólfin-Punta Tetas magmatic arc in the southern part of the peninsula, for which an age of 184 ± 1. Ma was determined. We suggest retaining the classification of Mejillonia as a tectonostratigraphic terrane, albeit in this new context.
dc.publisherElsevier
dc.sourceGondwana Research
dc.titleThe Mejillonia suspect terrane (Northern Chile): Late Triassic fast burial and metamorphism of sediments in a magmatic arc environment extending into the Early Jurassic
dc.typeJournal article
local.description.notesImported from ARIES
local.identifier.citationvolume25
dc.date.issued2013
local.identifier.absfor040303 - Geochronology
local.identifier.absfor040313 - Tectonics
local.identifier.absfor040304 - Igneous and Metamorphic Petrology
local.identifier.ariespublicationu4027924xPUB266
local.type.statusPublished Version
local.contributor.affiliationCasquet, Cesar, Universidad Complutense de Madrid
local.contributor.affiliationHerve, Francisco, Universidad de Chile
local.contributor.affiliationPankhurst, Robert J, British Geological Survey
local.contributor.affiliationBaldo, Edgardo, Universidad Nacional de Cordoba
local.contributor.affiliationCalderon, M., Servicio Nacional de Geología y Minería
local.contributor.affiliationFanning, Christopher, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationRapela, Carlos W, Universidad Nacional de La Plata
local.contributor.affiliationDahlquist, Juan A., Universidad Nacional de Cordoba
local.description.embargo2037-12-31
local.bibliographicCitation.startpage1272
local.bibliographicCitation.lastpage1286
local.identifier.doi10.1016/j.gr.2013.05.016
local.identifier.absseo970104 - Expanding Knowledge in the Earth Sciences
dc.date.updated2015-12-09T09:15:09Z
local.identifier.scopusID2-s2.0-84893805216
local.identifier.thomsonID000332429600029
CollectionsANU Research Publications

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