K-bentonites in the Argentine Precordillera contemporaneous with rhyolite volcanism in the Famatinian Arc

New U–Pb radiometric dates for K-bentonite horizons within the Lower Cambrian to Middle Ordovician platform carbonates from the Precordillera terrane of NW Argentina provide further constraints on models for the allochthonous or parautochthonous accretion of this terrane. Two K-bentonite layers from...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Fanning, Christopher, Pankhurst, Robert J., Rapela, Carlos Washington, Baldo, Edgardo G., Casquet, César, Galindo, Carmen
Formato: Articulo
Lenguaje:Inglés
Publicado: 2004
Materias:
Ciencias Naturales
Geología
U–Pb
SHRIMP
Ordovician
Gondwana
terranes
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/128923
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-128923
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Naturales
Geología
U–Pb
SHRIMP
Ordovician
Gondwana
terranes
spellingShingle Ciencias Naturales
Geología
U–Pb
SHRIMP
Ordovician
Gondwana
terranes
Fanning, Christopher
Pankhurst, Robert J.
Rapela, Carlos Washington
Baldo, Edgardo G.
Casquet, César
Galindo, Carmen
K-bentonites in the Argentine Precordillera contemporaneous with rhyolite volcanism in the Famatinian Arc
topic_facet Ciencias Naturales
Geología
U–Pb
SHRIMP
Ordovician
Gondwana
terranes
description New U–Pb radiometric dates for K-bentonite horizons within the Lower Cambrian to Middle Ordovician platform carbonates from the Precordillera terrane of NW Argentina provide further constraints on models for the allochthonous or parautochthonous accretion of this terrane. Two K-bentonite layers from the Talacasto section yield indistinguishable sensitive high-resolution ion microprobe (SHRIMP) U–Pb zircon dates of 469.5 ± 3.2 Ma and 470.1 ± 3.3 Ma respectively. These are within uncertainty of the U–Pb SHRIMP zircon date of 468.3 ± 3.4 Ma for a porphyritic rhyolite from the Famatinian magmatic arc, Sierra de las Planchadas, near Rio Chaschuil. Geochemical and isotope data also demonstrate the similarity of the K-bentonite and Chaschuil rhyolite parent magmas. Thus, it is highly probable that the Famatinian arc volcanoes provided the ash for the K-bentonite horizons, suggesting proximity to the Precordillera terrane during the deposition of the Lower Cambrian to Middle Ordovician platform carbonates. This implication supports a mid-Ordovician collision model, but could also be compatible with a parautochthonous model for docking of the Precordillera terrane, by movement along the Pacific margin of Gondwana, rather than across the Iapetus Ocean.
format Articulo
Articulo
author Fanning, Christopher
Pankhurst, Robert J.
Rapela, Carlos Washington
Baldo, Edgardo G.
Casquet, César
Galindo, Carmen
author_facet Fanning, Christopher
Pankhurst, Robert J.
Rapela, Carlos Washington
Baldo, Edgardo G.
Casquet, César
Galindo, Carmen
author_sort Fanning, Christopher
title K-bentonites in the Argentine Precordillera contemporaneous with rhyolite volcanism in the Famatinian Arc
title_short K-bentonites in the Argentine Precordillera contemporaneous with rhyolite volcanism in the Famatinian Arc
title_full K-bentonites in the Argentine Precordillera contemporaneous with rhyolite volcanism in the Famatinian Arc
title_fullStr K-bentonites in the Argentine Precordillera contemporaneous with rhyolite volcanism in the Famatinian Arc
title_full_unstemmed K-bentonites in the Argentine Precordillera contemporaneous with rhyolite volcanism in the Famatinian Arc
title_sort k-bentonites in the argentine precordillera contemporaneous with rhyolite volcanism in the famatinian arc
publishDate 2004
url http://sedici.unlp.edu.ar/handle/10915/128923
work_keys_str_mv AT fanningchristopher kbentonitesintheargentineprecordilleracontemporaneouswithrhyolitevolcanisminthefamatinianarc
AT pankhurstrobertj kbentonitesintheargentineprecordilleracontemporaneouswithrhyolitevolcanisminthefamatinianarc
AT rapelacarloswashington kbentonitesintheargentineprecordilleracontemporaneouswithrhyolitevolcanisminthefamatinianarc
AT baldoedgardog kbentonitesintheargentineprecordilleracontemporaneouswithrhyolitevolcanisminthefamatinianarc
AT casquetcesar kbentonitesintheargentineprecordilleracontemporaneouswithrhyolitevolcanisminthefamatinianarc
AT galindocarmen kbentonitesintheargentineprecordilleracontemporaneouswithrhyolitevolcanisminthefamatinianarc
bdutipo_str Repositorios
_version_ 1764820451685564418

Ejemplares similares