IGEBA   23946
INSTITUTO DE GEOCIENCIAS BASICAS, APLICADAS Y AMBIENTALES DE BUENOS AIRES
Unidad Ejecutora - UE
artículos
Título:
The Gondwana connections of northern Patagonia
Autor/es:
PANKHURST, ROBERT; RAPELA, CARLOS ; LÓPEZ DE LUCHI, MÓNICA; RAPALINI, AUGUSTO E.; FANNING, M.; GALINDO, C.
Revista:
JOURNAL OF THE GEOLOGICAL SOCIETY
Editorial:
GEOLOGICAL SOC PUBL HOUSE
Referencias:
Lugar: Londres; Año: 2014 vol. 171 p. 313 - 328
ISSN:
0016-7649
Resumen:
A multidisciplinary
study (U-Pb SHRIMP geochronology, Hf and O isotopes in zircon, Sr and Nd
isotopes in whole-rocks, as well as major and trace element geochemistry) has
been carried out on granitoid samples from the area west of Valcheta, North
Patagonian Massif, Argentina.
These confirm the Cambrian age of the Tardugno Granodiorite (528 ± 4 Ma) and
the Late Permian age of granites in the central part of the Yaminué complex
(250 Ma). Together with petrological and structural information for the area, we
consider the possibility that the Cambrian and Ordovician granites of
northeastern Patagonia represent continuation
of the Pampean and Famatinian orogenic belts of the Sierras Pampeanas,
respectively. Our interpretation does not support the hypothesis that Patagonia
was accreted in Late Palaeozoic times as a far-travelled terrane, originating
in the Central Transantarctic Mountains,
and the arguments for and against this idea are reviewed. A parautochthonous
origin is preferred with no major ocean closure between the North Patagonian
Massif and the Sierra de la Ventana fold belt.