INVESTIGADORES
RAPELA Carlos Washington
artículos
Título:
A revised age for the granites of the central Somuncura Batholith, North Patagonian Massif
Autor/es:
PANKHURST, R.J; RAPELA, C.W.; CAMINOS, R.; LLAMBÍAS, E.; PARICA, C.
Revista:
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
Editorial:
PERGAMON-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 1992 vol. 5 p. 321 - 325
ISSN:
0895-9811
Resumen:
Abstract
The age of the granites of the La Esperanza region of the Somuncura
Batholith, North Patagonian Massif has been revised, based in part on Rb-Sr
whole-rock data obtained by reanalyzing samples from a previous study. The new
ages are 258 ± 15 Ma for the Prieto Granodiorite and 259 ± 16 Ma for the Donosa
Granite, both from the older La Esperanza plutonic complex, and 239 ± 4 Ma for
the Calvo Granite, from the younger volcano-plutonic Dos Lomas complex. The
initial 87Sr/86Sr ratios are all in the range
0.7070?0.7076. The ages probably correspond stratigraphically to Late Permian
and Early Triassic for the two complexes, respectively, consistent with
traditional geologic interpretation. Together with recently published Triassic
ages from the Batholith of Central Patagonia, it is clear that the acidic
volcano-plutonic associations of northern Patagonia are very latest Paleozoic
and Mesozoic in age. They are not obviously related to terrane collision but
are part of a Permo-Triassic acid magmatic province that extends throughout the
central Andes and that preceded, or was associated with, the early rifting of
Gondwana.