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Alvaro Rodrigo Iriarte,Umberto Giuseppe Cordani,Kei Sato
Pág. 403 - 441
The Cordillera Real granitoids are a suite of Triassic and Oligocene plutons in the core of the Eastern Cordillera of the Central Andes of Bolivia. Their tectonic setting, chemical and ore compositions make them part of the so-called ?Inner Magmatic Arc?...
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Stella Poma,Eduardo O. Zappettini,Sonia Quenardelle,Joao O. Santos,?Magdalena Koukharsky,Elena Belousova,Neal J. McNaughton
Pág. 267 - 292
We have carried out zircon U-Pb SHRIMP dating and Hf isotope determinations as well as geochemical analyses on three plutonic units of Gondwanan magmatism that crop out in NW Argentina. Two episodes of different age and genesis have been identified. The ...
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Alejandro Sanchez,Polina Pavlishina,Estanislao Godoy,Francisco Herve,Mark Fanning
Pág. 413 - 432
On the west coast of Tierra del Fuego, south of Cabo Nariz, in Chile, Upper Cretaceous to Paleocene sedirnentary successions of the Magallanes foreland basin crop out. The presence of dinoflagellate cysts, as well as radiometric U-Pb SHRIMP dating of det...
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Victor Maksaev,Francisco Munizaga,Victor Valencia,Fernando Barra
Pág. 264 - 287
New U-Pb zircon dating of volcanic intercalations in the lower conglomeratic part of the Cerrillos Formation shows that its deposition extended in time at least from 110.7±1.7 to 99.7±1.6 Ma. The significantly younger U-Pb zircon age of 69.5±1.0 Ma obtai...
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Ricardo Varela,Ana M. Sato,Miguel A.S. Basei,Oswaldo Siga Jr.
Pág. 265 - 284
Igneous and metamorphic units formed mainly during the Middle Proterozoic and Early Paleozoic times have been distinguished in the Sierra de Umango crystalline basement. These include granitic orthogneisses, a sequence of schists and marbles, amphibolite...
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Robert J. Pankhurst,Ian L. Millar,Francisco Herve
Pág. 35 - 42
ABSTRACT. A U-Pb zircon age 0f 285.7+/-1.5 Ma is presented for granodiorite from the Chanchoquin pluton of the Guanta Unit, Elqui Superunit of the Elqui-Limari Batholith. This is the first U-Pb zircon age reported from this batholith and is interpreted a...
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Estanislao Godoy,Werner Loske
Pág. 119 - 127
RESUMEN. Tres fracciones granulometricas de circones en una diorita de dos piroxenos (charnoquita 'precambrica' segun estudios anteriores), que aflora en Laguna Verde, y dos fracciones de su equivalente neisico de Punta Curaumilla, indicaron edades conco...
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