INGEOSUR   20376
INSTITUTO GEOLOGICO DEL SUR
Unidad Ejecutora - UE
artículos
Título:
The Marifil Volcanic Complex at Sierra de Pailemán: implications for the Early Jurassic magmatic evolution of the Eastern North Patagonian Region
Autor/es:
PAVÓN PIVETTA, CECILIA; GERALDES, MAURO C.; GREGORI, DANIEL A.; BARROS, MERCEDES V.; STRAZZERE, LEONARDO; BENEDINI, LEONARDO
Revista:
INTERNATIONAL GEOLOGY REVIEW
Editorial:
TAYLOR & FRANCIS INC
Referencias:
Año: 2021 vol. 64 p. 844 - 866
ISSN:
0020-6814
Resumen:
The Sinemurian Marifil Volcanic Complex at Sierra de Pailemán, located in the east part of the NorthPatagonian Region, Argentina, includes five lithofacies and three volcanic events. The volcanicactivity begins with subaerial pyroclastic-fall deposits, massive lapilli tuffs with eutaxitic textures,and subaerial silicic domes? emplacement. The upper part of the sequence is formed by pyroclasticfall deposits that pass to massive lapilli tuffs and rhyolitic lava flows. These lithofacies indicate thecollapse of explosive eruption columns, coeval with small silicic domes? emplacement, and lavaflows? eruption. The volcanic episode at Sierra de Pailemán was generated during continuousmagmatic activity because no erosional or unconformity surfaces were recognized. The MarifilVolcanic Complex?s age at Sierra de Pailemán is 191.2 ± 1.3 Ma (Sinemurian) and belongs to the V0phase of volcanism. These rocks are high-K rhyolites, possibly produced by partial melting of thelower crust, promoted by fluids derived from a subducted plate in back-arc settings that change toan intraplate setting. The Lu-Hf isotopes suggest the possibility of magma mixing in the source andrecycling or re-melting of a more evolved crust related to subduction zones. The Lower Jurassicmagmatic activity in the western North Patagonian Region and the Patagonian Cordillera ofArgentina and Chile correspond to continental arcs.