Abstract

GRECCO, Laura; MARFIL, Silvina  and  MAIZA, Pedro. Geoquímica y mineralogía de un depósito de caolín del área de los menucos, provincia de Río negro. Rev. Asoc. Geol. Argent. [online]. 2014, vol.71, n.2, pp.201-209. ISSN 0004-4822.

Mineralized area Blancón is located at 9 km from Los Menucos, Province of Río Negro. It is a kaolin deposit enclosed in a rhyolitic tuff of the Sierra Colorada Formation of Middle Triassic-Middle Jurassic age. In this work petrographic studies and chemical analyses of major, minor and trace elements on bulk samples were carried out. Mineralogical studies by SEM, XRD, DTA-TG and IR were made over kaolin veins, also isotopic analyses δ18O and δD. The presence of alunite and pyrophyllite, the high concentrations of Ba and Sr, the REE distribution and the δ18O and δD values allow to conclude that the kaolin was formed from hydrothermal alteration of rhyolitic tuffs.

Keywords : Hydrothermal alteration; Argillaceous minerals; Pyrophyllite; Alunite.

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