Abstract

KIETZMANN, Diego A; PALMA, Ricardo M  and  FERREYRA, Teresita M.A. Análisis de facies y asignación estratigráfica de los depósitos fluviales innominados del jurásico medio de la cuenca Neuquina Surmendocina. Rev. Asoc. Geol. Argent. [online]. 2016, vol.73, n.1, pp.104-116. ISSN 0004-4822.

Stratigraphic-sedimentological studies were performed on Middle Jurassic unnamed fluvial deposits of the Southern Mendoza Neuquén Basin, cropping out in the Malargüe anticline and Bardas Blancas. In the first area we recognized braided fluvial systems facies stacked in three depositional sequences showing a gradual decrease in the accommodation space, whereas in the second we recognized anastomosing fluvial systems facies grouped into two depositional sequences with a progressive increase in the accommodation space. Stratigraphic relationships and stacking pattern in the Malargüe anticline suggests the assignment of this unit to the late Bajocian-Bathonian and its correlation with the Lajas Formation, so the name of Puesto Pacheco Formation nov. nom. is proposed, with its stratotype in the Loncoche creek section. In the Bardas Blancas area the presence of limestone clasts and oysters fragments at the base of the unit, would establish that unnamed fluvial deposits would have been deposited after the Intracallovian unconformity. In this area it is given a middle-late Callovian age and the assignment to the Lotena Formation.

Keywords : Fluvial; Sequence stratigraphy; Lotena Formation; Lajas Formation.

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