Facial analysis, correlation, age and general revision of the San José and Río Salí Formations (Middle Miocene), Catamarca, Tucumán and Salta Provinces, Argentina

Abstract

?Facial analysis, correlation, age and general revision of the San José and Río Salí Formations (Middle Miocene), Catamarca, Tucumán and Salta Provinces, Argentina?. The facies analysis of the San José and Río Salí (Neogene) Formations in NW of Argentina established the presence of a low land topography (lacustrine and muddy plains), that could be related with the marine transgression cf the Chaco-pampean plains in the Middle Miocene (Paraná Formation). This relation is stressed by the presence in the lower section of San José Fm. of ?Protelphidium? tuberculatum among other benthonic foraminifera.

The sucession can be divided in two sequences divided by a prominent sandy coastal assamblage. The sandy facies are over the foraminifera beds in the Santa Marfa Valley (San José Formation) and mostly laying uncorformably over the Paleogene in the Choromoro and Nío Valleys (Río Salí Formation). This coastal facies are considered almost synchronic and were used as a correlation horizon