Revisión del área de Cerro del Corral (San Ramón). Nuevos afloramientos de rocas piroclásticas en la Cantera El Diamante y Sierra del Piojo (Cantera Carin IV), Tandilia, Argentina.
Year: 2025
Type: article
Abstract: New studies conducted on previously recognized pyroclastic rocks, along with newly discovered outcrops in the sedimentary sequence of the Tandilia ranges, have enabled the establishment of correlations between areas with sparse and isolated exposures in the western, central, and southeastern sectors of Tandilia. In critical zones—due to poor outcrop quality and ambiguous stratigraphic positioning—several vertical profiles were analyzed on clay-rich levels and adjacent lithologies. Petrographic and X-ray diffraction analyses allowed for the identification of paragenetic clay associations, hydrothermal alteration zoning, and metasomatic replacement features. Geochemical analyses, including major oxides, trace elements, and rare earth elements, were performed on representative samples from the studied units. These data revealed a clear correlation between the basic pyroclastic rocks of the Sierra de los Barrientos (southeast) and those of the Sierra del Piojo (northwest). Additionally, equivalent levels of acid pyroclastic rocks were recognized in the Olavarría Formation, permitting stratigraphic correlation among quarry exposures in the Barker and Olavarría localities. We interpret the Las Águilas Formation as a basic pyroclastic event within the Cerro Largo Formation. Although both the Las Águilas and Olavarría Formations occur in the central Tandilia region (Barker area), they are not stratigraphically equivalent, being separated by the upper section of the Cerro Largo Formation. Consequently, we propose reclassifying the Las Águilas Formation as the Las Águilas Member within the Cerro Largo Formation.
Language: Spanish
Subfield: Geochemistry and Petrology
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W7215190276