The Luingo caldera: The south-easternmost collapse caldera in the Altiplano-Puna plateau, NW Argentina

This article identifies the Pucarilla-Cerro Tipillas Volcanic Complex and its major eruptive source, the Luingo caldera (26 degrees 10'S-66 degrees 40'W). Detailed geological mapping, stratigraphic sections, facies analysis and correlations, including the identification of typical caldera components, allow us to infer the position of a collapse caldera, elongated at N65 degrees and with a diameter of 19 km x 13 km, which is responsible for an eruption of 135 km(3) (DRE) of magma. The high-crystal contents of the associated ignimbrites, combined with its tectonic setting, indicate that regional and local tectonic structures played a crucial role in the formation of the caldera. The Luingo caldera is located on the south-eastern border of the Puna, and is the south-easternmost recognised caldera of the Altiplano-Puna plateau. The age of the caldera and its products is 12.1 to 13.5 Ma. Based on its location near the Cerro Galan Complex (2 to 6.5 Ma), we can imply that volcanism existed in the area for about 10 Ma. The caldera morphology and product distribution account for a middle Miocene paleao-topography similar to the present one. (C) 2010 Elsevier B.V. All rights reserved.