Petrology of the Luingo caldera (SE margin of the Puna plateau): A middle Miocene window of the arc-back arc configuration

► Luingo caldera is modelled by AFC-r as a mixture of 20:80 crustal/mantle melts. ► Presence of garnet in the source indicates crustal thickening (Coira and Kay, 1993). ► Major thickening event during the middle Miocene in the western portion of SCVZ. ► Major thickening event during the upper Miocene in the eastern portion of SCVZ. ► Distribution of volcanics and geochemistry help to envisage a broad arc in the SCVZ.