Originally, the Granada ignimbrite was also considered to be a product of an earlier eruption of the Vilama caldera; later research indicated that it has its own eruptive centre at Abra Granada that is unrelated to Vilama. According to this older theory of caldera history, the Granada ignimbrite was the first stage of caldera formation, with the second stage generating the Vilama ignimbrite proper. This theory also envisaged two later stages of activity, the first linked to the Cerro Morado mafic volcanics and the Salle and Ceja Grande ignimbrites, while the fourth produced the Bonanza ignimbrite from the Coruto caldera as well as additional volcanoes including Cerro Zapaleri.