 Several phases of volcanic activity have been inferred from the deposits; most of them feature either pumiceous or scoriaceous pyroclastic flow deposits with varying contents of juvenile lapilli, lithics and ash fall deposits.In addition, three tephras in neighbouring lakes dated to 16,748 - 16,189, 15,597 - 12,582 and 12,708 - 12,567 years before present may originate from Quetrupillán but they have also been attributed to Sollipulli.All these tephras are of rhyolitic to rhyodacitic composition and the eruptions that generated them have an estimated volcanic explosivity index of 3.