The volcano has evolved in close contact with glacial ice. It differs from many calderas in that Sollipulli appears to have collapsed in a non-explosive manner. The age of collapse is not yet known, but it is presently filled with ice to thicknesses of . The ice drains through two glaciers in the west and the north of the caldera. Sollipulli has developed on a basement formed by Mesozoic and Cenozoic geological formations.