 Nyorai kupfuurira kweiyi ndima - Brokeoff Volcano inomiririra chikamu chePleistocene cheLassen volcanic complex, nzvimbo yekuputika kwemakomo kwemakore anopfuura mamiriyoni matatu. Yakaumbwa mukati menguva yebasa rokuputika anenge makore 600 000 akapfuura panhevedzano yezvikanganiso; chikuru zvikurusa cheizvi kuputika chakanga chakasimba kakapetwa ka50 kupfuura kuputika kwa1980 kweGomo St. Helens. Munguva yePleistocene, marasha anogara achivandudzwa andesite aiyerera achibva pamhepo iri pakati pegomo rinoputika. Kuputika kwemapopoma emvura inonaya yakaungana kuti igadzire gomo rinoputika. Pakasvika pakukura kwazvo, gomo racho rakanga rakakura zvikuru, richikura kubva pasi kusvika pakati nepakati uye rakareba kupfuura. Basa paBrokeoff rakapfuurira kwamakore anenge 200.000. Kuputika kwacho kwakasiyana-siyana kubva pakudzingwa kwezvinhu zvinopisa kusvika pakuyerera kwemvura inonaya inonzi andesitic yakavakwa zvikurukuru nefeldspar, pyroxene, uye olivine. 