 Later , a debris flow named Veladero ( also known as Quebrada de Veladero Ignimbrite ) occurred in a glacier valley south of the caldera . It is rich in lithics and pumice . These lithics are derived from Sierra de Veladero , Cerro Bonete Chico , and Pircas Negras lavas . The debris flow ranges from 15 to 25 metres ( 49 to 82 ft ) in thickness 5 kilometres ( 3 @.@ 1 mi ) south of the caldera to 10 to 15 metres ( 33 to 49 ft ) farther south , the total volume being 0 @.@ 7 – 0 @.@ 5 cubic kilometres ( 0 @.@ 17 – 0 @.@ 12 cu mi ) . The debris flow does have a different composition from the main Incapillo ignimbrite , as it contains red @-@ brown dacite and clasts . It has a massive ungraded composition and is likely a lahar or debris flow deposit , probably influenced by glacial or crater lake water . Wind @-@ driven effects have generated hummocky ridges . 
