Parinacota volcano, north Chile. This 6000 rn high volcano, located on the frontier between Chile and Bolivia, experienced a major collapse about 13 300 years ago. The resulting debris avalanche deposit blocked surrounding drainages, and impounded Lake Chungara, seen in the foreground. In the middle distance, large slide blocks (roevas) of pale-coloured dacites are evident. Post-collapse eruptions have largely masked any evidence of the failures on the cone itself. Photo by P. Francis.