Soon before or after the buried ice had melted away, dacite lava quietly erupted from Opal Cone southeast of the Atwell Peak plug dome 10,700 to 9,300 years ago and flowed down Ring Creek on Garibaldi's southern and southwestern flanks without encountering any residual glacial ice. One of the lava flows traveled down a 30% to 35% grade over the landslide scar on the western flank. About of dacite erupted in Garibaldi's third period of activity. This lava forms a thin layer of solid rock on the southern and western sides of the volcano and contains well-defined lava flow margin levees. The Ring Creek lava flow is very unusual because lengthy lava flows are usually attained by fluid basalt flows, but the Ring Creek flow is dacite.