One feature that provides evidence that a volcano existed in the past is the presence of volcanic rocks and lava flows. These rocks are typically found near the volcano's vent and can be identified by their unique composition and texture. Additionally, volcanic ash layers or pyroclastic deposits, which are made up of fragmented volcanic material, can also indicate the presence of a volcano. Other features that suggest a past volcano include volcanic cones or craters, lava tubes, and volcanic gas emissions.
