Lava broad, shallow slopes formed from predominantly effusive eruptions of relatively fluid basaltic lava flows, to steeply-sided stratovolcanoes (also known as composite volcanoes) made of alternating layers of ash and more viscous lava flows typical of intermediate and felsic lavas. A caldera, which is a large subsidence crater, can form in a stratovolcano, if the magma chamber is partially or wholly emptied by large explosive eruptions; the summit cone no longer supports itself and thus collapses in on itself afterwards. Such features may include volcanic crater lakes and lava domes after the event. However, calderas can also form by non-explosive means
Ice-marginal lava flow its subglacial beginnings. Currently the volcano is surrounded on all sides, except the south, by glaciers. What does Hoodoo mountain have to do with ice-marginal lava flows? Well, the entirety of the mountain is also surrounded by enormous lava cliffs, ranging from 50m-200m in height, as seen in Figure 3. The clearest example of these lava cliffs is seen on the southwestern side of the mountain whereas the northern formation of these cliffs has been overridden by recent lava flows and glacial erosion. Scientists are able to diagnose these lava cliff formations as a result of ice-marginal lava flows because