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
Lava bear Alfred Bayne. As late as 1981, scientist were being asked to identify small bear tracks in the Fort Rock area to determine if they were made by lava bears. Today, it is accepted that lava bears are actually common American black bears. It is also generally acknowledged that all of the animals that were killed or captured between 1917 and 1934 were either black bear cubs or small adults stunted from malnutrition. In 1924, Bend Senior High School selected the lava bear as the school’s sports mascot. The mascot was chosen shortly after a living bear was exhibited in Bend.