Volcanic Edifices and Volcanic Deposits

Abstract

Young volcanoes contrast with most other mountains by forming lovely cones or impressive edifices sometimes rising high above their surroundings. Even small volcanoes, which almost always occur in groups, greatly enhance the attraction of an otherwise morphologically bland landscape. Obviously, areas dotted with young volcanoes are major tourist attractions (Chap. 15). In addition to appreciating the aesthetic appeal of volcanoes, volcanologists, during their professional life, develop the ability to delve beneath a volcano’s morphology. They learn how to deduce the internal structure, type of deposit and, therefore, the physical properties of the magma whose eruption makes up the stuff of a volcano (Figs. 9.1, 9.2). Questions that come to mind: what does the form of a volcano tell us about the composition, the gas content and, therefore, the viscosity of the magma? Can we deduce something from the size of a volcano about magma mass eruption rates and thus processes within the magma reservoir, or even the magma production rates in the Earth’s mantle? How are different eruptive mechanisms (especially the difference between magmatic and hydromagmatic processes) reflected in the form and architecture of a volcano? How strongly and how often have the volcano flanks collapsed and subsequently rehealed?