Objectives - Chapter 4
List and describe factors that determine the nature of volcanic eruptions.
Describe how temperature and silica content affect the viscosity of magma.
Distinguish among eruption styles of volcanoes that erupt silica-rich magmas, silica-poor magmas, and intermediate composition magmas.
- Name the extrusive igneous rocks that each magma produces.
Describe the formation of calderas, shield volcanoes, composite volcanoes and cinder cones. Describe the tectonic settings in which each is likely to occur.
Describe the following rock textures and explain how each forms:
- glassy
- porphyritic
- vesicular
- pyroclastic.
Explain the world-wide distribution of composite volcanoes; relate the distribution of volcanoes to plate tectonics.
Describe the hazards that different types of volcanoes present to humans.
Define and understand the “Terms to Remember” on page 99.