1. Coach Williams Room 310B

2.  Volcanoes

3.  Objectives: 1.Describe the major parts of a volcano. 2.Compare/contrast shield, cinder-cone, and composite volcanoes. 3.Contrast the volcanism that occurs at plate boundaries. 4.Explain the relationship between volcanism and hot spots.

4.  Volcano: mountain of cooled lava  Vent: opening in crust  Crater: bowl shaped depression  Calderas: larger depressions

5.  Shield: broad, gentle slope. Circular base  Cinder-Cone: steep sides. Smaller  Composite: fragments layered with lava. ◦ Larger

7.  Tephra: rock fragments thrown in air ◦ Dust: <2mm ◦ Ash: >2mm ◦ Lapilli “little stones”: rock size ◦ Volcanic blocks: large, angular ◦ Volcanic bombs: large rounded  Pyroclastic flows: deadly flow of volcanic material (gas, ash, tephra)

8.  Most at plate boundaries  80%: convergent boundaries  15%: divergent boundaries  Hot spots: hot regions of Earth’s mantle ◦ Volcanoes far from plate boundaries

10.  Section Title