Chapter 18-Volcanoes

The smallest tephra

Most dangerous type of volcano

Large angular volcanic fragments

Mushroom shaped pluton

Has broad, gently sloping sides and nearly circular base

A mixture of molten rock, gases, and suspended materials

Bowl shaped depression that forms around the vent of a volcano

Opening in Earth's surface that allows jlava to escape

Largest pluton

Pluton that cuts across pre-existing rocks

Plates moving away from each other

Location of a large Caldera in the United States

Chain of volcanoes in Pacific Ocean

Type of magma that produces calmest eruptions

Most volcanoes form along

Rock fragments thrown into the air during a volcanic eruption

Process responsible for many plutons being formed

Small volcano with steep sides

Pressure under Earth's surface

Fast moving clouds of ash, gas, and other tephra

Large rounded streamline tephra

When magma reaches the surface

Intrusive igneous rock body

Forms when the top side of a volcano collapses into the magma chamber