Volcanoes and igneous rocks

Volcanic belts form along

• islands in the Pacific Ocean
• North American mountain ranges
• the boundaries of Earth's plates
• the coast of Antarctica

The formation of the Hawaiian Islands is one example of

• volcanoes forming over a hot spot
• volcanoes forming along a plate boundary
• the Ring of Fire
• continental drift

If a volcano's magma is high in silicia, the volcano will probably

• erupt quietly
• remain dormant
• erupt explosively
• produce dark color lava

What type of volcano is built almost entirely from ejected lava fragments?

• cinder cone
• composite cone
• shield volcano
• pahoehoe volcano

The particles produced in volcanic eruptions are called ____.

• laccoliths
• pyroclastic material
• calderas
• volcanic stocks

Highly explosive volcanoes tend to have what type of magma?

• magma with high silica, high viscosity, and higher gas content
• magma with low silica, low viscosity, and lower gas content
• magma with low silica, high viscosity, and lower gas content
• magma with no silica, high viscosity, and no gas content

A lava flow with a surface of rough, jagged blocks and sharp, angular projections is called a(n) ____.

• pyroclastic flow
• aa flow
• pahoehoe flow
• ash flow

Which of the following factors helps determine whether a volcanic eruption will be violent or relatively quiet?

• amt of dissolved gases
• temp of magma
• composition of magma
• all of the above

Which of these volcanic particulates is the smallest in size?

• Block
• Ash
• Bomb
• Lapilli

A  line of volcanic activity that surrounds the Pacific Ocean basin is the 

• Ring of Fire
• Aleutian Islands
• Hawaiian Islands
• Caribbean Islands