Exam 5: Igneous Processes and Volcanism

Approximately what percentage of Earth's active volcanoes occurs at convergent plate boundaries?

Basalt magmas tend to form narrow and steep conical volcanoes, whereas andesite and rhyolite magmas tend to form broad, gently sloping volcanoes.

Which is a volcanic landform built up from alternating lava flows and beds of pyroclasts?

The tallest mountain in the world is which kind of volcanic landform?

Approximately how many volcanoes erupt each year?

Which of the following properties of a magma increases with increasing silica content?

What is the effect of water on rock melting?

-Which of the following volcanic chains formed at a tectonic setting similar to C?

Which kind of magma is least likely to have large catastrophic pyroclastic eruptions?

Which of the following igneous bodies is a discordant intrusive rock?

Which of the following mountain chains is made up primarily of volcanoes formed at an ocean-continent subduction zone?

What is the term for a large, steep-walled, basin-shaped depression that forms by the collapse of a magma chamber roof after a violent eruption?

Which of the following volcanic eruptions was predicted by geoscientists, enabling evacuation of the area?

Which lava type is least likely to form a volcanic dome?

-Which of the following best describes the igneous rock depicted in the diagram above?

Which of the U.S. volcanoes listed below is considered to pose the greatest risk to the population?

What is the plate tectonic environment that has caused the formation of the volcanoes of the Cascade Range in Oregon and Washington States (including Mt. Rainier, Mt. St. Helens)?

Which statement regarding fissure eruptions is true?

-Which of the following best describes the gray igneous rock depicted in the cross section above?

-Which of the following volcanic chains formed at a tectonic setting similar to A?