Exam 8: Volcanoes and Plutons

Explain why and what type of lava is created at rift zones.

Explain what causes some volcanic rocks to contain holes called vesicles.

If you saw an igneous pluton in the field that had oozed between rock layers, what did you see?

Explain how the melting of minerals increases the size of a magma chamber.

If you were a volcanologist, which type of magma would you expect to erupt the most violently because it has the highest percentage of silica content?

Which process causes crystallization of magma to form igneous rock?

If global warming reduced the amount of precipitation in the Yellowstone region, the confining pressure on superheated groundwater would decrease and may lead to more frequent hydrothermal explosions.

If magma experiences an increase in pressure, how does this affect magma? ________________

Explain how peridotite magma turns into basaltic magma and how the two magma types differ.

Explain how scientists have determined the origination of the Earth's first continental crust.

Identify and describe the differences among the three tectonic environments in which magma is formed.

____ joints are regularly spaced cracks that form in lava flows and grow downward.

The eruption of Mount Helens in 1980 produced such great ash and sulfur clouds that Earth's surface temperatures were cooler for the following two years.

____ explosions occur in regions in which the groundwater has been heated past the boiling point.

If you are looking at a volcano and its sides gently slope from the vent at angles between 6° and 12°, you are looking at a cinder cone volcano.

Continental crust is typically composed of ____.

If you are in Hawaii and see lava that has a jagged, broken surface, what is the specific name of the lava?

If scientists can show that seismic waves rapidly slow down allowing S waves not to register beneath Mount Vesuvius, this means molten magma still exists at that depth and could erupt again in the future.

Which type of intrusive igneous body existed to form the Sierra Nevada Range?

Basaltic magma has longer chains of silicate tetrahedra than granitic magma allowing it to increase in velocity and this would cause basaltic volcanoes to erupt more violently than volcanoes with granite magma.