When magma reaches Earth's surface it is called __________.
Where is andesitic magma found?
|A)||on islands in the Pacific, such as Hawaii|
|B)||at the margins of continents|
|C)||in the middle of oceanic crust|
|D)||inside of continental crust|
When does magma form?
|A)||when volcanoes erupt|
|B)||when temperatures are hot enough to melt rock|
|C)||when grains have been compacted together|
|D)||when new minerals form due to chemical changes in the rock|
What type of magma has the lowest silica content and is the least explosive?
Rhyolitic magma has the __________ viscosity, the __________ gas content and the __________ silica content of any type of magma.
|A)||highest, lowest, lowest|
|B)||lowest, lowest, lowest|
|C)||highest, highest, highest|
|D)||lowest, highest, highest|
__________ is the internal resistance to flow of a liquid.
Why does magma move up to and through Earth's crust?
|A)||It is less dense than surrounding rock.|
|B)||It is cooler than the crust.|
|C)||It is more dense than surrounding rock.|
|D)||It is more viscous than ocean water.|