6.2 Review

Where do most igneous rocks form from?

• Sediment
• Pressure
• Magma and Lava
• Chemical Reactions

What determines the texture of igneous rocks according to the text?

• Rate of erosion
• Rate of cooling
• Humidity levels
• Pressure

Which type of magma is described as containing large amounts of iron and magnesium and is made from hot, liquid magma?

• Felsic
• Mafic
• Intrusive
• Extrusive

How do intrusive rocks differ from extrusive rocks?

• Intrusive rocks form at the Earth's surface.
• Extrusive rocks cool slowly.
• Intrusive rocks have a coarse texture.
• Extrusive rocks contain large crystals.

What is the texture of extrusive rocks with tiny crystals described as?

• Glassy
• Fine grained
• Porphyry
• Smooth

When is magma called lava?

• When it cools slowly
• When it hardens quickly
• When it reaches Earth’s surface
• In the presence of water

What can underground magma cooling slowly and then suddenly forced to the surface form?

• Fine grained texture
• Porphyry
• Glassy texture
• Coarse texture

Which type of rock originates from volcanic particles and may share features of both igneous and sedimentary rocks?

• Granite
• Basalt
• Tuff
• Quartz

How do crystals form in rocks that cool rapidly?

• They are microscopic or absent
• They are large and well-defined
• They are glassy in texture
• They are fine grained

Which of the following describes the composition of felsic magma?

• High iron and magnesium
• High silica and low iron
• Low silica and high iron
• Low calcium and high silica