ICP Ch. 23 Review Part 2

Coal is composed of 

• petrified wood.
• a combination of oil-rich sediments and calcareous ooze.
• buried animal material that has partially decayed.
• buried plant material that has partially decayed.

The oldest rocks that have been dated by radioactivity are approximately

• 200 million years old.
• 10 billion years old.
• 2 million years old.
• 4 billion years old.

Rocks can begin to melt if

• the rocks' water content increases thereby decreasing the rocks' melting point.
• heated by rising magma from Earth's interior.
• a decrease in pressure results in a sufficient decrease in the rocks' melting point.
• all of the above.

Igneous rock is formed from 

• lava that freezes on Earth's surface.
• crystallization of magma.
• high temperature and pressures acting on subsurface rock.
• all of the aove

Rocks are grouped into three classes depending on how the rock was 

• shaped.
• formed.
• discovered.
• located.

A sedimentary rock can turn into an igneous rock by 

• compaction and cementation.
• melting and cooling.
• compaction.
• weathering and lithification.

Contact metamorphic rocks are typically not foliated because 

• contact metamorphism does not produce minerals, such as the micas, which are needed for foliation to occur.
• the parent rock does not contain the correct type of minerals to produce foliation.
• contact metamorphism occurs from heat and not from deformation due to stress.

Rocks altered by heat and pressure beneath Earth's surface are

• metamorphic rocks.
• igneous rocks.
• extrusive sedimentary rocks.
• intrusive igneous rocks.

The metamorphic equivalent of limestone is

• quartzite.
• marble.
• schist.
• gneiss.

Metamorphism caused by the close proximity of a magma source is called 

• contact metamorphism.
• regional metamorphism.
• dynamic metamorphism. 
• none of the above.