How Rocks Change

Processes That Cause Change

• it can take thousands of years for a rock to weather and erode– it can take many more for eroded pieces to

change into sedimentary rock

• high heat and pressure change rocks– sometimes rocks can melt completely– when it cools and hardens it has turned from

metamorphic to igneous

• a rock can be changed many times– some part of the first rock will still be there

after each change

The Rock Cycle

• rock cycle: the never-ending rock changes– the rock cycle has many different paths

• as rocks move through the rock cycle the materials that make them up are used over and over

Summary

• rocks change from one kind of of rock to another in the rock cycle

• some of the processes in the rock cycle are: – weathering, erosion, melting, compaction,

and cementation