Rock cycle

Science

Definition

The rock cycle is the continuous process by which rocks are transformed between three types — igneous, sedimentary, and metamorphic — through processes like melting, cooling, weathering, erosion, deposition, compaction, cementation, and heat/pressure.

How It Works

  1. Magma cools and crystallizes to form igneous rock (either intrusive or extrusive).
  2. Weathering and erosion break igneous (or any) rock into sediments.
  3. Sediments are transported, deposited, compacted, and cemented into sedimentary rock.
  4. Heat and pressure deep underground transform existing rock into metamorphic rock.
  5. Metamorphic rock can melt back into magma, restarting the cycle, or be uplifted and weathered.

Examples

  • Granite (igneous) weathering into sand that becomes sandstone (sedimentary)
  • Limestone transformed into marble under heat and pressure (metamorphic)
  • Volcanic lava cooling to form basalt (igneous)

Related Terms

Igneous sedimentary metamorphic Mechanical weathering Chemical weathering Erosion and deposition

Study This Concept

Practice rock cycle with free review games in these units:

Earth Science Unit 1: Minerals and Rocks