How Rock Becomes Rock Again

Written by Studio AM.

Rocks can change from one type into another over time. When molten rock, called magma, cools and hardens underground or after a volcanic eruption, it forms igneous rock.

At the surface, weathering can break rocks into smaller pieces. Water, wind, or ice may carry these pieces elsewhere, where they settle as sediment. Layers can be compacted by material above them and cemented together by minerals, forming sedimentary rock. Some sedimentary rocks also form when minerals come out of water.

Buried rock can change under heat and pressure without melting. Its minerals and texture change, producing metamorphic rock. If any rock melts, it can become magma and later cool into igneous rock again.

These connected processes make up the rock cycle. They do not follow one fixed order. An igneous rock can become metamorphic without first becoming sedimentary. A rock may also remain in place for a very long time. Geologists study its minerals and texture for clues to the conditions it has experienced.

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  1. Question 1 of 4

    In this passage, 'magma' refers to rock that is

  2. Question 2 of 4

    How can layers of sediment become sedimentary rock?

  3. Question 3 of 4

    The best title for the central idea of this passage is

  4. Question 4 of 4

    Based on the passage, what would have to happen for a metamorphic rock to become igneous rock?

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