Book 24, Question 122
How does loose sand become solid sandstone?
Sand that is buried deep under more layers gets squeezed by their weight. Water seeping through it carries dissolved minerals, such as silica or calcite, which fill the gaps between the grains. These minerals act like glue. Over millions of years, the loose sand turns into a hard rock.
More fun facts
- Sandstone forms from layers of sand that get pressed together and turn into rock.
- Over time, the weight of new layers on top squeezes the sand grains below.
- This slow change of loose sediment into solid rock is called lithification.
- Sandstone is one of the best known rocks made from broken bits of other rocks.
- Rocks like this are called clastic sedimentary rocks.
Sources: National Geographic Education
Questions kids ask
Where does this squeezing usually happen?
Often on the bottom of oceans and other bodies of water, where sand and clay pile up.