Ima

Key words:

1. Sediment 

2. Layers

3. Pressure

4. Water 

5. Cementation

6. Compaction

7. Fossils

8. Soft

Definition:

Sedimentary rocks are rocks that form on the Earth’s surface, not deep underground.They are made when small broken pieces of other rocks fall, settle, and collect in one place.These small pieces are called sediments.Sediments can be:

• sand

• tiny stones

• mud

• clay

• shells

• pieces of plants or animals

Over a very long time, more and more layers fall on top.These layers get pressed (compacted).Then minerals in the water act like glue and stick the layers together.This process is called cementation.When the layers harden, they become a sedimentary rock.

Sedimentary rocks are usually:

• soft compared to igneous rocks

• light in colour

• made in layers

• sometimes having fossils inside

Examples

• Sandstone – made from sand

• Shale – made from clay

• Limestone – made from shells or sea creatures

  
  

Fun Fact

Some sedimentary rocks act like a time machine — because their layers can tell us what Earth was like millions of years! Scientists can read the layers just like reading .