A little about Sedimentary Rocks

Sedimentary rocks are formed when sand, small pieces of rock, or mud are deposited as layers of sediment.  These layers of sediment are pressed together over a long period of time and form a sedimentary rock from the pressure and cementation process.  Sedimentary rocks are unique because they can be formed from any other rocks type: igneous, metamorphic and even other sedimentary rocks.  Rocks are broken down by wind and water and the pieces are transported to oceans and lakes by rivers and smaller streams.  The rock pieces are deposited in the lakes and oceans in the layers which later become a sedimentary rock.

Sedimentary Rocks

 

Sedimentary rocks are unique because they are the only types of rocks that can contain fossils of sea shells and animals.  Fossils form when the soft parts of plants and animals decay and leave the hard parts (such as bones) behind.  The hard parts that are left are then covered with layers of sediment.  When the sediment becomes a rock, the hard parts are preserved in the rock as a fossil.

 

Find out more about rocks and minerals at MiniMeGeology.com!

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