 Most sedimentary rock forms this way  Sediment is material that settles out of water or air Sand at the beach Mud in the bottom of a lake Pebbles in a river Dirt in your yard Dust on furniture  Rock develops when layers of sediment build up on land or water and get cemented together

 Rain Washes away rock particles as it runs down slopes  Water Streams can move sediment that ends up in lakes or the ocean  Wind Strong wind can pick up sand and rock dust and carry it to distant places  As this sediment is transported it gets laid down in layers

 As layers of sediment layer on top of each other the pressure causes the layers to form into rock Silt and clay  Other times minerals need to crystallize between sediment acting as cement.

 Made mainly of sand-size weathered debris (1/16 – 2 millimeters in diameter)  Forms mostly where large amounts of sand accumulate Beaches Deserts Flood plains Deltas

 Fine-grained  Formed from silt and clay-size minerals Otherwise known as mud  Made of thin layers

 Does not contain any minerals  Made from the remains of plants and animals  Takes millions of year to form  Conditions must be right Forms from ancient swamps

 Made of carbonate minerals like calcite  Shells and skeletons of ocean organisms have these minerals  Ocean organisms die and their remains go to the bottom of the ocean Over time the shells/skeletons get cemented together because their minerals dissolve and re- form  Coral reefs also consist of limestone As the coral grows its old shells die

 Minerals are dissolved in water  When water evaporates it leaves the minerals behind  These minerals then recrystalize to form rock  Rock salt or halite is an example Detroit has a huge deposit of this under the city

 The only type of rock that fossils can be found in Tell us about plants and animals that lived in the past  Crossbeds Show the direction wind was blowing over sand dunes  Ripples Show the direction water was traveling over the sand  Mud Cracks Show periods of wet followed by dry periods  Floods Shown when sediment size is layered large up to small