PSNB+5.3

toc =5.3 Sedimentary Rocks (pg. 144)=

= =


 * S****ediment:** Tiny pieces of material that develop from different rocks, of living things.
 * Deposition:** The process of sediment in the water that goes out by either wind or water.
 * Compaction:** The procedure in which time compresses sediments together.
 * Cementation:** The method in which crystallization takes place in dissolved minerals, and keeps pieces of sediment together.
 * Clastic Rock:** A type of sedimentary rock that is created when tiny pieces of rock are compressed together.
 * Organic Rock:** Created from the leftovers of plants/ animals are left and formed into big, thick layers.
 * Chemical Rock:** Created from dissolved materials that have crystallized either by time, or as an experiment.

From Sediment to Rock

 * Sedimentary rocks form from pieces of other materials deposited by wind and water
 * Erosion**
 * Destructive forces are always breaking/wearing away rocks


 * Deposition**
 * Eventually erosion forces slow down and deposit the sediment
 * After sediment is deposited, compaction+cementation change it into a rock
 * Living things may turn into fossils in the rock
 * Compaction**
 * First sediment is loose, then it gets pushed together by new sediment
 * This happens for years
 * Sometimes the sediment layers are visible
 * Cementation**
 * Minerals in rock dissolve in water
 * This makes it like "glue," hardening the rock

Clastic Rocks

 * Some rocks of made only of other rocks
 * Shale**
 * Forms from tiny clay pieces
 * Is so compact that no "glue" is needed
 * Splits evenly, kind of like cleavage
 * Sandstone**
 * Sandstone is formed from pieces of sand
 * Sandstone has many small holes because it is so lo0osely packed
 * Conglomerate and Breccia**
 * Sometimes clastic rocks have big and small rock sizes
 * Breccia are rocks with sharp edges
 * Conglomerate are rocks with rounded edges

Organic Rocks

 * Organic rocks form from the remains of plants and animals
 * Coal**
 * Coal is created from swamp plants
 * The plants form layers;then take years to form coal
 * Limestone**
 * Limestone forms from skeletons and hard shells

Chemical Rocks

 * Chemical rocks are formed when minerals crystallize
 * They can also be formed from solutions
 * This process creates many common rocks

Uses of Sedimentary Rocks

 * There are many uses of limestone
 * The white house is made of sandstone, and so is the Taj Mahal!

Back to Homepage