SEDIMENTARY ROCKS

How sedimentary rocks form… Wind, water, ice, sunlight, and gravity cause rocks to weather into sediments. These sediments are moved from one location to another by the process of erosion. The sediments are eventually deposited on to older layers and form new ones. The sediments become compacted and dissolved minerals separate from water and form a natural cement—Lithification. Sedimentary rocks are formed.

Strata and stratification Layers of rock STRATIFICATION process in which sedimentary rocks are arranged in layers

Layered rocks in the grand canyon

Clastic sedimentary rocks Made from fragments (sediments) of rocks that are cemented together by minerals . They are classified according to the size of the fragments. EXAMPLES: conglomerate, sandstone, siltstone, shale

Loose sediments Clastic Sedimentary Rock

Chemical sedimentary rocks Form from solutions of dissolved minerals and water. EXAMPLE: halite

Halite that has formed when the minerals crystallized.

Organic sedimentary rocks Form from remains or fossils of once living things. EXAMPLE: limestone, coal COAL---- Forms underground when partially decomposed plant material is buried beneath sediment and is changed into coal the pressure from layers above. This process takes millions for years. Non-renewable fossil fuel

Formation of coal