sediment Solid fragments of inorganic or organic material from the weathering of rock are carried and deposited by wind, water, or ice.
Weathering is the decomposition of Earth's rocks, soils and minerals through direct contact with the planet's atmosphere.
3 types of sedimentary rocks 1. clastic 2. chemical 3. organic
Sedimentary rocks 1. clastic rocks: formed from fragments of OTHER rocks. e.g. shale, sandstone, conglomerate 2. chemical 3. organic
shale Shale is a clastic sedimentary rock that is made up of clay-size (less then 1/256 millimeter in diameter) weathering debris. It typically breaks into thin flat pieces.
3 types of sedimentary rocks 1. clastic: shale, sandstone, conglomerate 2. chemical: sedimentary rocks formed when form when dissolved materials precipitate from solution (by evaporation or chemical action) E.g. rock salt, some limestones 3. organic
Rock salt (halite)
3 types of sedimentary rocks 1. clastic: shale, sandstone, conglomerate 2. chemical: rock salt, some limestones 3. organic: formed from remains of plants and animals. E.g. some limestones, coal
Limestone forming environment a coral reef system from the Kerama Islands in the East China Sea southwest of Okinawa. Here the entire seafloor is covered by a wide variety of corals which produce calcium carbonate skeletons.
coal forms from the accumulation and preservation of plant materials, usually in a swamp environment
3 types of sedimentary rocks 1. clastic 2. chemical 3. organic How do clastic rocks form
Clastic rocks 1. Come from the weathering of other rocks. 2. From small to large fragments, ranging from pebbles to gravels to microscopic flakes. 3. Carried by winds, waves, and water. 4. sediments are deposited when a stream slows down.
Clastic rocks 5. IMPORTANT: Dissolved minerals like silica, calcite, and iron oxide act as cement, or glue. These minerals settle into the spaces between sand grains or pebbles, and bind the fragments.
Sorting of sediments
conglomerate Formed from pebbles, sand grains Quartz is the most common mineral. (it’s very durable)
sandstone Formed largely from grains of quartz. Up to 30% of sandstones may be air space, making them porous and permeable.
shale Formed from tiny clay flakes. (of mineral kaolin)