Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Coulter • Sediment is small, solid pieces of material that come from rocks or living things. • Most sedimentary rocks are formed through a series of processes: erosion, deposition, compaction, and cementation. • Destructive forces are constantly breaking up and wearing away all the rocks on Earth’s surface. • Running water, wind, or ice loosen and carry away fragments of rock. • Is the process by which sediment settles out of the water or wind carrying it. • The process that presses sediments together. • Thick layers of sediment build up gradually over millions of years. These layers press down on the layers beneath them. This weight further compacts the lower layer. • Layers often remain visible in sedimentary rock. • Is the process in which dissolved minerals crystallize and glue particles of sediment together. • Dissolved minerals seep into the spaces between particles and then harden. • There are three major groups of sedimentary rocks: • Clastic rocks •Organic rocks • Chemical rocks • Clastic rock is a sedimentary rock that forms when rock fragments are squeezed together. • These fragments can change in size from clay particles you would need a microscope to see to large boulders that are to heavy to lift. • Common clastic rocks include shale, sandstone, conglomerate, and breccia. • shale forms tiny particles of clay • Sandstone form from the sand on beaches, ocean floor, riverbeds, and sand dunes. • Most sand particles consist of quartz. • Conglomerate have rounded edges • Breccia large sharp edges • Forms where the remains of plants and animals are deposited in thick layers. • Coal and limestone are two important organic rock. • Coal forms from the remains of swamp plants buried in water. Layer upon layer of plant remains build up, the weight of the layers squeezes the decaying plant. Over millions of years, they slowly change into coal. • Limestone forms in the ocean, where many living things have hard shells or skeletons made of calcite. The shells of animals pile up and over millions of years compaction and cementation change the sediment into limestone. • Chemical rocks are minerals that dissolve in a solution and crystallize. • Chemical rocks can also form from mineral deposits left when seas or lakes evaporate. • Example: rock salt is made of the mineral halite, which forms by evaporation. • People have used sedimentary rocks throughout history for many different purposes, including building materials and tools. • People made arrowheads out of flint for thousands of years. • Flint is a hard rock that can be shaped. Sedimentary and limestone have been used in building for thousands of years, because they are easy to cut. the white house is built of sandstone.