Presentation on theme: "Sedimentary Rock Sedimentary rock is rock that is formed from the accumulation and consolidation of sediments (weathered particles of other rocks). Lithification."— Presentation transcript:
Sedimentary Rock Sedimentary rock is rock that is formed from the accumulation and consolidation of sediments (weathered particles of other rocks). Lithification is the process by which sediments become rock. –E–Ex: s ss sandstone, s ss shale, c cc conglomerate
Compression Compression Compression occurs as the pressure created by water and overlying sediments becomes great enough to force particles of sediment close together, drive out any water, and compact the sediments into rock. shale A good example is shale.
Cementation Cementation Cementation occurs as the addition of minerals, such as silica, lime, or iron oxide, tends to “glue” rock particles together to form solid rock. sandstone conglomerate Examples are sandstone and conglomerate, which are composed of particles of sand, pebbles and small rocks.
Formation by Chemical Process Some sedimentary rocks form as the result of chemical processes such as evaporation and precipitation. Rocks formed by the evaporation of water are called evaporites Rocks formed by the evaporation of water are called evaporites. limestonerock salt rock gypsum Examples are limestone, rock salt and rock gypsum.
Examples of Sedimentary Rocks Formed by Chemical Processes
Formation by Biological Processes Some sedimentary rocks form as a result of processes acting on the remains of once living organisms. Coal is formed from the compression of dead plants. Limestone is formed from the remaining shells of dead sea-life.
Fossils Sedimentary rocksalso form and contain remains or impressions of plants and animals. These impressions are calledfossils Sedimentary rocks also form and contain remains or impressions of plants and animals. These impressions are called fossils.
3 Kinds of Sedimentary Rocks Clastic Clastic sedimentary rocks form from the compaction and cementation of fragments of other rocks. Chemical Chemical sedimentary rocks form from mineral grains that precipitate out by evaporation or other chemical action. Organic Organic sedimentary rocks form from the remains of plants and animals.
Properties of Sedimentary Rocks Rocks may have one or all of these properties at the same time: Discrete layersDiscrete layers Fragmental particlesFragmental particles Organic compositionOrganic composition Range of particle sizes, orRange of particle sizes, or –Predominance of one particle size.
Metamorphic Rock Any kind of rock can become a metamorphic rock.Any kind of rock can become a metamorphic rock. Metamorphic rock morphismMetamorphic rock is rock produced by morphism –Morphismchange –Morphism means to change, so these rocks are formed by the transformation of preexisting rocks into distinct new rocks. Metamorphic rocks form as a result of the recrystalization of unmelted material under conditions of extremely high temperature and pressure over long periods of time.Metamorphic rocks form as a result of the recrystalization of unmelted material under conditions of extremely high temperature and pressure over long periods of time.
Classification of Metamorphic Rocks Texture Texture refers to the appearance and mineral arrangement of metamorphic rocks. Foliated layers Foliated rocks have minerals that pressure has aligned into layers that are easy to split. Bandinglayers of alternating minerals Banding occurs when there are thin layers of alternating minerals. Metamorphic rocks are in many ways similar to their parent material.
How Does Morphism Occur? Metamorphic rocksform as a result of: Metamorphic rocks form as a result of: –High temperatures –High pressures –Combination of both –BUT without the rock melting in the process.
Types of Metamorphism Contact Metamorphism Contact Metamorphism occurs when molten rock comes in contact with surrounding rocks. The heat from the magma alters the rock in contact with it. Regional Metamorphism Regional Metamorphism accounts for the greatest amount of metamorphism and occurs when large areas of rock are under intense heat and pressure.
What is the Rock Cycle? The rock cycle is a theory relating to various rock forming processes of the common rock typesThe rock cycle is a theory relating to various rock forming processes of the common rock types