sedimentary rock sedimentary rock is rock that is formed from the accumulation and consolidation of...
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Sedimentary RockSedimentary Rock
• Sedimentary rockSedimentary rock is rock that is formed from the accumulation and consolidation of sediments (weathered particles of other rocks).
• LithificationLithification is the process by which sediments become rock.– Ex: sandstonesandstone, shaleshale, conglomerateconglomerate
CompressionCompression
CompressionCompression 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.
A good example is shaleshale.
CementationCementation
CementationCementation occurs as the addition of minerals, such as silica, lime, or iron oxide, tends to “glue” rock particles together to form solid rock.
Examples are sandstonesandstone and conglomerateconglomerate, which are composed of particles of sand, pebbles and small rocks.
Formation by Chemical Formation by Chemical ProcessProcess
Some sedimentary rocks form as Some sedimentary rocks form as the result of chemical processes the result of chemical processes such as evaporation and such as evaporation and precipitation.precipitation.
Rocks formed by the evaporation of Rocks formed by the evaporation of water are called evaporiteswater are called evaporites.
Examples are limestonelimestone, rock saltrock salt and rock gypsumrock gypsum.
Examples of Sedimentary Examples of Sedimentary Rocks Formed by Chemical Rocks Formed by Chemical
ProcessesProcesses
Formation by Biological Formation by Biological ProcessesProcesses
• Some sedimentary rocks form as a result of processes acting on the remains of once living organisms.
• CoalCoal is formed from the compression of dead plants.
• LimestoneLimestone is formed from the remaining shells of dead sea-life.
FossilsFossils
Sedimentary rocksSedimentary rocks also form and also form and contain remains or impressions contain remains or impressions of plants and animals. These of plants and animals. These impressions are calledimpressions are called fossilsfossils.
3 Kinds of Sedimentary 3 Kinds of Sedimentary RocksRocks
Clastic Clastic sedimentary rocks form from the compaction and cementation of fragments of other rocks.
ChemicalChemical sedimentary rocks form from mineral grains that precipitate out by evaporation or other chemical action.
OrganicOrganic sedimentary rocks form from the remains of plants and animals.
Properties of Sedimentary Properties of Sedimentary RocksRocks
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.Predominance of one particle size.
Metamorphic RockMetamorphic Rock• Any kind of rock can become aAny kind of rock can become a
metamorphic rock.metamorphic rock.• Metamorphic rockMetamorphic rock is rock produced by
morphismmorphism– MorphismMorphism means to changechange, so these rocks
are formed by the transformation of preexisting rocks into distinct new rocks.
• Metamorphic rocks form Metamorphic rocks form as a result of as a result of the the recrystalizationrecrystalization of unmelted of unmelted material under conditions of extremely material under conditions of extremely high temperature and pressure over high temperature and pressure over long periods of time.long periods of time.
Classification of Metamorphic Classification of Metamorphic RocksRocks
TextureTexture refers to the appearance and mineral arrangement of metamorphic rocks.
FoliatedFoliated rocks have minerals that pressure has aligned into layerslayers that are easy to split.
BandingBanding occurs when there are thin layers of alternating mineralslayers of alternating minerals.
Metamorphic rocks Metamorphic rocks are in many are in many ways similar to their parent ways similar to their parent material.material.
How Does How Does MorphismMorphism Occur?Occur?
Metamorphic rocksMetamorphic rocks form as a form as a result of:result of:– High temperaturesHigh temperatures– High pressuresHigh pressures– Combination of bothCombination of both
– BUTBUT without the rock melting without the rock melting in the processin the process..
Types of Types of MetamorphismMetamorphism
Contact MetamorphismContact Metamorphism occurs when molten rock comes in contact with surrounding rocks.The heat from the magma alters the rock in contact with it.
Regional MetamorphismRegional 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 What is the Rock Cycle?Cycle?
•The The rock cyclerock cycle is a is a theory relating to theory relating to various rock forming various rock forming processes of the processes of the common rock typescommon rock types
Rock Cycle Transition Rock Cycle Transition ZonesZones
• The process that creates a transition zone between rock type is contact metamorphismcontact metamorphism