Weathering, Soil And Sedimentary Rocks

1y ago
11 Views
2 Downloads
2.49 MB
24 Pages
Last View : 2d ago
Last Download : 2m ago
Upload by : Laura Ramon
Transcription

Sediments andSedimentary RocksChapter 6Weathering, SoilandSedimentary RocksSediments, Soils & Sedimentary RocksProcesses of the rock cycle Weathering(Soils) Erosion Transportation Deposition (sedimentation) Burial DiagenesisIntroductionIntroduction Rocks and minerals are disintegrated anddecomposed by the processes of mechanical andchemical weathering. How does weathering differ from erosion? Weathering is the mechanical and chemicalalteration of Earth materials at or near the surface Erosion involves removing weathered materialsfrom their place of origin-by running water orwind, for example. This breakdown occursbecause the parentmaterial reacts with itsnew physical andchemical environmenttransforming it into a newequilibrium state.Geo-inSight 4., p. 136Fig. 6.2, p. 1351

How Are Earth Materials Altered?How Are Earth Materials Altered? The products of weathering include soluble salts,ions in solution, and solid particles Weathering and erosion take place at different rates These products of weathering can be eroded andbecome sedimentary rock or modified in place tobecome soils. This can occur even onthe same body of rockbecause rocks are notcompositionally andstructurally homogenousthroughout, therebyproducing unevensurfaces.Fig. 6.1, p. 134How Are Earth Materials Altered?Geo-inSight 9., p. 137How Are Earth Materials Altered? Mechanical Weathering Mechanical Weathering Frost Action When water freezes in cracksin rocks it expands and then itcontracts when it thaws, thusexerting pressure andopening the cracks wider. Repeated freezing andthawing disaggregates rocksinto angular pieces that maytumble downslope andaccumulate as talus. Frost action Pressure release Thermal expansion andcontraction Crystal growth Activities of organisms. The products of mechanical weathering arechemically the same as their parent materials.Fig. 6.9d, p. 1424. Physical weathering: frost wedgingFig. 6.3a, p. 138How Are Earth Materials Altered? Mechanical Weathering Pressure Release and Sheet Joints Sheet joints are fractures that more or less parallel exposed rocksurfaces, especially rocks now at the surface that formed undergreat pressure at depth. These joints form in response to pressure release; that is, when therocks formed, they contained energy that is released by outwardexpansion.Frost wedging due the expansion of freezingwater can turn small cracks into large onesFig. 6.4 a-b, p. 1382

Mechanical /Physical weathering: exfoliationExfoliation occurs where large flat & curved sheetsof rock fracture and detach from outcropHow Are Earth Materials Altered?Mechanical / Physical weathering: joints in rocksBreakage along natural bedding joints plus crackingfrom expansion due lowered pressure at surfaceMechanical / Physical weathering: tree roots Mechanical Weathering How do organisms contribute to mechanical andchemical weathering? Any organic activity such astree roots growing in crackscontributes to mechanicalweathering Organic acids and thetendrils of mosses andlichens aid in the chemicalalteration of parent material.Fig. 6.5b, p. 139How Are Earth Materials Altered?The force of the growing roots pry the cracks apartHow Are Earth Materials Altered? Chemical Weathering These processes cause a change in the chemicalcomposition.Chemical weathering The parent material is transformed into productsincluding ions in solution, soluble salts and clayminerals. Solution Oxidation Hydrolysis Hot and wet environments accelerate chemical weathering. Chemical weathering occurs in all environments, except,possibly, permanently frozen polar regions.Fig. 6.7, p. 141Fig. 6.6, p. 1403

How Are Earth Materials Altered? Chemical Weathering Solution – rocks dissolve Carbonate Rocks Rocks such as limestone(CaCO³) are nearly insoluble inneutral or alkaline solutions, butthey rapidly dissolve in acidicsolutions The atoms making up theminerals dissociate, that is, theyseparate and the rock dissolves.Chemical weathering:carbon dioxideChemical weathering:carbon dioxideHow Are Earth Materials Altered? Chemical Weathering Oxidation – rocks rust Rocks such assandstone may containiron minerals that willbreakdown whenexposed to theatmosphere The atoms making upthe minerals dissociate,that is, they separate asthe rock rusts away.Geo-inSight 4., p. 1364

Chemical weathering Role of oxygen in weathering:from iron silicates to iron oxides ferric and ferrous iron hematite, a common mineral red and brown – the colors ofoxidized ironChemical weathering: red means ironChemical weathering: iron and oxygenPyroxene dissolves,releasing silica andferrous iron.Pyroxene (FeSiO3)Ferrous iron is oxidized,forming ferric iron.SilicaFerric iron precipitatesa solid, iron oxide.FerrousironFerric ironIron oxide (hematite)Fe2O3How Are Earth Materials Altered? Chemical Weathering Hydrolysis – breakdown to clays Potassium Feldspar During hydrolysis hydrogenions react with and replacepositive ions in potassiumfeldspar The result is clay minerals andsubstances in solution such aspotassium and silica.Chemical weathering: thedisintegration of graniteChemical weathering: thedisintegration of graniteGranite is made upof several mineralsthat decay atdifferent rates.FeldsparMagnetiteBiotiteQuartzMr. Granite5

Chemical weathering: thedisintegration of graniteChemical weathering: thedisintegration of graniteGranite is made upof several mineralsthat decay atdifferent rates.The decay progresses,and the rock weakensand disintegrates.Granite is made upof several mineralsthat decay atdifferent rates.Cracks form alongcrystal teBiotiteQuartzQuartzCracks form alongcrystal boundaries.Chemical weathering: the role ofincreasing surface area 24 sq cmHow Are Earth Materials Altered? Chemical Weathering Factors That Control the Rate of Chemical Weathering Mechanical weathering enhances chemical weathering bybreaking material into smaller pieces, thereby increasing thesurface area for chemical reactions. Because chemical weathering is a surface process, the moresurface exposed, the faster the weathering.2 cm2 cmFig. 6.8 a-c, p. 141Chemical weathering: the role ofincreasing surface area 24 to 48 sq cmChemical weathering: the role ofincreasing surface area 24 to 48 sq cm2 cm2 cm1 cm1 cm2 cm1 cm2 cm1 cmLarge rocks have lesssurface area for chemicalweathering weathering 6

Chemical weatheringChemical stability: a speed control forweathering2 cm1 cm1 cm2 cmLarge rocks have lesssurface area for chemicalweathering weathering Solubility (halite high, quartz low) rate of dissolution (feldspar higher thanquartz) relative stability of common rockrockforming minerals (halide to iron oxide) than small rocks do,so smaller rocks weathermore quickly.Weathering factorsA. duration of weatheringB. bedrock type - stability of mineralsC. climatei. water & temperature chemical weathering;ii. lower temperature mechanical weathering;iii. more acidity chemical weatheringD. topographyi. steep slopes mechanical/physical weathering;ii. gentle slopes chemical weatheringweatheringHow Does Soil Form and Deteriorate? The Soil Profile Soils consist of weathered materials, air, water,humus and also the plants which they support.Fig. 6.10a, p. 1437

How Does Soil Form and Deteriorate?How Does Soil Form and Deteriorate? Factors That Control Soil Formation Climate - Certainly climate is the most important factor becausechemical processes operate faster where it is warm and wet. The Soil Profile Soil formation produceshorizons that are known indescending order as O, A,B, and C. These horizons differ fromone another in texture,structure, composition andcolor. Soils known as pedalfersdevelop in humid climates suchas that of the eastern UnitedStates and much of Canada. Soils of arid and semiarid regionsare known as pedocals, and maycontain hard, irregular masses ofcaliche (calcium carbonate) inhorizon B.Fig. 6.10b, p. 143How Does Soil Form and Deteriorate?Fig. 6.11, 6.12, p. 144-145How Does Soil Form and Deteriorate? Factors that Control Soil FormationOther Factors That Control Soil Formation Laterite is a deep red soil typical of the tropics wherechemical weathering is intense. Laterites are made up ofclays and the mostinsoluble compoundsthat were present in theparent material. Parent material Organic activity Relief and slope TimeFig. 6.12, p. 145How Does Soil Form and Deteriorate?Fig. 6.7, p. 141How Does Soil Form and Deteriorate? Soil Degradation - Any soil losses, physicalchanges, or chemical alteration is called soildegradation, and all lead to reduced soil productivity. Causes include erosion, compaction, and any kindof chemical pollution that inhibits plant growth.Fig. 6.14, p. 147 Soil Degradation Soil erosion is caused mostly by sheet andrill erosion. It is a problem in some areas, especiallywhere accelerated by human activities suchas construction, agriculture, ranching, anddeforestation.Fig. 6.13, p. 1468

How Does Soil Form and Deteriorate? Soil DegradationThe Dust Bowl – AnAmerican Tragedy Nutrient depletion Loss of nutrients is most prevalent in areas of landoveruse. Improper disposal of chemicals andconcentrations of insecticides can destroy soil.Fig. 6.14, p. 147Geo-Focus Fig. 1 a-c, p. 149Sedimentary rocks are produced bysurface processes in the rock cycle.Weathering and Resources Intense chemical weathering causes theconcentration of valuable mineral resources Residual concentrations – bauxite and othervaluable minerals are concentrated by selectiveremoval of soluble substances during chemicalweathering Bauxite, which forms in lateritic soils in the tropics, occursin areas where chemical weathering is so intense that onlythe most insoluble compounds accumulate in the soil. Aluminum is just such an insoluble compound. Lateritesare the primary source of aluminum oxide, called bauxite.It is the main source of aluminum ore. Weathering processes break up rock to create sediment.Physical - Mechanical breakage and disintegration.Chemical - Decomposition by reaction with water.Weathering processes occur at Earth’s surface.- Rocks react with hydrosphere, atmosphere & biosphere.- Low temperature and pressure.Weatheringto sediment Gossans - hydrated iron oxides formed on theearth’s surface by oxidation of iron. Sulfide mineralsleach out and concentrate as deposits of iron ore,copper ore, lead and zinc ore beneath the gossan.Sediment and Sedimentary Rock The two primary types of sediment are detritaland chemical. Sedimentary rock is simply rockmade up of consolidated sediments. Detrital sediment consistsof solid particles, productsof mechanical weathering.Physical Weathering Mechanical breakup; doesn’t change mineral makeup. Creates broken fragments or “detritus.” Detrital fragments classified by size.– Coarse grained – Boulders cobbles and pebbles.– Medium grained – Sand-sized.– Fine grained – Silt and clay (mud). Chemical sedimentsconsist of mineralsprecipitated from solutionby inorganic processesand by the activities oforganisms thru chemicalweathering.Fig. 6.15, p. 1509

SOURCE OF SEDIMENTChemical Weathering Weathering often forms stable from less stable minerals.– Dissolution.– Hydrolysis.– Oxidation.– Hydration. Dissolution– halite, gypsum, &calcite dissolve. Hydrolysis– Water breaks apart cations that hold silicates together.– Dissolved cations - Clay minerals.– Alteration residues - Iron oxides (rust).MECHANICALWEATHERING(gravel, sand, silt,clay–sized particles)TRANSPORTCHEMICALWEATHERING(clay minerals and ions,compounds in solution)TransportTransportPrecipitationfrom solutionDeposition(detrital sediments)Used byorganismsDeposition(chemical sediment)LithificationLithificationDetrital sedimentary rocks(e.g.,sandstone)Chemical sedimentary rock(e.g., limestone)Sediment and Sedimentary RocksSediment and Sedimentary Rocks Sediment Transport and Deposition Sediment Transport and Deposition Sedimentary material weathers, undergoes erosionand transport to a new location. Transportation of sediment results in rounding andsorting. Why are rounding and sorting important insediments and sedimentary rocks? Both are important in determining how fluids movethrough sediments and sedimentary rocks The amount of rounding and sorting depends onparticle size, distance of transportation, anddepositional processes.Stepped ArtFig. 6-15 (top), p. 150 Eventually the sediment comes to rest in adepositional environment. Depositional environments are areas of sedimentdeposition that can be defined by their physicalcharacteristics (topography, climate, wave andcurrent strength, salinity, etc.). They provide geologist with clues as to how the rockformed and what the geologic past was like.Sediment and Sedimentary RocksSedimentary environments Sediment Transport and Deposition Major depositional settings are continental,transitional, and MetamorphicrocksPlutons Each of these depositional settings includesseveral specific subenvironments.Fig. 6.17, p. 15110

Weatheringbreaks downrocks.Processes formingsedimentary rockWeatheringbreaks downrocks.Erosion carriesaway morphicrocksPlutonsWeatheringbreaks downrocks.MetamorphicrocksPlutonsErosion carriesaway particles.Transportation movesparticles downhill.Process transportWeatheringbreaks downrocks.Erosion carriesaway particles.GlacierProcess DepositionTransportation movesparticles yalakeSedimentaryrocksDeposition occurswhen particlessettle out onsWeatheringbreaks downrocks.Processes n carriesaway particles.Process –BurialTransportation movesparticles downhill.Weatheringbreaks downrocks.Erosion carriesaway edimentaryrocksMetamorphicrocksPlutonsProcess –DiagensisTransportation movesparticles downhill.DesertPlayalakeDeposition occurswhen particlessettle out orprecipitate.Burial occursas layers cksPlutonsDeposition occurswhen particlessettle out orprecipitate.Burial occursas layers ofsedimentaccumulate.Diagenesis causeslithification of thesediment, makingsedimentary rocks.11

Sediment ClassesSediments are diverse, as are the rocks made from them.Sedimentary rocks divide to groups based on sediments type.1) Siliciclastics – Made from weathered rock fragments(clasts primarily of silicates).2) Biological & Chemical (Bio/Chemical) - subdivided as– Bioclastic seds.– Shells of organisms (reefs, clams, etc)– Chemical seds.– Minerals crystallized directly from water– Organic seds.– Carbon-rich remains of plants OrganicChemicalChemicalSorting examples : Well vs PoorSedimentary rocks are produced bysurface processes in the rock cycle.Transport agents - oceans, wind (minor/yr),rivers (25 billion ton/yr), etcCurrent strength distance affect: particle size strong 50cm/s – gravel weak 20cm/s - mudsTransport distance affect: Size of clastic particles Sorting of clastic particles Rounding of clastic particlesSize & rounding versus transport distanceSorting affected by strength, distance, time, agentMore rounding with longer transport, strongercurrent, low rock hardness, clay mineralsSize & rounding versus transport distanceSedimentary rocks are produced bysurface processes in the rock cycle.Chemical mixing vats: Oceans LakesSalinity varies with water input &evaporation. e.g. Great Salt Lake, Ut (NaCl)NaCl) Tularosa Basin, NM ( 65( 65-50 ma,white sands (CaSO4) precipitate)More rounding with longer transport, strongercurrent, low rock hardness, clay minerals12

Sedimentary basins Sediments tend to accumulate indepressions in the Earth’Earth’s crust. Depressions are formed by subsidence. Sedimentary basins are depressions filledwith thick accumulations of sediment. Theyare sinks for sediment.Sedimentary environmentsTypes of environments:1. ContinentalLakeRiver (alluvial)DesertGlacier3. Sedimentary environments3. Sedimentary environmentsTypes of environments:Types of environments:2. ShorelineDeltaTidal flatBeachSedimentaryenvironments3. MarineContinental shelfOrganic reefContinental marginContinental slopeDeep sea3. Sedimentary environments13

Sedimentaryedimentary environmentsSedimentary environmentsEnvironments of chemical andbiological sediments:1. Carbonate deposits (organic reefs,beaches, shelves, and tidal flats)2. Siliceous environments (deepsea)3. Evaporite environments (lakes)Environments of siliciclasticsediments:1. Continental (alluvial, desert,lake, and glacial)2. Shoreline (deltas, beaches,and tidal flats)3. Marine (shelf, margin, slope,and deep sea)Sediment and Sedimentary RockSediment and Sedimentary RockHow Does Sediment Become Sedimentary Rock?How Does Sediment Become Sedimentary Rock? Thru the process of lithification of sediment isconverted into sedimentary rock. Lithification involves twoprocesses Lithification involves twoprocesses 1. Compaction - The volumeof a deposit of sedimentdecreases as the weight ofoverlying sediment causes areduction in pore space (openspace) as particles pack moreclosely together. Compaction alone is sufficientfor lithification of mud intoshale. 2. Cementation is a processthat glues the sedimentstogether. The most common cementsare calcium carbonate andsilica, but iron oxide and ironhydroxide are important insome rocks. Compaction alone will not formrocks from sand and gravel.Cementation is necessary toglue the particles together intorocks.Fig. 6.19c, p. 153SedimentGravel 2 mmProcessRockCompaction/cementationTypes of Sedimentary RockConglomerate Detrital Sedimentary Rocks are made of solidRounded clastsparticles of pre-existing rocks.SedimentarybrecciaAngular clastsSand 2 mm–1/16 mm Compaction/cementationQuartz sandstone(mostly quartz)SandstoneMudrocksCompactionSiltstoneMostly siltMudstoneSilt and clayClaystoneMostly clayShale iffissile**Fissile refers to rocks capable of splitting along closely spaced planes. Detrital sedimentary particles are classified according tograin (particle) sizes, in decreasing diameter:Arkose( 25% feldspars)Silt 1/16 mm–1/256 mm Compaction/cementationClay 1/256 mmFig. 6.18, p. 152 Gravel (including boulders, cobbles and pebbles) Sand Silt Clay (or mud).Stepped ArtFig. 6-18, p. 15214

Types of Sedimentary RocksTypes of Sedimentary Rocks Detrital sedimentary rocks are classified on the basis ofparticle size. Examples include conglomerate, breccia, sandstone, siltstone,mudstone, and shale. How do conglomerate and sedimentary breccia differ? Both begin as detrital gravel. Conglomerate consists of roundedgravel, breccia consists of gravel with sharp edges. Chemical and BiochemicalSedimentary Rocks Chemical and biochemical sedimentary rocksare substances derived from solution byinorganic or biochemical processes. Some have a crystalline texture, meaning theyare composed of a mosaic of interlockingcrystals Others have a clastic texture, meaning that theyare made of fragments, like shells that areglued together.Fig. 6.19 a and b , p. 153Types of Sedimentary RocksTypes of Sedimentary Rocks Chemical Sedimentary Rocks Chemical sedimentary rocks are classifiedon the basis of composition. Chemical Sedimentary Rocks Evaporites Bedded rock salt (halite) androck gypsum are chemicalevaporite sediments formed byprecipitation of minerals duringthe evaporation of water. Carbonate rocks consist primarily of mineralscontaining the carbonate ion, such as limestoneand dolostone. Dolostone forms when magnesium replacescalcium in limestone.Fig. 6.20b-d, p. 154Types of Sedimentary RocksFig. 6.21a-b, p. 155Types of Sedimentary Rocks Chemical Sedimentary Rocks Biochemical Sedimentary Rocks Coal is a biochemical sedimentary rock composedlargely of altered land plant remains Bedded ChertMarin County, CaliforniaThe origin of chert is highlydebated.Fig. 6.21c, p. 155Fig. 6.21d, p.15515

Sedimentary FaciesSedimentary Facies Geologists realize that if they trace a sedimentarylayer far enough, it will undergo changes incomposition and/or texture. Marine Transgression and Regression Bodies of sediment or sedimentary rocks which arerecognizably different from adjacent sediment orsedimentary rocks and are deposited in a differentdepositional (sub) environment are known assedimentary facies. Today we recognize modern facies changes whenwe go from an inland area with rivers to the beach. A marine transgressionoccurs when sea level riseswith respect to the land,resulting in offshore faciesoverlying nearshore facies. A marine regression,caused when the land risesrelative to sea level, results innearshore facies overlyingoffshore facies Note the difference in thevertical rock sequence thatoccurs in a transgressionversus a regression.Three Stages of Marine TransgressionOffshoreNear shoreLow-energy High-energyLandLimestone Shale Sandstone surfacefaciesTimelinefaciesFig. 6.22, p. 156Three Stages of Marine RegressionfaciesTimelinesCross-bedded SandstoneTimelinesOld land surfaceOld landsurfaceStepped ArtPeter KresanFig. 6-22, p. 156Sedimentary structuresSedimentary structures – all kindsof features in sediments formed atthe time of deposition.Bedding (stratification)CrossCross-beddingGraded beddingRipplesBioturbation structuresFig. 7.6Reading the Story in Sedimentary Rocks Sedimentary Structures Some sedimentary structures, such as ripple marks, bedding,cross-bedding, and mud cracks form shortly after deposition. Sedimentary structuresare useful in determiningthe types ofenvironments in whichthe sediments weredeposited. Sediments are mostcommonly deposited flatin water. One of the mostcommon is strata orbedding.Fig. 6.23 a, p. 15816

Reading the Story in Sedimentary RocksFormation of Cross-beds Sedimentary StructuresDepositional environments are also inferred by comparison of thesestructures with present-day depositional environments. Cross-bedding preserves layers deposited at an angle. They are common in depositional environments like sanddunes, shallow marine deposits and stream-channel deposits How is cross-bedding used to determine ancient currentdirections? Understanding how physical features like cross-beds form today canreveal important ancient climate information such as currentdirections.Fig. 7.7Fig. 6.23b-c, p. 158RipplesReading the Story in Sedimentary Rocks Sedimentary Structures Cross-bedding Depositional environment: streams or shallow marine? Streams have a current and leave behind asymmetric dunes. Shallow marine crossbeds exhibit a symmetrical shape from therocking motion of the waves.Fig. 6.25 a-d, p. 15917

Fig. 7.9Reading the Story in Sedimentary RocksBioturbation structures Sedimentary Structures Mud cracks Depositional environment: Lagoons and mudflatsFig. 6.26 a-b, p. 159Reading the Story in Sedimentary RocksReading the Story in Sedimentary Rocks Sedimentary Structures Fossils-Remains and Traces of Ancient Life Graded Beds Depositional environment: Submarine fans – tell usthe location of the ancient shelf marginFig. 6.24a-b, p. 158 Fossils are the remains of past life and are usually foundonly in sediments and sedimentary rocks. They provide the only record of prehistoric life, and are usedby geologists to correlate strata, and to interpret depositionalenvironments.Fig. 6.27 a-b, p. 16018

Burial and diagenesisBurial is the preservation ofsediments within a sedimentarybasin.Diagenesis is the physical andchemical change that convertssediments to sedimentary rocks.19

Burial and diagenesisLithification includes:CompactionCementationClassification of siliciclastic sedimentsand sedimentary rocksClassification of sediments byparticle sizeClassification of sedimentaryrocks by texture and composition20

7. Classification of chemical andbiological sedimentary rocksLimestoneChertEvaporiteOrganicsPhosphorite21

Organic reef developmentOrganic reef rockOrganic reef developmentForaminifer in the Eye of aNeedleChevron CorporationFig. 7.17Fossiliferous LimestonePeter Kresan22

One Model for theFormation of EvaporitesFig. 6-17, p. 109Reading the Story in Sedimentary RocksReading the Story in Sedimentary RocksDetermining the Environment of Deposition How do we know that the Navajo Sandstone formed as adesert dune deposit?Determining the Environment of Deposition Sedimentary Rocks in the Grand CanyonFig. 6.28 a, p. 161Important Resources inSedimentary Rocks Many important natural resources aresedimentary rock deposits. These include: Sand and gravel Coal Clay Evaporites (like salt) Banded-iron formations. Oil and gasFig. 6.28 b, p. 161Important Resourcesin Sedimentary RocksPetroleum and Natural GasMost oil and gas reserves are found within sedimentary rocks. What are stratigraphic and structural traps? Both are areas wherepetroleum, natural gas, or both accumulate in economic quantities. Stratigraphic traps form because of facies changes in the rock layers(strata).Fig. 6.29a p. 16223

Important Resources inSedimentary RocksImportant Resources inSedimentary Rocks Petroleum and Natural Gas Petroleum and Natural Gas Structural traps form as the result of folding or fracturing(faulting) of rocks. Oil shale is a fine-grained sedimentary rockthat contains kerogen from which liquid oil andcombustible gases can be derived. None is mined atpresent in the UnitedStates because oil andgas from conventionalsources are cheaper. Oilshale and tar sands areincreasingly importantpetroleum reserves.Fig. 6.29b, p. 162Important Resources inSedimentary RocksFig. 6.29c p. 162Important Resourcesin Sedimentary Rocks Uranium Banded Iron Formation Most uranium is used in nuclear reactors. Theuranium comes from the minerals carnotite anduraninite. The richest ores are found in Wyoming, Utah, Arizona and NewMexico in ancient stream deposits. Large reserves of low grade ore is found in the ChattanoogaShale, which covers portions of several states. Why is banded ironformation such animportant sedimentaryrock? Banded iron formation consists of alternating thinlayers of chert and iron minerals, mostly iron oxides.Nearly all of Earth’s iron ore is mined from ancientbanded iron formations.Fig. 6.30 a-b, p. 163Fig. 6.30b, p. 163End of Chapter624

The result is clay minerals and substances in solution such as potassium and silica. Mr. Granite Chemical weathering: the disintegration of granite Feldspar Magnetite Biotite Quartz Granite is made up of several minerals that decay at different rates. Chemical weathering: the disintegration of granite

Related Documents:

Sedimentary Rocks and Sedimentary Basins Reading Stanley, S.M., 2015, Sedimentary Environments, - Ch. 5. Earth Systems History On Ecampus Sedimentary Rocks Intro Origin of sedimentary rocks - Clastic Rocks - Carbonate Sedimentary Rocks Interpreting Sedimentary Rocks - Environment of deposition

Sedimentary rocks Sedimentary rocks are those rocks which are formed by the weathered sediments of pre existing rocks (igneous or metamorphic rocks). The geological processes that involved in the formation of sedimentary rocks are as under: 1. Weathering, 2. Erosion, 3. Deposition, 4. Compaction 5. cementation

XY chart: Metamorphic rocks XY chart: Metamorphic and weathering processes. XZ chart: Ignmus rocks. . XZ chart'. Sedimentary rocks XZ chafi Metamorphic rocks and processes, and weathering si chart: Igneous rocks. . . si chart: Sedimentary rocks . . si chart: Metamorphic rocks and processes, and weathering k chart

Chapter 5 - Sedimentary Rocks 1 CHAPTER 5: SEDIMENTARY ROCKS This chapter is a summary of sedimentary rocks and their terminology. Most of the sedimentary rock units in the Fells are secondary to the igneous rocks in the previous chapter and have mostly been lightly metamorphosed. As a result, this will not be a comprehensive treatment of the .

Section 1 Rocks and Weathering Objectives After this lesson, students will be able to G.4.1.1 Explain how weathering and erosion affect Earth’s surface. G.4.1.2 Identify what causes mechanical weathering and chemical weathering. G.4.1.3 Describe the factors that determine how fast weathering occurs. Target Reading Skill Relating Cause and Effect

Metamorphic Rocks and the Rock Cycle Section 2: Igneous and Sedimentary Rocks. Section 2 and 3: Rocks and the Rock Cycle There are 3 different types of rocks: Sedimentary Igneous Metamorphic They are all made of minerals One rock can turn into a different type, during the rock cycle. All rocks are formed during different processes.

Fundamental Rock Types Igneous Rocks: form when magma solidifies Sedimentary Rocks: form when sediment becomes cemented into solid rock Metamorphic rocks: form when heat, pressure, or hot water alter a rock . The Rock Cycle . Sedimentary Rocks . Sedimentary Rock Types Clastic –

MINERALS, ROCKS, AND SOIL Weathering Rocks Purpose To model different kinds of weathering and compare how they change rocks. Process Skills Predict, observe, compare, collec