SEDIMENTS & SEDIMENTARY ROCKS

ROCK CYCLE

Relative Percentages of Sedimentary Rocks

SEDIMENTFromWeathering & ErosionPrecipitation from saturated solutioncalcite, quartzProduct of evaporationhalite, gypsumUnconsolidated- NOT cemented

SEDIMENTParticle sizePebbles, cobbles, bouldersGravel- > 2mmSand- 2mm - 0.063mmSilt - 0.063mm - 0.004mmClay- < 0.004Deposition Clay-sized particle vs. clay mineral

SEDIMENTTransportationAbrasionRoundingSortingDepositionEnvironment of deposition- specificPreservation

SEDIMENTTransportationAbrasionRoundingSortingDepositionEnvironment of deposition- specificPreservation

SEDIMENTLithificationCompactionDecrease in pore spacefor very fine grain size (clay)CementationClastic textureCements- silica, calcite, iron oxideCrystallizationCrystalline texture

SEDIMENTLithificationCompactionDecrease in pore spacefor very fine grain size (clay)CementationClastic textureCements- silica, calcite, iron oxideCrystallizationCrystalline texture

SEDIMENTLithificationCompactionDecrease in pore spacefor very fine grain size (clay)CementationClastic textureCements- silica, calcite, iron oxideCrystallizationCrystalline texture

TYPES OF SEDIMENTARY ROCKS Clastic or DetritalChemical- inorganic precipitation or evaporationBiochemical- Organic remainsshells, charcoal, plant fragments

CLASTIC (Detrital) ROCKSBreccia and Conglomerate (> 2mm)Sedimentary Breccia- angular fragmentsConglomerate- rounded fragmentsSandstone (2mm - 0.063mm)Quartz sandstoneArkose (feldspar)Graywacke (appreciable amounts of silt/clay)Fine-grained MatrixUsually from turbidity currents

CLASTIC (Detrital) ROCKSBreccia and Conglomerate (> 2mm)Sedimentary Breccia- angular fragmentsConglomerate- rounded fragmentsSandstone (2mm - 0.063mm)Quartz sandstoneArkose (feldspar)Graywacke (appreciable amounts of silt/clay)Fine-grained MatrixUsually from turbidity currents

Quartz Sandstone

CLASTIC ROCKSFine-grained RocksShale- fissile (in sheets)SiltstoneClaystoneMudstone (silt and clay)

CHEMICAL SEDIMENTARY ROCKSCarbonate RocksLimestone- made of calciteInorganic varietiesmicrite, oolites, travertineDolomiteRecrystallizationChert- silicaEvaporitesRock gypsumRock salt

BIOCHEMICAL SEDIMENTARY ROCKSCoalDevelops from peatplant fragmentsLigniteBituminous CoalCarbonate RocksLimestone- made of calciteorganic varietiesCoquinaFossiliferous LimestoneChalk

BIOCHEMICAL SEDIMENTARY ROCKSCoalDevelops from peatplant fragmentsLigniteBituminous CoalCarbonate RocksLimestone- made of calciteorganic varietiesCoquinaFossiliferous LimestoneChalk

SEDIMENTARY STRUCTURESBEDDING-Principle of Original HorizontalityBedding planeCross-beddingGraded bedMud cracksRipple marksFossils

SEDIMENTARY STRUCTURESBEDDING-Principle of Original HorizontalityBedding planeCross-beddingGraded bedMud cracksRipple marksFossils

DUNES

SEDIMENTARY STRUCTURESBEDDING-Principle of Original HorizontalityBedding planeCross-beddingGraded bedMud cracksRipple marksFossils

SEDIMENTARY STRUCTURESBEDDING-Principle of Original HorizontalityBedding planeCross-beddingGraded bedMud cracksRipple marksFossils

Mudcracks

SEDIMENTARY STRUCTURESBEDDING-Principle of Original HorizontalityBedding planeCross-beddingGraded bedMud cracksRipple marksFossilsBody FossilsTrace Fossils

FORMATIONSLarge enough to show on a mapDistinctive from neighboring rock unitsNamed after geographic locationsCONTACTseparation between 2 distinct rock unitsSedimentary contactOther contacts

INTERPRETATION OF SEDIMENTARY ROCKSSource AreaEnvironment of DepositionGlacial environmentsTillitesAlluvial fanArkoseRiver channel and flood plainInterbedded shales and sandstones; cross-beddedLakeShales; interbedded siltstones and mudstonesDelta

INTERPRETATION OF SEDIMENTARY ROCKSSource AreaEnvironment of DepositionGlacial environmentsTillitesAlluvial fanArkoseRiver channel and flood plainInterbedded shales and sandstones; cross-beddedLakeShales; interbedded siltstones and mudstonesDelta

Glacial Environment & Till

INTERPRETATION OF SEDIMENTARY ROCKEnvironment of DepositionBeach, Barrier Island, DuneVery well sorted quartz sandstonesLagoonShalesShallow marine shelfInterbedded sandstones and shales; burrowedReefSkeletal LimestonesDeep marine environmentTurbidites- sequence of GRADED sandstones to shales

INTERPRETATION OF SEDIMENTARY ROCKEnvironment of DepositionBeach, Barrier Island, DuneVery well sorted quartz sandstonesLagoonfine grained sedimentShallow marine shelfInterbedded sandstones and shales; burrowedReefSkeletal LimestonesDeep marine environmentTurbidites- sequence of GRADED sandstones to shales

CALCAREOUS

INTERPRETATION OF SEDIMENTARY ROCKEnvironment of DepositionBeach, Barrier Island, DuneVery well sorted quartz sandstonesLagoonShalesShallow marine shelfInterbedded sandstones and shales; burrowedReefSkeletal LimestonesDeep marine environmentTurbidites- sequence of GRADED sandstones to shales

INTERPRETATION OF SEDIMENTARY ROCKPlate Tectonics and Sedimentary RocksAt convergent boundariesUplift results in Very rapid rates of erosionThick accumulations of clastic sedimentAt transform boundariesRapid rates of erosion, deposition and burialGood basins for petroleum explorationAt divergent boundariesInitial stages of rifting- thick wedges of gravel and coarse sediment

ResourcesNon-MetallicSand and gravelLimestoneClayGypsumEnergy ResourcesOil and gasCoal

Formation of Oil and Gas

U.S. Coal Production