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1、SEDIMENTARY ARCHIVESSedimentary StructuresCross-bedding or Cross-stratificationSEDIMENTARY ARCHIVESSedimentary StructuresCross-bedding or Cross-stratificationBeds in which one set is inclined to othersAdvance of delta or dunesCurrent dominated environmentWind or waterSlope of cross-bed can indicates
2、 current or prevailing wind direction SEDIMENTARY ARCHIVESSedimentary StructuresCross-bedding or Cross-stratificationTabularorPlanarSEDIMENTARY ARCHIVESSedimentary StructuresCross-bedding or Cross-stratificationTroughSEDIMENTARY ARCHIVESSedimentary StructuresGraded bedsSEDIMENTARY ARCHIVESSedimentar
3、y StructuresSole marksSEDIMENTARY ARCHIVESSedimentary StructuresFlute castsSEDIMENTARY ARCHIVESSedimentary StructuresTool marksSEDIMENTARY ARCHIVESSedimentary StructuresFlame StructuresSEDIMENTARY ARCHIVESSedimentary StructuresGeopetal Structures or Which Way is UP?Load structuresSEDIMENTARY ARCHIVE
4、SSedimentary StructuresGeopetal Structures or Which Way is UP?MudcracksSEDIMENTARY ARCHIVESSedimentary StructuresGeopetal Structures or Which Way is UP?Planar Cross-bedsSEDIMENTARY ARCHIVESSedimentary StructuresGeopetal Structures or Which Way is UP?Trough Cross-bedsSEDIMENTARY ARCHIVESSedimentary S
5、tructuresGeopetal Structures or Which Way is UP?Oscillation ripplesSEDIMENTARY ARCHIVESSedimentary StructuresGeopetal Structures or Which Way is UP?Tool marksSEDIMENTARY ARCHIVESSedimentary StructuresGeopetal Structures or Which Way is UP?FossilsSEDIMENTARY ARCHIVESSedimentary StructuresGeopetal Str
6、uctures or Which Way is UP?FossilsSEDIMENTARY ARCHIVESSedimentary StructuresGeopetal Structures or Which Way is UP?Raindrop ImpressionsSEDIMENTARY ARCHIVESInterpretation of Sedimentary RocksProvide information about conditions in and near the site of depositionSuch as:source area from compositionamo
7、unt of transport erosionQtz vs. Feldspar (clay and ironcompounds) vs FerromagnesiansImmature vs matureSEDIMENTARY ARCHIVESClassification of Sedimentary RocksSystems of classification are not hatracks, objectively presented to us by nature. They are dynamic theories developed to express particular vi
8、ews. Stephen Jay GouldSEDIMENTARY ARCHIVESClassification of Sedimentary RocksSEDIMENTARY ARCHIVESClassification of Sedimentary RocksSEDIMENTARY ARCHIVESClassification of Sedimentary RocksTEXTURESEDIMENTARY ARCHIVESClassification of Sedimentary RocksSEDIMENTARY ARCHIVESClassification of Sedimentary R
9、ocksQuartz Arenite 90% Quartz Cement: silica calciteSEDIMENTARY ARCHIVESClassification of Sedimentary RocksFeldspathic AreniteArkose 25% Feldspar Granitic source Remainder is quartz Cement: clay calcite iron oxidesSEDIMENTARY ARCHIVESClassification of Sedimentary RocksLithic AreniteGreywacke 33% roc
10、k fragments Immature sandstone Poorly sorted, angular Remainder is quartz,feldspar Cement: very little mostly claysSEDIMENTARY ARCHIVESClassification of Sedimentary RocksCompositionCarbonate rocks consist of limestone and dolostone. The minerals present in each are: Limestone Calcite Aragonite Dolos
11、tone Dolomite SEDIMENTARY ARCHIVESClassification of Sedimentary RocksCarbonates SEDIMENTARY ARCHIVESClassification of Sedimentary RocksCarbonatesMost of marine originDirectly or indirectly related to biological processesSkeletal remains may be visibleCan be evaporitesChanges in water temp., alkalini
12、ty, CO2 conc.Clear, shallow tropical watersSEDIMENTARY ARCHIVESClassification of Sedimentary RocksCarbonatesCharacteristics of most marine carbonate environments: Warm water Tropical climate (30 N - 30 S of equator) Shallow water (less than 200 m deep) Clear water (low to no terrigenous input) Sunli
13、ght required for photosynthesis by algaeSEDIMENTARY ARCHIVESClassification of Sedimentary RocksCarbonatesSEDIMENTARY ARCHIVESClassification of Sedimentary RocksCarbonatesOrigin of carbonate sedimentsMuch lime mud forms from the disintegration of calcareous algae (such as Halimeda and Penicillus). Wh
14、en the calcareous algae die, their skeletons break down and disintegrate producing aragonite needle muds. These lime muds lithify to form fine-grained limestone. SEDIMENTARY ARCHIVESSEDIMENTARY ARCHIVESClassification of Sedimentary RocksCarbonatesFossiliferous limestoneBiomicriteBiospariteSEDIMENTAR
15、Y ARCHIVESClassification of Sedimentary RocksCarbonatesOolitic limestoneOomicriteOospariteSEDIMENTARY ARCHIVESClassification of Sedimentary RocksCarbonatesDolostoneComposed of dolomite (CaMg(CO3)2) The Dolomite “Problem”Dolomite is believed to form when magnesium that has been concentrated in sea wa
16、ter replaces calcium carbonate in a previously deposited limestone. Today, dolomite only forms in a few areas of the world where intense evaporation of seawater concentrates the magnesium. Extensive areas of carbonate rocks of Precambrian, Paleozoic, and Mesozoic age have been altered to dolomite. D
17、olomitization may be related to times of high sea level worldwide, under favorable climatic conditions. SEDIMENTARY ARCHIVESClassification of Sedimentary RocksClays, Mudrocks and ShalesMudrocks are a very fine-grained Composed of clay and silt-sized particlesIf the mudrock is fissile it is a -shale
18、Typically form in low energy environmentsSEDIMENTARY ARCHIVESSea Level ChangesEustatic Sea Level ChangeGlobal change in sea level positionCaused by: Glacial advance and retreatChange in spreading ratesEffect lowland areasSEDIMENTARY ARCHIVESSea Level ChangesSequence StratigraphyEpeiric seasSeas cove
19、red continentsProduced packages called sequencesLed to sequence stratigraphySEDIMENTARY ARCHIVESSea Level ChangesSequence StratigraphySequence StratigraphyA group of relatively conformable strata that represents a cycle of deposition and is bounded by unconformities or correlative conformities. Sequ
20、ences are the fundamental unit of interpretation in sequence stratigraphy. Sequences comprise systems tracts. SEDIMENTARY ARCHIVESSea Level ChangesSEDIMENTARY ARCHIVESSea Level ChangesVail CurveSequence StratigraphySEDIMENTARY ARCHIVESSea Level Changeshttp:/strata.geol.sc.edu/clastic-movie.htmlSEDIM
21、ENTARY ARCHIVESSea Level ChangesSequence StratigraphyTHE FOSSIL RECORDPaleontologyAttempts to understand all aspects of the successionof plants and animals over time.Based on study of fossilsArchaeopteryxTHE FOSSIL RECORDPaleontologyFossil PreservationCover this aspect in laboratoryFossilization for
22、tuitousChances enhanced byHard partsRapid burialEnvironments Oceans, lakes and streamsTHE FOSSIL RECORDTaphonomyWhat happens to an organism from time of death to preservation as a fossilSoft parts usually lostTHE FOSSIL RECORDThe Rank and Order of LifeBinomial nomenclatureA system of binomial nomenc
23、lature is used to name organisms. The first of the two names is the genus and the second name is the species. The genus and species names are underlined or italicized. The name of the genus is capitalized, but the name of the species is not.Examples: Felis domesticus, the house catFelis leo, the African lionFelis onca, the jaguarCanis familiaris, the dogHomo sapiens, the human
