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1、SEDIMENTARY ARCHIVES,Sedimentary StructuresCross-bedding or Cross-stratification,SEDIMENTARY ARCHIVES,Sedimentary 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 indica
2、tes current or prevailing wind direction,SEDIMENTARY ARCHIVES,Sedimentary StructuresCross-bedding or Cross-stratification,TabularorPlanar,SEDIMENTARY ARCHIVES,Sedimentary StructuresCross-bedding or Cross-stratification,Trough,SEDIMENTARY ARCHIVES,Sedimentary StructuresGraded beds,SEDIMENTARY ARCHIVE
3、S,Sedimentary StructuresSole marks,SEDIMENTARY ARCHIVES,Sedimentary StructuresFlute casts,SEDIMENTARY ARCHIVES,Sedimentary StructuresTool marks,SEDIMENTARY ARCHIVES,Sedimentary StructuresFlame Structures,SEDIMENTARY ARCHIVES,Sedimentary StructuresGeopetal Structures or Which Way is UP?Load structure
4、s,SEDIMENTARY ARCHIVES,Sedimentary StructuresGeopetal Structures or Which Way is UP?Mudcracks,SEDIMENTARY ARCHIVES,Sedimentary StructuresGeopetal Structures or Which Way is UP?Planar Cross-beds,SEDIMENTARY ARCHIVES,Sedimentary StructuresGeopetal Structures or Which Way is UP?Trough Cross-beds,SEDIME
5、NTARY ARCHIVES,Sedimentary StructuresGeopetal Structures or Which Way is UP?Oscillation ripples,SEDIMENTARY ARCHIVES,Sedimentary StructuresGeopetal Structures or Which Way is UP?Tool marks,SEDIMENTARY ARCHIVES,Sedimentary StructuresGeopetal Structures or Which Way is UP?Fossils,SEDIMENTARY ARCHIVES,
6、Sedimentary StructuresGeopetal Structures or Which Way is UP?Fossils,SEDIMENTARY ARCHIVES,Sedimentary StructuresGeopetal Structures or Which Way is UP?Raindrop Impressions,SEDIMENTARY ARCHIVES,Interpretation of Sedimentary RocksProvide information about conditions in and near the site of depositionS
7、uch as:source area from compositionamount of transport erosionQtz vs.Feldspar(clay and ironcompounds)vs FerromagnesiansImmature vs mature,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,Systems of classification are not hatracks,objectively presented to us by nature.They are dynamic theorie
8、s developed to express particular views.Stephen Jay Gould,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,TEXTURE,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,SEDIME
9、NTARY ARCHIVES,Classification of Sedimentary Rocks,Quartz Arenite,90%Quartz Cement:silica calcite,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,Feldspathic AreniteArkose,25%Feldspar Granitic source Remainder is quartz Cement:clay calcite iron oxides,SEDIMENTARY ARCHIVES,Classification of
10、Sedimentary Rocks,Lithic AreniteGreywacke,33%rock fragments Immature sandstone Poorly sorted,angular Remainder is quartz,feldspar Cement:very little mostly clays,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,CompositionCarbonate rocks consist of limestone and dolostone.The minerals presen
11、t in each are:Limestone Calcite Aragonite Dolostone Dolomite,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,Carbonates,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,CarbonatesMost of marine originDirectly or indirectly related to biological processesSkeletal remains may be visib
12、leCan be evaporitesChanges in water temp.,alkalinity,CO2 conc.Clear,shallow tropical waters,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,CarbonatesCharacteristics of most marine carbonate environments:Warm water Tropical climate(30 N-30 S of equator)Shallow water(less than 200 m deep)Cle
13、ar water(low to no terrigenous input)Sunlight required for photosynthesis by algae,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,Carbonates,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,CarbonatesOrigin of carbonate sedimentsMuch lime mud forms from the disintegration of calcar
14、eous algae(such as Halimeda and Penicillus).When the calcareous algae die,their skeletons break down and disintegrate producing aragonite needle muds.These lime muds lithify to form fine-grained limestone.,SEDIMENTARY ARCHIVES,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,CarbonatesFossil
15、iferous limestoneBiomicriteBiosparite,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,CarbonatesOolitic limestoneOomicriteOosparite,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,CarbonatesDolostoneComposed of dolomite(CaMg(CO3)2)The Dolomite“Problem”Dolomite is believed to form w
16、hen magnesium that has been concentrated in sea water 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
17、Mesozoic age have been altered to dolomite.Dolomitization may be related to times of high sea level worldwide,under favorable climatic conditions.,SEDIMENTARY ARCHIVES,Classification of Sedimentary Rocks,Clays,Mudrocks and ShalesMudrocks are a very fine-grained Composed of clay and silt-sized partic
18、lesIf the mudrock is fissile it is a-shale Typically form in low energy environments,SEDIMENTARY ARCHIVES,Sea Level Changes,Eustatic Sea Level ChangeGlobal change in sea level positionCaused by:Glacial advance and retreatChange in spreading ratesEffect lowland areas,SEDIMENTARY ARCHIVES,Sea Level Ch
19、anges,Sequence StratigraphyEpeiric seasSeas covered continentsProduced packages called sequencesLed to sequence stratigraphy,SEDIMENTARY ARCHIVES,Sea Level ChangesSequence Stratigraphy,Sequence StratigraphyA group of relatively conformable strata that represents a cycle of deposition and is bounded
20、by unconformities or correlative conformities.Sequences are the fundamental unit of interpretation in sequence stratigraphy.Sequences comprise systems tracts.,SEDIMENTARY ARCHIVES,Sea Level Changes,SEDIMENTARY ARCHIVES,Sea Level Changes,Vail Curve,Sequence Stratigraphy,SEDIMENTARY ARCHIVES,Sea Level
21、 Changes,http:/strata.geol.sc.edu/clastic-movie.html,SEDIMENTARY ARCHIVES,Sea Level Changes,Sequence Stratigraphy,THE FOSSIL RECORD,Paleontology,Attempts to understand all aspects of the successionof plants and animals over time.Based on study of fossils,Archaeopteryx,THE FOSSIL RECORD,Paleontology,
22、Fossil PreservationCover this aspect in laboratoryFossilization fortuitousChances enhanced byHard partsRapid burialEnvironments Oceans,lakes and streams,THE FOSSIL RECORD,TaphonomyWhat happens to an organism from time of death to preservation as a fossilSoft parts usually lost,THE FOSSIL RECORD,The
23、Rank and Order of LifeBinomial nomenclatureA system of binomial nomenclature 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,
