地质学完美教程【英文版】概况课件

1、SEDIMENTARY ARCHIVESClassification of Sedimentary RocksCarbonates第1页，共18页。SEDIMENTARY ARCHIVESClassification of Sedimentary RocksCarbonatesOrigin of carbonate sedimentsMuch lime mud forms from the disintegration of calcareous algae (such as Halimeda and Penicillus). When the calcareous algae die, th

2、eir skeletons break down and disintegrate producing aragonite needle muds. These lime muds lithify to form fine-grained limestone. 第2页，共18页。SEDIMENTARY ARCHIVES第3页，共18页。SEDIMENTARY ARCHIVESClassification of Sedimentary RocksCarbonatesFossiliferous limestoneBiomicriteBiosparite第4页，共18页。SEDIMENTARY AR

3、CHIVESClassification of Sedimentary RocksCarbonatesOolitic limestoneOomicriteOosparite第5页，共18页。SEDIMENTARY ARCHIVESClassification of Sedimentary RocksCarbonatesDolostoneComposed of dolomite (CaMg(CO3)2) The Dolomite “Problem”Dolomite is believed to form when magnesium that has been concentrated in s

4、ea 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 Mesozoic age have been altered to dolomi

5、te. Dolomitization may be related to times of high sea level worldwide, under favorable climatic conditions. 第6页，共18页。SEDIMENTARY ARCHIVESClassification of Sedimentary RocksClays, Mudrocks and ShalesMudrocks are a very fine-grained Composed of clay and silt-sized particlesIf the mudrock is fissile i

6、t is a -shale Typically form in low energy environments第7页，共18页。SEDIMENTARY ARCHIVESSea Level ChangesEustatic Sea Level ChangeGlobal change in sea level positionCaused by:Glacial advance and retreatChange in spreading ratesEffect lowland areas第8页，共18页。SEDIMENTARY ARCHIVESSea Level ChangesSequence St

7、ratigraphyEpeiric seasSeas covered continentsProduced packages called sequencesLed to sequence stratigraphy第9页，共18页。SEDIMENTARY ARCHIVESSea Level ChangesSequence Stratigraphy第10页，共18页。Sequence StratigraphyA group of relatively conformable strata that represents a cycle of deposition and is bounded b

8、y unconformities or correlative conformities. Sequences are the fundamental unit of interpretation in sequence stratigraphy. Sequences comprise systems tracts. SEDIMENTARY ARCHIVESSea Level Changes第11页，共18页。SEDIMENTARY ARCHIVESSea Level ChangesVail Curve第12页，共18页。Sequence StratigraphySEDIMENTARY ARC

9、HIVESSea Level Changes第13页，共18页。/clastic-movie.htmlSEDIMENTARY ARCHIVESSea Level ChangesSequence Stratigraphy第14页，共18页。第15页，共18页。THE FOSSIL RECORDPaleontologyAttempts to understand all aspects of the successionof plants and animals over time.Based on study of fossilsArchaeopteryx第16页，共18页。THE FOSSIL RECORDPaleontologyFossil PreservationCover this aspect in laboratoryFossilization fortuitousChances enhanced byHard partsRapid burialEnvironments Oceans, lakes and