第2章沉积古地理学-1汇总

Chapter2Sedimentarypaleogeography

第2章沉积古地理学2.1conceptsandlaws2.2sed.-faciesindicators2.3sed.environments(自主互动)1Sed.environments2Sedimentaryfacies3Facieschangesandanalysisofsed-facies4Walther’slaw5Uniformitarianism

2.1Conceptsandlaws1沉积环境(sedimentaryenvironments):一个具有独特的物理、化学和生物特征的自然地理单元2沉积相(Sedimentaryfacies)——反映沉积记录成因（环境、条件和沉积作用）的岩石特征和生物特征的综合。即沉积记录成因的物质表现。岩相(lithofacies,petrofacies)生物相(biofacies)CarbonatefaciesShalefaciesSandstonefaciesShale&coalfacies3相变——地层的岩石特征和生物特征及其所反映的沉积环境和沉积作用在空间（横向）上的变化。FacieschangesFacieschanges?Faciessequence相分析三要素4相分析(faciesanalysis)——综合地层的岩石特征和生物特征，推断其成因（沉积环境和沉积作用）●Material●

Principles●

MethodologySubaerial,mostlikelysemi-humidenvironment1000MaMudcracks+RaindropsApalaeo-scene

(theevidence)Theyaredinosaurfootprintsandtheycantellusabout:Groupbehavior;Seasonality&temperature;Foodweb&competitionintensity;TheirlivingenvironmentYourinterpretation:Methodology–adetective’sapproach

Induction（归纳）;Deduction（演绎）2.1Conceptsandlaw1Sed.environments2Sedimentaryfacies3Facieschangesandanalysisofsed-facies4Walther’slaw5Uniformitarianism

●Stratigraphicalconformities●GradualtransgressionHowaboutregression?transgression瓦尔特相（定）律亦称相对比原理(JWalther，1894):只有那些目前可以观察到是相互毗邻的相和相区，才能原生地重叠在一起;即在垂向上整合叠置的相是在侧向上相邻的沉积环境中形成的。Walther’slaw(rule)orlawoffaciescorrelation:

Onlythosefaciesandfacies-areascanbesuperimposedprimarilywhichcanbeobservedbesideeachotheratthepresenttime(translatedbyMiddleton,1973);inotherwords,

faciesoccurringinaconformableverticalsequenceofstratawereformedinlaterallyadjacentenvironments.

SketchshowingWalther’slawSignificanceforWalther’sLaw●时间上的相随反映空间上的并列●指导和检验相分析工作2.1Conceptsandlaw1Sed.environments2Sedimentaryfacies3Facieschangesandanalysisofsed-facies4Walther’slaw5Uniformitarianism

WhatisanUniformitarianism“Thepasthistoryofourglobemustbeexplainedbywhatcanbeseentobehappeningnow”(JamesHutton).ItwasnamedUniformitarianismbyCharlesLyell(1830;Hutton,1795)现实类比Uniformitarianism-1？Example-1Uniformitarianism-2？MarsBrachiopods

（Productida,O3-P)现代腕足动物以正常浅海为主，各种水深均能生存(0-6000m+);古生代腕足类大多数生活在盐度正常的浅海环境中，但中生代以来发现它们与某些深水类别共生Uniformitarianism-3?将古论古-蜓生态：浅海底栖生活于100m左右热带亚热带的平静浅海环境。地史分布：始现:C13,极盛:P1,衰退:P3,绝灭:P末。蜓-FusulininaZoophycosUniformitarianism-4?Desiccationcracks

&Syneresiscracks,

1500Ma,大红峪组Uniformitarianism-5a?Uniformitarianism-5b?Desiccationcracks

&Syneresiscracks,

1200Ma,北大尖组Uniformitarianism-4?1thinbiofilmsofcyanobacteriaadheretothesurfacesofgrains;2biofilmsdevelopandbecomethicker;3biofilmsofallgrainsarejointedtogether.Scales:2mmBiostabilization将今天论未来Uniformitarianism-6a?Deepbiosphere-1Deepbiosphere-2热液流体海水温度（℃）360～3652酸度（25℃时）3.357.8溶解氧00.076硫化氢（mM）2.3～3.50钠（mM）537464钾（mM）17.19.8钙（nM）30.810.2镁（mM）052.7硅（mM）20.750.2氯化物（mM）636541硫（mM）027.9锰（µM）6800铁（µM）55900.0015铜（µM）98～1200.007锌（µM）47～530.01热液喷口是最具化学多样性的微生物生长地.地球化学梯度和热梯度提供了多种微生物（嗜冷、温、热、压、酸、碱、盐菌）聚集的小生境表层生物圈仅占生物生成空间的3%，深部生物圈则占生物生成空间的97%，深海极端条件下生活的极端生物，其2/3的基因与迄今科学上的已知基因不同。深海热液体系的物质-能量循环模式AerobicS2-(HS-,H2S,S0)+CO2+O2+H2O→SO42-+[CH2O]CH4+O2→[CH2O]+H2O4H2+O2+CO2→[CH2O]+3H2ONH3+O2+CO2→[CH2O]+HNO3AnaerobicChemolithotrophicSO42-reduction:CO2+SO42-+H2→[CH2O]+S2-+5H2OHeterotrophicSO42-reduction:CH3COOH+SO42-→CO2+S2-+2H2OCO2+6H2→[CH2O]+CH4+3H2O高生长速率;高生产力；高生物多样性;历史悠久.（古菌evolvesince4billionyearsago)Deep

biosphere-3生命的

温度界限古菌细菌藻类真菌原生动物植物Rothschild&Mancinelli,2001Mesophiles-嗜温菌生命的酸碱度界限古菌细菌藻类真菌原生动物植物Rothschild&Mancinelli,2001各类生物能容忍的上限为~11

某些古菌，三种真菌可容忍0Carp-鲤鱼；protists-原生生物Rotifers-轮虫；sph