第2章沉積古地理學(xué)-1匯總

Chapter2Sedimentarypaleogeography

第2章沉積古地理學(xué)2.1conceptsandlaws2.2sed.-faciesindicators2.3sed.environments(自主互動)1Sed.environments2Sedimentaryfacies3Facieschangesandanalysisofsed-facies4Walther’slaw5Uniformitarianism

2.1Conceptsandlaws1沉積環(huán)境(sedimentaryenvironments):一個具有獨(dú)特的物理、化學(xué)和生物特征的自然地理單元2沉積相(Sedimentaryfacies)——反映沉積記錄成因（環(huán)境、條件和沉積作用）的巖石特征和生物特征的綜合。即沉積記錄成因的物質(zhì)表現(xiàn)。巖相(lithofacies,petrofacies)生物相(biofacies)CarbonatefaciesShalefaciesSandstonefaciesShale&coalfacies3相變——地層的巖石特征和生物特征及其所反映的沉積環(huán)境和沉積作用在空間（橫向）上的變化。FacieschangesFacieschanges?Faciessequence相分析三要素4相分析(faciesanalysis)——綜合地層的巖石特征和生物特征，推斷其成因（沉積環(huán)境和沉積作用）●Material●

Principles●

MethodologySubaerial,mostlikelysemi-humidenvironment1000MaMudcracks+RaindropsApalaeo-scene

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

Induction（歸納）;Deduction（演繹）2.1Conceptsandlaw1Sed.environments2Sedimentaryfacies3Facieschangesandanalysisofsed-facies4Walther’slaw5Uniformitarianism

●Stratigraphicalconformities●GradualtransgressionHowaboutregression?transgression瓦爾特相（定）律亦稱相對比原理(JWalther，1894):只有那些目前可以觀察到是相互毗鄰的相和相區(qū)，才能原生地重疊在一起;即在垂向上整合疊置的相是在側(cè)向上相鄰的沉積環(huán)境中形成的。Walther’slaw(rule)orlawoffaciescorrelation:

Onlythosefaciesandfacies-areascanbesuperimposedprimarilywhichcanbeobservedbesideeachotheratthepresenttime(translatedbyMiddleton,1973);inotherwords,

faciesoccurringinaconformableverticalsequenceofstratawereformedinlaterallyadjacentenvironments.

SketchshowingWalther’slawSignificanceforWalther’sLaw●時間上的相隨反映空間上的并列●指導(dǎo)和檢驗(yàn)相分析工作2.1Conceptsandlaw1Sed.environments2Sedimentaryfacies3Facieschangesandanalysisofsed-facies4Walther’slaw5Uniformitarianism

WhatisanUniformitarianism“Thepasthistoryofourglobemustbeexplainedbywhatcanbeseentobehappeningnow”(JamesHutton).ItwasnamedUniformitarianismbyCharlesLyell(1830;Hutton,1795)現(xiàn)實(shí)類比Uniformitarianism-1？Example-1Uniformitarianism-2？MarsBrachiopods

（Productida,O3-P)現(xiàn)代腕足動物以正常淺海為主，各種水深均能生存(0-6000m+);古生代腕足類大多數(shù)生活在鹽度正常的淺海環(huán)境中，但中生代以來發(fā)現(xiàn)它們與某些深水類別共生Uniformitarianism-3?將古論古-蜓生態(tài)：淺海底棲生活于100m左右熱帶亞熱帶的平靜淺海環(huán)境。地史分布：始現(xiàn):C13,極盛:P1,衰退:P3,絕滅:P末。蜓-FusulininaZoophycosUniformitarianism-4?Desiccationcracks

&Syneresiscracks,

1500Ma,大紅峪組Uniformitarianism-5a?Uniformitarianism-5b?Desiccationcracks

&Syneresiscracks,

1200Ma,北大尖組Uniformitarianism-4?1thinbiofilmsofcyanobacteriaadheretothesurfacesofgrains;2biofilmsdevelopandbecomethicker;3biofilmsofallgrainsarejointedtogether.Scales:2mmBiostabilization將今天論未來Uniformitarianism-6a?Deepbiosphere-1Deepbiosphere-2熱液流體海水溫度（℃）360～3652酸度（25℃時）3.357.8溶解氧00.076硫化氫（mM）2.3～3.50鈉（mM）537464鉀（mM）17.19.8鈣（nM）30.810.2鎂（mM）052.7硅（mM）20.750.2氯化物（mM）636541硫（mM）027.9錳（μM）6800鐵（μM）55900.0015銅（μM）98～1200.007鋅（μM）47～530.01熱液噴口是最具化學(xué)多樣性的微生物生長地.地球化學(xué)梯度和熱梯度提供了多種微生物（嗜冷、溫、熱、壓、酸、堿、鹽菌）聚集的小生境表層生物圈僅占生物生成空間的3%，深部生物圈則占生物生成空間的97%，深海極端條件下生活的極端生物，其2/3的基因與迄今科學(xué)上的已知基因不同。深海熱液體系的物質(zhì)-能量循環(huán)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高生長速率;高生產(chǎn)力；高生物多樣性;歷史悠久.（古菌evolvesince4billionyearsago)Deep

biosphere-3生命的

溫度界限古菌細(xì)菌藻類真菌原生動物植物Rothschild&Mancinelli,2001Mesophiles-嗜溫菌生命的酸堿度界限古菌細(xì)菌藻類真菌原生動物植物Rothschild&Mancinelli,2001各類生物能容忍的上限為~11

某些古菌，三種真菌可容忍0Carp-鯉魚；protists-原生生物Rotifers-輪蟲；sph