Chapter2 Sedimentary paleogeography 第2章沉积古地理学 2.1 concepts and laws 2.2 sed -facies indicators 23sed. environments(自主互动
Chapter 2 Sedimentary paleogeography 第2章 沉积古地理学 2.1 concepts and laws 2.2 sed.-facies indicators 2.3 sed. environments (自主互动)
2.1 Concepts and laws 1 Sed environments 2 Sedimentary facies 3 Facies changes and analysis of sed-facies 4 Walther's law 5 Uniformitarianism
1 Sed. environments 2 Sedimentary facies 3 Facies changes and analysis of sed-facies 4 Walther’s law 5 Uniformitarianism 2.1 Concepts and laws
小沉积环境( entary environments一个具有 独特的物理、化学和生物特征的自然地理单元 OCEAN Folded sedimentary bid Metamorphic curren neous 2沉积相 edimentary facies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。 →物相若相
1 沉积环境(sedimentary environments): 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(Sedimentary facies)——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。 生物相(biofacies) 岩相(lithofacies, petrofacies)
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。 Carbonate Shale Sandstone Shale facies facies facies coal facies Facies change装 0:420 Sea Level
Carbonate facies Shale facies Sandstone facies Shale & coal facies 3 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。 Facies changes
FAcies change
Facies changes? Facies sequence
4相分析( facies 1000Ma analysIs 综 Mudcracks+ Raindrops 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 相分析三要素 ○ Material O Principles ● Methodology Subaerial. most likely semi-humid environment
相分析三要素 4 相分析(facies analysis)——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 ● Methodology Subaerial, most likely semi-humid environment 1000Ma Mudcracks+Raindrops
Methodology- a detective's approach nduction(归纳); Deduction(演绎) Your interpretation: hHaeoeseeite They are dinosaur footprints and they can tell us about: Group behavior; Seasona lity temperature Food web competition inte nsity; Their living environment
A palaeo-scene (the evidence) They are dinosaur footprints and they can tell us about: • Group behavior; • Seasonality & temperature; • Food web & competition intensity; • Their living environment Your interpretation: Methodology– a detective’s approach Induction(归纳); Deduction(演绎)
2 Concepts and law 1 Sed environments 2 Sedimentary facies 3 Facies changes and analysis of sed facies 4 Walther's law 5 Uniformitarianism
2.1 Concepts and law 1 Sed. environments 2 Sedimentary facies 3 Facies changes and analysis of sedfacies 4 Walther’s law 5 Uniformitarianism
How about regression? m瓦尔特相(定)律亦 称相对比原理(J Walther,1894):只有 灰岩 水并 那些目前可以观察到 半咸水页岩 是相互毗邻的相和相 泥岩 淡水灰岩 区,才能原生地重叠 页岩 transgression在一起;即在垂向上 砂岩 侵蚀面 o Stratigraphical conformities 整合叠置的相是在侧 Sketch showing Walthers law7中形成的沉积环境 e Gradual transgression 向上相邻 Walther's law(rule) or law of facies correlation Only those facies and facies-areas can be superimposed primarily which can be observed beside each other at the present time(translated by Middleton, 1973); in other words, facies occurring in a conformable vertical sequence of strata were formed in laterally adjacent environments
●Stratigraphical conformities ● Gradual transgression How about regression? transgression 瓦尔特相(定)律亦 称相对比原理(J Walther,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’s law (rule) or law of facies correlation : Only those facies and facies-areas can be superimposed primarily which can be observed beside each other at the present time (translated by Middleton, 1973); in other words, facies occurring in a conformable vertical sequence of strata were formed in laterally adjacent environments. Sketch showing Walther’s law
Significance for Walthers Law 冲积平原 淡水 水 灰岩 泥坪水 半咸水页岩 Q或滑泽锁水泥坪家多 煤 泥岩 淡水灰岩 页岩 ::::: ●时间上的相随反映空间上的并列 砂岩l:侵蚀面 ●指导和检验相分析工作
Significance for Walther’s Law ●时间上的相随反映空间上的并列 ●指导和检验相分析工作