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 )
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
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。 岩相 (lithofacies,petrofacies)生物相 (biofacies)
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 changes?
Fac
ies
se
quenc
e
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
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)
2.1 Concepts and law
1 Sed,environments
2 Sedimentary facies
3 Facies changes and analysis of sed-
facies
4 Walther’s law
5 Uniformitarianism
● 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 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
2.1 Concepts and law
1 Sed,environments
2 Sedimentary facies
3 Facies changes and analysis of sed-
facies
4 Walther’s law
5 Uniformitarianism
What is an
Uniformitarianism
―The past history of our globe must be explained by what can be seen to be
happening now‖ (James Hutton),It was named Uniformitarianism by Charles
Lyell (1830; Hutton,1795)
现实 类比
Uniformitarianism-1?
Example-1
Uniformitarianism-2?Mars
Brachiopods
( 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 -Fusulinina
Zoophycos
Uniformitarianism-4?
Desiccation cracks
& Syneresis cracks,
1500Ma,大红峪组
Uniformitarianism-5a?
Uniformitarianism-5b?
Desiccation cracks
& Syneresis cracks,
1200Ma,北大尖组
Uniformitarianism-4?
1 thin biofilms of
cyanobacteria
adhere to the
surfaces of grains;
2 biofilms develop
and become thicker;
3 biofilms of all
grains are jointed
together,Scales,
2mm
Biostabilization
将今天论未来
Uniformitarianism-6a?
Deep biosphere-1
Deep biosphere-2热液流体 海水温度( ℃ ) 360~ 365 2
酸度( 25℃ 时 ) 3.35 7.8
溶解氧 0 0.076
硫化氢( mM) 2.3~ 3.5 0
钠( mM) 537 464
钾( mM) 17.1 9.8
钙( nM) 30.8 10.2
镁( mM) 0 52.7
硅( mM) 20.75 0.2
氯化物( mM) 636 541
硫( mM) 0 27.9
锰( μM) 680 0
铁( μM) 5590 0.0015
铜( μM) 98~ 120 0.007
锌( μM) 47~ 53 0.01
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
Aerobic
S2-(HS-,H2S,S0)+CO2+O2+H2O
→SO 42-+[CH2O]
CH4+O2→[CH 2O]+H2O
4H2+O2+CO2→[CH 2O]+3H2O
NH3+O2+CO2 →[CH 2O]+HNO3
Anaerobic
Chemolithotrophic SO42- reduction:
CO2+ SO42-+H2 →[CH 2O]+S2-+5H2O
Heterotrophic SO42- reduction:
CH3COOH+ SO42-→CO 2 +S2-+2H2O
CO2+6H2 →[CH 2O]+CH4+3H2O
高生长速率 ; 高生产力;高生物多样性 ; 历史悠久,(古菌 evolve
since 4 billion years ago)
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,2001
Mesophiles-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 0
Carp-鲤鱼; protists-原生生物
Rotifers-轮虫; sphagnum-泥炭藓
Heather sedges-石南花莎草
Uniformitarianism; 类比分析
The present is the key to the past
将今论古将古论今将古论古将今论未来将天论地将地论天跨时间域? or !
跨空间域? or !
The earth is the key to the celestial bodies
The End