Zementbildung

Christian Björn Muñoz GuerreroAlexander KellermeierYunsang JoTong Zhang

25. April 2018

Gliederung

1. Definition Zementation& Unterschied Matrix/Zement2. Quarz-Zementation3. Feldspat4. Tonminerale5. Karbonat6. Phosphat7. Sulfat/Sulfid8. Eisenoxid

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Definition Zement/Zementation

• Zement: Verfüllung des Porenraums

zwischen den Sedimentpartikeln mit

einer authigenen Mineralbildung welche

durch die Diagenese induziert wird

(Kalzit, SiO2,…)

• Zementation: Ausfällung und/oder

Kristallisation von Mineralen

(diagenetische Veränderung)

Ausfällung zwischen den Partikeln bewirkt Porenraumverkleinerung

Grotzinger & Jordan 2010 3

Zement & Matrix

• Bildet in der Regel die Grundmasse eines

Sedimentgesteins

• Unterschied:

• Zement (postsedimentär): kristallin

• Matrix (synsedimentär): feinkörniges

sedimentäres Material

Zusätzlich: Unterschiede in Bildungszeit, -ort, -merkmale und Gefüge (direkter Vergleich in Füchtbauer (1988)

Earth Science Australia, http://earthsci.org

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Zement - Quarz

Stylolitisierung

Rekristallisationsprozesse

Feldspat-Lösung

5Oelkers et al.,1996

Zement ‐ Quarz

Mechanismen/Raten von Qz-Zementation verstehen für die Quantifizierung von Wechseln bei physikalischen Eigenschaften während der Versenkung

Rate der Qz-Zementation als Funktion der Zeit, Temperatur (T) und Qz-Oberfläche

Analysen mittels Isotopenverteilung δ18O im Bezug auf die Temperatur

Harwood et al. 2013

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Zement - Feldspat

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Zemente können Aussagen über dasAblagerungsmilieu wiedergeben; Tendenz:Kalifeldspat: kontinental, arid(Füchtbauer, 1974; Houareau,1974; Waugh, 1978)Albit: marin (Almon et al., 1976)

Vorkommen: Im Bereich der Diagenese und bei schwachen Metamorphosegraden (abhängig von der Gesteinszusammensetzung(Füchtbauer, 1988)

1) Lösungsprozesse:   4 KAlSi3O8+ 4 H2OAl4(OH)8Si4O10+ 2K2O+ 8SiO2

2) Albitisierung: KAlSi3O8 + Na+NaAlSi3O8+K+

ementation of Clay mineral:

Cement in sandstone reservoir is dominated by

ceous and carbonate cement,

h minor amounts of clay minerals and sulfides.

Kaolinite (Al2Si2O5(OH)4)

early diagenetic (eogenetic) origin

Chlorite (Fe-Mg)5Al2Si3O10(OH)8)

burial diagenetic (mesogenetic) origin

Illite (KAl3Si3O10(OH)2)

burial diagenetic (mesogenetic) origin

nerally, clay minerals are dominated by kaolinite and chlorite, followed by illite and mixed-layer

e/ smectite. With the increase of the buried depth of sandstone, the content of illite is increasing.

Wüstefeld, P, 2

Near-surface diagenesis

Ca. 70℃

Kaolinite (Al2Si2O5(OH)4)

•Early diagenetic (eogenetic) origin

•Low temperature/ shallow depth

•as fillings in primary pores, secondary

pores in the shapes of books and worms,

with the throat in the local partProcess:

Kaolinite is precipitated after most of

the feldspar has been dissolved

Major controlling Parameter:Abundance of feldspars, effective meteoric

water flux and sea-water

Depositional facies: marine and fluvial sandstones

R. H. Worden, 2003, M. J. Wilson, 20

SEM image showing oldest cement in the sandstones consisting of intergrown kaolinite (orange) and calcite (blue)

Scanning electron microscope (SEM) micrographs illustrating Well-ordered kaolinite in discrete booklets

ESEM images showing typical cement habits and dissolution of He8 sandstones; Book-like kaolinite occludes pore and pore throat

b

c d

Kaolinite (Al2Si2O5(OH)4)• Process:

Kaolinite is precipitated after most of

the feldspar has been dissolved by

chemical weathering during early diagenesis

Nedkvitne and Bjørlykke, 1992; Bjørlykke, 2010

A2K(Na)AlSi3O8+2H+9H2O=FeldsparAl2Si2O5(OH)4+4H4SiO4+2K(2Na)Kaolinite

Precondition for the formation of clay minerals:

1)Silicates provide a source of material for

authigenic clays

2)Silicate dissolution increases the

microporosity (secondary porosity) of

rock

A

Kaolinite (Al2Si2O5(OH)4)• Process:

Kaolinite is precipitated after most of

the feldspar has been dissolved by

chemical weathering during early diagenesis

Nedkvitne and Bjørlykke, 1992; Bjørlykke, 2010

B

2K(Na)AlSi3O8+2H+9H2O=FeldsparAl2Si2O5(OH)4+4H4SiO4+2K(2Na)Kaolinite

Precondition for the formation of clay minerals:

1)Silicates provide a source of material for

authigenic clays

2)Silicate dissolution increases the

microporosity (secondary porosity) of

rock

B

Kaolinite (Al2Si2O5(OH)4)

• Major controlling parameter:

1. Type and amount of water

Fresh water (low pH, low ionic strength)

Marine (high pH, high ionic strength)

2. Water influx versus evaporation rate

3. Temperature

4. Organic matter component etc.

“Saturated”A B C

Kaolinite (Al2Si2O5(OH)4)

The role of depositional environment on clay mineral patterns in sandstones will be divided between subaerial and marine syste

Continental environments will be split between warm and wet versus arid.

• Major controlling parameter:

1. Type and amount of water

Fresh water (low pH, low ionic strength)

Marine (high pH, high ionic strength)

2. Water influx versus evaporation rate

3. Temperature

4. Organic matter componant etc.

Kaolinite (Al2Si2O5(OH)4)• Depositional environments: Cont. environment (warm and wet)

Alluvial-fluvial environments (alluvial fans, fluvial braided streams, fluvial meandering streams)

• Pore waters in humid, warm (subtropic

to temperate) environments are dilute

Low ionic concentrations in pore

waters close to main channel

• Abundance of organic matter that

undergoes bacterially mediated decay

(Berner, 1980)

Organic (humic) acids in abandoned

channels

Encouraging extreme feldspar

weathering

R. H. Worden, 2003

Stagnate -> saturated ions

Organic acids

Kaolinite (Al2Si2O5(OH)4)• Depositional environments: Cont. environment (arid)

Prograding fluvial deltas (prograding into a playa=dry delta)

• Clay eodiagenesis in arid eogenetic

environment

• In the unsaturated zone of aquifers,

clay infiltration occurs,

if percolating waters contain

suspended clay menerals

(Moraes & de Ros, 1990)

When ground water evaporation

exceeds the rate of percolation =>

leaving the suspended clay mineral

coated on sand grains

Kaolinite may form from detrital feldspars i

the aquifer if the groundwater is flowing

and being recharged.R. H. Worden, 2003

Kaolinite (Al2Si2O5(OH)4)• Depositional environments: Cont. environment (arid)

Prograding fluvial deltas (prograding into a playa=dry delta)

• Clay eodiagenesis in arid eogenetic

environment

• In the unsaturated zone of aquifers,

clay infiltration occurs,

if percolating waters contain

suspended clay menerals

(Moraes & de Ros, 1990)

When ground water evaporation

exceeds the rate of percolation =>

leaving the suspended clay mineral

coated on sand grains

Kaolinite may form from detrital feldspars i

the aquifer if the groundwater is flowing

and being recharged.

(A, B & C) SEM images of coated sand grain from sample B10 65-70 cm. (D) EDX spectra of coat indicating the presence of kaolinite.Patrick J. Dowey, 2017

Karbonatzemente

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Karbonatzemente

• Die meisten Kabonatzemente entstehen während der Diagenese

• Karbonatzemente sind oft an der Verfüllung des Porenraums von Sandsteinen beteiligt

• Karbonatzemente typischerweise in Quartz-Areniten vertreten

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Aragonit, Kalzit

Tucker/Wright,1996

Tucker/Wright,1996

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Tucker/Wright, 1996

High‐/Low Mg Kalzit und Aragonit1 Kallkspatzement in kalten, Tiefwasser-Sedimenten, Sedimenten in geringen Breitengraden und temperierten Flachwasser-Sedimenten2 high-Mg Kalzitzement in Riffen (selten)3 high-Mg Kalzitzement in Riffen und Kalksanden 4 Aragonitzement in Riffen und Kalksanden 5 low-Mg Kalkspatzement in meteorischer Umgebung6 low-Mg Kalzit in Speleothemen und Travertinen7 Aragonit in Speleothemen (selten)

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Dolomitisierung

Tucker/Wright,1996

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Tucker/Wright, 1996

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Pettijohn, 198723

Tucker/Wright, 1996

Keine allgemeine Ausfällungsabfolge bestimmbarAusfällung der unterschiedlichen Karbonattypen abhängig vom Ablagerungsmilieu•Offene oder geschlossene Systeme•Ausgangszusammensetzung und Stabilität der einzelnen Komponenten•Salinität•Mg/Ca-Verhältnis•pH-Wert •Eh-Wert•T-P-Bedingungen•Zeit

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Bildung von Zementen

Phosphat, Sulfate und Sulfide bzw Eisenoxide

PhosphatZement

K. P. KRAJEWSKI 1984

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Entstehung

K. P. KRAJEWSKI 1984

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Phosphate Cement fabrics

K. P. KRAJEWSKI 1984

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Zusammenfassung• Vorkommen von Phosphat‐Zementen‐feinkörniges marines Sediment‐Ein früh diagenetisches marines Phänomen‐Hohe Phosphatkonzentration im Sediment‐organisches Material als Phosphatquelle nötig

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Sulfate und Sulfide Zement

• Gips CaSO4*H20• Anhydrit CaSO4

• Baryt BaSO4

• ______________________• Pyrit FeS2 (kubisch)• Markasit FeS2 (orthorhomb)

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Anhydrit‐Zemente im Persischen Golf

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Anhydrit‐Zemente im Persischen Golf

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Eisenoxid Zement 

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Nielsen et al., 2014

Chemismus• Hematite:2Fe2+(aq) + 0,5 O2(g) + 2H2O(l) = Fe2O3(s) + 4H+

(aq)

goethite:• 2Fe2+(aq) + 0,5 O2(g) + 3H2O(l) = 2FeO(OH)(s) +4H+

(aq)

dehydration of goethite:2FeO(OH)(s) = Fe2O3(s) + H2O(l)

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ZusammenfassungMineralische  Porenwässer  gelangen  in  die  Porenräume  des  Lockersediments  undfällen dort aus. (Die Porosität wird dadurch verringert)Die  kontrollierte  Parameter  für  die  Bildung  von  Zement  sind  chemisch  undphysikalisch.  (z.B.  Druck,  Temperatur,  Porosität,  Mineralzusammensetzung  vonKomponent, pH‐Wert, Eh‐Wert usw.)Zemente  bestehen meist  aus  Kalziumkarbonat  (Kalzit,  Dolomit)  oder  Siliziumdioxid(Quarz, Feldspat,Kaolinit), seltener aus anderen Mineralen.Es  gibt  häufig  zwei  oder  mehr  Generationen  von  Zement.  Um  die  verschiedenenGenerationen von Zemente oder Sammelkristallisation der Matrix  zu unterscheidenist  nicht  nur  lichtmikroskopische  Untersuchung  sondern  auch  Kathodolumineszenz‐Mikroskopie erforderlich.

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Literatur• Pettijohn, F.J.;Potter,P.E.;Siever,R., 1987: Sand and Sandstone,Springer Verlag, 2. Auflage

• Tucker, M.E.;Wright, V.P.,1996: Carbonate Sedimentology, Backwell Science Ltd

• Füchtbauer, H., 1988. Sediment-Petrologie, Teil 2: Sedimente und Sedimentgesteine, Schweizerbart, 4. Auflage. S.165, 167f,174f, 177f, 376, 421ff

• Füchtbauer,H.; Müller,1977:Sediment-Petrologie, Teil 2-Sedimente und Sedimentgesteine, Schweizerbart´sche Verlagsbuchhandlung, 3. Auflage

• Elbracht,J., 2002: Karbonatische Zementation pleistozäner Lockersedimente NW-Deutschlands, Dissertation Universität Hannover

• R. H. Worden and S. Morad., 2003. clay minerals in sandstones: controls on formation, distribution and evolution

• Meng Wang, Hongming Tang and Feng Zhao., 2017. controlling factor analysis and prediction of the quality of tight sandstone reservoir: A case study of the He8 member in the eastern Sulige GasField, Ordos Basin, China. Journal of Natural Gas Science and Engineering 46 (2017) 680-698

• S. Morad, Khalid Al-Ramadan, J. M. Ketzer, and L. F. De Ros., 2010. the impact of diagenesis on the heterogeneity of sandstone reservoirs: A review of the role of depositional facies and sequence stratigraphy. AAPG Bulletin, v. 94, no. 8 (August 2010), pp. 1267–1309

• Dowey, Patrick J., Worden, Richard H., Utley, James, Hodgson, David M., 2007. Sedimentary controls on modern sand grain coat formation, Sedimentary Geology.

• Patrick Wüstefeld, Ulrike Hilse, Bastian Koehrer, Dirk Adelmann, Christoph Hilgers., 2017. Critical evaluation of an Upper Carboniferous tight gas sandstone reservoir analog: Diagenesis and petrophysical aspects

• Rahimpour-Bonab H., Esrafili-Dizaji B., Tavakoli V. (2010): Dolomitization and Anhydrite Precipitation in Permo-Triassic Carbonates at the South Pars Gasfield, Offshore Iran: Controls on Reservoir Quality. Journal of Petroleum Geology, Vol. 33 (I), Seite 43-66.

• Krajewski, K. P. (1984), Early diagenetic phosphate cements in the Albian condensed glauconitic limestone of the Tatra Mountains, Western Carpathians Sedimentology Volume 31, Issue 4, pages 443–470, August 1984

• Nielsen, G.B., Chan, M.A., and Bowen, B.B. (2014): IRON-RICH HORIZONS IN THE JURASSIC NAVAJO SANDSTONE,SOUTHWESTERN UTAH: PROGRESSIVE CEMENTATION AND PERMEABILITY INVERSION. UGA Publication 43 (2014)

• Harwood, J., 2013, Quartz Cementation History of Sandstones Revealed By High-Resolution Sims Oxygen IsotopeAnalysis: Journal of Sedimentary Research, v.83(7), p.522-530

• Grotzinger, J., Jordan, T., 2010. Understanding Earth (6. Auflage). W. H. Freeman and Company, New York

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