smectites

SmectitesSmectites

Heather JordanHeather Jordan

GEOSC 440GEOSC 440

03/17/200503/17/2005

What are smectites?What are smectites?

• Single octahedral sheet between 2 tetrahedral sheetsSingle octahedral sheet between 2 tetrahedral sheets– 2:1 Phyllosilicates:2:1 Phyllosilicates:

• SmectiteSmectite

• VermiculiteVermiculite

• IlliteIllite

What are smectites?What are smectites?

• Layer charge from substitutions:Layer charge from substitutions:– Octahedral:Octahedral: Mg Mg2+2+, Fe, Fe2+2+, Mn, Mn2+2+or Alor Al3+3+

– Tetrahedral:Tetrahedral: Al Al3+3+ or Fe or Fe3+3+ for Si for Si4+4+

• Interlayer expands (up to 30% by volume); “swelling clays”Interlayer expands (up to 30% by volume); “swelling clays”– Separation depends on interlayer cations present & ionic strength of Separation depends on interlayer cations present & ionic strength of

solutionsolution

What are smectites?What are smectites?• Platelet Platelet

DimensionsDimensions– 200-500 nm in 200-500 nm in

diameterdiameter– 0.93 nm thick0.93 nm thick

• General Formula:General Formula: – AA0.30.3DD2-32-3[T[T44OO1010]Z]Z22 •nH •nH22OO

• 2:1 2:1 1:1 1:1– Ratio of Ratio of

tetrahedral: tetrahedral: octahedral sheetsoctahedral sheets

– WeatheringWeathering

Smectite Group MembersSmectite Group Members• Allettite:Allettite:

CaCa0.20.2MgMg66(Si,Al)(Si,Al)88OO2020(OH)(OH)44• 4H• 4H22OO

• Beldellite:Beldellite: (Na,Ca(Na,Ca0.50.5))0.30.3AlAl22(Si,Al)(Si,Al)44OO1010(OH)(OH)22 •nH •nH22OO

• Hectorite:Hectorite: NaNa0.30.3(Mg,Li)(Mg,Li)33SiSi44OO1010(F,OH)(F,OH)22

• Montmorillonite:Montmorillonite: (Na,Ca)(Na,Ca)0.330.33(Al,Mg)(Al,Mg)22SiSi44OO1010(OH)(OH)22•nH•nH22OO

• Nontronite:Nontronite: NaNa0.30.3FeFe22(Si,Al)(Si,Al)44OO1010(OH)(OH)22 •nH •nH22OO

• Saponite:Saponite: CaCa0.250.25(Mg,Fe)(Mg,Fe)33(Si,Al)(Si,Al)44OO1010(OH)(OH)22 •nH •nH22OO

• Sauconite:Sauconite: NaNa0.30.3ZnZn33(Si,Al)(Si,Al)44OO1010(OH)(OH)22 •4H •4H22OO

• Stevensite:Stevensite: (Ca,Na)(Ca,Na)xxMgMg33SiSi44OO1010(OH)(OH)22

• Swinefordite:Swinefordite: Li(Al,Li,Mg)Li(Al,Li,Mg)44(Si,Al)(Si,Al)88OO2020,(OH,F)4 •xH,(OH,F)4 •xH22OO

• Volkonskoite:Volkonskoite: CaCa0.30.3(Cr,Mg,Fe)(Cr,Mg,Fe)22(Si,Al)(Si,Al)44OO1010(OH)(OH)22 •4H •4H22OO

• Yakhontovite:Yakhontovite: (Ca,Na)(Ca,Na)0.50.5(Cu,Fe,Mg)(Cu,Fe,Mg)22SiSi44OO1010(OH)(OH)22 •3H •3H22OO

• Zincsilite:Zincsilite: ZnZn33SiSi44OO1010(OH)(OH)22 •4H •4H22OO

ThixotrophyThixotrophy

• Ability to form stiff Ability to form stiff gels at low gels at low concentrations that concentrations that change viscosity as change viscosity as shear application shear application changeschanges

– No Shear:No Shear: Double layers Double layers repelled & + surface repelled & + surface attracted to - edgeattracted to - edge “house of cards” “house of cards” configurationconfiguration

– Shear:Shear: Aligns clay Aligns clay particles & ↓ viscosityparticles & ↓ viscosity

Smectite-Illite (S-I) TransitionSmectite-Illite (S-I) Transition

• Temperature, Temperature, Pressure & TimePressure & Time

• Abiotic Reaction:Abiotic Reaction:

– 300-450300-450ooCC– 100 MPa100 MPa– 4-5 Months4-5 Months

• Biological Reaction:Biological Reaction:

– Metal-Reducing BacteriaMetal-Reducing Bacteria– Room TemperatureRoom Temperature– 1 atm1 atm– 2 weeks2 weeks

http://www.sciencemag.org/cgi/reprint/303/5659/830.pdf

http://www.sciencemag.org/cgi/reprint/303/5659/830.pdf

Structural Comparison:Structural Comparison: Smectite to Illite Smectite to Illite

On the mechanical role of On the mechanical role of smectite in subduction zonessmectite in subduction zones

Peter VrolijkPeter Vrolijk

Department of Geological Sciences,Department of Geological Sciences,

University of MichiganUniversity of Michigan

What is a decollement?What is a decollement?

• ““A shallow dipping to subhorizontal fault or shear zone”A shallow dipping to subhorizontal fault or shear zone”• French:French: “Ungluing”“Ungluing”• The detachment of the upper cover from its substratum The detachment of the upper cover from its substratum

Also known as:Also known as:- Detachment - Detachment faultfault- Decollement - Decollement FaultFault- Sole Fault- Sole Fault

(Image modified from Demian’s lecture sketch)

Objective of the StudyObjective of the Study

• Find out if subduction zone decollements occur Find out if subduction zone decollements occur in smectite-rich horizonsin smectite-rich horizons

• Review previous researchReview previous research::– Rock DeformationRock Deformation– Physical Properties of SedimentsPhysical Properties of Sediments– Smectite-Illite (S-I) TransitionSmectite-Illite (S-I) Transition

• How these effect seismicity in subduction zonesHow these effect seismicity in subduction zones

Why is this research relevant?Why is this research relevant?• The characteristics of The characteristics of

sediments at subduction sediments at subduction zones could tell us where zones could tell us where decollements formdecollements form

• By understanding what By understanding what happens at decollements happens at decollements we learn more about the S-I we learn more about the S-I transitiontransition

• Aspects of the S-I transition Aspects of the S-I transition process at decollements process at decollements tells us something about tells us something about seismicityseismicity

Previous Research:Previous Research: Subduction Zones Subduction Zones

• Sediment-Rich:Sediment-Rich:– Long decollementsLong decollements– Smectite-rich sedimentsSmectite-rich sediments

• Decollements:Decollements:– Formation is associated with prism structureFormation is associated with prism structure– ↑ ↑ Fluid pressureFluid pressure ↓ friction↓ friction ↓ tapering↓ tapering– ↑ ↑ ploughing up of prismploughing up of prism ↓stress↓stress & zones of & zones of ↑ porosity↑ porosity


Previous Research:Previous Research: Subduction Zones Subduction Zones

• Pelagic Sediments:Pelagic Sediments: subducted subducted

• Terrigenous Deposits:Terrigenous Deposits: accrete at prism base accrete at prism base

• Changes in mechanical properties result in peeling of terrigenous Changes in mechanical properties result in peeling of terrigenous from pelagicfrom pelagic

• Decollement is just beneath area of partition at base of smectite-rich Decollement is just beneath area of partition at base of smectite-rich zonezone


Methods:Methods: Data Collection Data Collection

• Sediments from an active decollement have only been Sediments from an active decollement have only been collected oncecollected once

• Seismic reflection data Seismic reflection data mineralogical composition of mineralogical composition of sedimentssediments

• Decollement geometry from drill coresDecollement geometry from drill cores

(Image taken from Demian’s Lecture Presentation)

ResultsResults

• Not enough dataNot enough data

– Smectites & decollement Smectites & decollement formationformation

– More drilling neededMore drilling needed

• 2 Regions with the 2 Regions with the most data:most data:

– Decollements occur in Decollements occur in smectite-rich zonessmectite-rich zones

(Image taken from Demian’s Lecture Presentation)

Implications:Implications: For Decollement Generation For Decollement Generation

• Mineralogical Reasons Mineralogical Reasons why smectite is weakest why smectite is weakest sediment in subduction sediment in subduction zoneszones

– Recall smectite structureRecall smectite structure

– Water = weakness (H-bonds)Water = weakness (H-bonds)

– Relative Deformation Relative Deformation StressesStresses

– Water tightly adsorbed to Water tightly adsorbed to smectitesmectite

• Remains during Remains during deformation (↑ porosity)deformation (↑ porosity)

What dictates smectite distribution in ocean sediments?What dictates smectite distribution in ocean sediments?

• Transformation from Transformation from volcanic ashvolcanic ash

– Abundant ashAbundant ash

– Sufficient time & Sufficient time & pressurepressure

– Between pelagic & Between pelagic & hemipelagic hemipelagic sediments (due to sediments (due to dilution & age)dilution & age)

• Detrital clay influxDetrital clay influx

Sediment Minerology Evolution:Sediment Minerology Evolution: S-I Transition S-I Transition

• Metamorphic transitions Metamorphic transitions on subducting plateon subducting plate

• 80% complete 100-11080% complete 100-110ooCC

• ↑ ↑ Rate of subduction; ↓ S-I Rate of subduction; ↓ S-I transition ratetransition rate

• Subduction Observations:Subduction Observations:

– Japan Trench (fast)Japan Trench (fast)

– Barbados (slow)Barbados (slow)

Implications:Implications: For Subduction Zones For Subduction Zones

• S-I:S-I: Sediment Strengthening Sediment Strengthening• How it relates to seismicityHow it relates to seismicity

Does this lead to development of the seismic front?Does this lead to development of the seismic front?

• During S-I, ↓ smectite (as it is converted to illite)During S-I, ↓ smectite (as it is converted to illite)• Decollement strengthenedDecollement strengthened• Friction ↑Friction ↑• Deformation & strain on overriding plateDeformation & strain on overriding plate• Seismicity resultsSeismicity results

ConclusionsConclusions

• Decollements form in smectite-rich sedimentsDecollements form in smectite-rich sediments

• More drilling needed at prismsMore drilling needed at prisms

• Columb Wedge Theory:Columb Wedge Theory: coefficient of basal coefficient of basal sliding friction may need modificationsliding friction may need modification

• Seismicity related to strengthening (due to S-I)Seismicity related to strengthening (due to S-I)

Comments & Criticisms:Comments & Criticisms: Where to Begin?Where to Begin?• Overgeneralization from too small a Overgeneralization from too small a

sample sizesample size

• Too little is known about the Too little is known about the lithology to draw conclusions about lithology to draw conclusions about the relationship of smectite to the relationship of smectite to decollement formationdecollement formation

• Keeping physical models in mind Keeping physical models in mind (structure, hydration, the effect of (structure, hydration, the effect of shear, S-I, etc.), Is the model shear, S-I, etc.), Is the model logical?logical?– Shear reduces viscosity (house of Shear reduces viscosity (house of

cards to plates)cards to plates)

– S-I (squeezes out water; no more H-S-I (squeezes out water; no more H-bonds to break)bonds to break)

– Leads to strengtheningLeads to strengtheningSeismicitySeismicity

• Would I have published this? NO!!!Would I have published this? NO!!!

??QuESTIONS????QuESTIONS??

For more thoroughly exhilarating reading on smectites:For more thoroughly exhilarating reading on smectites:• Alba, M.D, Alba, M.D, et al.et al. (2001) Hydrothermal reactivity of Lu-saturated smectites: Part I. A long-range order (2001) Hydrothermal reactivity of Lu-saturated smectites: Part I. A long-range order

study. study. American MinerologistAmerican Minerologist. . 86:86: 115-123. 115-123.• Alba, M.D., Alba, M.D., et al.et al. (2001) Hydrothermal reactivity of Lu-saturated smectites: Part II. A short-range order (2001) Hydrothermal reactivity of Lu-saturated smectites: Part II. A short-range order

study. study. American MinerologistAmerican Minerologist. . 86:86: 124-131 124-131• Blum, A.E., Eberl. D.D. & Rutherford, D.W. Quatitative Determination of Smectite Surface Areas by the Blum, A.E., Eberl. D.D. & Rutherford, D.W. Quatitative Determination of Smectite Surface Areas by the

sorption of polyvinylpyrrolidone. sorption of polyvinylpyrrolidone. Ninth Annual V.M. Goldschmidt ConferenceNinth Annual V.M. Goldschmidt Conference . . 7567.pdf7567.pdf• Cervini-Silva, J., Cervini-Silva, J., et al.et al. (2001) Transformation of Chlorinated Aliphatic Compounds by Ferruginous (2001) Transformation of Chlorinated Aliphatic Compounds by Ferruginous

Smectite. Smectite. Environmental Science and Technology.Environmental Science and Technology. 35:35: 805-809. 805-809.• Ghosh, A & McSween Jr., H.Y. Normative Minerology and Possible Origin of Mars Pathfinder Soils. Ghosh, A & McSween Jr., H.Y. Normative Minerology and Possible Origin of Mars Pathfinder Soils.

Online.Online. • Guangyao, H.L., Guangyao, H.L., et al.et al. (2003) Sorption and Desorption of Pesticides by Clay Minerals and Humic Acid- (2003) Sorption and Desorption of Pesticides by Clay Minerals and Humic Acid-

Clay Complexes. Clay Complexes. Soil Science Society Americal Journal.Soil Science Society Americal Journal. 67:67: 122-131. 122-131.• Johnston, C.T. Johnston, C.T. et al.et al. Spectroscopic Study of Nitroaromatic—Smectite Sorption Mechanisms. Spectroscopic Study of Nitroaromatic—Smectite Sorption Mechanisms.

Environmental Science & TechnologyEnvironmental Science & Technology . American Chemical Society.. American Chemical Society.• Kasama, T., Kasama, T., et al.et al. (2001) Experimental mixtures of smectite and rectorite: Re-investigation of (2001) Experimental mixtures of smectite and rectorite: Re-investigation of

“fundamental particles” and “interparticle diffraction”. American Minerologist. “fundamental particles” and “interparticle diffraction”. American Minerologist. 86:86: 105-114. 105-114. • Parry, W.T., Jasumback, M. & Wilson, P.M. (2002) Clay Minerology of Phyllic and Intermediate Agrillic Parry, W.T., Jasumback, M. & Wilson, P.M. (2002) Clay Minerology of Phyllic and Intermediate Agrillic

Alteration at Bingham, Utah. Alteration at Bingham, Utah. Economic GeologyEconomic Geology. . 97:97: 221-239. 221-239. • Stixrude, L & Peacor, D.R. (2002) First-principles study of illite-smectite and implications for clay-Stixrude, L & Peacor, D.R. (2002) First-principles study of illite-smectite and implications for clay-

mineral mineral systems. systems. Nature.Nature. 420:420: 165-168. 165-168.• Trentstesaux, A., Trentstesaux, A., et al.et al. (2003) Data Report: Pleistocene Paleoclimatic Cyclivity of Southern China: Clay (2003) Data Report: Pleistocene Paleoclimatic Cyclivity of Southern China: Clay

Mineral Evidence Recorded in the South China Sea (ODP Site 1146). Mineral Evidence Recorded in the South China Sea (ODP Site 1146). Proceedings of the Ocean Proceedings of the Ocean Drilling Program, Scientific Results.Drilling Program, Scientific Results. 184:184: 1-10. 1-10.

• Vrolijk, P. & van der Pluijm, B.A. (1999) Clay Gouge. Vrolijk, P. & van der Pluijm, B.A. (1999) Clay Gouge. Journal of Structural GeologyJournal of Structural Geology . . 21:21: 1039-1048. 1039-1048.

For more thoroughly exhilarating reading on smectites:For more thoroughly exhilarating reading on smectites:• http://www.smm.org/general_info/bhop/Smectiteandbentoniteclay.html• http://www.mindat.org/min-11119.htmlhttp://www.mindat.org/min-11119.html• http://www.renneckerltd.com/rltd_aboutsmectite.htmhttp://www.renneckerltd.com/rltd_aboutsmectite.htm• http://www.rtvanderbilt.com/veegum.pdfhttp://www.rtvanderbilt.com/veegum.pdf• http://www.claytone.net/clay/cchem.htmlhttp://www.claytone.net/clay/cchem.html• http://www7430.nrlssc.navy.mil/biogeochemistry/smectiteillite.htmhttp://www7430.nrlssc.navy.mil/biogeochemistry/smectiteillite.htm• http://chemical.kowa.com/coop_chemical.htmlhttp://chemical.kowa.com/coop_chemical.html• http://www.cnr.berkeley.edu/~rsutton/cmsabstract.htmlhttp://www.cnr.berkeley.edu/~rsutton/cmsabstract.html• http://www.rtvanderbilt.com/veegumdd_a.htmhttp://www.rtvanderbilt.com/veegumdd_a.htm• http://www.oilvel.com/Dutta_quotes2.htmlhttp://www.oilvel.com/Dutta_quotes2.html• http://www.workpage.com/e/58/177e.htmhttp://www.workpage.com/e/58/177e.htm• http://www.renneckerltd.com/Products/rltd_magnabrite01.htmhttp://www.renneckerltd.com/Products/rltd_magnabrite01.htm• http://www-odp.tamu.edu/publications/184_SR/VOLUME/CHAPTERS/210.PDFhttp://www-odp.tamu.edu/publications/184_SR/VOLUME/CHAPTERS/210.PDF• http://cips.berkeley.edu/research/cervini-silva_transformation.pdfhttp://cips.berkeley.edu/research/cervini-silva_transformation.pdf• http://www.cnr.berkeley.edu/~rsutton/modelclay.htmlhttp://www.cnr.berkeley.edu/~rsutton/modelclay.html• http://www.cnr.berkeley.edu/~rsutton/clays.htmlhttp://www.cnr.berkeley.edu/~rsutton/clays.html• http://www.glossary.oilfield.slb.com/Display.cfm?Term=smectite+clayhttp://www.glossary.oilfield.slb.com/Display.cfm?Term=smectite+clay• http://www.permont.com/11/1112/tsld002.htmhttp://www.permont.com/11/1112/tsld002.htm• http://www.geo.wvu.edu/%7Ekite/Geol321Lect04Weathering2002/http://www.geo.wvu.edu/%7Ekite/Geol321Lect04Weathering2002/• http://members.segweb.org/PDF97-2/221_Prry.pdfhttp://members.segweb.org/PDF97-2/221_Prry.pdf• http://www.quanterra.org/Patissier.htmhttp://www.quanterra.org/Patissier.htm• http://www-odp.tamu.edu/publications/178_SR/chap_08/chap_08.htmhttp://www-odp.tamu.edu/publications/178_SR/chap_08/chap_08.htm• http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=343765http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=343765• http://www.claytone.net/pain/pain.htmlhttp://www.claytone.net/pain/pain.html• http://www.eytonsearth.org/claychemistry.htmlhttp://www.eytonsearth.org/claychemistry.html• http://www.seismo.berkeley.edu/~jill/silweath.htmlhttp://www.seismo.berkeley.edu/~jill/silweath.html• http://www.gly.uga.edu/schroeder/geol3010/smectite.gifhttp://www.gly.uga.edu/schroeder/geol3010/smectite.gif• http://www.petrotech-assoc.com/prod01.htmhttp://www.petrotech-assoc.com/prod01.htm• http://www.glossary.oilfield.slb.com/DisplayImage.cfm?ID=183http://www.glossary.oilfield.slb.com/DisplayImage.cfm?ID=183• http://energy.usgs.gov/factsheets/Petroleum/SEM.htmlhttp://energy.usgs.gov/factsheets/Petroleum/SEM.html• http://homepages.uc.edu:8000/~maynarjb/603/GeochemWater/ClayImages.htmhttp://homepages.uc.edu:8000/~maynarjb/603/GeochemWater/ClayImages.htm• http://www.kimb.or.kr/im_data/picture/mineral/img/montmorillonite.jpghttp://www.kimb.or.kr/im_data/picture/mineral/img/montmorillonite.jpg

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