cee 437 lecture 2 minerals - university of washington · bowen’s reaction series. weathering...
TRANSCRIPT
![Page 1: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/1.jpg)
CEE 437 Lecture 10Minerals and Mineral
PropertiesThomas Doe
![Page 2: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/2.jpg)
Outline
Rock cycleRock Forming MineralsMineral Physical PropertiesClay MineralsMicrofractures and Fracture Mechanics
![Page 3: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/3.jpg)
Crustal Composition
Main Elemental GroupsSilicaAluminumFerro-MagnesianCa, Na, K
![Page 4: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/4.jpg)
Rock Cycle
Metamorphic Rocks
Sedimentary Rocks
Igneous Rocks
Sediments
Lithification
Magma
Weathering, Erosion
Burial, metamorphism, recrystallization
Melting
Crystallization at depth or extrusion at surface
Burial, metamorphism, recrystallization
![Page 5: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/5.jpg)
Mineral DifferentiationPlate tectonics and Igneous Processes
selective melting, selective recrystallizationdifferentiation by density
Weathering and ErosionSelective weatheringConcentration of quartz (pure Si02)Conversion of alumino-silicates to claysConcentration of soluble residues in seawater
DepositionCourser materials near sediment sourceFiner materials far from sediment sourceRedeposition of salts and solutes by evaporative (Na,KCl; CaSO4) or biological processes (CaCO3,; )
![Page 6: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/6.jpg)
Subduction Zone – Island Arc
![Page 7: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/7.jpg)
Evolution of Continents — North American Craton
![Page 8: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/8.jpg)
Differentiation of Crustal Composition
Weathering differentiating towards higher Silica
Preferential melting of high-silica materials
Concentration of C, Ca, Na, K in sea and air
Original basaltic composition of crust
Carbonate concentrated by organic processes
![Page 9: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/9.jpg)
Convergent Margin - Continental
![Page 10: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/10.jpg)
Bowen Reaction Series
How to get many different rocks from one melt composition?Differentiation by selective crystallization and removal from system
![Page 11: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/11.jpg)
Bowen’s Reaction Series
![Page 12: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/12.jpg)
Weathering Cycle
![Page 13: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/13.jpg)
Elemental Fates
Silicon tends to concentrate in crust — quartz is very long livedAluminum — transforms from feldspars to claysMica — transform to clays Fe-Mg-Ca-Na-K concentrate in some clays and micas, concentrate in oceans in biosphere
![Page 14: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/14.jpg)
Sedimentary Differentiation
Sorting by Deposition MediumSorting by Energy
![Page 15: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/15.jpg)
Mineral Definition
Naturally occurring material with unique combination of chemical composition and crystalline structureNatural non-minerals — glasses, coal, amorphous silicaPseudomorphs: diamond:graphite
![Page 16: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/16.jpg)
Mineral Groups
Silicates: Major rock forming mineralsCarbonates: Minor in igneous rocks, mainly found in organic-derived rocks (limestones) and low-temperature cements and fracture fillings
Dissolution relationshipsSulfates (Gypsum) and Halides (salt, potash): Products of evaporation
Extreme dissolutionOxides
Weathering productsSulfides: Ores
Late stages of igneous melts, reducing conditionsAcid production, reactivity problems in concrete
![Page 17: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/17.jpg)
Galena, PbS Graphite, C
![Page 18: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/18.jpg)
Crystalline Structure of Calcite
![Page 19: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/19.jpg)
Crystalline Symmetry Groups
![Page 20: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/20.jpg)
Isomorphic Crystal Forms, Cubic System
![Page 21: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/21.jpg)
Mineral Identification
DensityHardnessColor, luster (metallic, non-metalic, semi-metallic)Crystalline habitCleavageOptical microscopyMineral chemistry, x-ray diffraction
![Page 22: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/22.jpg)
Hardness Scale
![Page 23: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/23.jpg)
X-Ray Diffraction
Bragg’s Law
![Page 24: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/24.jpg)
Physical Properties
Density (Gravity)Electrical Conductivity (Resisitivity)Thermal ExpansionStrengthElasticity (Mechanical properties,
Seismic/Acoustic VelocityRheology (Plasticity,Viscosity)
![Page 25: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/25.jpg)
Properties and Mineral Symmetry
![Page 26: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/26.jpg)
Tensor Properties of Crystals
Cubic Group
Lower Symmetry Groups
General Form for Heat Flow (for example)
![Page 27: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/27.jpg)
Discussion: How to Rock Properties Relate to Mineral Structure
How will anisotropy vary with crystal symmetry class?
Rock Salt versus Quartz?How will aggregates of minerals (with same mineral behave?
Cubic versus non cubicRock fabricMaterial property contrasts
![Page 28: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/28.jpg)
Rock Forming Minerals
Composition of CrustDominantly O, Si, Fe, Mg, Ca, Na, KNear surface importance of bio-processesSilicates from inorganic processesCarbonates mainly from shell-forming organisms
![Page 29: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/29.jpg)
Crustal Composition
Main Elemental GroupsSilicaAluminumFerro-MagnesianCa, Na, K
![Page 30: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/30.jpg)
Major Silicate Groups
Silicon Tetrahedronseparate tetrahedra — olivinesingle chains — pyroxenedouble chains — amphibolesheet silicates — micas and claysframework silicates — feldspars (with Al substitution), quartz as pure silica
![Page 31: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/31.jpg)
Silica Tetrahedron
![Page 32: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/32.jpg)
![Page 33: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/33.jpg)
Forms of Silicates
![Page 34: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/34.jpg)
Deformation Mechanisms
![Page 35: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/35.jpg)
Effects on Physical Properties
AnisotropyProperties differ by direction
HeterogeneityProperties vary by location
Mineral properties may have strong anisotropy when crystals are alignedHeterogeneity may have strong mechanical effects when different minerals have different deformation properties
![Page 36: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/36.jpg)
Weathering Fates
Feldspars to clays (clays, shales)Quartz endures (siltstones, sandstones)Calcium recirculated into carbonate minerals by organic processes (limestones)
Consequence:Over time, evolution of less dense more silicic continental crust
![Page 37: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/37.jpg)
Clay Minerals
Extremely Important Mineral GroupSealsStabilityPore pressureChemical interactionSwellingSlaking
Confusion as both “Size” and “Mineral” Classification
![Page 38: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/38.jpg)
Clay Rock Cycle
![Page 39: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/39.jpg)
Clay Viewed from Electron Microscope
![Page 40: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/40.jpg)
Clay Sources
WeatheringHydrothermal AlterationDepositionClay Transformations
Feldspar IlliteFerro-Magnesian ChloriteVolcanics (alkaline conditions) SmectiteVolcanics (acidic conditions) Kaolinite
Bentonite: plastic, highly swelling
![Page 41: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/41.jpg)
Clay Units
From West, Geology Applied to Engineering, Prentice Hall, 1995)
![Page 42: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/42.jpg)
Two and Three-Layer Clay Structure
From West, Geology Applied to Engineering, Prentice Hall, 1995)
![Page 43: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/43.jpg)
Mixed Layer Clays
From West, Geology Applied to Engineering, Prentice Hall, 1995)
![Page 44: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/44.jpg)
![Page 45: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/45.jpg)
Minerals versus Rocks
Minerals ElementsAnisotropy from crystal structure
Elastic PropertiesThermal PropertiesOptical Properties
DeformationShear transformationsDislocations
Rock ElementsIntragranular
Anisotropy from fabricCrystal anisotropy if preferred orientationAnisotropy from bedding, foliation, flow structures
IntergranularCementsMicrocracks
HeterogeneityMineral compositionOther segregration processes
![Page 46: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/46.jpg)
Translation of Mineral Properties to Rock Properties
Comparison of mineral properties to rock properties
Rocks have lower strength, especially tensile strengthAnisotropy of minerals and heterogeneity of minerals
ElasticityThermal expansionDiversity of mineral orientation
Creation of microcracks on mineral boundaries
![Page 47: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/47.jpg)
![Page 48: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/48.jpg)
LEFM: Linear Elastic Fracture Mechanics
Rocks are cracked materialsLEFM represents alternative view of material strength that accounts well for scale and geometric effectsImportant in brittle materials
Liberty ShipsComet passenger aircraft
![Page 49: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/49.jpg)
![Page 50: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/50.jpg)
Stress Intensity:
Y – geometric factor
σ – stressa – crack half length
![Page 51: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/51.jpg)
Critical LEFM Elements
Stress IntensityConcentration of stress at Crack Tips
Fracture Toughness Measure of resistance to fractureDepends partly on plasticity of materialsLower in brittle materials
![Page 52: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/52.jpg)
![Page 53: CEE 437 Lecture 2 Minerals - University of Washington · Bowen’s Reaction Series. Weathering Cycle. Elemental Fates](https://reader030.vdocuments.us/reader030/viewer/2022011809/5ceb216c88c993886b8c1257/html5/thumbnails/53.jpg)