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Basics of Geochemistry
Powerpoint file of this section on Basics of Geochemistry 
Abundance and speciation of the elements
Atoms
Abundance of the elements
Binding energy and elemental abundance
Abundance and form of the most abundant elements in Earth's continental crust
Cations and anions I: definitions
Cations and anions I: some geochemical realities
Cations and anions III: geochemical perspectives on ionic bonding
Cations and anions IV: the meaning of the superscripts
Variation in ionic radius between and within elements
Ionic Potential
Hardness and softness of ions I: an introduction
Hardness and softness of ions II: a spectrum across the periodic table
An Earth Scientist's Periodic Table of the Elements and Their Ions
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A bit of the Earth Scientist's Periodic Table of the Elements and Their Ions as a cross-section of the Earth
Categorizing cations
Categorizing anions
The importance of oxygen
The special situation of silicon
Redox chemistry
A brief review of redox chemistry
A periodic table of redox behavior
Common redox reactions in the oxidation of organic matter
Characterization of solutions by pH and Eh - the canonical view
Characterization of solutions by pH and Eh - a data-based view
Why oxidation commonly leads to acidification
Redox, ionic potential, and the behavior of cations
The geochemical redox conditions of some important elements
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Solutions and aqueous speciation of ions
Solutions, colloids, and suspensions
Speciation of cations in aqueous solution I
Speciation of cations in aqueous solution II
The power of polydentate ligands
Aqueous speciation of some hard cations across the periodic table
Variation in hydrated radius of ions
Aquoacidity of cations, in context
Silicon in aqueous solution
Conductivity as a proxy for total dissolved solids
Solutions, CO2, HCO3-, CO32- and CaCO3
Speciation of inorganic carbon in aqueous solution
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Variation in the dissociation constants of H2CO3 and HCO3- with temperature and salinity
PCO2 of atmospheres and pH and HCO3 - concentration of solutions
Carbonate equilibria in solutions exposed to the atmosphere I
Carbonate equilibria in solutions exposed to the atmosphere II
The carbon, and carbonate, cycle
Ca2+ and HCO3- concentrations in natural waters. Part I: a plot
Ca2+ and HCO3- concentrations in natural waters. Part Ia: an inset
Ca2+ and HCO3- concentrations in natural waters. Part Ib: an inset
Ca2+ and HCO3- concentrations in natural waters. Part II: observations
The reaction for equilibrium of CaCO3 with natural waters
Reactions for the dissolution of CaCO3
Reactions for the precipitation of CaCO3
Degassing of CO2 and precipitation of CaCO3
Adsorption of hydrated Mg2+ on calcite as an inhibitor of calcite growth
minerals" in the section on Carbonate minerals below.
Basics of Mineralogy
Powerpoint file of this section on Basics of Mineralogy The meaning of "mineral"
The definition of "mineral", Part I: The 1800s (and their influence today)
The definition of "mineral", Part II: The 1900s
The definition of "mineral", Part III: The 2000s, and a modern definition
The diverse meanings of "mineralize"
Compendia of minerals
Crystallinity, coordination, and chemistry
Crystallinity and mineral stability I
Crystallinity and mineral stability II
The ubiquity of crystallinity
Coordination of anions around cations
Two-fold and three-fold coordination
Four-fold (tetrahedral) coordination
Six-fold (octohedral) coordination
Eight-fold (cubic) coordination
Twelve-fold coordination
Coordination and radius ratios
Variation in C-O and Si-O coordination
Chemical Bonding
Mineralogical implications of the hardness and softness of ions
Repulsion between cations, and mineral stability
Linkage of polyhedra in minerals
Systematic Mineralogy
A table of systematic mineralogy I: basic categories
A table of systematic mineralogy II: redox implications
A table of systematic mineralogy III: redox pairs
A table of systematic mineralogy IV: numbers of minerals
Notes to accompany "A table of systematic mineralogy"
A table of hybrid minerals
Radical groups in minerals, and the oxysalts,
sulfosalts, seleniosalts, tellurisalts, and fluosalts
Patterns in the compositions of minerals I: carbonates and sulfates
Patterns in the compositions of minerals II: silicates and phosphates
Patterns in the compositions of minerals III: the oxysalt or "ate" minerals
Patterns in the compositions of minerals IV: chlorides and oxides
Patterns in the compositions of minerals V: the "ide" minerals
Patterns in the compositions of minerals VI: a summary
Growth and stability of minerals: nano-scale models
Surface features on a growing or dissolving crystal: terraces, kinks, and steps
Particle size and reactivity: It's all about edges and corners, rather than surface area
An explanation of the free-energy barrier to nucleation of crystals
Thermodynamics of nucleation of a new crystal vs. growth on an existing crystal
A thermodynamic perspective on Ostwald ripening
A thermodynamic perspective on Ostwald's Step Law
An illustrative example of Ostwald's Step Law: silica
An explanation of transport-limited and surface-reaction-limited crystal growth
How rate of solute supply can control crystal morphology
Phenomena at mineral surfaces
Sorption: adsorption and absorption
Surfaces, double layers, and adsorption I: some historical scientific context
Surfaces, double layers, and adsorption II: the interaction of H2O with mineral surfaces
Surfaces, double layers, and adsorption III: variation with pH
Surfaces, double layers, and adsorption IV: a diffuse layer in the Gouy-Chapman model
Surfaces, double layers, and adsorption V: a compact layer in the Stern model
Surfaces, double layers, and adsorption VI: models of specific or "Type II" adsorption
Surfaces, double layers, and adsorption VII: different surfaces in one crystal
Adsorption of cations, and adsorption isotherms
An explanation of "point of zero charge" - Part I
An explanation of "point of zero charge" - Part II
An explanation of why distribution coefficients vary with precipitation rate and temperature
Adsorption of hydrated Mg2+ on calcite as an inhibitor of calcite growth
Mineral Groups
Powerpoint file of this section on Mineral Groups Silicate minerals
The many forms of silica (SiO2) I: minerals and solutes
The many forms of silica (SiO2) II: rocks and other aggregates
Feldspars and feldspathoids I: tetrahedral substitutions
Feldspars and feldspathoids II: the common feldspars
Feldspars and feldspathoids III: the feldspars of large cations
Feldspars and feldspathoids IV: the boron-bearing feldspars
Feldspars and feldspathoids V: a summary of the feldspars
Feldspars and feldspathoids VI: feldspar polymorphism and solid soutions
Feldspars and feldspathoids VII: the feldspathoids
Feldspars and feldspathoids VIII: the limits of interstitial cations
Generalized trends in silicate minerals in igneous rocks
Bowen's Reaction Series
Bowen's Reaction Series I: The original document
Bowen's Reaction Series II: A silicon-centered explanation
Bowen's Reaction Series III: Melting temperatures of oxides
Bowen's Reaction Series IV: Toward a broader explanation
Bowen's Reaction Series V: A summary explanation
Clay minerals
Clay Mineralogy I: Phyllosilicate Minerals
Clay Mineralogy II: T-O-T phyllosilicate Minerals
Clay Mineralogy III: Compositions of T-O-T phyllosilicate minerals
Why clay (Al-phyllosilicates) is clay (fine-grained minerals)
X-ray diffraction and the powder method
Carbonate minerals
Cation sites in the common carbonate minerals
CaCO3 minerals
Stability and solubility of carbonate minerals of divalent cations
Factors favoring precipitation of CaCO3 as calcite or as aragonite
Adsorption of hydrated Mg2+ on calcite as an inhibitor of calcite growth
Mg-bearing carbonate minerals
Solubility of common carbonate minerals
Occurrence of common carbonate minerals
The diversity of carbonate minerals
The many wonders of CaCO3
Properties of Minerals
Powerpoint file of this section on Properties of Minerals Properties of minerals
Density of minerals
Density of Minerals I: Inter-radical cations
Density of Minerals II: Complex anions in oxysalts
Density of Minerals III: Oxides and stoichiometry
Density of Minerals IV: Simple anions
Density of Minerals V: Coordination
Density of Minerals VI: The effect of structural H2O
Density of Minerals VII: The effect of OH- in oxysalts
Density of Minerals VIII: The significance of crystal structure
Hardness of minerals
Hardness of Minerals I: the Mohs Scale
Hardness of Minerals II: Variation with structure and bonding
Hardness of Minerals III: hydrous vs. anhydrous minerals
Hardness of Minerals IVa: variation with bond length and cation size
Hardness of Minerals IVb: variation with bond length and anion size
Hardness of Minerals Va: Variation among oxides and oxysalts
Hardness of Minerals Vb: Variation among oxides and oxysalts
Hardness of Minerals VI: Effect of crystal face and direction
Density and hardness of minerals
Density and hardness I: a first look
Density and hardness II: a look using normalized density
Density and hardness III: Knoop hardness and normalized density
Melting temperature and hardness of minerals
Melting temperature and hardness of minerals
Color of minerals
Color of minerals
Color in the olivine-group minerals
Color in carbonate minerals
Topics in Geochemistry
Powerpoint file of this section on Topics in Geochemistry Isotopic geochemistry
Isotopes
Relative abundance of stable isotopes: even-odd relationships
Commonly used stable isotopes
The delta symbol in stable isotope geochemistry
Isotope notations: %s, δ values, and ε values
A simple mass spectrometer
Isotopic mixing curves
An explanation of why isotopic fractionation varies with precipitation rate and temperature
Oxgyen isotope composition of calcite as a function of temperature and water composition
A graphic explanation of fractionation of oxygen isotopes between water and calcite
Oxygen isotope fractionation in the precipitation of calcite and aragonite
The "clumped isotope" paleotemperature method for carbonates
Rock-water ratios and the stability of δ13C and δ18O values in carbonate materials
C and O stable isotope compositions of Cenozoic Earth-surface materials of all sorts, Part I
C and O stable isotope compositions of Cenozoic Earth-surface materials of all sorts, Part II
The δ13C record of marine limestones
The δ18O record of marine limestones
Correlation of charge and δ13C in Earth-surface C-bearing materials
Parallels in fractionation of isotopes and partitioning of trace elements
Half-lives and abundances of radioactive isotopes
Half-lives of radioactive atoms and measurement of age
Decay systems commonly used in radiometric dating
Radiometric dating via U-series disequilibrium I
Radiometric dating via U-series disequilibrium II
Terrestrial carbonates
Earth's naturally occurring carbonate materials
Degassing of CO2 in caves and precipitation of speleothems
Controls on the δ13C and δ18O of spelean CaCO3
C and O stable isotope compositions of speleothems
Sources of C and O in the CaCO3 of speleothems, or,
Why δ13C varies more than δ18O in speleothems
Isotopic evolution of cave waters with degassing of CO2 and evaporation
C and O stable isotope compositions of pedogenic carbonates
δ13C and δ18O profiles in pedogenic carbonates
Pedogenic CaCO3 (caliche) as a record of ancient atmospheric concentration of CO2
Organic geochemistry
Organic and inorganic compounds
Organic and inorganic compounds, and biogenic and non-biogenic materials
Unpaired electrons of atoms and the compositions of simple molecular substances
Organic structures and functional groups relevant to geochemistry and environmental chemistry
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C-H-O chemistry of some naturally occurring organic substances
C-H-O chemistry of some naturally occurring redox reactions
Atmospheric geochemistry
Why the gases of the atmosphere are gases
The chemical composition of Earth's atmosphere I
The chemical composition of Earth's atmosphere II: the big two
The chemical composition of Earth's atmosphere III: the noble gases
The chemical composition of Earth's atmosphere IV: water vapor
The chemical composition of Earth's atmosphere V: the major carbon-bearing species
The chemical composition of Earth's atmosphere VI: anthropogenic inputs
The multiple forms of oxygen
The chemical composition of Earth's atmosphere VII: the O-bearing radicals
The chemical composition of Earth's atmosphere VIII: the role of the OH radical
The chemical composition of Earth's atmosphere IX: residence times
Acid Rain I: the big picture
Acid Rain II: the details
The Suess Effect
Geochemistry of some natural waters
Chemistry of some river waters with respect to bedrock lithology
Variation in groundwater chemistry with host lithology
Variation in groundwater pH and total dissolved solids with depth
Change in pH and total dissolved solids of groundwater with depth and time
Variation in concentration of dissolved silica with depth
Variation in dissolved O2 with depth in groundwater
Chemistry of lacustrine waters
Size and salinity of lakes, and the ocean(s) I
Size and salinity of lakes, and the ocean(s) II
Weathering, soils, and soil development
Carbon dioxide in soil
Goldich's Weathering Series explained in terms of bond strength
Mineralogy of soils from the Piedmont and Blue Ridge of the southeastern United States
Soil development through time I
Soil development through time II
Chemistry of seawater / marine chemistry / chemical oceanography
The twenty-four most abundant solutes in seawater
Density of seawater at the sea surface
Marine nutrient cycles I: Nitrogen
Marine nutrient cycles II: Phosphorous
Marine nutrient cycles III: Silicon
Marine nutrient cycles IV: Iron
Iron as a limiting nutrient in the ocean
Variation in concentration of solutes in the oceans I: Nutrients (nitrate, phosphate, silica)
Variation in concentration of solutes in the oceans Ia: Nutrients and biological productivity
Variation in concentration of solutes in the oceans II: Dissolved oxygen (O2)
Variation in concentration of solutes in the oceans III: Carbon dioxide (CO2)
Variation in concentration of solutes in the oceans IIIa: Carbon dioxide and the carbonate compensation depth (CCD)
Variation in concentration of solutes in the oceans IV: Oxidation of sinking organic particles - a summary
Variation in δ13C of dissolved inorganic carbon in the oceans
Variation in concentration of solutes in the oceans V: Scavenged ions
Variation in concentration of solutes in the oceans VI: The conservative solutes
Concentrations and residence times of solutes in seawater I: an oceanographic perspective
Concentrations and residence times of solutes in seawater II: a geochemical perspective
Concentrations and residence times of solutes in seawater III: a combined perspective
A mid-ocean ridge vent or "black smoker", Part I
A mid-ocean ridge vent or "black smoker", Part II
The Warm Saline Deep Water hypothesis
Box models of the long-term carbon cycle
Boron in marine calcite as an indicator of ancient PCO2
The Black Sea
The Black Sea I: Geography
The Black Sea II: A schematic cross-section
The Black Sea IIIa: Variation with depth
The Black Sea IIIb: Chemical variation with depth
Isotopic records of the Cenozoic
Oxygen isotope records of Cenozoic global cooling and glaciation
The Paleolithic in the context of oxygen isotope records of Cenozoic cooling and glaciation
The last 150,000 years of human and glacial history
Terminology and timing of some later Quaternary climatic events
Holocene ice core isotopic records, climatic events, and human history
Democracy in the context of human and glacial history
Environmental issues
DDT, Part I: chemical and ecological aspects
DDT, Part II: Silent Spring and the banning of agricultural use of DDT
Chlorofluorocarbons (CFCs) and related compounds: a gallery
CFCs and related compounds, and their environmental history
Chlorofluorocarbons (CFCs) and related compounds: a tabular summary
Chlorofluorocarbons (CFCs) and related compounds: atmospheric concentrations through time
Simple CFCs in the spectrum from carbon tetrachloride to carbon tetrafluoride
Toxicology and past use of Pb (lead)
Greenland ice records of lead transport in the atmosphere
Geochemistry of deep-basin brines
Deep-basin brines I: Density, TDS, and chloride
Deep-basin brines II: Variation in major cations
Deep-basin brines III: Dominance of Ca2+ among cations
Deep-basin brines IV: Dominance of Cl- among anions
Deep-basin brines V: Effect of Ca2+'s dominance on pH and SO42- concentration
Deep-basin brines VI: Comparison with shallower groundwater
Contextual Materials
Powerpoint file of this section of contextual illustrations Basic Geology
Rocks, Part I
Rocks, Part II - the rock "cycle"
Rocks, Part III
Origins of melts and magmas I
Origins of melts and magmas II
Metamorphism and metamorphic rocks
The origin of sedimentary rocks
The origin of siliciclastic and biochemical sedimentary rocks
Lithification of sediments to sedimentary rocks I: Proceses
Lithification of sediments to sedimentary rocks II: Possible pathways
Lithification of sediments to sedimentary rocks III: Compaction
Lithification of sediments to sedimentary rocks IV: Cementation
Steno's princples of sedimentary layers
Unconformities and their significance to geologic time
Movement of facies of sediment with rising sea level
The Bigger Picture
Earth at a glance
Plate tectonics: divergent, convergent, and transform boundaries
Sources of geological information in the field
Large-scale flow in Earth Systems
What is an ocean, and how many does Earth have?
Variation of atmospheric pressure between and within climatic belts
The Trade Winds and Westerlies wind belts
The Ekman spiral, dynamic topography, and coastal and equatorial upwelling
Interactions of currents, tides, and waves
Interactions of currents, tides, and waves II
The age of the Earth and our solar system
The standard geologic time scale
A Phanerozoic paleoenvironmental timeline
Possible causes of sea-level change
The size of things
The Quaternary
