C.W. Post
Department of Earth and Environmental Science
Prof. Vic DiVenere

Minerals
Igneous Rocks
Volcanoes
Sedimentary Rocks
Metamorphic Rocks
Geologic Structures
Earthquakes

atoms and minerals
calcite (calcium carbonate), quartz, feldspars, muscovite and biotite mica, amphiboles (hornblende), pyroxenes (augite), olivine
- the eight most abundant chemical elements in the crust (especially oxygen & silicon)
- protons, neutrons, electrons and how they compose atoms
- the difference between atoms, elements, ions, compounds, minerals, and rocks
- chemical bonding: covalent and ionic
- mineral classes (silicates and non-silicates)
- mafic vs. felsic silicate minerals, relative amounts of covalent vs. ionic bonding, and resistance to weathering
- the difference between silicon, silica, and silicate (ugh!)
      silicon: the element
      silica: covalent compound between silicon and oxygen
      silicate: any mineral containing silica combined with various metal cations (Fe²⁺, Mg²⁺, Ca²⁺, Na⁺, K⁺, etc.)

igneous rocks and igneous bodies
granite, rhyolite, diorite, andesite, gabbro, basalt
- melt: magma, lava
- melting/crystallization temperature of felsic (low) vs. mafic (hi) minerals
- solid-liquid-gas phases of matter and phase change melting/crystallization
      temperature = avg. kinetic energy
      physical (molecular) difference between solid and liquid (and gas) phases
- Igneous Texture: coarse-grained, fine-grained, porphyritic, glassy
      and mode of emplacement: plutonic (intrusive), vs. volcanic (extrusive)
- Color/Composition: felsic, intermediate, mafic, ultramafic
- classification of igneous rocks (texture and color/composition) 

igneous bodies: volcanoes and igneous intrusions
- lava viscosity & temperature/composition; viscosity vs. volcano slope
- dissolved gases (CO₂ & water vapor), viscosity, and explosive eruptions
- pyroclastic material (bombs, ash, lapili), angle of repose
- shield volcanoes, cinder cones, stratovolcanoes (composite cones), calderas
- what type and viscosity of lava is associated with each
- aa & pahoehoe lava
- intrusive bodies: stocks, batholiths, dikes, sills

weathering and sedimentary rocks
conglomerate, sandstone, shale, limestone, coal
the 5 steps in the formation of sedimentary rocks
      1. weathering of pre-existing rocks produces sediments
      2. transport
      3. deposition
      4. compaction
      5. cementation
1. weathering
mechanical:
      stream abrasion, sand blasting, frost wedging
chemical:
      formation of carbonic acid:most natural surface waters slightly acidic
      hydrolysis: silicate minerals in acid solution alter to clays + soluble ions
      dissolution, oxidation
weathering products: gravel sand, silt, clay, dissolved ions
2. transport: via streams, wind, glaciers, waves
      sorting and rounding
3. deposition (e.g., when stream velocity drops)
      sediments are deposited in horizontal layers (cross-bedding not withstanding)
      oldest layers are on the bottom, younger toward the top
4. compaction, from weight of sediments deposited on top
5. cementation:
      crusts of minerals precipitated from ions dissolved in water into the voids between sedimentary particles
      common cements: silica, calcite (fizzes), hematite (red)
classification of sedimentary rocks
      clastic: conglomerate (and breccia), sandstone, shale
      biogenic (biochemical): limestone, dolomite, coal
      chemical precipitates: halite, limestone (incl. oolitiic limestone)
the importance of sedimentary rocks
      fossil evidence for past life
      record of past geography: marine vs. terrestrial, stream deposits, desert deposits

metamorphic rocks
slate, schist, gneiss, quartzite, marble
conditions for metamorphism
      high pressure, temperature (not so much to melt the rocks), hydrothermal fluids, time
regional metamorphism (our main interest)
      caused by deep burial associated with tectonic collisions and mountain building
      both high pressure and temperature
other types include contact, hydrothermal, and cataclastic metamorphism
protolith --> meta rx (characteristics of meta rx compared to their protolith)
- orientation of foliations relative to the applied (tectonic) forces (perpendicular)
examples:
foliated (w/ slaty cleavage, schistosity, gneissic banding)
      shale --> slate (characteristics of each)
            bedding plane cleavage, relict bedding
      shale --> schist
      granite --> gneiss
non-foliated
      sandstone --> quartzite
      limestone --> marble

structural geology
joints, faults, folds, metamorphic foliation
- compression, tension, shearing stress
- initial elastic response to stress
- brittle vs. ductile response to stress
- folds
      anticlines and synclines
      fold axis, axial plane, plunging folds
      Valley and Ridge topography: differential weathring of folded sedimentary strata
- foliation
      axial planar cleavage
- joint sets
     controls surface weathering and topography
- the 3 categories (4 types) of faults and the stress environments in which they are found
     normal faults: hi angle, hanging wall moves down, extension
            crustal thinning and lengthening
            Basin and Range topography (horst and graben)
            half-grabens (Newark Basin)
     reverse faults: hi angle, hanging wall moves up, compression
     thrust faults: low angle, hanging wall moves up, compression
            crustal thickening and shortening
            mountain belts, collisions (e.g., modern Himalayas, ancient Appalachians)
     strike-slip faults: vertical fault, horizontal movement, shearing
            San Andreas Fault
- orientation of faults, folds, and foliation relative to the applied (tectonic) forces
- topography related to underlying structure
      basin and range topography
      valley and ridge topography resulting from differential weathering of folded strata
be able to draw simple maps and profiles of faults and folds, etc.

earthquakes
- strain buildup -> rupture (slippage) on faults -> seismic waves propagate outward through Earth
- body waves: P waves, S waves
- surface waves: Love waves, Rayleigh waves
- epicenter and focus (hypocenter)
- basic principal of seismometers (inertial mass that remains stationary as the crust moves)
- determining distance from earthquake by S-P interval
- earthquake location via triangulation (S-P interval from three seismic stations)
- information needed to determine an earthquake's magnitude
      peak amplitude of ground motion at recording station
      S-P interval (to determine distance)
- the Richter magnitude scale of the amount of ground motion in an earthquake: logarithmic scale (powers of 10)
- moment magnitude scale of the stress energy released in an earthquake (better measure for large earthquakes)
- Mercalli scale of earthquake intensity (intensity of observed effects)
- first motion studies for determining type of fault and direction of fault motion
- earthquake prone regions (mostly associated with plate boundaries)
- type of plate boundary where worst (greatest magnitude) earthquakes tend to occur
      convergent plate boundaries where an oceanic plate subducts (sinks) beneath another overriding plate
- earthquake probability estimates