Textbook: CH 4 (p. 92-107), CH 5 (p. 121-135), CH 6 (p. 136-162), CH 7 (p. 163-172), CH 9 (p. 221-224, 228-230, 238-240, 242-247).

On-line earthquake lectures: all 6 at
http://www.seismo.unr.edu/ftp/pub/louie/class/100/100-earthquakes.html

Class notes, handouts, especially gravity measurements and structural geology.

Outline of Topics:

• Sedimentary Rocks
  • sediment transport, velocity, suspension, saltation, bed load
  • sedimentary structures
    • bedding: cross-bedding, planar laminations, graded bedding
    • bedding-plane features: ripple marks, flute casts, mud cracks, loading structures
  • lithification and diagenesis: cementation, compaction, alteration (<200 C)
• Metamorphic Rocks
  • classification: protolith, metamorphic grade, metamorphic facies
  • greenschist, blueschist, skarn, migmatite
  • contact, regional, and blueschist metamorphism: pressure, temperature, and plate-tectonic environments (>200 C)
  • metamorphic minerals: micas, garnets
  • texture, fabric: slaty, schistose, gneissic
• Gravity and Isostacy
  • acceleration units, galileo unit, mGal, 1g ~ 980 Gal on Earth's surface
  • acceleration less w/ distance/height, equatorial bulge (20 km)
  • 1^st and 6^th floor AB experiment: scale factors, sign of change, height, errors
  • isostatic compensation: mountains, roots, densities, depth of compensation, crust vs. mantle densities, elastic lithosphere vs. soft asthenosphere
  • isostatic rebound: lakes (Lahontan), icecaps
• Earth's Magnetism
  • dipole field, inclination and declination, magnetic poles
  • Curie temperature for permanent magnets
  • current loops make magnetic fields
  • self-generating dynamo: outer-core convection, Earth's spin, secular variations
  • magnetic reversals, normal and reversed epochs, Cox and Dalrymple, magnetostratigraphy
• Plate Tectonics
  • earthquake locations define plate boundaries
  • where plate tectonics works: oceanic plates, not always continental interiors
  • history: Wegener's continental drift theory, lack of sensible driving force, evidence from shapes, paleoclimate, fossils
  • Hess and seafloor spreading, mid-ocean ridges and transforms, magnetic anomalies and transform earthquake focal mechanisms, seafloor age record
  • driving forces: ridge push, slab pull, slab suction, hot mantle under ridges
  • compressional examples: Tibet, Andes, rain shadow, angle of subduction
  • plate tectonic examples from other planets
  • Nevada plate tectonics: 12% of Pacific-North America motion, basin and range extension, Walker Lane strike-slip, high elevations and hot mantle
• Rock Deformation
  • temporary or dynamic vs. static or permanent
  • elastic (temporary) vs. plastic, ductile, or viscous (permanent flow)
  • brittle (faulted and fractured) vs. ductile (plastic or flow)
  • folds: axis, limb, anticline, syncline, plunge, symmetry, rounded, chevron, overturned, recumbent, isoclinal, blind thrust
  • joints: parallel (extension, cooling), intersecting (compression or shear)
  • strike, dip: definitions
  • faults: headwall and footwall; normal, reverse, thrust, strike-slip
  • elastic rebound (permanent deformation after earthquake)
  • seismic waves: particle motion, travel direction, P waves, S waves, velocities
  • earthquake moment: M0 = (mu)Ad ; torque; fault rigidity, area, displacement
• Earthquakes
  • seismometers and seismograms, Landers earthquake record played as sound
  • wave arrival times and distance, S-P times, locating earthquakes from several stations
  • magnitude (one intrinsic value) vs. intensity (many from one event)
  • Richter magnitude scale:
    • calculated from wave amplitude and distance
    • magnitudes felt, damage to poorly or well-constructed buildings
    • calculated from moment or energy through the logarithm
    • review of base-10 logarithms
  • earthquake effects:
    • cultural factors: construction quality, time of day, preparedness
    • direct effects: fault offset, ground uplift or sinking (radar)
    • secondary effects: seismic shaking, liquefaction, landslides, tsunamis
    • soft, water-saturated soils increase and lengthen shaking
    • Kobe example: heavy roofs, weak 5th floors, concrete column failures
    • earthquake-triggered fires: Kobe, San Francisco in 1906 and 1989
    • liquefaction and settling, pile foundations
• Earth Structure
  • asthenosphere, lithosphere, mantle, core
  • refraction of light in a prism, or seismic waves at the core-mantle boundary
  • S waves can't propagate in liquids, outer core
  • shadow zones: S-wave shadow, P-wave shadow from refraction, estimating the size of the core
  • seismic tomography of the mantle: fast, cold, dense sinkers vs. slow, hot, light plumes; relation to locations of ridges and subduction zones, to core
• Geologic History Diagrams
  • Steno's Laws: original horizontality, superposition, cross-cutting relations, sequencing
  • unconformities: long interruption in deposition; erosion, angular unconformities and histories of deposition, tectonic activity, erosion, subsidence, later deposition
  • labeling sediment layers in order of deposition
  • what cuts what: sequence of folding, faulting, diking, and erosional events