IX. Seismic Sections
        A. the characteristics of seismic "waves"
                1. wavelength l, period T, velocity (v and V)
                2. v = fl , f = 1/T
                3. z = V t/2
                4. what affects velocity? (besides lithology!)
                        a. water, consolidation, weathering, fracturing
                            age, burial
                5. why do points and ends look like hyperbolae on unmigrated sections?
                6. vertical resolution and wavelength, horizontal resolution
                7. using two-way travel time t to calculate depth of a reflector
                8. using two-way travel time and a stacked section to calculate
                    dip on a reflector.
        B. scale
                1. vertical resolutions usually >3 m
                2. horiz. resolutions usually >100 m
                3. sections are miles long, miles deep
        C. examples worked on highres Dixie Val section and in lab

X. Seismic stratigraphy
        A. migrated sections - getting rid of the hyperbolae
        AA. limited to clastic deltas on passive margins
                1. very useful in finding oil and gas
                        a. reservoir - porous, permeable coarse sands
                        b. seal - impermeable silt and clay
                        c. oil lighter than water, migrates up
        B. seismic sequence - package of reflectors bound by truncation surfaces
                1. represents one instance of delta-lobe progradation
                2. each sequence boundary is a hiatus in deposition
        C. seismic facies - Interior geometry of a seismic sequence, interpreted
            as a "systems tract"  (see below)
                1. examples covered: oblique, sigmoid, complex, shingled
                    divergent, parallel, hummocky
                2. facies suggests location in sequence and energy of deposition
        D. seismic attributes - not covered, used by geophysicists
        E. truncations and angular relations define seismic sequence boundaries
                1. crucial to know direction of sequence progradation
                2. false boundaries can be ruled out from truncation angle
                    counter to progradation
        F. "reflectors are isochrons"
                1. top-discordant boundaries
                        a. erosional boundary - high energy, coarse sand
                        b. toplap - paleo shelf edge
                2. base-discordant boundaries
                        a. onlap - landward limit of deposition
                        b. downlap - toe of slope, sediment starvation
                            - often is apparent in seismic data where reflector
                               gets too thin

XI. Geophysical downhole logs
        A. "wireline" log of the geophysical properties near a drill hole
                1. examples: resistivity, gamma-ray radiation, caliper,
                    self-potential, acoustic
                2. need to know properties of drilling mud, filtrate, cake
                3. hole will be surrounded by flushed and invaded zones
                        a. to a few meters from bore
                        b. longer logging tools get behind drilling effects
        B. geophysical attributes are relatable to
                1. rock type
                2. fluid properties
                3. porosity/permeability
        C. "shape" of log curves can be interpreted as changes in lithology and
            can be used in lateral correlation
                1. again limited to clastic deltaics