1. Blind Thrust
    A thrust fault that dies out in the subsurface as it loses slip and stratigraphic separation
  2. Detachment Fault
    A low angle normal fault or low angle thrust fault
  3. Dip-slip fault
    A fault in which the movement is parallel to the dip of the fault plane, such as a normal, reverse, or listric fault
  4. Footwall Block
    The block that underlies a non-vertical fautl
  5. Fossil Assemblages
    A group of fossils that occur at the same stratigraphic level
  6. Growth Fault
    A fault that forms contemporaneously with depsoition in sedimentary rock
  7. Hanging-wall block
    The block that overlies a non-vertical fault
  8. Heave
    The amount of horizontal displacement on a fault
  9. Index Fossil
    A fossil that identifies and dates the starat in which it is found
  10. Key Beds
    A well-defined, easily identified starta that is distinctive enough to be useful in coreelation in mapping
  11. Listric Fault
    A fault with a curved fault plane. nea the surface the fault plane is steeply dipping, but it becomes progressively flatter with depth
  12. Net Slip
    The distance between tow formerly adjacent points on either side of the fault
  13. Normal fault
    A dip-slip fault in which the hanging wall has moved down relative to the footwall
  14. Oblique-slip fault
    A fault in which movement is not parallel to the strike or dip of the fault plane
  15. Offset
    The horizontal component of displacement measured perpendicular to the strike of the disrupted unit
  16. Reverse Fault
    A dip-slip fault in which the hanging wall has moved up relative to the footwall. The dip of the fault is between 45 and 90 degrees
  17. Rule of V's
    The outcrop pattern of a formation as it crosses a valley forms a V shape. The V points in the direction that the formation underlies the valley
  18. Strike Separation
    The horizontal distance between the stratigraphic unit offset by a fault, measured along the strike of the fault
  19. Stike-slip fault
    A fualt in which the movement is parallel to the strike of the fault plane
  20. Throw
    The amount of vertical displacement on a fault, also the vertical component of net slip
  21. Thrust fault
    A reverse fault in whihch the fault plane dips less than 45 degrees
  22. Type Locality
    The place where a geologic feature was first recognized and described
  23. Type Section
    The orginially described strata that constitutes a stratigraphic unit to which other parts of the unit may be compared
  24. Unconformity
    A gap in the geologic record; an interruption in the depositional sequence that implies uplift and erosion have removed par of the geologic record or non-deposition has occured
  25. Law of Superposition
    The oldest layer is on the bottom and the younges layer is on the top; beds become younger in the direction of dip
  26. The Law of Initial Horizontality
    Assumes that the sequence of lyaers was deposited horizontally or nearly so.
  27. Index Fossils
    Distinguishable from other fossils, have lived during a short geologic time span, lived in different environments, be distributed in a wide geographic area and be abundant
  28. Physical Continutity
    starta are generally continuous unless eroded, interupted by fualting, truncated by an unconformity, shaped as a lenticular body, or deposited locally
  29. Angular Unconformity
    Strata below the unconformity are cut off and are overlain at an angle by the beds above the unconformity
  30. Nonconformity
    sedimentary deposits rest upon older igneous or metamorphy rocks
  31. Disconformity
    beds above and below an unconformity are parallel, but the unconformity is not parallel to the bedding
  32. Paraconformity
    unconformity is parallel to the strata above and below it
  33. Rule of V's: Horizontal Bedding
    V upstream parallel to topography
  34. Rule of V's: Dip Upstream
    V upstream, outside topography
  35. Rule of V's: Vertical Bedding
    straight lines cutting across valley topography
  36. Rule of V's: Dip downstream greater than valley gradient
    V downstream
  37. Rule of V's: Dip downstream equals valley gradient
    parallel lines along valley sides
  38. Rule of V's: Dip downstream less than valley gradient
    V upstream inside topography
  39. Sills
    Concordant features (emplaced along zones of weakness)
  40. Dikes
    discordant features (cutting across many lithologic units
  41. Divergent Plate Boundary
    The plates are moved apart by molten materail of the asthenosphere that is forced up into the crust between the plates; sea floor spreading
  42. Transform Plate Boundary
    plates slide past each other
  43. Convergent Plate Boundary
    Plates collide or converge at a subduction zone
Card Set
ASBOG Study Guide Chapter 3 - Geolgoic Map and Cross Section Interpretation