Sedimentary Rocks

  1. Detritus
    "Grain Sized" loose rock derived from older rock- CLAY
  2. Weathering
    • How sedimentary rocks are made
    • Physical and chemical breakdown of rocks
  3. Erosion
    Removal of weathered material
  4. Mass Wasting
    Action of gravity on large masses of rock or sediment.
  5. Deposition
    Build-up of sediment, soil or rock on other landforms.
  6. Percent of earths surface that is sedimentary rock
    70 percent
  7. Sedimentary rock "hosts.."
    gas and oil accumulations, coal, mineral deposits and other resources.
  8. 3 Ways Sedimentary Rocks Form
    • Detrital Sediments
    • Chemical Precipitates
    • Organic Accumulations
  9. Examples of Detrital Sediments
    • Oolitic Limestone, Sand, Silt
    • (Detrital- Held together by cement/matrix)
  10. Examples of Chemical Precipitates
    Gypsum, Halite, Limestone
  11. Examples of Organic Accumulations
    Coquina, Chalk, Coal, (some limestone)
  12. Bedding
    "Layers" always present in sedimentary rocks. (Sometimes present in volcanic rock)
  13. Oncoids
    Small round features (fossil cyanobacteria)
  14. What does the "gray area" deal with?
    Organic and Chemical sedimentary rocks.
  15. Lithification
    Process of cementing rocks
  16. Compaction
    Compacting of rocks (Clay)
  17. White Sand is made out of what?
    Gypsum - which is used for drywall.
  18. Potash
    Evaporite minerals that can be extracted from earth by injecting hot water.
  19. Chert
    Precipitation of quartz, was used for Native American spear points.
  20. Coal
    Made from pressed plants, 300 or more years left of coal.
  21. Depositional Basin
    Thicker than 1km, accumulation of sedimentary rocks.
  22. Structural Basin
    Down warping of the crust.
  23. Ocean crust thickness
    0 to 15 km thick
  24. Continental Crust
    0 to 35 km thick
  25. Metamorphism
    Process that results in changes to the crystallinity or bulk composition of a rock due to heat, pressure, shock or hydrothermal fluids.
  26. Average Geothermal Gradient
    25 to 30 C/km
  27. Types of Metamorphic Rocks
    • Regional
    • Contact
    • Burial
    • Hydrothermal
    • Shock
    • Fault Zones
  28. Regional Metamorphism
    Occurs during mountain building (roots of the mountain)
  29. Contact Metamorphism
    Contact with magma chamber
  30. Burial Metamorphism
    Effects of geothermal gradient.
  31. Hydrothermal
    Contact with hot fluids.
  32. Shock Metamorphism
    Meteorite Impacts
  33. Fault Zones (Metamorphism)
    Shearing of minerals and development of new materials. (two plates sliding against one another)
  34. When minerals recrystallize...
    They become larger in size and change in orientation. Also, mineral grains change.
  35. Parent Rock
    All metamorphic rocks have/come from a parent rock.
  36. Limestone (Parent)
    Marble (Kid rock)
  37. Shale (Parent)
    Slate (Kid Rock)
  38. Quartz and Sandstone (Parent)
    Quartzite (Kid Rock)
  39. Granite (Parent)
    Gneiss (Kid Rock)
  40. Basalt and Gabbro (Parent)
    Amphibolite (Kid Rock)
  41. Metamorphic Grade
    Determined by amount of heat and pressure
  42. Subduction Zone
    High Pressure, Low Heat
  43. Contact (Metamorphic Grade)
    Low Pressure, High Heat
  44. Regional (Metamorphic Grade)
    High Pressure, High Heat
  45. Texture of Metamorphic Rocks
    Foliated, Weakly Foliated, or Non-Foliated.
  46. 3 types of Meteorites
    • Stony Materials (most common)
    • Stony Iron
    • Iron-Nickel meteorite
  47. Oldest rocks found on earth
    4.4 Ga (Billion years)
  48. Types of Radioactive Decay
    • Alpha Decay
    • Beta Decay
    • Gamma-Rays
  49. Alpha Decay
    Loses two neutrons and protons. Helium Ion
  50. Beta Decay
    An electron released when neutron decays into a proton.
  51. Gamma-Rays
    High energy photons (packets of energy)
  52. Earths Layers;
    • Inner Core
    • Outer Core
    • Mantle
    • Upper Mantle
    • Crust
  53. How we know what we know about plate tectonics.
    • -Seismic wave behavior and velocities
    • -Diamond anvil presses
    • -mantle xenoliths
    • -meteorites
  54. Thickness of crust
    0 to 70km thick
  55. Thickness of Mantle
    Made of?
    • 2900 km thick
    • 75 percent of earths volume.
    • Mostly made of peridotite.
  56. Seismic Velocity
    Increases with depth except at velocity zone (200 to 250km deep).
  57. Alfred Wegner
    • hypothesized centrifugal force separated continents, continental drift hypothesis.
    • (WRONG)
  58. Harry Heis
    Plate tectonic hypothesis. Convection cells in the mantle drove plate tectonics.
  59. 4 Sources of Magma
    • Spreading Centers
    • Subduction Zones
    • Deep Crustal Zones
    • Mantle Plumes
  60. Outer Core (Made of)
    Mostly Iron and Nickel
  61. Inner Core
    Always solid due to pressure.
  62. Craton
    Very old stable part of continental crust, usually in the middle of a continental plate.
  63. Shields
    Cores of Cratons that are exposed.
  64. Platforms
    Craton covered by thin layer of sedimentary rock.
  65. Orogens
    Linear belts of mountains at collisional boundaries.
  66. Basins
    Structural and sedimentary features where crust has been down-warped.
  67. Tectonic plates include
    Crust and uppermost mantle
  68. Deformation (where)
    Most common at tectonic plate boundaries.
  69. Types of rock deformation
    • Elastic
    • Brittle
    • Ductile
  70. Elastic Deformation
    bend and rebound, causes earthquakes.
  71. Brittle Deformation
    Faults and Fracturing
  72. Ductile
    • Creates Folds;
    • Strata can be folded
    • Stress and strain (compressional forces)
  73. Types of Folds
    • Anticline
    • Syncline
    • Domes
    • Basins
  74. Anticline
    "Closed" Direction
  75. Syncline
    "Open" Direction
  76. Thrust Fault
    Low-angle reverse fault (results of compression)
  77. Strike Slip
    Two tectonic plates rubbing against one another (shearing).
  78. Isostasy
    Vertical "drop" in land due to weight. (Explains why mountains have roots)
  79. Hawaiian Islands
    Emperor Seamount Chain, 43 Million year bend caused by absolute plate motion.
Card Set
Sedimentary Rocks