EAR 101 Test 3

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  1. What is the law of superposition?
    in an undeformed sequence of sedimentary rocks, each bed is older than the one above and younger than the one below
  2. What are cross cutting relationships?
    A rock is younger than any rock through which it cuts
  3. What is a halflife?
    The time required for half of a sample to decy
  4. How can we determine half lives?
    When the quantities of the parent and daughter are equal
  5. What elements make useful geologic clocks?
    • Potassium-Argon
    • Carbon-14
  6. What is the half life of 40K?
    1.3 billion years
  7. What is the half life of 238U?
    4.5 billion years
  8. How is 14C dating different from other forms of radiometric dating?
    It has a half life 5,730, so it dates more recent things
  9. What is the Shroud of Turin?
    Cloth bearing image of man, used radioactive testing, from 1260-1390
  10. How does radioactive 14C Form?
    • Produced in the upper atmosphere
    • Cosmic Rays shatter gas atoms releasing neutrons
  11. What is the oldest rock on earth?
    Precambrian, metamophic rocks
  12. What is the oldest terrestrial mineral on Earth?
    zircon---4.3 billion years
  13. When did the Archean Period end?
    2,500 million years ago
  14. What is special about 543 million years ago?
    The Paleozoic Era began
  15. What is the age of the Earth?
    4.6 billion years old
  16. What is the half life of 14C?
  17. Can we calculate the half life of a radioactive element without waiting for half of it to decay?
    Yes, when the parent and daughter quantities are equal
  18. What kinds of evidence makes us more convinced that geochronologic ages are correct?
  19. What is significant about the Cambrian Period of geologic time?
    It is the first evidence of abundant fossils
  20. What is ground water?
    Any water in saturation zone
  21. What is a water table?
    The upper limit of the saturation zone
  22. What is the shape of the water table?
    it replicates the topography of the land
  23. What is permeability?
    the measure of interconnected pore spaces, or ability of water to flow through pores
  24. What is porosity?
    The measure or water that soaks into the ground
  25. What rocks have high porosity/permeability?
    Coarse grained rocks
  26. What is an aquifer?
    Permeable rock strata that transmit groundwater freely
  27. What is an aquiclude?
    solid impermeable body that acts as a barrier to groundwater
  28. What is a perched aquifer?
    Small aquifer with a local water table that sits above the main aquifer
  29. What are some problems with ground water?
    • -Use more then put in
    • -Ground sinkage
    • -Saltwater Contamination
    • -Pollution
  30. How much fresh water does groundwater account for?
    24% or 83.3 billion gallons per day
  31. What is Karst?
    Large areas that have been shaped by the dissolving power of ground water
  32. What are speleotherms?
    Dripstone features found in caverns
  33. What is a stalagmite?
    Speleotherms that form on the form reaching upward
  34. What is a stalacite?
    Speoleotherms that form on the ceiling coming down (think icicles)
  35. What is a sink hole?
    depression produced in a region where soluble rock has been removed by groundwater
  36. How can you determine how fast groundwater moves?
    • Velocity= K* (h2-h1)/L
    • K-coefficient of permeability
  37. What is Darcy's Law?
    Showed velocity of groundwater flow is proportional to the slope
  38. How do you find the hydraulic gradient?
  39. What is the cone of depression?
    The cone groundwater makes from wells
  40. What is an artesian well?
    A well drilled into an aquifer where the hydraulic head is higher than ground surface
  41. What is a spring?
    Where the water table intersects Earth's surface
  42. What does the unsaturated zone mean?
    A mix of air and water
  43. What is a glacier?
    A permanent mass of moving ice made of compressed snow on land
  44. What are the different kinds of glacier?
    • Alpine (mountain)
    • Continental
  45. How do glaciers move?
  46. How many glacial period have there been in the past 1 million years?
    About 10
  47. How many glacial periods have been in the last 2 million years?
    about 30
  48. How do fossils and oxygen isotopes help in understanding glaciations?
    • Helps to tell times or warmth and glaciation
    • Normal to high levels of oxygen isotopes means glaciation
  49. What are Arretes?
    Sharp edged ridges
  50. What are horns?
    Sharp pyramid like peaks projecting above surroundings
  51. What are Cirques?
    Bowl shaped depressions with precipitous walls on 3 sides but are open downvalley
  52. What are hanging valleys?
    Where glaciers recede and valleys of tributary glaciers are left standing
  53. What is a tarn?
    Small lake from where a glacier used to be
  54. What is a fjord?
    flooded glacial valley
  55. What are striations?
    Grooves in the glacier
  56. What is an erractic glacier?
    "Rock out of place"
  57. What is a kettle lake?
    A large block left behind
  58. What are Moraines?
    glacial till deposited at the sides and ends of glaciers
  59. What are Drumlins?
    Whale shaped object composed of glacial till
  60. What is a lateral moraine?
    Parallel ridges of debris along the side of glaciers
  61. What are medial morraine?
    The middle part of the glacier
  62. What are ground moraines?
    At the base of the ice
  63. What are the 3 cycles of the Milankovitch Cycle?
    • 1. Eccentricity
    • 2. Change in tilt of Earth's rotational axis
    • 3. Change in precession of Earth's rotational axis
  64. What causes seasons?
    Rotational axis tilt causes seasons
  65. What is plastic flow?
    Movement within the ice
  66. What is basal slip?
    Meltwater acts as a hydraulic jack and helps move ice over rock
  67. What is Firn?
    The granular recrystallized snow
  68. How many kilometers are in a mile?
  69. How many Liters in a gallon?
  70. How many pounds in a kilogram?
  71. How many inches in a centimeter?
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EAR 101 Test 3
2011-11-15 01:42:21
earth science syracuse university

EAR 101 Test 3 - Syracuse University
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