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GEO 1111 Midterm 2

Deleted user User has deleted their subject information English 103 cards

GEO 1111 Midterm 2

Cards in this deck (103)

  1. 1Factors that determine the "violence" of eruptionshigh viscosity = explosive eruption (bubbles cant continuously escape, builds up)
    1) composition : high silica = high viscosity
    2) temp : low temp = high viscosity
    3) gasses in magma : low [gas] = high viscosity
  2. 2Materials Extruded from a VolcanoFelsic materials : silica rich, high viscosity
    (continental rock)
    Mafic (basalt) : silica poor, low viscosity
    (mantle)
  3. 3How does magma get silica rich if it comes from the mantle?the mantle is mainly mafic, but when the mantle rock melt reaches the crust (felsic, high silica), it melts the crust as well, which makes the melt more felsic.
    ** rarely ever felsic in oceans **
  4. 4—Pahoehoe Lava (EFFUSIVE)
    twisted, ropey structure    Pahoehoe Lava (EFFUSIVE) twisted, ropey structure
  5. 5—Aa Lava (EFFUSIVE)
    rough, jagged, blocky    Aa Lava (EFFUSIVE) rough, jagged, blocky
  6. 6—Pillow Lava (EFFUSIVE)
    found underwater    Pillow Lava (EFFUSIVE) found underwater
  7. 7—Lava Dome (EFFUSIVE)
    bulbous mass of congealed lava
    low [gas], so it seems like it should be explosive, but isn't    Lava Dome (EFFUSIVE) bulbous mass of congealed lava low [gas], so it seems like it should be explosive, but isn't
  8. 8Pyroclastic MaterialsTephra: fine dust fragments
    Cinders: pea sized fragments
    Pumice: rock with lots of pores (frothy lava)
    Lapilli: walnut sized fragments
    Blocks: hardened/cooled lava
    Bombs: Ejected as hot lava, then cools when in air, makes teardrop shape
  9. 9Eruption Columnsmade up of a cloud of tephra
    heavier material falls back to earth
    can cause volcanic winter
  10. 10Lateral Blastside of the volcano blows out instead of top.
    earthquakes can cause the eruptions that occur to be lateral; if the volcano breaks apart on the side, it will be easier for the lava to eject on the side.
  11. 11Pyroclastic Flow & Surgesmix of hot gas and rock
    flows like an avalanche, moves fast
    usually in valleys
    due to column/dome collapse
  12. 12Eruption Types: Hawaiianlow viscosity
    non explosive
    little/no pyroclastic material
  13. 13Eruption Types: StrombolianBlasts of lava
    includes bombs & tephra
    low elevation columns & pyroclastic flows
    mildly explosive
  14. 14Eruption Types: Vulcaniansustained explosions of super viscous lava
    columns reach many km high, then collapse to pyroclastic flows
    very explosive
  15. 15Eruption Types: Peleancollapse of lava domes
    violently explosive
  16. 16Eruption Types: Piiniansustained ejection of magma
    eruption column 45 km high
    huge ash clouds
    violently explosive
  17. 17Eruption Types: Phreaticmagma mixes with shallow groundwater; flashes to steam
    explosively erupts
    no new magma reaches the surface in this eruption
  18. 18Volcanic Landforms: Volcanic conethe hill/mountain
  19. 19Volcanic Landforms: Ventsurface source of eruption (where it actually erupts)
  20. 20Volcanic Landforms: Crater/Calderathe depression that surrounds the vent
    caldera = large
    crater = small
  21. 21Volcanic Landforms: Fissurescracks in the ground that ooze the lava
    usually low viscosity lava (basalt)
  22. 22Volcanic Landforms: Volcanic Pipes & Necksshort conduits that connect the magma chamber to the surface
  23. 23Volcanic Landforms: Lava Tubehot underneath, crystallizes on top
  24. 24—Shield Volcano
    created from effusive eruptions near main vent, grows slowly over time
    little pyroclastic materials
    composition: mafic
    Viscosity: low    Shield Volcano created from effusive eruptions near main vent, grows slowly over time little pyroclastic materials composition: mafic Vis...
  25. 25—Stratovolcano
    most common
    created from many layers that get covered by lava over and over again
    most violent eruptions    Stratovolcano most common created from many layers that get covered by lava over and over again most violent eruptions
  26. 26—Cinder Cone
    usually less than 1 km base
    tephra and loose pyroclastic material    Cinder Cone usually less than 1 km base tephra and loose pyroclastic material
  27. 27—Volcanic Domes
    bulbous mass of congealed lava
    most associated with explosive eruptions of gas-poor magma    Volcanic Domes bulbous mass of congealed lava most associated with explosive eruptions of gas-poor magma
  28. 28Fumarolesa vent where gases emerge at the surface of the earth
    CO2, SO2, H2O
  29. 29Hot/Thermal Springscold water at surface sinks into the permeable volcanic rock, stops at the impermeable rock, then moves along until reaches a magma body, heats up, then comes to surface
    gently rises to the surface
  30. 30Geyserif the water builds up pressure when coming up to the surface, or flow gets restricted, makes a geyser
  31. 31Volcanic Eruptions : Secondary Effects Lahartephra & water; can happen right after eruption or years later
  32. 32Volcanic Eruptions : Secondary Effects Debris Avalanches/flowsunconsolidated volcanic material that flows down slope due to gravitational instability
  33. 33Volcanic Eruptions : Secondary Effects Tsunamiresults from flows, avalanches, landslides, and caldera collapses entering body of water
  34. 34Volcanic Eruptions : Secondary Effects Atmospheric Effectsboth solid and gas particles are released during eruptions
    CO2: can raise temp by a few degrees for long periods of time
    SO2: can cause acid rain
    Dust: can cover the sun - lower temp
  35. 35Volcanic Eruptions : Secondary Effects Positive Effectsgeothermal energy
    metallic ore deposits
    fertile soil = food&drink
    most of historical atmospheric composition contributed by volcanoes sending gas into the air
  36. 36Volcanic Monitoring: Short term Seismic Monitoringearthquakes usually come before a volcanic eruption
    Volcanic tremor: continuous rhythmic shaking
  37. 37Volcanic Monitoring: Short term P&S wavesS waves cant go through liquids, so if sent through one side, and not shown on other, then magma body full of magma
  38. 38Volcanic Monitoring: Short term Ground Deformationdue to the inflation of the magma chamber when magma flows in
    Tilt Meters: use meters to measure angle of ground, track angle changes
  39. 39Volcanic Monitoring: Short term change in magnetic fieldmany rocks have minerals that are magnetic
    when temp rises to certain level, minerals can stop being magnetic
  40. 40Volcanic Monitoring: Short term changes in gas compositiongas coming out of a volcano changes before an eruption
    increase of HCl & SO2
  41. 41Volcanic Monitoring: Short term electrical resistivityall other changes cause a change in electrical resistivity
    when magma moves in, resistivity decreases
  42. 42Volcanic Monitoring: Short term Ground water changeswhen magma enters, changes in the ground water system can happen
    can make the water rise or fall
  43. 43Volcanic Monitoring: Short term heat flowwhen magma comes close to the surface, the temp of the surface/ground water will increase
  44. 44Volcanic Monitoring: Long termmostly the knowledge of the geologic and eruption history of the area
    long term more easy to monitor
    eg. mapping bedrocks
  45. 45Divergent Marginsplates moving apart
    can happen in ocean or continent
    always leads to the creation of an ocean basin
    crust is stretched and thinned
  46. 46Transform Boundariesslide along one another
    no igneous activity
    plates are conserved
  47. 47Convergent Boundariesplates moving toward each other
    gravity is driving force; old tectonic plates sink and get recycled at the mantle
    crustal thickening, igneous activity. nature depends on types of plates involved
  48. 48Ocean-ocean Convergencemarked by deep ocean trench & volcanic island arc
    has subduction zone    Ocean-ocean Convergence
  49. 49Ocean-continental ConvergenceMarked by ocean trench, volcanic arc & mountain belt, has subduction zone
    thermal heating & lots of igneous activity & some crustal shortening    Ocean-continental Convergence
  50. 50Continental-continental Convergencemarked by mountain belts and thrust faults
    extreme thermal heating, some igneous, lots of crustal shortening    Continental-continental Convergence
  51. 51FaultsFractures in bedrock where there was movement
    loss of cohesion of a body when its under the influence of stress
    Considered active if movement happened in last 15 000 years
  52. 52Hanging Wallhappens above a fault plane
  53. 53Footwalloccurs below fault plane
  54. 54Normal faultHanging wall moves down in respect to the foot wall
    results in thinning of crust
  55. 55Transform Fault (Strike-slip)Displacement is horizontal
    hanging wall and foot wall slide past each other
  56. 56Reverse/thrust FaultsHanging wall moves up with respect to foot wall
    results in compressional forces & thickening of crust
  57. 57JointsFractures/cracks in bedrock where essentially no movement has occurred
  58. 58Domean upward displacement of rocks
  59. 59Basina downward displacement of rocks
  60. 60What Produces an Earthquake?when rock bodies past one another, the rocks bend and store elastic energy (a build up of strain)
    when the frictional resistance holding the rocks is overcome, causes earthquake
  61. 61What is Seismology?the study of earthquake waves
  62. 62Types of Seismic waves: S wavesperpendicular to direction of movement, cant pass through liquids
  63. 63Types of Seismic waves: P wavesparallel to direction of movement
  64. 64Types of Seismic waves: Surface wavesdue to long periods of amplitude of motions. travels along outer part of earth
  65. 65Types of Seismic waves: Rayleigh (R) wavesmoves like an ocean wave
    the most destructive
  66. 66Types of Seismic waves: Love (L) wavesmoves side to side
  67. 67How do you Locate the Epicentre???
  68. 68Intensitythe measure of the amount of shaking at a given location based on amount of damage
  69. 69MagnitudeEstimates the amount of energy released at the source of the earthquake
  70. 70Types of Magnitude Scales: Richter scalebased on the size of the S wave on seismic gram
    (less than 2.0 not felt, I unit inc. = 10x wave, 33x energy)
  71. 71Types of Magnitude Scales: Moment-magnitude Scalegauges the earthquakes total energy
    (Total length rupture X depth of rupture X total amount of slip along rupture X strength of rock)
  72. 72What contributes to the amount of damage of an earthquake?the intensity & duration of the vibrations
    the type of material above the ground
    the design of the structures
  73. 73What kind of destruction usually occurs from an earthquake?Liquefaction : disconnected materials saturated with water changes into a mobile fluid (NO water added!)
    Seiches : uniform sloshing of water in water systems, can weaken walls of containers, cause destruction
  74. 74Rock BehavioursElastic : deformed material return to original shape afterwards, has a limit
    Plastic : permanent deformity, this also has a limit
    Rupture/Brittle : material will rupture
  75. 75Earthquake Predictions : Long TermSeismic gaps : an active fault that has been "quiet" for some time
    Strain monitors & ground deformations
  76. 76Earthquake Predictions : Short Termsmall foreshocks occur beforehand
    a bulge in the crust/land
    the seismic wave velocity will decrease
    changes in gases & groundwater
  77. 77Composition of Ore Mineralsmost ore minerals are found as sulphides
    some others are found as oxides
    very rare amount occur alone
  78. 78Cause/affect of Acid Mine Drainagewhen the sulphides are mined, the left over materials (gangue) that contain sulphur will become oxidized, when this happens, an acidic environment will be created.
    This can damage many ecosystems, and create many environmental issues.
  79. 79Hydrothermal Mineral Depositsconcentration by hot water flowing through fractures/pores in rocks
    Veins, Disseminated, VMS, Sediment associated
  80. 80Magmatic Mineral DepositsConcentration by magmatic processes in a body of igneous rock
    Fractional crystallization, Immiscibility, Pegmatites
  81. 81Sedimentary Mineral DepositsConcentration by precipitation for sea water
    Banded Iron formations
  82. 82PlacersConcentration by weathering processes
    eg. gold
  83. 83Deposits Associated with WeatheringConcentration by weathering processes
    Supergene, Residual Enrichment
  84. 84Fractional Crystallizationa magmatic ore deposit
    heavy minerals will crystallize early, then settle and concentrate at the bottom of the magma chamber
  85. 85ImmiscibilityMagmatic Ore deposit
    the sulphides will separate from the magma before it crystallizes (still liquid), then it will settle at the bottom of magma chamber because more dense liquid
  86. 86PegmatitesMagmatic Ore Deposit
    the crystallization occurs in the shallow crust, where there are large fractures. because of the large fractures, the crystals that form are large, and course grained. the metals will transport down
  87. 87Deposit Associated with Metamorphism (Skarns)a closed system
    the igneous body will change its surrounding bodies, as well as the surrounding bodies will change the igneous body
  88. 88VeinsHydrothermal Ore Deposit
    originates from igneous bodies; hot water will flow along fractures, cool, then precipitate the metallic ions to produce vein deposits (usually in areas with lots of faults)
  89. 89DisseminatedHydrothermal Ore Deposits
    associated with igneous activity;
    Metals are distributed throughout the rock body, instead of concentrated in veins. you need a large volume of rock to get a profitable amount of ore. usually found in volcano (copper)
  90. 90VMS (Volcanogenic Massive Sulphides)Hydrothermal Ore Deposit
    where massive sulphide deposits are found; black smokers will release metal particulate matter, which will undergo a change in pressure, pH, etc when coming out and reacting with water. causes sulphides to precipitate to ocean floor
  91. 91Associated with sediments : SEDEX (Sedimentary Exhalative Deposits)Hydrothermal Ore Deposit
    fractures along the sea floor allow fluids to come up, which creates sulphides.
  92. 92Associated with sediments : Unconformity-Associated UraniumHydrothermal Ore Deposits
    in sediments, uranium containing fluids will become oxidized, then reduced again. this changes the chemical aspects, causing the precipitation of uranium metals
  93. 93Associated with sediments : Mississippi Valley-type DepositsHydrothermal Ore Deposit
    oxidized metal-bearing salt waters that migrate toward a basin edge and fill cavities in limestone
  94. 94Banded Iron FormationsSedimentary Ore Deposits
    formed in reducing conditions, during early history of earth, dissolved iron would accumulate in ocean basins and would crystallize
  95. 95Placer Depositsformed when heavy metals are mechanically concentrated by currents in rivers & gravity
    EG. gold is sourced in pure form crystallized somewhere else, then transferred in a stream and gets stuck & accumulates
  96. 96SupergeneAssociated with Weathering
    soluble minerals are dissolved near the surface, then are brought somewhere deeper, where it is re-precipitated near water table (semi precious)
  97. 97Residual Enrichmentconcentrates metals into economically valuable concentrations
    Laterite: forms by deep weathering of parent rock and leaching out elements like silica
  98. 98Diamondsfound in the ultramafic rocks "kimberlites"
    kimberlite magma originates in great depth, and rises quickly to surface, picking up diamonds in upper mantle
  99. 99Kimberlite Pipeslike the neck of a volcano, melts deep into lithosphere, then erupts
    picks up diamonds in upper mantle
  100. 100Coalformed from decay and compression of land plants
    organic matter is accumulated in swamps (anoxic environments) where there is little O2 & rapid sedimentation
  101. 101Oil & gasderived from marine plants and animals
    remains under anoxic conditions
    burial over millions of years produces hydrocarbons
  102. 102Tar & Oil Sandsviscous, cannot be simply pumped out
    Alberta has major resources: 20% can be mined, the rest has to be heated and pumped due to being too deep    Tar & Oil Sands
  103. 103Oil & Shale Gasuse "fracking" to get it out
    has less environmental impacts that coal power plants, lower greenhouse gas emissions, and high economic value
    can cause water contamination, leaks methane to atmosphere, could cause earthquakes    Oil & Shale Gas

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User has deleted their subject information Flashcards on GEO 1111 Midterm 2, created by Deleted user on 01/04/2018.
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Deleted user · Apr 2018
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Apr 1, 2018
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  • Created by abby Radske · Feb 25, 2018
  • Copied by abby Radske · Apr 1, 2018
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