1. Earth Science
    sciences that seek to study the earth and its neighbors in space
  2. three types of renewable resources
    • sun
    • wind
    • water
  3. Hypothesis:
    A tentative explanation for a phenomenon which can be tested for validity
  4. Theory
    hypothesis has been extensively tested and has survived detailed scrutiny then the hypothesis can be promoted to the level of theory
  5. Scientific Methods
    • 1)Collection of scientific facts and
    • measurements.

    • 2)Development of individuals hypothesis
    • or models.

    • 3)Development of observations and
    • experiments to test hypothesis.

    • 4)Acceptance, modification or rejection
    • of the hypothesis and models based on testing.
  6. Evolution of the Earth: Two Hypothesis:
    The Nebular Hypothesis (gas )

    The Planetisimal Hyposthesis (part of the sun)
  7. how old is the earth
    4.5 billion or 4500 million years old
  8. atmosphere
    gases that envelope the earth
  9. biosphere
    all living or once living materals
  10. hydrosphere
    water on or near the earths surface
  11. geosphere
    rocks and other inorganic mater that make up the earth service
  12. Bulging at the equator and
    flattened at the poles.
  13. Equatorial diameter is
    greator than the polar diameter
  14. crust
    outer most layer of the earth
  15. 2 parts of the crust
    contental (land) and oceanic ( ocean) crust
  16. mantel
    largest in volume and the middle part
  17. core
    the innermost later
  18. plate tectonics
    broken into pieces that move in relationship with each other resulting in shfting contents valcano eruptions and new crust
  19. convergent
    plates move towards one another
  20. divergent
    plates move away for each other
  21. transform
    plates slide by one another
  22. elements
    cant be broken to other substances
  23. atoms
    smallest possilbe particle of an element. has all the properties of an element
  24. earths chemical composits of the crust
    largest oxygen(O) Silicon(Si) and Aluminum(AL)
  25. crystallinity
    atoms are aranged in 3dimensional orderly or regulary repeating
  26. silicon-oxygen tetrahedron
    two most abundent elements in the crust
  27. 5 charistics of a mineral
    • naturally occuring
    • solid
    • definite
    • definite crystalline structure
  28. 8 properties of a mineral

  29. Color
    Fundamental property. But cannot base the identification on it solely.
  30. Streak:
    • More reliable than color. Obtained by rubbing the mineral on a piece of unglazed porcelain (called streak
    • plate). Minerals that are metallic often leave a color on the plate
  31. External Crystal Form:
    External appearance of the mineral based on the internal arrangement of atoms.
  32. Hardness
    Resistance of a mineral to scratching. Measured using the Mohs Scale of Hardness ranging from 1 (softest) (talc)to 10 (hardest).(diamond)
  33. Cleavage
    the mineral to break in smooth planes
  34. fracture
    breaks along a haphazard manner
  35. specific gravity
    weight of a mineral compared to a equal volume of water
  36. Special Properties:
    • Smell: Clays have an earth smell.
    • Taste: Halite tastes salty.
    • Magnetite: Being attracted to a magnet.
    • Striations: Plagioclase feldspar exhibits straight parallel lines on its surface.
  37. Chemical Tests:
    Calcite minerals reacts with
    hydrochloric acid
  38. 3 elements of weathering
    • wind
    • water
    • ice
  39. rock
    naturally occuring consolidated materals comprising of minerals
  40. rock cycle
    relationship between rocks
    formed from once molten material called magma
  42. 2 types of igneous rocks
    Plutonic rocks are coarser grained (see the crystals) owing to slow cooling.

    Volcanic rocks are fine grained (sometimes glassy) owing to rapid cooling.
  43. Characteristics of
    Igneous Rocks:
  44. plutonic
    (Intrusive-slow cooling) form below the surface of the earth. (e.g. granite).
  45. valcanic
    Extrusive-fast cooling) form at or close to the surface of the earth (e.g. basalt).
  46. natural glass
    (sudden chilling) volcanic glass (e.g. obsidian).
  47. Porphyry
    intermediate rate of cooling slow and fast (porphyrtic)
    Based on texture and mineral composition.
  49. darker rocks
    ligher color
    • higher melting point
    • less dence
  50. Sedimentary Rocks
    • Rocks that have been formed from material derived from
    • preexisting rocks
  51. Some Characteristics of Sedimentary Rocks:
    Lithification is when the sediments are transformed into rocks.

    Clastic sedimentary rocks are the products of mechanical breakup of other rocks (e.g. conglomerate, sandstone, and shale).

    Chemical sedimentary rocks are not from mechanical but forms via chemical precipitation or growth from solution (e.g. limestone).

    Organic sediments consists of carbon rich remains of once living organism (e.g. coal).
  52. more compression eaquals more
  53. Metamorphic Rocks:
    Rocks that have been formed under action of heat and/or pressure of preexisting rocks.
  54. Some Characteristics of Metamorphic Rocks:
    • Contact Metamorphisms: When heat is
    • dominating agent (e.g. marble).

    Regional Metamorphism: When pressure is the dominant factor (e.g. gneiss).

    • Foliation: When the pressureon the rock is too great, then it will result in striations of the rock. With
    • increasing pressure the banding becomes more prominent and goes from slate (low pressure)-phyllite, schist, and gneiss (high pressure).
  55. Weathering
    The physical breakdown (disintegration) and chemical alteration (decomposition) of rocks at or near the earth’s surface..
  56. Mass wasting
    The movement of rock and soil downslope under the action of gravity.
  57. Erosion
    The removal of materials by agents such as wind, water, and ice.
  58. Transportation
    Movement of eroded particles by wind, water, and ice
  59. Deposition
    When transported material comes to rest
  60. Mechanical Weathering
    • The physical disintegration of the rocks. Breaks up the rocks but does not change the chemical
    • composition. E.g., frost wedging, unloading, and biological activity.
  61. Chemical Weathering
    • Decomposition of the rock by exposure to water and
    • atmospheric gases. Changes the chemical composition and structure. E.g., oxidation, calcite dissolved when chemically weathered. Same effect observed for limestone and marble.
    • The weathering of the minerals depends upon the composition of the mineral, as well as the
    • internal arrangement of atoms. The weathering sequence is the same as that of the Bowen’s reaction
    • series.
  63. who is the bighest factor of erosion
    we are
  64. Rock Characteristics
    • The chemical make up of the rock can establish how quickly a rock can weather. There are some minerals that weather faster in comparison to others. This is
    • evident from comparing headstones. For
    • instance, headstones made of granite are more resistant than marble ones.
  65. Climate
    Climatic factors such as temperature and moisture are instrumental in establishing the rate of weathering. For instance, regions with higher temperatures and precipitation will allow for chemical weathering to take place as opposed to colder and drier regions.
  66. Differential Weathering:
    Different rates of weathering for different areas. Not all rocks weather uniformly. The weather depending on their composition as well the climatic conditions of the region they are located in.
  67. SOILS
    Formed as a product of weathering.

    • Layer of weathered material on top of the
    • bedrock, consisting of unconsolidated
    • pore spaces, mineral, and organic matter.
  68. Soil Texture:
    The soil texture refers to the proportions of different particle sizes.
  69. Factors Affecting
    Soil Formation:

    (1941) mentioned that soils formed as a function of the following five factors:
    Climate, Organic Matter, Relief, Parent Material, and Time (CLORPT).
  70. soil horizons
    • Soil Horizons:
    • O-Horizon: Upper most layer. The organic horizon.
    • A-Horizon: Dark colored soil. Contains humus.
    • Also called the Zone of Loss/Leaching.
    • B-Horizon: Accumulation of materials lost from A-Horizon. Also called the Zone of Gain.
    • C-Horizon: Incompletely weathered parent material below the B-Horizon.
    • R- Bedrock: Unexposed unweathered portion
    • of the rock.
    Gravity is the controlling force of mass wasting.
  72. Role of Water
    When saturated with water the material becomes heavy and more likely to move downslope. As the amount of water in the debris increases the rate of movement increases as well.
  73. Oversteepened Slopes:
    Stream undercutting a valley or waves hitting against the base of a cliff. This results in mass wasting as the gradient is steep. Angle of repose is the angle where material remains stable.
  74. Removal of Vegetation:
    Vegetation keeps the soil in place. Removal of vegetation increases the risk of mass wasting
  75. Earthquakes as Triggers
    Just an instigation for mass wasting to occur. Earthquake results in ground motion and shaking and this may disturb the material making it unstable and may result in mass wasting.
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