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Rocks and weathering - Coggle Diagram

- - - - Coastline fit of continents
      - Orogenic belt fit
      - Fossil remains in india match australian ones, animals that cant swim
      - Glacial deposits brazil match west Africa
      - Identical sedimentary along atlantic coastlines
    - - Continental
        
        35-70km thick
        
        1500 years old
        
        Granite composition
        
        Rich in Silicon and aluminium
        
        Less dense, lighter colour
      - Oceanic
        
        6-10km thick
        
        < 200 years old
        
        Basalt composition
        
        Rich in Iron and Magnesium
        
        Denser, Darker colour
    - - Convection Theory
        
        Radioactive decay in earths core produces heat. Hot magma rises in convention, cools at surface then sinks as it is denser when colder
      - Hotspots
        
        Lava plume through mantel responsible for original crust rifting. Outward flow of viscous magma creates drag force on plates causing movement
      - Ridge push
        
        Magma intrusion at ocean spreading ridges, propels two plates apart
      - Slab pull
        
        The force that the sinking (colder and denser) edge of the plates exerts on the rest of the plate
  - - - Oceanic
      - Continental
      - Plates move apart from one another
      - Caused from rising convection that lifts the lithosphere, creating ridges or fault lines, may create rift valleys that can be filled by water e.g southernmost mozambique to beira
      - Exposed magma fills gap/fissure
    - - Plates forced together, can result in both volcanoes and earth quakes. An oceanic and a continental plate
      - Ocean trenches form when oceanic dense crust drags down crustal material during subduction
    - - Between to continental plates moving towards eachother
      - Fold mountains
      - Minimal subduction
    - - Plates move past one another
      - earth quakes occure
      - Stike-slip
      - Transform
  - - - Creates oceanic crus
      - Where lava cools and retains the magnetic polarity of erth ath the time of cooling. a process called palaeomagnetism
      - Slow spreading is a result of the ridge being fed by small discontinuous magma chambers
    - - denser plate is pushed into the upper mantle
      - continues as it is driven by the weight of the plate
    - - e.g himilayas
      - no magma escapes
      - can happen at collison and destructive plat boundaries
    - - at divergent plate boundaries
      - series of parallel ridges, central double ridge separated by a ridge valley
      - result of tensions and stretching a central block may fall
    - - found at subduction zones
      - found next to land and island arcs
    - - subducting plate heats up
      - magma formed and rises to the surface meeting overriding plate, material added to crust and builds up a volcanoes
      - If upper plate also oceanic, the volcano piles up until poking through the surface forming the island arc
- - - - Rapid change in temperature
    - - Pressure release
    - - Roots can penetrate soil and help break-up underlying bedrock
  - - - 2KAlSi3O8 + 2H2O --> Al2Si2O5(OH)4 + K2O + 4SiO2
    - - CaSO4 + 2H2O <-- --> CaSO4.2H2O
    - - CO2 + H2O <-- --> H2CO3
  - - - Humid areas have faster weathering
      - Polar areas experience freeze-thaw
      - Carbonation may take place at lower tempretures