Rocks & Weathering

Rocks & Weathering

1. Rocks = mixtures of minerals

   • Sedimentary
     • Sediment grains stuck & deposited- soft / crumbly
       • eg. Sandstone
     • Porous
   • Metamorphic
     • Interlocking crystals due to high temp & pressure
       • Eg. Slate
     • Hard, smooth, shiny
     • Non-Porous
   • Igneous
     • Interlocking crystals
     • Molten rock cools & solidifies
     • Very hard
       • eg. Granite
     • Non-Porous
   • Porous rocks
     • Grains = gaps so water / air gets in
       • Bubbles appear if put in water, as air escapes
         • Mass increases in water
   • Non-Porous rocks
     • Interlocking = no gaps for air / water

2. Physical Weathering

   • Temp breaks down rocks
     • Freeze-thaw
     • Onion skin - expand contract

3. Landscapes & Weathering

   • Scree slope at bottom of cliffs as breakdown & fall

4. Rain & Weathering

   • Rain = acidic - chemical weathering on rocks
     • Pollution eg. sulphur dioxide = speeds up weathering
       • Rocks change colour

5. Transportation

   • Pieces of rock - transported by glaciers
     • Glaciers = slow moving rivers of ice
       • Rocks carried then deposited when melting
         • Smaller rocks carried further

6. Evaporates

   • Salts in water evapotae - leave sediment

7. Fossils

   • Remains of plants & animals in sedimentary rocks
     • Fossil fuels = coal, oil, gas - take millions of years to form & non-renewable
       • Contribute warming when burned