Geology pt.2

Geology pt.2

1. Fossils

   • Remains
     • Rare- soft parts of an organism
     • Original hard parts- bones, shells
   • Petrified wood and bones
     • Remains changed to stone
     • Each cell replaced by stone
   • Impressions
     • Hard part dissolves
     • Leaves impression in surrounding rock
   • Traces
     • Preserved footprints
   • Random
     • Classified like animals and plants
     • Harder to find on land
       • Less sediment deposited
       • Less disturbance
     • P&A decompose quick with air
     • Decomposition rate slows when buried
     • Preserved naturally in the crust
     • Dating- relies on Zone/Index fossils

2. Metamorphic Rocks

   • Originally Igneous/Sedimentary
   • Changed- Pressure & Heat
   • Rocks at surface covered with sediments=Pressure
   • Earth's movement= flatten, twist, stretch rocks
   • Heat&Pressure= crystals grow, new minerals form, gases released
   • Folding&Faulting= twist and squeeze, change
   • crust moves= strain=cracks
   • Joint- no movement along crack
   • Fault- crack with movement
   • Fold- Yield to strain
   • Contact Metamorphism- locally melted, direct contact with hot igneous rock
   • Regional Matemorphism- buried deep=H&P,
     • Limestone=Marble
     • Siltstone=Slate

3. Rock Cycle

   • Endless process
   • Mixing and Reusing Earth's rocks
   • Metamorphic/Igneous both can melt=Magma
   • Igneous/Sedimentary can both be Metamorphic

4. Daily Use

   • Tools, shelter, fuel, transport, recreation materials
   • Evolutionary advantage in hunting, defence, food prep to mankind
   • WA dependant on rocks/mining
   • Either finite or non-renewable resources
   • Classifications
     • Petroleum (Natural gas&oil)
       • Fossil Fuels, oil, gas
       • decomposed P&A remains compressed,extreme pressure
       • Extracted from ground
         • shipped/piped to refineries
           • physically & chemically changed
             • Distillation- separates heavy and light into groups called fractions of hydrocarbons
               • fuel oil- heating- car diesel
               • naphtha- gasoline
               • butane- cigarette lighters
               • propane- bottled gas
               • Ethane- component of natural gas
               • Petrochemical plant- made into substances
                 • Xylene Propylene Benzene Ethylene Toluene
                 • Processed into well-known materials (polyethylene, nylon etc)
       • Hand lotion, shampoo, hair colouring, lipstick, perfume, nail polish, mobile phones
     • Metallic Minerals
       • are ores used to make metals
       • opaque
       • good conductors of electricity
       • Shiny
       • Platinum, silver, mercury, titanium, cobalt, gold, zinc
       • Not found pure, mixed
       • Alloy- 2+ metals combined
       • Brass-Copper, zinc Bronze, Copper, zinc, tin
     • Non-Metallic
       • Translucent
       • form as crystals
       • asbestos, quartz, talc, sulphur
       • ceramic & chemical industries
       • Roads & Buildings
     • Rock-forming minerals
       • Major building materials of the Earth
       • Largely silicates (contains silicon & oxygen)
       • Silicon- non-metallic, always mixed, 2nd main element after oxygen in Earth's crust
       • large families of micas, garnets etc.
     • Metallic, non-metallic, rock-forming, petroleum/plastic, coal
   • Toothpaste
     • silica is abrasive, to clean
     • Fluoride, from Fluorite makes teeth strong
     • Titanium, makes white, in white paint
     • Mica to make it sparkle

5. Plastics(Petroleum cont.)

   • Strong=waste problem
   • Research
     • Biodegradable
     • Photodegradable= degrades by sunlight
     • made from plants= decomposes to compost
     • Made from hydrocarbons
     • Want to reduce polymer chain= lose strength-brittle-degrade into co2/h2o
   • Biodegradable-expensive
   • Carseeonigetic-causes cancer when burnt

6. Coal

   • millions of years
   • remains of living things
   • found in layers/seams under Earth's surface
   • heating/ production of steel
   • ingredient in pencils, paint, plastics
   • Peat-Lignite-Coal

7. Removal of resources

   • Exploration
     • searching for something you want to find
     • geologist
     • process of finding areas where minerals can be found
     • Aerial methods
       • Geomagnetic
       • gravity
       • Electromagnetic surveys
     • On-site
       • Seismic surveys
       • geochemical surveys
     • satellite images
   • Mining
     • Removal of the resource from the ground
     • WA dependant
     • oil and gas= drilling
   • Enrichment
     • concentration of the resource
     • sometimes removing materials which aren't needed
   • Extraction
     • the process of removing the material from the ground