EVM END OF TERM Flashcards
Earth’s Crust
It floats on the mantle, it forms the surface layer, it is very thin, and it is the most important layer for people. It is made of a variety of rocks, which provides building stone and minerals.
Mantle
A thick shell of molten rock. The outer part of the mantle is the source of the magma that reaches the surface of the earth during a volcanic eruption.
Core (inner core and outer core
is at the center of the earth, it is hotter than 4000° C.
3 types of rocks
Igneous, Sedimentary, and Metamorphic
IGNEOUS ROCK
made when liquid magma cools to form solid rock. Formed by fire associated with volcanic activity.
Types of Igneous Rock
Granite – which is made of magma.
Basalt – which is made of lava
SEDIMENTARY ROCK
– formed from sediment (small particles of rocks)
Process:
⦁ Breakdown of existing rocks to smaller rocks (weathering).
⦁ Sediments are transported by water and wind (erosion).
⦁ Sediments accumulate into layer by getting pressurized due to the newer deposits on top of them (compaction). Forming layers is cementation (e.g. limestone, sandstone)
METAMORPHIC ROCK
type of rock formed by heat and pressure when igneous / sedimentary rock is heated or pressured it changes it metamorphic rock.
What are Mineral?
substances obtained by mining.
Mining
Human activity that involves extraction or removal of mineral.
Metallic Minerals
⦁ Ferrous minerals – Iron
⦁ Nonferrous minerals – Copper – Tin
⦁ Precious Mineral – Gold & Silver
Non-Metallic Minerals
⦁ Minerals for agriculture-phosphorus
⦁ Minerals for energy – coal
⦁ Precious gemstone – diamonds
What is mineral reserves
a known source of the mineral which has not been yet mined, the mineral is mined in future when needed.
Uses of Rocks and minerals in industrial Processes
Chalk – cement Gravel – concrete
Clay – bricks & pottery Sand – glass
IRON VS ALUMINIUM
Iron is a widespread mineral and is considered as the raw material of steel.
Aluminum widely used since it is light and less liable to corrosion but weaker than steel
What are the uses of LIMESTONE?
⦁ Making cement (greyish)
⦁ Construction of roads
⦁ Building stone
USES OF VARIOUS MINERALS
Uranium → nuclear power
Phosphate → fertilizer
Lead → electricity
THERE ARE TWO METHODS SEARCH AND EXTRACTION OF ROCKS AND MINERALS
⦁ Open cast/surface mining
⦁ Deep mining
PROCESS FOR SURFACE/OPEN CAST MINING
⦁ Clear vegetation and remove topsoil.
Break the rock by using explosives
⦁ Use the digger to remove loose soil.
⦁ Tip the rock or mineral into truck.
DISADVANTAGES OF SURFACE/OPEN CAST MINING
⦁ Deforestation
⦁ Air pollution due the dust
⦁ Dynamites would kill animals
PROCESS OF DEEP MINING
⦁ Acquire the geographical survey (Geologist)
⦁ Sinking a vertical shaft for ventilation (supply of air)
⦁ Making a horizontal tunnel
⦁ Extracting minerals by digging either by miners or machines
⦁ Extracting the minerals to put it on the moving train moving it up
Impact of all types of mining on environment
⦁ Deforestation and wildlife habitats are cleared to make roads.
⦁ Dust and fumes from chimneys causing air pollution.
⦁ Water pollution due to rivers/streams flowing through old mine site.
Disadvantages of Deep Mining
⦁ The roof may collapse
⦁ Flooding may occur
⦁ Miners trapped inside because their route is blocked
DEEP MINING AND ITS BAD EFFECT
⦁ Usually on miners.
⦁ Suffer from major injuries at work or even death.
⦁ Problems with air supply and a lot of dust cause chest/breathing issues like a disease named silicosis
