17
Pages 182 - 219 Unit: Earth & Space Observatory: Chapter 6 The Lithosphere & The Hydrosphere
Pages 182 - 219
Unit: Earth & Space
Observatory: Chapter 6
The Lithosphere &
The Hydrosphere
• It is 6300 km from the Earth’s surface to its centre.
• The hard shell is, on average, 100 km thick
General Information
• The lithosphere is the hard shell.
• It consists of both the crust and the top part of the upper mantel.
• It contains all the minerals and rocks.
Lithosphere
Use diagram from 184 in TB
• Minerals are inorganic substances that cannot be made. (not from animals nor plants)
• With over 4000 minerals, each have certain characteristics or properties defined by their composition.
• Cubic shape → salt (NaCl)• Gold (Au), Silver (Ag), Tin (Sn), etc.• Quartz → silicone dioxide (SiO2)
Minerals
• Minerals can be classified according to:
1) Colour: – An ‘idiochromatic’ mineral is a specific colour
since a certain element is present in its composition. (azurite, ruby, etc.)
- An ‘allochromatic’ mineral is colourless when they
are chemically pure. (quartz, diamonds, etc.)
Mineral Classification
Quartz
Example: Allochromatic Mineral
2) Transparency: - how much light is able to pass through (transparent, translucent, opaque)
3) Hardness: - depends on strength of bonds between atoms - Mohs scale measures resistance to scratching
(0 is liquid, 1 is softest (talc) and 10 is hardest (diamond))
Mineral Classification
4) Streak: - after mineral is rubbed onto unglazed porcelain
(idochromatic leaves brightly coloured powder)(allochromatic leaves white or pale powder)
Mineral Classification
1) Locate the mineral.
2) Extract from lithosphere as an ‘ore’. Ore is a rock that contains the mineral. Deposit refers to a large quantity a mineral available
for mining.
3) Mineral is separated from ore. Each ore is processed differently.
• Gold is crushed, treated with chemicals and is melted. (500 kg ore yields 6 g)
Mining Process
• 1) Open-pit mine– Deposit is found near the surface– Upper layers are removed by drilling machines,
excavators, and dump trucks
Type of Mines
• 2) Mine Drift– Deposit is too far below the surface– Vertical shafts with drifts that run alongside the vein of
the deposit– Each drift needs air ducts and water supply lines
Type of Mines
• Minerals can cluster together heterogeneously to form rocks.
• There are two theories on the formation of rocks:
– 1) Neptunism: by pressure of water
– 2) Plutonism: by volcano
Rocks
• 1. Igneous Rocks– Formed from solidified magma,• extrusive (hardens on contact with air) or • intrusive (hardens before reaching
surface)• 2. Sedimentary Rocks– Formed from eroded rock fragments
combine with plant and animal remains under pressure
Rock Types
• 3. Metamorphic Rocks– Formed from the transformation of igneous or
sedimentary rocks into metamorphic rock under high temperature and pressure
– Properties and appearance will change
Rock Types
What rock is it?
metamorphic igneous sedimentary
