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Earth Rocks :rocket: - Coggle Diagram
Earth Rocks :rocket:
Weathering & erosion
Physical weathering: geological processes breaks apart rock formation e.g. onion skin weathering & freeze-thaw weathering
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Biological weathering: living things e.g. animals or plants, put pressure on the rock weathering e.g. roots pushing into a rock & animals cracking the rock under foot
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Igneous
granite, peridotite and pegmatite
Formation: igneous rocks are formed through the cooling and solidification of magma (lava). As hot, molten rock rises to the surface, it undergoes changes in temperature and pressure that cause it to cool, solidify, and crystallize. Deep within the ground is magma and it sometimes this bursts through the surface in the form of volcanoes
Rocks formed in the ground are known as intrusive igneous rock. Rocks formed once the magma has burst through the surface, is called extrusive igneous rock
Appearance: Igneous rocks that have crystals large enough to be seen by the naked eye are called phaneritic; those with crystals too small to be seen are called aphanitic. Generally speaking, phaneritic implies an intrusive origin; aphanitic an extrusive one. Igneous rock did not have fossils in it because any fossils in the original rock will have melted when the magma formed.
Fossils
After an animal dies, the soft parts of its body decompose leaving the hard parts, like the skeleton, behind
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As more layers of sediment build up on top, the sediment around the skeleton begins to compact and turn to rock (sedimentary rock)
Sedimentary
Formation: small particles of rock are formed by weathering and are transported into the sea where they are deposited (sink) & form a sediment. over millions of years, the pressure of layers formed above & the effects of salts, cement the sediment together to give sedimentary rocks
e.g. sandstone, mudstone & siltstone
Appearance: consists of lots of small particles & may be soft and crumbly. Don't normally contain crystals but may have fossils trapped inside the rock. Often possible to see layers on a cliff face of sedimentary rock (very compact)
Metamorphic
Appearance: they are usually denser and harder than sedimentary rocks & they give off a zig-zag arrangement. Often have layer structures of crystals caused by the effect of heat and pressure.
e.g. marble, granulite and slate
Formation: they are formed from other rocks that are changed because of heat or pressure. They are not made from molten rock (igneous rock). Earth movements can cause rocks to be deeply buried or squeezed. As a result, the rocks are heated and put under great pressure
Raw material & crude oil
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Millions of years ago tiny plants & animals called plankton lived in the sea. When the plankton died their remains fell to the bottom of the sea. Layers of sand & mud, known as sediment was deposited on top of the sea plankton. over millions of years the dead animals got buried deeper & deeper. Heat and pressure gradually turned the mud and sand into rock & the dead plankton into oil. Oil companies drill down through the layers of rock to the oil underneath. Crude oil can be refined to produce usable products such as gasoline, diesel, and various other forms of petrochemicals
Raw materials can be finite as we might not have infinite amounts of that substance, meaning that eventually it will run out. This will also mean that we are using the substance quicker than its being made