Shaping The Earth Flashcards
What is the difference between extrusive and intrusive rocks?
extrusive rock igneous rock that forms when lava cools above the Earth’s surface
intrusive rock igneous rock that forms when magma cools below the Earth’s surface
describe the lithosphere
The lithosphere is the solid outer section of Earth, which includes Earth’s crust, as well as the underlying cool, dense, and rigid upper part of the upper mantle.
define the Mohs’ hardness scale
Mohs Hardness Scale is a scale that characterises the scratch resistance of various minerals through the ability of a harder material to scratch a softer material.
explain the differences between igneous, sedimentary and metamorphic rocks
Igneous rock is formed through the cooling and solidification of magma or lava.
Sedimentary Rocks formed through the deposition and solidification of sediment, especially sediment transported by agents.
Metamorphic were previously Igneous or Sedimentary rocks that have under gone additional heat/pressure.
How does crystal size depends on the cooling rate?
The slower the cooling process, the more time crystals can grow, the faster the cooling, the less time crystals can form.
explain how crystals can be used to identify rock types
Intrusive Rocks cool slower as they are in the mantle and have more time to cool, extrusive rocks cool faster giving less time for crystals to form.
Describe the meaning of lustre when identifying minerals.
How the mineral reflects light from its cut surface. Might be described as dull, metallic, pearlescent, glassy, brilliant, waxy or silky.
Describe a minerals streak.
Is the colour and texture of the mark that the mineral leaves behind when it is scratched across a hard white surface.
Describe a minerals hardness.
A measure of how easily the surface of the mineral is scratched or dented.
Describe a minerals cleavage.
The appearance of the break when a sample of the mineral is snapped.
Describe how metamorphic rocks form.
Metamorphic rocks form when igneous or sedimentary rocks undergo additional heat and pressure and are chemically changed.
Describe how sedimentary rocks from.
Brocken down rock are deposited and build up in layers, the pressure on top squashes the sediments at the bottom. Water is squeezed out of the sediments and forms crystals, it then forms a glue and sticks the sediments together
Describe how igneous rocks form
Igneous rock is formed through the cooling and solidification of magma or lava.
Describe solidification
Freezing, or solidification, is a phase transition in which a liquid turns into a solid when its temperature is lowered below its freezing point.
What is contact metamorphism?
Where rock minerals are changed due to heat due to contact with magma.
