Extrusion & Intrusion
- An extrusion is the emission of magma onto the Earth's surface where it forms a lava flow.
- An intrusion is igneous rock formed below the Earth's surface. The magma can be forced into pre-existing rocks, for example, either along bedding planes and joints, or by cutting across the existing rocks.
1 of 13
Weathering & Erosion
- Weathering is the breakdown of rocks in situ.
- Erosion is the removal of weathered material, usually by the physical action of transported fragments.
2 of 13
The Rock Cycle - Sedimentary
- Transport is the means by which weathered material is moved from one place to another by water, wind, ice or gravity.
- Deposition is the laying down of a sediment that occurs when a transporting agent loses energy.
- Burial occurs when sediment is covered by younger layers of sediment accumulating on top of it.
- Diagenesis defines all processes that take place in sediments at low temperature and pressure at or near the Earth's surface.
3 of 13
The Rock Cycle - Metamorphic
- Recrystallisation is the solid state process that changes minerals into new crystalline metamorphic minerals.
- Metamorphism is the changing of rocks in the Earth's crust by heat and/or pressure and/or volatile content. It is isochemical and occurs in the solid state.
4 of 13
The Rock Cycle - Igneous
- Partial melting is the incomplete melting of rock in the lower crust or upper mantle.
- Magma accumulation is magma collecting within a magma chamber.
- Crystallisation occurs during the cooling of magma or lava so that solid mineral crystals form.
- Intrusions are igneous rock formed below the Earth's surface. The magma can be forced into pre-existing rocks, for example, either along bedding planes and joints, or by cutting across the existing rocks.
- Uplift is the return of buried rocks to the Earth's surface by tectonic forces.
5 of 13
- A thing (0.03mm) slice of rock that is translucent, mounted on a glass slide and viewed through a microscope.
6 of 13
- An aggregate or mixture of one or more minerals.
7 of 13
- Naturally occurring inorganic crystalline compounds with a definite chemical composition.
8 of 13
- A fragment of broken rock.
9 of 13
Sedimentary, Metamorphic and Igneous Rock
- A sedimentary rock is a rock composed of fragments that have been deposited compacted and cemented.
- A metamorphic rock is formed by the recrystallisation of other rocks in the solid state due to pressure, temperature or both.
- An igneous rock is a rock that has crystallised from a magma.
10 of 13
- The most important and abundant group of rock-forming minerals, with an atomic structure containing SiO4 arranged as tetrahedra.
11 of 13
- A texture in metamorphic rocks formed by the preferred alignment of flat/tabular minerals.
12 of 13
The Geological Column
- The geological column is a table that contains all the eras and systems in the correct time sequence.
- An era is a major unit of time that contains several periods/systems.
- A System refers to rocks laid down in a named time period and is shorter than an era.
13 of 13
Similar Geology resources: