Science W6

Igneous Rock

Formed from the cooling of molten rock and can be intrusive or extrusive

Sedimentary Rock

Formed from a build up of sediments compacting and cementing

Metamorphic Rock

Formed from heat and/or pressure

Erosion

The movement of sediment or soil from one location to another by means of water, ice or wind

Weathering

The breaking down or disintegration of substances such as rocks and minerals by physical, chemical or biological processes

Streak Test

The rock is scratched on a hard ceramic surface and then analysed by the colours left behind

Rocks

A solid aggregate of minerals

Minerals

A solid, naturally occurring inorganic substance

Crystals

A piece of a homogeneous solid substance having a natural geometrically regular form with symmetrically arranged faces

Inner Core

The earths inner most layer. Approximately 5,150km below surface level

Outer Core

A liquid layer of Earth's interior, situated between the mantle and the inner core, made up mainly of molten iron and nickel

Mantle

The thick, middle layer of the planet located between the crust and the outer core

Crust

The planet's outermost solid layer of rock, which is broken into tectonic plates

Lithosphere

The rigid, outermost layer of Earth, composed of the crust and the uppermost solid part of the mantle

Geology

The study of Earth’s physical structure

Deep Time

The multimillion-year time frame in which the earth has existed

Rock Cycle

A continuous process that describes how the three main rock types are created and transformed into one another

Magma

Molten rock underground

Lava

Molten rock above ground

Meteorite

A piece of rock or metal that has fallen to the earth's surface from outer space

Sediments

Created from weathered and eroded rocks

Physical Weathering

Weathering caused by ice, wind, water or temperature

Chemical Weathering

Weathering caused by water or acid rain

Biological Weathering

Weathering caused by plants, animals or humans

Karst

A landscape made up of limestone which has been eroded, producing ridges, towers, fissures and sinkholes

Deposition

The process of dropping eroded rock sediments

Cementation

The binding together of rock sediments

Compaction

The exertion of force on something so that it becomes more dense

Fossil

The preserved remains, impression, or trace of a once-living organism

Heat & Pressure

The process that forms metamorphic rocks

Radioactivity

The emission of ionising radiation or particles caused by the spontaneous disintegration of atomic nuclei

Intrusive

Magma cooling below the surface becomes intrusive igneous rock

Extrusive

Lava cooling above the surface becomes extrusive igneous rock

Conglomerate

A type of red and orange sedimentary rock with small pebbles imbedded

Breccia

A type of rock consisting of angular fragments of stones cemented by finer calcareous material

Ore

A naturally occurring solid material from which a metal or valuable mineral can be extracted profitably

Mohs Scale

A scale of hardness used in classifying minerals. It runs from 1 to 10 using a series of reference minerals, and position on the scale depends on ability to scratch minerals rated lower

Opaque

Blocks all light from passing through

Transparent

Allows light to pass through completely, so objects can be seen clearly on the other side

Translucent

Allows some light to pass through, but diffuses it, so objects on the other side are blurry or unclear

Cleavage

The tendency of a rock, especially fine-grained metamorphic rock, to split into layers or sheets along closely spaced, parallel planes that are formed by pressure and deformation