Adit: A horizontal tunnel driven into the side of a hill for access and drainage purposes
Asthenosphere: The layer of mantle below the crust which behaves as a ductile solid due to the prevailing temperature and pressure conditions
Brachiopod: An animal which lives within a shell in a similar manner to bivalves such as oysters
Conglomerate: A coarse grained sedimentary rock which contains large, round fragments which are known as clasts
Convergent plate boundary: A convergent plate boundary is where crust is being destroyed. In the case of oceanic and continental crust meeting it is the denser oceanic crust which is subducted. The west coast of South America is a convergent plate boundary
Divergent plate boundary: An area on the Earth's surface where crust is being produced. At a divergent plate boundary two pieces of crust are pulling apart which enables magma to flow up through the crack, soldify and thus form new crust. An example of a divergent plate boundary is the mid-Atlantic ridge
Fault breccia: A fragmented, clay-like rock created when rock is crushed during movement on a fault
Impermeable: An impermeable rock is one that transmits fluids readily because the pores within the rock are large (in relation to the grain size) and often connected
Level: A horizontal or gently sloping tunnel in a mine
Lithification: The conversion of an unconsolidated sediment into a sedimentary rock by a combination of compaction, cementation, crystallisation, and desiccation
Millet seed: A texture found in aeolian sandstones where the grains are all small, rounded and of an equal size
Opencast: A method of mining which takes place at the surface by removing the overlying material one layer at a time
Ore mineral: A mineral which can be extracted for profit at the time of mining
Ore-shoot: A portion of the ore body which is somewhat richer than the rest
Oxidised: The result of the chemical reaction between iron and oxygen which causes the iron content of a rock to turn red
Porous (porosity): Porosity is the term used to describe a rock based on the the number and size of the pores it contains
Shaft: A vertical or steeply inclined excavation which connects underground levels to the surface and also with each other
Stratigraphy: The branch of geology which groups together rocks with similar characteristics that represent the same depositional environment
Transform plate boundary: At a transform plate boundary one piece of crust is moving past the other. A classic example is the San Andreas Fault