biosphere: environments that support life - land, water, air

continental plates: tectonic plates upon which the land masses of the earth are located, 20-80km thick

crust: uppermost layer of the earth, 7km thick under oceans

geosphere: the solid, rocky part of the earth

mantle: a layer of the earth beneath the crust, consisting of slightly fluid rock up to 3000km thick

organic material: living or once living material based on carbon

subduction zones: areas where one tectonic plate moves under another and is absorbed into the mantle

tectonic plates: large areas of the earths crust which float on the mantle

(this is the glossary for an earth recycling page)