a process existing in or produced by nature (rather than by the intent of human beings)

a science that deals with the history of the earth as recorded in rocks

gradual formation of new land, by recession of the sea or deposit of sediment

the gradual transformation of habitable land into desert; is usually caused by climate change or by destructive use of the land

the process of deformation that produces continents and ocean basins in the earth's crust

(geology) the mechanical process of wearing or grinding something down (as by particles washing over it)

a geological process that causes a bend in a stratum of rock

a science that deals with the history of the earth as recorded in rocks