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Water and wind can also cause the weathered rock to be conveyed from one place to another. Rivers and streams carry away material both in solution and as gravel, sand, silt or mud, and the disintegration of the particles continues in the rivers and lakes and on the sea-shore. Wind can carry the smaller and lighter products of weathering; and the glaciers of the high mountains and the ice-sheets of the Arctic and Antarctic can carry enormous masses of rock debris. The material which has been weathered by rain, wind and frost, or transported by river, sea, wind or ice, is finally deposited in sea, river-bed, sand dune or glacier moraine. If not disturbed further, it will here become gradually harder and more compact, and will eventually form a new rock.

Material carried away in solution may be deposited in warm seas and inland lakes where the evaporation of water leads to a concentration of the solution. It is also used by many organisms for building their shells and skeletons, which, in the case of coral reefs, may reach vast dimensions. The accumulations which are thus formed by deposition in the sea, in rivers, in lakes or in deserts are termed sediments, and when compacted, sedimentary rocks. After their deposition, the newly-formed sediments are gradually cemented and hardened, and during this process new minerals are formed and existing minerals may be re-crystallised. Like all rocks on the earth’s surface, the newly formed sedimentary rocks may again be exposed to the agents of erosion, and the cycle begins again. If igneous and sedimentary rocks are involved in the processes of mountain building, or have their temperature and pressure raised by ascending masses of magma, the minerals of which they are made may be completely altered. Rocks formed in this way are termed metamorphic.