Sediments are usually formed from matter which falls to the bottom of
Sedimentary rocks cover 75–80% of the Earth's land area, but they make up only 5% of the
Squeezed and compressed over time, the sediments become 'consolidated' (made solid) into layers of rock.
Otherwise, rocks may have the water squeezed out, yet remain for long periods with their character unchanged. There are many
Consolidated rocks may be changed some more, by water seeping through, or by heat and extreme