The granite is subjected to weathering by rain, wind and repeated freezing and thawing. By this means, over very long periods of time, granite rocks are weathered down to small particles. These particles of mineral are eroded away by rainfall and wind; are carried away from the site of formation by run-off and streams, and eventually they end up in a slow-flowing body of water such as a lake, estuary or lagoon.
Because the water in a lagoon, estuary or lake is slow-moving, the particles are able to settle to the bottom. After a further extremely long time, layers of particles are buried by later depositions of particles. This subjects the lower layers of sediment to pressure, and when there is enough pressure, they are compressed into a sedimentary rock.
Sedimentary rocks are characterised by (1) their softness compared with igneous rocks like granite, and (2) the presence of strata or obvious layers. These layers can be "read" for information about the environments of deposition.
Because the water in a lagoon, estuary or lake is slow-moving, the particles are able to settle to the bottom. After a further extremely long time, layers of particles are buried by later depositions of particles. This subjects the lower layers of sediment to pressure, and when there is enough pressure, they are compressed into a sedimentary rock.
Sedimentary rocks are characterised by (1) their softness compared with igneous rocks like granite, and (2) the presence of strata or obvious layers. These layers can be "read" for information about the environments of deposition.
