cementation:
Cementation involves irons that are carried in groundwater to form new material within sediment this is how sediment becomes rock The new minerals form bridges between sediment binding them together. However, sand becomes stone and gravel. Cementation occurs some times below the water table regardless of sedimentary grain sizes. Also, the Large volumes of pored water must pass through sediment pores for new mineral to crystallize. Also, common minerals include quartz or pre-quartz silica , iron oxide, and clay minerals.