Lithification is the process of compacting sedimentation and then cementing the mass together under intense pressure. This creates sandstone, a form of sedimentary rock. Grains of sand, plant biomass and fossils are some of the materials that may be compressed into sandstone.
Often sediment is created by the weathering and erosion of solid rock. High or continual winds usually start the weathering process. The small fragments collect and are then moved from their original location by erosion. The material can be caught up in a rock or mud slide, scraped away by glaciers or transported by running water. Sometimes the processes of weathering and erosion overlap.
At some point the sediment becomes too heavy for the water to carry and it is deposited. Plants or animal remains may be buried in the process. As the sediment deposit thickens, it becomes heavier, beginning the lithification process. The compaction forces the grains of sand and other materials closer together, forcing out air and most of the water.
As the mixture is compacted, the pores in the sediment become smaller. Minerals contained in the residual water deposit in these pores. As the water continues to squeeze out and the pressure increases, the mineral deposits start to harden, cementing the entire mass and creating sandstone.