Final answer:
The transformation of rock pieces into sedimentary rock occurs through lithification, which includes the steps of compaction and cementation. Compaction reduces the space between sediment grains, while cementation binds the sediments with precipitated mineral matter, resulting in sedimentary rock formation.
Step-by-step explanation:
The process that changes pieces of rocks into sedimentary rock is known as lithification, which involves two main steps: compaction and cementation.
During compaction, the porosity of sediments is reduced as grains are pressed together under the weight of accumulating sediments above, similar to compacting trash in a garbage can to make more room. Cementation occurs concurrently, where water is squeezed out from the pore spaces between the sediments. This water, carrying dissolved minerals, precipitates mineral matter, such as calcite, quartz, or pyrite, within pore spaces that act as a glue to bind the sediments into rock.
Clastic sedimentary rocks are a type of sedimentary rock formed from weathered particles of pre-existing rocks that undergo this lithification process. Quartz, being very stable, often makes up a significant portion of clastic sedimentary rocks like sandstone. Over geologic time, rocks undergo cyclical changes where they can shift between being igneous, metamorphic, or sedimentary, driven by the movement of tectonic plates and the processes of weathering, erosion, and lithification.