Which process is primarily responsible for the formation of sedimentary rocks?

Sedimentary rocks are formed through the processes of compaction and cementation of sediments. This begins when particles of minerals or organic materials, which are often the result of weathering and erosion, accumulate in layers over time. These sediments can come from various sources, including rock fragments, minerals, and biological materials.

As additional layers of sediments are deposited on top, the weight of the overlying material exerts pressure on the lower layers. This pressure causes the sediments to compact, reducing the space between them. Subsequently, minerals precipitate from groundwater and fill the gaps between the sediment grains, acting as a glue that binds them together. This process is known as cementation. Together, compaction and cementation transform loose sediments into solid, structured sedimentary rock.

The other processes mentioned, such as cooling and solidification of magma, are associated with igneous rock formation, while metamorphism pertains to the alteration of existing rocks under heat and pressure, leading to metamorphic rocks. Erosion and transport of igneous materials do not contribute to sedimentary rock formation directly but rather to the reworking of existing materials from other rock types.