Why do most sediments formed by weathering consist of silicate minerals?

Silicate minerals make up the majority of the Earth's crust because they consist of the most abundant elements on Earth, including oxygen, silicon, and aluminum. Therefore, when rocks are broken down through weathering, it is likely that the sediments produced will have a high content of silicate minerals due to their relative abundance in the parent rock.

Silicate minerals are characterized by their complex lattice-like structures, in which silica tetrahedra (SiO4) are interconnected with metals such as aluminum, magnesium, iron, and calcium. This structure provides stability and resistance to decomposition, which is a crucial property for sediments to persist in the weathering environment. Additionally, these minerals are harder and less soluble than minerals such as carbonates, which makes them less prone to dissolution during the chemical weathering process.

There are two main types of weathering: physical and chemical. Physical weathering involves the mechanical breakdown of rocks without changing their chemical composition. This process primarily affects silicate minerals, as their structures are harder and more resistant to fragmentation. Chemical weathering involves the breakdown of rocks through chemical reactions, such as dissolution, oxidation, and hydrolysis. Since silicate minerals are less soluble and more stable than other minerals, they are less likely to be completely dissolved or chemically altered during weathering. As a result, silicate minerals often remain as residual particles in sediments. In summary, most sediments formed by weathering consist of silicate minerals due to their abundance in the Earth's crust, their stable lattice-like structures, and their relative resistance to decomposition during weathering processes.