What to role does oxygen present in the air play in the formation of soil?

Dear Student, Formation of soil occur through the process of rock weathering. Weathering is the breakdown of rocks into smaller particles when in contact with water (flowing through rocks), air or living organisms. Weathering can occur physically, biologically or chemically. Formation of soil with help of oxygen comes under criteria of chemical weathering. Oxygen in air helps in formation of soil this process is called oxidation. In oxidation oxygen from the air reacts with iron in rocks to form iron oxides. This reaction creates a rusty brown colouration on rocks. And when these rocks turn into soil, then this soil become red soil. Regards