How Do Soils Form? Dig down deep into any soil, and youâll see that it is made of layers, or horizons. Put the horizons together, and they form a soil profile. Like a biography, each profile tells a story about the life of a soil. Every soil originally formed from parent material: a deposit at the Earthâs surface. The material could have been bedrock that weathered in place or smaller materials carried by flooding rivers, moving glaciers, or blowing winds.