What is glaciation?

Glaciation refers to the process where large masses of ice, known as glaciers, advance and recede over significant areas of land over geological time. This process profoundly shapes the landscape by eroding land surfaces, depositing sediments, and creating various geographical features such as valleys, fjords, and moraines. The movement of glaciers involves both the accumulation of snow that compacts into ice and the subsequent melting during warmer periods, which can lead to the formation of features like eskers and kettles. This cyclical advance and retreat is influenced by climatic conditions and can have lasting effects on both the environment and ecosystems.

The other options pertain to different geological processes. Rock melting into magma involves igneous rock formation, while soil erosion by wind refers to processes affecting topsoil and land degradation. The formation of new rocks from sediments describes sedimentary processes, each distinct from glaciation.