Which term refers to the breaking down of rocks into smaller pieces without altering their chemical composition?

The term that refers to the breaking down of rocks into smaller pieces without altering their chemical composition is mechanical weathering. This process involves the physical fragmentation of rocks due to various forces, such as temperature changes, freeze-thaw cycles, abrasion from wind or water, and pressure from overlying materials.

Mechanical weathering occurs in various environments and is a crucial part of the rock cycle. For instance, when water seeps into cracks in rocks and freezes, it expands and exerts pressure on the surrounding rock, causing it to break apart. Importantly, throughout mechanical weathering, the minerals within the rocks remain chemically unchanged, distinguishing it from chemical weathering, where the mineral composition is altered due to chemical reactions.

This process is essential for soil formation and the creation of sediment, which are vital for ecosystems. Understanding how rocks are broken down without any change to their chemical structure provides insight into geological processes and landscape evolution.