Here's why:

* Glaciers are powerful erosive forces. As they move, they pick up rocks, soil, and other debris, carrying them along.

* As glaciers melt or retreat, they deposit this material. This deposited material is what forms moraines.

* Moraines are essentially piles of glacial debris. They come in different shapes and sizes, depending on how and where the glacier deposited the material.

So, moraines are a direct result of glacial activity and serve as a visible reminder of past glacial periods.