Moraines are deposits of rock, gravel, and dirt left behind by glaciers.

Here's why:

* Glaciers are massive sheets of ice that move slowly over land. As they move, they pick up and transport rock, gravel, and dirt.

* When glaciers melt, they deposit the material they carried, forming moraines. These deposits can be found at the edges of glaciers (lateral moraines), in the middle of glaciers (medial moraines), or at the end of glaciers (terminal moraines).