Answer: Sand and gravel deposits.
Step-by-step explanation:
Glaciation is a natural phenomenon in which the temperature of the earth drops considerably over a long period, this causes the glaciers of the poles to expand to cover large extensions of continental and oceanic terrain.
When the temperature rises again and the ice from the glaciers recedes, large deposits of sand and gravel are formed. This is because the deglazing process is slow, and the retreating glaciers remove the surface layers of the earth, therefore mineral deposits are formed. Also, the deglaciation process forms rivers and lakes that leave large deposits of sand and gravel.
I hope this informacion can help you.