Moraines are unconsolidated sediments deposited by moving glaciers. This is distinct from the tills that form at the melting end of a glacier, although those are often called terminal moraines.
The sediments are unsorted and often angular, although they may include fieldstones or river stones that have been picked up by the moving glacier.
As a glacier moves over a river valley, the depression becomes a collection point of gravels and boulders which may be transported for hundreds of miles. This process results in large underground gravel beds which can be valuable aquifers such as beneath Moraine, Ohio.