Commonly ground moraines are composed of lodgment till. Sediment clasts suspended in the ice at the bottom of the glacier have greater friction with the ground than the ice does. This causes the sediment to be slowed down disproportionately to the ice and eventually fall out or get stuck in the ground beneath the ice.
Most common moraines consist of lodgment till. The sediment particles carried by the glacier's ice are slowed down more than the ice itself due to friction, leading to their release or entrapment in the underlying ground.