Acting like a giant bulldozer, it pushed sediment toward the South dumping its load to form a moraine that runs through central Long Island and extends to the south fork. This is the Ronkonkoma moraine. The sediment in these moraines is typical glacial till, composed of unsorted material. Meltwaters running over the moraines deposited finer sediment called outwash. The outwash created the plains of Long Island.
Glaciers transport an enormous amount of sediment.
When the material is unloaded from the various areas of the glacier, distinct landforms are created. Sand particles blew in the wind and acted like sandpaper, abrading rocks flat on one side. Rocks shaped in this way are called ventifacts. The rocks carried within the glacier were banged around during transport. The results of this are small crescent shaped indents called chattermarks.