|East Beach ~ Barrier Beach|
Where did all that sand come from?
When glaciers move across land, they scrape off all the rocks and sediments, leaving the land bare. The glacier carries the rock scrapings and sediments along with it as it moves. When a glacier melts, the sediments and sand that were mixed in the ice are carried away with the melting water. A glacier leaves large piles of debris behind when it retreats or melts. These deposits eventually erode, forming gravel, sand, and silt.
Do glaciers leave anything behind?
As a glacier moves, a large hill of till is pushed up in front of (terminal moraine) and to the sides of (lateral moraine) the glacier. When the glacier melts or retreats, these deposits of sediments are left behind.
(The arrow in the photo below points to the terminal moraine called the Charlestown Moraine as it is seen from East Beach.)
The advance and retreat of the continental glaciers left two terminal moraines in southern Rhode Island. You can see both of them from East Beach. Looking southward, you see Block Island, an island off the coast of southern Rhode Island. This island, along with Long Island, Martha's Vineyard, and Nantucket islands are what is left of a terminal moraine (these islands are found in the states of New York and Massachusetts, respectively). Looking northward from the beach, you can see the Charlestown Moraine (see photo above). These moraines are easy to spot because their elevation is much higher than the land around them.