These huge boulders lie at the east end of Hammonasset Beach, part of the long line of rocky recessional moraines that fringe Connecticut's Coast from the Rhode Island border on the east to the Norwalk Islands on the west.

moraine. Each recessional moraine marks a brief standstill in the retreat of glaciation from New England where, for a short time, the forward flow of the river of ice once again balanced melting. There are two main lines of recessional moraines along Connecticut's Coast which parallel each other and the shoreline; in Madison they turn inland and run across the Coastal Slope and into Rhode Island. Known as the Madison Moraine and Old Saybrook Moraine, these low ridges are much smaller than the Long Island-Fishers Island terminal moraine. For reasons still not understood, the recessional moraines are much rockier than the sandy terminal moraines. In places, the recessional moraines are filled with huge, almost dump-truck sized boulders. On the east end of Hammonasset beach lies one such bouldery stretch of recessional moraine.

A Coast on the Move

Because of the great natural seawall of Long Island, Connecticut has a sheltered coast. But the calmer wind and water do not mean that Connecticut's Coast is a fait accompli. As long as the tide rises and the weather changes, the Coast will keep on realigning and reshaping itself. And unlike other land regions in Connecticut, this constant adjustment of the Coast takes place at a rate and scale that is well within the human time frame -often disastrously so.

Change on the Coast comes about through erosion of some areas and deposition of sediment in others. Some spots are subtracted from while others are added to. Overall, additions and subtractions probably roughly balance each other, but at any one particular place either erosion or deposition may dominate. When processes of addition exceed subtraction, beaches, salt marshes, and mud flats form. However, even these growing areas later may experience severe erosion. It's a shifty business.

The main sources of sediment for places of accumulation are the erosion of other areas and new sediment dumped by rivers. In Connecticut, as discussed earlier, the fine, muddy river sediment goes into marshes and mud flats. Connecticut's beaches, on the other hand, are

89