Cape Cod is composed almost entirely of rock debris deposited by the ice age glaciers over 18,000 years ago. Most of this debris, called "glacial till", consists of clay, sand, and pebbles, but the ice age also deposited larger stones.
Doane Rock is one of the largest ice-carried boulders in southeastern New England. It stands 18 feet (5.5m) high and extends below ground an estimated 12 feet (3.7m)
Other glacial boulders may be seen along the beach nearby where winds and waves have dislodged them from the glacial till of the eroding sea cliffs.
Between 18,000 and 25,000 years ago a giant ice sheet crept over this region. Doane Rock was plucked up by the ice in the Massachusetts Bay area and carried to Cape Cod.
Doane Rock, also called Enos Rock, is 45 feet (14m) long. The grinding action of the glacier has rounded its contours.
The ice sheet gathered up rocks and transported them many miles, depositing them as glacial till where the ice melted.