the fore-edge lake formed by glacial meltwater expanded to be about the same size as present-day long island sound; it may have been connected at times with similar freshwater lakes in block island sound and buzzards bay, while sea level was low. the fairly shallow average depth of 78 feet (24 m) of today's long island sound is the result of fine lake-bottom sediments deposited as glacial outwash slowed in lake connecticut. suspended as rock flour, the fine sediments would have rendered lake connecticut a turquoise blue-green.