Paleontology and geology
Ice sheets advanced over Connecticut several times during the Quaternary. Evidence of Pleistocene glaciation includes deposits left behind by Glacial Lake Hitchcock, a large lake that formed behind a natural dam of glacial debris. You can still see remains of this dam near the present town of Rocky Hill. Glacial striations (scratch marks) on bedrock are easy to find throughout the state. Quaternary fossils are found along the coast of Connecticut’s Long Island Sound and in northwestern Connecticut. These include fossils of marine and intertidal organisms, including clams, oysters, snails, crustaceans, rare bryozoans, sponges, insects and trace fossils. Many of these fossils are from animals very similar to those of today.