Connecticut's rocks divide into three belts. On the west are the state's highest hills, bearing rocks largely dating from the Taconic orogeny, when an ancient island arc collided with the North American plate in Ordovician time about 450 million years ago. On the east are the deeply eroded roots of another island arc that arrived some 50 million years later in the Acadian orogeny, of Devonian age. In the middle is a large trough of volcanic rocks from Triassic times (about 200 million years ago), an abortive opening related to the birth of the Atlantic Ocean. There dinosaur tracks are preserved in a state park.
More About Connecticut Geology
More Connecticut resources on About.com:
Colonial Connecticut
Connecticut Campgrounds
Connecticut Maps
Connecticut Scenic Roads
Connecticut Geography, State Symbols & Facts
Connecticut Attractions & Sightseeing
