The Cadillac Mountain Intrusive Complex is part of the Coastal Maine Magmatic Province, consisting of over a hundred mafic and felsic plutons associated with the Acadian Orogeny. Mount Desert Island bedrock consists mainly of Cadillac Mountain granite. Perthite gives the granite its pinkish color. The Silurian age granite ranges from 424 to 419 million years ago (Mya). Diabase dikes trend north-south through the complex. Almost 300 million years of erosion followed before the deposition of glacial features during the Pleistocene. Glacial polish, glacial striations, and chatter marks are evident in granitic surfaces. Other glacier-shaped features include The Bubbles (two rôche moutonnées) and the U-shaped valleys of Sargent Mountain Pond, Jordan Pond, Seal Cove Pond, Long Pond, Echo Lake, and Eagle Lake. Somes Sound is a fjard and terminal moraines form the southern end of Long Pond, Echo Lake, and Jordan Pond. Bubble Rock is an example of a glacial erratic.