The maximum elevation of Appledore is about 80 feet above sea level.[2] The majority of the island has a metamorphic makeup, with gneiss being the most prevalent.[3] The formation of the island is thought to be characterized by 5 major geological events, namely formation of the Rye Complex of Maine and New Hampshire, intrusion of diorites, Acadian orogeny, diabase dikes, and glaciation.[3]