Tombolo
(c) 2002 Andrew Alden, licensed to About.com, Inc. (fair use policy)
A tombolo is unusual among beach-related landforms: it extends outward from the shore, connecting with an island. In this tombolo, at Goat Rock Beach in northern California, the low, sandy bar is reinforced with boulders and serves as a parking lot.
The offshore hill, or stack, bends the incoming waves around it so that their energy sweeps sand onto the tombolo from both sides. Once the stack erodes down to the waterline, the tombolo will disappear. Stacks don't last long, and that's why tombolos are uncommon.
See this article for more about tombolos, and see this gallery for more pictures of tombolos.
Fossils
Geologic Features and Processes
Glaciers and Ice
Landforms
Minerals
Rocks
Geology and Society
