At the southern end of Thorney Island, about three miles S.S.W. of Emsworth, in West Sussex, there are low cliffs of London Clay covered by Pleistocene deposits. The London Clay has been folded near the top, and its surface presents a series of basin-like depressions, 3 to 10 feet in diameter, and evidently caused by downward pressure. These basins are occupied by Pleistocene gravel, which contains numerous erratics—many of igneous rocks—and resembles the better-known Erratic Gravel of Selsey. The Erratic Gravel is covered by Coombe Rock and Brickearth, which form the top of the cliff, as shown in the diagram.