Salt marshes may be formed behind a spit. The zone behind a spit becomes a sheltered area. Water movement slows down and so more material is deposited. Deposition may form a salt marsh.

Because waves can’t get past the spit, a sheltered area develops behind it. The water isn't moving much here, so it deposits sand and silt, so mud flats or salt marshes form. Spits can also form ...

signs of the ancient creatures are all around the salt marsh that rings Quonochontaug Pond, a coastal lagoon behind a barrier beach on the state’s southern shore. Traces of their tracks loop ...