full-size image (77 kb)

These structures are exposed only at low tide, on sandy tidal flats.

• Are these structures symmetrical or asymmetrical in cross section?
• They show another diagnostic feature: look carefully at this photograph, then at the annotated image.
• How did these structures form? By wave or current action?

Scale: The compass (above the blue bar) is 10 cm long

Grid reference: 859 291 at low tide