Coastal dunes are a ridge, or a series of ridges, that form at the rear of a beach and differ from most other constructional coastal landforms in that they are formed by the movement of air ...

Scientists have long questioned whether the ridges might represent the remnants ... no shortage of sand — a proper, vacation-style beach.” What’s more, it’s possible the Martian ...

In 1963, Fred Vine, Drummond Matthews, and others found that the crust surrounding the midocean ridges showed alternating bands -- each band magnetized with a polarity opposite the surrounding bands.