The area was uplifted and erosion exposed the volcanic rock.
The erosion of rain and wind had exposed them.
In modern times, continued erosion has exposed some of the underlying sediment.
After a storm in February 1970, tidal erosion exposed hundreds of well preserved wooden artifacts.
In Ireland, to cite a recent instance, erosion has exposed tons of dumped garbage, which is now tumbling into the sea.
These were typically in places such as valleys where erosion had exposed the coal veins.
In several locations erosion has exposed these beds.
The erosion exposed the foundations of private homes, leaving some uninhabitable.
This erosion can damage the environment and expose or unsettle the foundations of the structure.
In 1979, erosion from the river exposed the mass grave.