These extraordinary
structures can be seen in northern Italy, in wooded ravines on the Ritten
plateau, which is near the city of Bolzano. There are three groups of these
pillars, in separate valleys. They are at a height of around 3250 feet (1000
metres) above sea level.
Jagged, tapering
clay spires, some of them coloured in shades of red or violet, stand up to 130
feet (40 metres) high, most of them being crowned by a block of stone.
These pillars were
created at the end of the last Ice Age, about 10,000 years ago. As glaciers
moved across the land they carried rocks of various sizes hundreds of miles
from their original locations, as well as vast quanties of softer "boulder
clay". When the glaciers stopped and melted, the rocks were left in place
on a thick layer of boulder clay. Rainwater then carved gullies in the clay,
but where there was a rock, the clay beneath it was protected. The pillars seen
today are the result.
One factor that
could have accelerated the formation of the pillars was the development of
agriculture in the region in the 13th century. Clearing the forests to create
pastures and vineyards could have laid the land open to the erosive power of
rain.
Not surprisingly,
pillars like these - and they are found in a few other places around the world
apart from here - have gathered a certain amount of folklore and superstition
around them. They are known in north Italy as "little men" and
"earth mushrooms". In France there is a group known as "young
ladies with their hats on".
The pillars have been
there for thousands of years, but they will not last for ever. If a rock falls
from the top, the rate of erosion of the pillar will increase considerably
until there is nothing left. This will eventually be the fate of all the
pillars.
However, a fallen rock may then serve to protect the boulder clay on to which it has fallen and a new pillar will form. This process could continue until the base of the boulder clay layer is reached.
