Insubric line: the history of the world in rocks
In the Bocchetto Sessera area in Oasi Zegna, a major testimony to the formation of our continents
Insubric Line: not the sexiest of names perhaps, but it marks out an
area of crucial geological importance and is also a big attraction for tourists
in the Biella Alps.
The Insubric Line is named after
Insubria, a region no longer with clear confines and formerly inhabited
by the Insubres, who settled between the Po and the pre-Alpine lakes and (according
to Livy) founded Milan.
For the academics, this line is a geo-stitch, a
“stitching” in the earth’s surface following the collision between the European
and African tectonic plates. Today, it marks the “border” between the Eurasian
and Adriatic plates.
During the Jurassic era, Africa and Europe were separated by an ocean we call Tethys.
The African plate moved north towards the European plate. This shift caused a
gradual closing of the Tethys and finally an actual collision between the two plates
to produce the Insubric Line, whose composition is the result of the fusion of
the materials deposited along the two edges.
It’s an extremely interesting
area to study, given the role it played in forming the continents as we know
them today. Visitors to Oasi Zegna have the good fortune of being able
to literally see the Insubric line, which passes through the zone around Bocchetto
Sessera. Here you are practically standing astride Africa and Europe.
Knowing a lot about the geomorphology
of this territory and its many peculiarities, the nature guides from OverAlp, a firm set up by geologist Stefano Maffeo, organize walks in Oasi Zegna that are alsodesigned to
reveal fascinating historical details along the way, as at Bocchetto Sessera,
where the Insubric Line passes.