Ivrea Zone, Italy - the Moho
exposed?
The Mohorovicvic discontinuity, or Moho, defines the boundary
between
the
crust and mantle. It is seen as a rapid
increase in seismic velocity at depths of about
35-50 km beneath continents and about 6 km
beneath oceans. Understanding the changes
in composition and mineralogy causing this
change is an important problem. Rocks from the
Ivrea region in the Alps of northern Italy may
represent an exposed section of what used to
be the Moho. In this interpretation, the Moho
would occur between mantle lherzolites and lower
crustal pyroxenites.
(Photo by Seth Stein) |
