Moho mission to the foundations of continents: the ICDP DIVE drilling project in the Ivrea-Verbano Zone, Alps, Italy

Drilling has made it possible to explore the Earth’s interior, but still only to very shallow depths on the scale of the planet. Since 1960s, scientists have worked to reach the crust–mantle boundary known as the Moho. This boundary representing the foundations of continents is usually beyond the reach of our present-day technology. However, in some places on Earth, it is possible to reach the crust–mantle frontier without drilling to its original depth. The Ivrea-Verbano Zone in the Italian Alps is the prime target to explore the Moho at ~ 2-km depth for the first time in the history of science. This is because the collision between tectonic plates generating the Alps brought the crust–mantle boundary along with a cohesive and preserved crustal section to such a shallow depth. Thus, under conditions of low pressure and temperature, our present-day drilling technology can put down a borehole to this depth. Based on the collaborative effort involving > 100 scientists worldwide, the ICDP (International Continental Scientific Drilling Program) DIVE (Drilling the Ivrea-Verbano zonE) project tackles key questions on the chemistry and architecture of the lithosphere, the geophysical signatures, insights into the deep biosphere, and the nature of the Moho. Here our perspective contribution presents new speculations about the Ivrea-Verbano Zone Moho transition zone based on the lithological column explored and sampled in the two boreholes and the petrophysical properties (rocks’ compressional wave velocities and densities) of the pre-Permian and Lower Permian lower crust lithologies.