Image: Dr. Mattia Pistone has been funded for the DIVE (Drilling the Ivrea-Verbano zonE) project, which aims at unravelling the chemistry, physics, and microbiology of the roots of the Earth’s continental crust and the crust–mantle transition in the Ivrea–Verbano Zone (Western Alps, Italy). The Ivrea-Verbano Zone (IVZ) is one of the most complete and best studied archetype of a continental crust–upper mantle section on Earth. Recent evidence illustrates that the IVZ is an exceptional archive of trans-crustal continental magmatism documenting lower crustal processes of magma emplacement, crystallization and crustal assimilation, and of the development of near-surface magmatism, including evidence for protracted super-eruptions during the Permian. A defining feature of the IVZ is that the available geophysical evidence points to the surficial, indeed as shallow as 3 km or even less, presence of mantle-type high-velocity, high-density rocks. This structure is referred to as the Ivrea Geophysical Body, which, based on its classical interpretation, gained worldwide notoriety as the enigmatic “Bird’s Head”. As such, the IVZ provides a truly unique natural laboratory to fundamentally advance our understanding of the continental lower crust and the crust–mantle transition zone by a combination of geoscientific approaches and scientific drilling, complementing offshore attempts to drill through the crust–mantle transition. Drilling two 1-km deep holes into the IVZ at strategic locations will provide an unrivalled opportunity to link geophysical and geological data via core observations, downhole logging, microbiological sampling, hydrological studies, and various geophysical-geological surveys. This will address long-standing fundamental questions on the nature of the continental lower crust, resolve potential connections to the Ivrea Geophysical Body, allow for a comprehensive characterization of the physical and chemical rock properties and fabrics, explore the relation of permeability to fracturing, weathering, alteration, and unravel the nature and origin of the prevailing fluids. Together with studies on the extent and diversity of the subsurface biosphere and its relation to the volatile element budget of exhumed lower continental crust, these studies will contribute to advance our understanding of metabolic energy sources for microbial ecosystems in various crystalline bedrocks. Important societal benefits of the project notably comprise the development of educational platforms for schools and university students as well as the formation of the next generation of leading researchers in Earth Science. Finally, the interests of the larger public are enticed through active collaborations with the Val Grande National Park, the Sesia Val Grande UNESCO Global Geopark and local institutions including a new visitor centre.
