Geology

The BedrettoLab is an underground research facility dedicated to understanding how rocks deform and how fractures develop at depth within the Earth’s crust. Understanding these processes is relevant to geoenergies, natural hazards, and subsurface engineering.

The Rotondo granite formed approximately 295 million years ago and has since experienced a complex geological history linked to both pre-Alpine tectonics and the formation of the Alps. Detailed geological characterization (s. Ceccato 2024) shows that deformation in this rock mass occurred in multiple stages, ranging from early brittle fracturing formed during the breakup of the European continental margin to ductile deformation at high temperatures during Alpine mountain building, and finally to renewed brittle faulting as the rocks cooled and were uplifted toward the surface.

Structural inheritance and fracture reactivation

A key outcome of this research is the recognition that deformation is strongly controlled by pre-existing structures. Ancient fractures act as persistent zones of weakness that are repeatedly reactivated over millions of years, guiding the localization of strain and fluid flow. This structural inheritance is essential for understanding how faults evolve, how permeability pathways develop, and how stresses are distributed in the crust.

Relevance for BedrettoLab research

These geological insights are fundamental for a wide range of research fields addressed at the BedrettoLab. They provide the framework for experiments on earthquake physics, including the initiation and propagation of seismic rupture processes, as well as for studies related to geothermal energy, fluid circulation, and rock mechanics. By linking detailed geological observations with in situ experiments, the BedrettoLab enables a better understanding of subsurface processes that are critical for both natural systems and engineered applications.

Core inventory

The BedrettoLab maintains a comprehensive core inventory comprising over 3,000 meters of drill cores, most of which were recovered from the BedrettoLab itself, and some of which were recovered from the Grimsel Test Site and Mont Terri. These cores are stored in a dedicated facility in Zurich, where they are preserved and systematically documented. Both physical core material and associated core data are available to the scientific community upon request, supporting ongoing and future research on rock properties, structural geology, and subsurface processes.

Contact person: Alba Zappone (alba.zappone@sed.ethz.ch).