The Eifel region, Germany, hosts hundreds of distributed volcanoes of Quaternary age in an intracontinental setting and is renowned as the type locality of maar volcanism. Laacher See volcano in the eastern part of the region stands out as a sizable, dormant, but actively deforming and degassing system that represents the second youngest silicic-carbonatitic magmatic complex worldwide currently not erupting. Drilling in the Laacher See region has potential to enhance our knowledge on distributed volcanic fields and specific hazards resulting from high CO2 fluxes from the mantle to the surface.

Laacher See would be an ideal testbed to evaluate the physical and chemical properties of a shallow (~5–6 km depth at its top) intrusive silicic-carbonatitic complex formed by volatile-rich magmas and an associated hydrothermal system, both accessible to drilling. Only drilling can provide answers as to why the shallow hydrothermal system above a residual magma system after an eruption only 13,000 years ago is seemingly cold, although it is highly dynamic based on ongoing CO2 degassing, seismic activity, and exceptionally high rates of uplift on spatial scales of hundreds of kilometers. Moreover, silicic-carbonatitic magma systems are globally recognized as major hosts for critical metal deposits, which in case of Laacher See could be investigated in the making.

Keywords: Eifel, distributed volcanic fields, silicic-carbonatitic magma system, volcanic hazards critical metals