Janne Blichert-Toft

The 2022 Robert Wilhelm Bunsen Medal is awarded to Janne Blichert-Toft in recognition of fundamental research and unique applications of isotope geochemistry.

Blichert-Toft is a world leader in the application of isotope geochemistry to address key scientific questions on the origin and evolution of the Earth and planetary bodies, extending also into geoarchaeology. In the nineties she played a key role in establishing multi-collector ICP-MS as the revolutionizing technique it was to become, placing the field of isotope geochemistry on a brand-new trajectory for the new millennium. She is perhaps best known for her contributions to the geochemistry of radiogenic Lu-Hf isotopes to constrain the formation and evolution of Earth and the early Solar System, where she has made numerous contributions that are foundational in geochemistry and cosmochemistry. Taking advantage of her ability to analyse small aliquots of Hf precisely, she contributed to Lu-Hf isochron dating of mantle rocks, from peridotites to eclogites. Because of the robustness of the Lu-Hf system, her papers opened up the door for understanding a part of the thermal history of deep crustal or lithosphere rocks that was previously inaccessible.

Blichert-Toft has also become one of the global leaders in Pb isotopes. High quality analyses allowed her to integrate Pb isotopes with geophysical parameters to show a remarkable correlation between crustal thickness, age, and lower crustal Pb isotopic composition. Further, her measurements of iron meteorites provided new constraints on the age of our solar system. Entering an entirely new arena, her analyses of sediments and coinage provided new insights on archaeological questions including why the Roman empire collapsed, and how Carthage survived the Punic wars.

She plays a key role in the geochemical community, as editor and associate editor of multiple journals, a member of CNRS National Committee for the Earth Sciences, and an elected member of the
administrative and scientific councils of ENS de Lyon. She has consistently played a central role in the
organization of meetings, where she recently led the successful bid to host the Lyon Goldschmidt Conference.

Blichert-Toft has selflessly helped advance science and the careers of other geochemists by opening the doors of her lab to others. She hosts a steady stream of guests that include international collaborators and their students.

As an innovative researcher across a range of disciplines and as a generous colleague who works to support others, Blichert-Toft epitomises the Bunsen Medal qualities of research excellence, rigour and collegiality, and is therefore recognised as the recipient of the 2022 Robert Wilhelm Bunsen Award.