Professor Dr Christian Chopin

Research Priorities: Mineralogy, metamorphic petrology, high- and ultrahigh-pressure metamorphism, continental subduction, crystal chemistry of rock-forming minerals
Christian Chopin is a French geologist, with interest in the chemistry of minerals. He investigates metamorphic rocks and played a key role in establishing the field of ultrahigh-pressure metamorphism. He demonstrated the presence of the mineral coesite, a high-pressure silica phase, in the Western Alps and thus provided evidence for continental subduction. In 2007 the newly discovered phosphate mineral chopinite was named after him.
Metamorphism refers to the transformation of rocks due to changes in temperature or pressure conditions within the Earth. This process results in progressive changes in the chemistry and nature of rock-forming minerals, sometimes in the chemical composition of rock. Metamorphic rocks are exposed over very large areas, like the metamorphic belts of the Alps and Himalayas, for example. Regional metamorphism is a manifestation of the continuous activity of planet Earth, through plate tectonics, for instance the diving (subduction) of oceanic plates beneath continental plates.
Christian Chopin’s finding of the mineral coesite in the Western Alps proved that fragments of continental crust can also be dragged to depths exceeding 100 kilometres in subduction zones – and come back to the surface. Chopin was thus key to the discovery of ultrahigh-pressure metamorphism.
His experimental work on the stability of minerals is based on observations of nature. He has been working together with thermodynamicists on these experimental aspects, and with crystallographers on the crystal chemistry of various minerals, in particular complex phosphates. In 2007 the newly discovered high-pressure mineral chopinite, Mg3(PO4)2, was named after him.