Metamorphism of sedimentary rocks recognised by 19th century French naturalists: A case study from the Chavanon sequence marbles,Massif Central,France

The Chavanon metamorphic sequence in the Variscan French Massif Central contains marble lenses that have been exploited since at least the 18th century to produce lime. They provided an opportunity to some major pioneers among nineteenth century French geologists to understand how metamorphic rocks are formed. The intimate association between marbles and gneisses led them to propose that the initial pile of rocks was deposited as a single unit under water. They thoroughly described the attitude, folding and mineralogy of the marbles, making their works of great historical value. Originally written in French, their translation into English and the reproduction of original figures from the works they published will be very useful to the international community of geologists interested in the history of their science.