[Musealia : Fossils of the Trocadero]

Every month, Sorbonne University  invites you to discover an object from its heritage collections. This month, discover what fossils collected during the levelling of the Trocadero in the 1860s tell us about the geological history of the Paris basin.

To the west of Paris, the suburbs of Auteuil, Passy and the hill of Chaillot had not yet been integrated into the capital when in 1813 the exploitation of Parisian quarries was prohibited. The network of quarries in this area remained active until the annexation of these suburbs in 1860. The Chaillot quarries were extensively reworked as part of the major levelling work carried out in preparation for the 1867 Universal Exhibition. With the help of blasts fired into the foot of the quarry support pillars, which blew up "a prodigious quantity of rocks, stones and land", the mound of Trocadero was completely levelled.

This work to 'regularisation' the Trocadero led an important flora fossil collection published by Edouard Bureau, Gaston de Saporta and Ernest Munier-Chalmas (1843-1903). At the time, Munier-Chalmas was simply a preparator for the geology course at the Faculty of Science, where he collected numerous specimens still preserved in the Sorbonne University collections, such as this very well preserved leaf of a protea, collected in 1868 from a level of marly limestone from the Lutetian period (40 million years ago). The flora of this level indicates a significant but temporary drop in sea level in the Paris Basin at this time.

A "remarkable deposit in more ways than one", the Trocadero was still the subject of field trips by students from the Sorbonne's geology laboratory at the end of the 1870s. The Trocadero specimens in Sorbonne University's geoscientific collections are all the more interesting, both historically and scientifically, since this deposit is now completely inaccessible.