Considérations complémentaires relatives à la provenance du Téphra de Rocourt : minéraux mafiques volcaniques et âge

The Rocourt Tephra (RT) is a pyroclastic fallout deposit that was discovered in Belgium three-quarters of a century ago. Since then, the search for its source volcano has been in vain. Recently, however, two volcanoes of the West Eifel Volcanic Field have been put forward, namely the Dreiser Weiher and the Pulvermaar, but it has been shown by the geochemical fingerprints of associated pyroxenes that neither of them is compatible with the RT (Juvigné et al., 2024, DOI: 10.1007/s00445-024-01756-2). We present here additional arguments that support this conclusion. They arise from the comparison of volcanic mafic mineral associations of the RT and the Dreiser Weiher and Pulvermaar tephras. Furthermore, details of the stratigraphic study that led to the age estimate of between 70 and 80 ka for RT are reported, in order to widen the scope for determining the ages of volcanoes or tephras in the Eifel Volcanic Field (or elsewhere).