The rocourt tephra in the middle paleolithic site of remicourt (province of liège, Belgium) [Le téphra de rocourt dans le site paléolithique moyen de remicourt (province de liège, Belgique)]

摘要

In the Middle Paleolithic site of Remicourt, the Rocourt Tephra minerals were found as reworked material (cryptotephra) within the Humiferous Complex of Remicourt, which overlies the Rocourt Pedocomplex, the highest concentration of tephric material occurring in the middle part of the humiferous complex. Identification of the tephra is based on the mafic mineral suite, the morphology of glass shards and the chemical composition of mafic minerals: two types of clinopyroxene, an orthopyroxene, two types of amphibole and a chromian spinel. Volcanic glasses are typical blocky shards, and pyroxenes are fragments of megacrists, so that the material can be linked to one of the numerous phreatomagmatic eruptions that have taken place in the West Eifel volcanic field. Stratigraphical position of the tephra within the Humiferous Complex of Remicourt allows us to precise the time slice of the relevant eruption between 78 and 80 ka, during the final climatic phase of Weichselian Early Glacial encompassing Dansgaard-Oeschger interstadial 21 (MIS 5a).