The Rocourt Tephra, a Widespread 90–74 ka stratigraphic marker in Belgium

Abstract

A new study of the stratigraphy and composition of the Rocourt Tephra is performed at five sites in Belgium and brackets the age of the tephra between 90.3 and 74 ka. The volcanic glass grains have a typical shape of phreatomagmatic eruption products. A large set of tephra minerals were analyzed, namely clinopyroxene, orthopyroxene, amphibole, and Cr-spinel. The compositions of these minerals have been compared with the lava xenocrysts, megacrysts, and phenocrysts of the proximate Eifel volcanic province for which the origin has been determined (mantle xenoliths, high-pressure cumulates, and middle- to low-pressure magmatic phases). This allowed us to determine the likely origin of the tephra minerals. The Rocourt Tephra source could be a West Eifel volcano that was fed by a deep-seated magma batch rich in high- to middle-pressure minerals.

New approaches to European loess: a stratigraphic and methodical review of the past decade

“…In Palaeolithic archaeology the tephra is an excellent marker for the Middle to Upper Palaeolithic cultural transition in Europe [53,54]. In Belgium the Lower Weichselian "Rocourt tephra", originating from the West Eifel Volcanic Field [55], serves as a loess stratigraphic marker, as does the Upper Weichselian "Eltville Tephra" [22,23]. In the Danube Basin several distal tephra layers have been detected in loess (e.g., [9]) but exact provenance and age are not yet established.…”

Valley downcutting in the Ardennes (W Europe): Interplay between tectonically triggered regressive erosion and climatic cyclicity

“…Dating opportunities were provided by the peat layer, with a pollinic assemblage typical of a cold period and an age beyond the 14 C dating limit of 50 ka (Juvigné & Schumacker, 1985). Moreover, minerals of the Rocourt tephra dated between 90 and 74 ka (Pouclet et al, 2008;Lenaz et al, 2010) were found within the alluvial gravels below the peat. All this indicates that the capture, and therefore also the time when the erosion wave had reached Bernister, occurred during MIS 4, at some time between 78 and 50 ka.…”

Detailed characterization of the Late Pleistocene loess sequence stratigraphy of Remicourt (Hesbaye region, Belgium) with cone penetration tests

“…The lower and the medium parts are separated by a hiatus. Enstatite-rich volcanic minerals have been discovered in the two upper thirds of the HCR for the first time in the Gritten sand pit (Gullentops, 1954) and afterwards in many other sites in Belgium (Juvigné, 1977;Juvigné & Semmel, 1988;Juvigné et al, 2008Juvigné et al, , 2013Pouclet et al, 2008;Pirson & Juvigné, 2011). The enstatite-rich tephra was named by Juvigné as the Rocourt Tephra (Juvigné, 1977;Juvigné, 1993).…”

“…Ding et al, 1999;Schellenberger & Veit, 2006), mineralogical (e.g. Smykatz-Kloss et al, 2004;Pouclet et al, 2008;Pouclet & Juvigné, 2009) and chronostratigraphic (e.g. Buylaert et al, 2008;Roberts, 2008) studies.…”

“…Results of these studies point out a succession of layers and horizons including removed sediments, eventual tephra (e.g. Pouclet et al, 2008;Pouclet & Juvigné, 2009) and post-depositional processes as palaeosols formation (e.g. Antoine et al, 2013;Guo et al, 2013;Schellenberger & Veit, 2006), redox processes, chemical and mineralogical modifications (e.g.…”