New lithostratigraphical, sedimentological, mineralogical and palaeontological data on the Mesozoic of Belgian Lorraine: a progress report

A multidisciplinary study of some extensively cored boreholes together with the new 1/25.000 geological mapping of wallonia lead us to propose a new lithostratigraphic canvas for belgian lorraine. This area is located on the n-e border of the paris basin, south of the ardennes; the studied stratigraphic interval covers the keuper to the toarcian. Each of the newly defined units is sedimentologicaly interpreted on the basis of macroscopic and microscopic observations. Detailed palynological and claystratigraphical analyses have been performed, providingadditional stratigraphical, palaeoecological and sedimentological data. Moreover, a first sequence stratigraphic interpretation is proposed for this highly transgressive sedimentary body. The habay formation (conglomerates and red mudstones) is a fluvial unit, with immature channel conglomerates and paleosoils; the attert formation (dolomitic marls with gypsum and pseudomorphs) exhibites an evaporitic trend. The Mortinsart formation (sands and marls) corresponds to a restricted marine unit, evolving towards an alluvial plain (levallois member). The second cycle begins with the Jamoigne Formation (bioturbated marls and limestones), a marine subtidal restricted unit, evolving towards a more sandy sedimentary body (Metzert Member). The base of the third cycle corresponds to the rest of the Luxemburg Formation, comprising a succession of sandy waves. The Ethe Formation (laminar mudstones and marls) marks a deepening of the basin and the outset of open marine dysaerobic conditions. The Aubange Formation (bioturbated marls with sandstones and limestones) is characterized by the reappearance of a normal benthic fauna. The Grandcourt Formation (laminar mudstones and marls) marks a return to open marine dysaerobic conditions. The Mont-Saint-Martin Formation (marls, sandy marls and oolitic ironstone) is a highly regressive unit, while the Longwy Formation (limestones) marks the initiation of a carbonate platform