Update of the Devonian lithostratigraphic subdivision in the subsurface of the Campine Basin (northern Belgium)

1. IntroductionDuring the systematic lithostratigraphic description of the Palaeozoic deposits from the subsurface of the Campine Basin in northern Belgium (Lagrou, 2012), it appeared that certain stratigraphic intervals in deep boreholes, already identified and investigated as separated units by different authors (Langenaeker, 2000; Laenen, 2003), were not yet formally named. As one of the goals of the detailed stratigraphic study of Lagrou (2012) was to put all data in the Flemish web-based ‘Databank Ondergrond Vlaanderen’ (DOV), codes for the different lithostratigraphic units were needed. To be in accordance with DOV as well as with the Belgian official stratigraphy, the newly proposed lithostratigraphic units were submitted to the Belgian National Commission on Stratigraphy.This was the case for the Devonian Booischot Formation which is defined at the base of the Booischot borehole, above the Caledonian basement of the Brabant Massif. The Booischot borehole (Fig. 1A) has been drilled in 1963 for the Geological Survey of Belgium where the collection of cores is still stored and easily available. More generally, we present in this paper a complete stratigraphic overview of the Devonian from the Campine Basin, which has also been intersected by the Heibaart borehole (Fig. 1A). The study of the Heibaart borehole is mainly based on the unpublished report of Cornet (1976) illustrated by two photographic volumes of discontinuous cores with comments, which are stored in the Arch