1. INTRODUCTION

The synthesis of the bio- and lithostratigraphy of the Dinantian of Belgium published by Paproth et al. in 1983, followed an earlier one by Mortelmans & Bourguignon (1954) which was based on more than a century of investigations. The 1983 synthesis included the numerous advances in sedimentology and biostratigraphy which had occurred during this period and proposed a stratigraphic chart of the Dinantian which until now served as a reference for the Tournaisian and Visean series.

The resumption of the geological mapping in 1990, after a pause of almost a century, has provided many new observations, but has also raised new questions stimulating a revision of the existing lithostratigraphic scheme.

Re-evaluation, by Hance et al. (2001), of the Dinantian biostratigraphic pattern and the application of the concept of sequence stratigraphy to the whole Dinantian succession of southern Belgium, northern France (Avesnois, Boulonnais) and south-west England (Bristol area), has improved the understanding of the sedimentary history and clarified the stratigraphic succession of the sedimentary units in many places. In particular, the recognition of a third-order sequence (sequence 5 of Hance et al., 2001, corresponding to most of the Sovet Fm), developed only in the deeper part of the outer shelf and missing on the shallow shelf, has led to a better understanding of the Tournaisian-Visean boundary and more accurate lithostratigraphic correlations. In addition, the identification of paleogeographic sedimentary areas distinct from the structural units inherited from the Variscan orogeny and having their own tectono-sedimentary history, has shed some light on several lithostratigraphic features. These include, for example, the lithostratigraphic changes recorded in the Visé area, and the absence of Ivorian deposits in the Huy – Engis area.

These developments justify the updating of the synthesis of Paproth et al. (1983).