peer reviewed ; A detailed survey of the Sinemurian-Pliensbachian Hondelange Formation in southern Belgium led to propose a new lithostratigraphic status for this unit. Important lateral variations together with a 10° angular unconformity with respect to underlying formations suggest that the Hondelange Formation is a prominent element of the transgressive prism in Belgian Lorraine. This study also offers a sequence stratigraphic model for this area with precise description and location of transgressive and maximum flooding surfaces. These results are compared with previous models. A comparison of the magnetic susceptibility data (MS) with sequence stratigraphic units shows that no special effect of the system tract nature is observed. Depositional sequences however are characterized by different mean MS values according to their general sedimentary settings.