GEODYNAMICS CONTEXT OF THE COLLOVIAN-OXFO RDIAN TRANSITION IN THE NNEPARIS BASIN

In the Dommery area, near Signy-I'Abbaye (Ardennes county, France), 60 m of Upper Jurassic ''gaize'' facies crop out and correspond to less than 500,000 years of the Callovian-Oxfordian transition. Measured com paction rate reaches 1.3 to 1.4 indicating lithostatic overburden of a bout 200 m. Sedimentation rate is close to 16 cm per 1,000 years at le ast. Marine sedimentation occurred in a shallow water environment unde r weak hydrodynamic conditions. These new data suggest that the site i nvestigated was submitted to a continuous subsidence in a distensive t ectonic context.