(a) Outcrop photograph to the North-East of the sub-site A located in the Cordatum zone (Early Oxfordian). The sub-site A is composed of three main units, A1, A2 and A3 from the base to the top. Three samples have been collected: (b) in the basal lens of the sub-site A1 (sample A1), (c) in nodules (sample N) located about 5 m beneath, and (d) in tubes (sample T) located about 10 m beneath compared to regional stratigraphy So.