The Algero-Tunisian confines (Tebessa region) is partially composed of Cenomano- Turonian carbonate outcrops; therefore, it presents a good example to highlight the black shale levels reported over a short period, around the Cenomanian-Turonian boundary. The lithostratigraphic study made it possible to specify the paleoenvironment during the Cenomano-Turonian in the Tebessa region. At that time, the depositional environment emphasized a relatively deep, calm and often confined ocean environment that was significantly shalloweron the north part of the study area. The lithology and the distribution of the facies in the Constantine domain allow us to underline the pelagic influences during the Upper Cretaceous and neritic during the lower Cretaceous period. We note a maximum thickness of the Cenomano- Turonian in the southern zones and a minimum (100m) appears further north. This Palaeogeographic organization continue laterally in Tunisia on the extension of the Constantine mole.

The Algero-Tunisian confines (Tebessa region) is partially composed of Cenomano- Turonian carbonate outcrops; therefore, it presents a good example to highlight the black shale levels reported over a short period, around the Cenomanian-Turonian boundary. The lithostratigraphic study made it possible to specify the paleoenvironment during the Cenomano-Turonian in the Tebessa region. At that time, the depositional environment emphasized a relatively deep, calm and often confined ocean environment that was significantly shalloweron the north part of the study area. The lithology and the distribution of the facies in the Constantine domain allow us to underline the pelagic influences during the Upper Cretaceous and neritic during the lower Cretaceous period. We note a maximum thickness of the Cenomano- Turonian in the southern zones and a minimum (100m) appears further north. This Palaeogeographic organization continue laterally in Tunisia on the extension of the Constantine mole.

The Algero-Tunisian confines (Tebessa region) is partially composed of Cenomano- Turonian carbonate outcrops; therefore, it presents a good example to highlight the black shale levels reported over a short period, around the Cenomanian-Turonian boundary. The lithostratigraphic study made it possible to specify the paleoenvironment during the Cenomano-Turonian in the Tebessa region. At that time, the depositional environment emphasized a relatively deep, calm and often confined ocean environment that was significantly shalloweron the north part of the study area. The lithology and the distribution of the facies in the Constantine domain allow us to underline the pelagic influences during the Upper Cretaceous and neritic during the lower Cretaceous period. We note a maximum thickness of the Cenomano- Turonian in the southern zones and a minimum (100m) appears further north. This Palaeogeographic organization continue laterally in Tunisia on the extension of the Constantine mole.