Strontium isotopes correlation of the Tunisian Late Cretaceous Abiod Formation: Comparison to previous biostratigraphic assignments

• New unpublished strontium isotopes data for the Abiod Formation at El Djebil section (NW Tunisia) are presented.
• New strontium isotopes data correlated to published data of the Miskar Field (Mabrouk et al., 2005) are discussed.
• The numeric age ranges of the Abiod Formation at El Djebil section and in the Miskar Field are shown to be similar.
• Strontium isotopes numeric dating concurs with biostratigraphic attributions.
• The Abiod Formation of Miskar is a condensed chalk sequence that was deposited through Campanian-Early Maastrichtian time.

The Tunisian topmost Le Kef Formation and Abiod Formation were the focus of strontium isotopes numeric age dating. A representative outcrop section in NW Tunisia near Le Kef town (El Djebil section) constituted the main study material. In addition, a small outcrop section (Kodiet ez Zarbia) in NW Tunisia, equivalent of the base of the overlying El Haria Formation, was also examined. Results were compared to previous numeric dating by Mabrouk et al. (2005) of the Aleg (lateral equivalent of Le Kef Formation), Abiod and El Haria formations in four offshore wells from the Miskar Gas Field (Miskar W1, W2, W3, and W4), Gulf of Gabes, SE Tunisia. Strontium isotopes stratigraphy, overall, supports the previous biostratigraphic assignments and indicates that: (i) the age ranges of the Abiod Formation at El Djebil section and in the Miskar Field are very similar; (ii) the age of the Le Kef Formation at El Djebil section is younger than its equivalent Aleg Formation in the Miskar Field; (iii) the El Haria Formation, cored in Miskar W3 and sampled at Kodiet ez Zarbia, is of approximately the same age. The strontium isotopes dating concurs with biostratigraphic assignments and suggest that the Abiod Formation in Miskar W1 (SE) corresponds to most of that occurring at El Djebil section (NW) and is therefore a condensed chalk sequence that was deposited through Campanian–Early Maastrichtian time.