The Albian tectonic “crisis” in Central Tunisia: Nature and chronology of the deformations

• The classical Mid-Cretaceous tectonic «crisis» of Tunisia is actually mainly of Albian age.
• Synsedimentary deformations increased throughout the Early to Middle Albian.
• Extensional deformation preceded and triggered halokinetic movements.
• This Albian tectonics was related to the opening of the equatorial Atlantic Ocean.

The Mid-Cretaceous tectonic “crisis” is a classical feature of the tectono-sedimentary evolution of Tunisia. A reappraisal of synsedimentary deformation observed in the Tajerouine and Kasserine areas shows that deformation began in the earliest Albian, increased during the Early Albian, and culminated in the Middle Albian. Late Albian deposits overly, locally with a strong angular unconformity, Aptian to Early Albian sediments. In the southern part of the studied area, fault tectonics and tilted blocks dominate, whereas in the northern area, the occurrence of slumps and olistoliths suggests deformation related to incipient salt movements at depth. These new chronological constraints suggest that this tectonic event is most probably related to the final opening of the Atlantic Ocean at equatorial latitudes.