The Tertiary Thrust Belt Evolution of Southern Albania

Barbullushi, Roland, Consultant, London, England

The southern Albania thrust belt comprises Mesozoic - Eocene carbonate sequences incorporated into three major Tertiary thrust sheets verging towards the Apulia foreland in the southwest. The problem of the structural evolution has been previously approached through a hypothesis of merely orthogonal thin-skinned thrusting controlled by a differen­tial areal extent of Permo-Triassic evaporites.

This presentation addresses questions that include those relating to the subsurface geo­metric patterns of the thrust sheets, the kinematic framework the evaporites operated in, the role of the pre-existing faults and the timing of the evolution. This is done by constructing 14 regional cross sections as well as analysing fault slip data and structural relationships between thrust sheets and the foreland basin. A large data base of seismic profiles and wells as well as structural and kinematic data collected in the field is used.

Their integrated analysis demonstrates that significant along - strike changes character­ize the subsurface geometry of the thrust sheets. The Permo-Triassic evaporites facilitated their buttressing towards a buffer zone in the Apulian foreland under a rotational transpres­sional â “ compression regime. Pre-existing normal faults played a significant role on thrusting, accomodation of the strain partitioning and were inverted under the influence of a regional shear couple. The main structural events included thin-skinned thrusting during Oligocene â “ Aquitaniane, formation of a buffer zone in the foreland during Burdigalian and subsequent thrust - buttressing during the Miocene.