Salt Movement Role in the Evolution of the Ionian Zone of the Albanides

Velaj, Telo K., Warminster, PA

Surface and subsurface geological data show that Upper Triassic evaporites are widespread in the Ionian Zone. They have played a significant role in tectonics style and especially they have helped the thrusting process.

During rifting stage (T₃-J₃+ Cr₁) the Ionian Zone divided into blocks and grabens by extension normal and strike-slip faults. At this stage, the evaporites developed according to the gravitational principle at the depressive and tectonically weak loops. The evaporite model was a cupola form.

During the collision stage (J₃+Cr₁-Serravalian) the Ionian zone took place mainly under the influence of tangential forces and from evaporite contribution. In this time, the gradual folding occurred, the structures increased their dimension continuously and the extension normal fault were reactivated as thrust faults. In the meantime, the evaporites were not in equilibrium and started moving toward lower pressure sectors. The complication of the Ionian zone happened and the evaporites like diapir sheet through all regional faults of the structural belts (Berati, Kurveleshi and Cika), where each of them has to have overthrusted more than 20-30 km. and sometime backthrusted eastward 5-10 km. Also, the evaporites erupted through all the local faults of the structures, which overthrusted westward with a amplitude 8-10 km. Under these overthrusting faults occur the carbonate structures with hydrocarbon prospective. In all above cases, tectonics-screening traps are another opportunity for exploration.

During the post collision stage (Serravalian-Pliocene) the thrusting of the units of the Ionian zone over each other continued. Also, the overthrust of the Ionian zone onto Apulian platform continued and reach an amplitude of 50-100 km., hiding underneath a transitive zone with the perspective plays.

AAPG Search and Discovery Article #90031©2004 AAPG Eastern Section Meeting, Columbus, Ohio, October 3-5, 2004