Abstract: Neogene Dextral Oblique Convergence and Related Structural Traps in the Southern Carpathian Foreland (Romania)

LINZER, HANS-GERT

Kinematic analysis of deformation structures of the Mio-Pliocene foreland sediments and of the Carpathian nappe system facilitates a new interpretation of subsurface structures, migration pathways for hydrocarbons and their accumulation. The evolution of the Carpathian arc and its foreland is characterized by a pre-existing plate geometry formed by the Moesian plate in the south, the European Plate in the north and an oceanic embayment between them. In Oligocene times the embayment was isolated by the forward moving Alpine-Carpathian thrust system when the main source rocks of the Carpathians were deposited in a similar environment and extension as in the Black Sea.

The Getic/Dacic foreland basin was formed by the oblique thrusting of the South Carpathian nappes onto the Moesian Plate as an effect of west to east retreating subduction in Late Miocene times. The foreland basin is traced by dextral strike-slip faults which were active at least up to Romanian times (2Ma) as displacement transfer structures between the dextrally oblique fore and backthrusts. While the forethrusts were blocked in Meotian times (9 Ma) at the frontal edge of the thrust belt (limited to the extension of Badenian salt), the backthrusts developed simultaneously with dextral strike-slip faults to compensate the west to east movement of the South Carpathians. Oil fields lined up along dextral strike-slip faults indicate migration of hydrocarbons across the sole thrust.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria