Structural Restoration in Sedimentary Basins: A Tool to Analyze the Evolution of Adjacent Plate Boundaries – The Case Study of the Levant Basin and the Dead Sea Transform

Abstract

The Dead Sea Transform (DST) forms a 1000 km long strike-slip plate boundary between the Arabian and African plate. It is located adjacent to the Levant basin in the Eastern Mediterranean. It is widely accepted that the fault has propagated from south to north starting the Early to mid-Miocene times. Different controversies, however, exist regarding the exact timing of propagation and amount of displacement along the DST, especially in its central segment in Lebanon.

In this contribution, we aim address the following questions: (1) when was the transpressive segment of the DST active in Lebanon? and (2) how is the deformation in the adjacent sedimentary basins influenced by the evolution of this plate boundary?

To answer these questions, we undertook a series of 2D and 3D structural restoration over several anticlinal and fault structures in the Levant Basin. The horizon and fault planes were interpreted from seismic data and modelled in MOVE, a 3D restoration software. Data used consisted of high quality PSDM 3D seismic data covering about 15000 Km². Results showed three important deformation times in the basin: (1) Late Cretaceous to Eocene thrusting, mostly along the Lattakia Ridge, (2) Late Miocene, pre-Messinian, affecting all existing structures in the basin and accompanied by strike-slip faulting and intense folding, and (3) Plio-Quaternary, marked by a subtle stress-field rotation, causing minor folding and continuous strike-slip movement.

The deformation phases are consistent with regional geodynamics and the interaction of Afro-Arabia with Eurasia. The Late Cretaceous thrusting has affected mostly the area immediately adjacent to the Lattakia Ridge, while the Late Miocene event has affected the entire basin. This indicates that the Late Miocene event had a great amplitude and could be related to the initiation of the central transpressive DST segment. The final suturing of Arabia and Eurasia during the Plio-Quaternary have probably caused a variation in the regional stress field, resulting in the second phase of DST activity and strike-slip movement in the basin. These results show that deformation in sedimentary basins adjacent to major plate boundaries is strongly affected by the evolution of such boundaries and the resulting stress field. Undertaking restoration and structural analysis could greatly constrain the timing of activity of these faults to better understand their kinematics and effect on petroleum systems.

AAPG Datapages/Search and Discovery Article #90323 ©2018 AAPG Annual Convention and Exhibition, Salt Lake City, Utah, May 20-23, 2018