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Overview of the Tectonic Evolution of the Levantine Region on the Basis of Field Constrains

Catherine Homberg

The onshore Levantine region extends along the Eastern Mediterranean coast from the Red Sea rift to the south to the Bitlis suture to the north. It was deformed by several tectonic events during Mesozoic-Cenozoic times, in relation with the interaction of the African, Arabian, and Eurasian plates. The area shows many similarities, but it is composed of distinct sectors as a result of the complex tectonic evolution of the region. The prominent structure is the Dead Sea fault, a major N-S transform which shows a restraining NE-SW bend in Lebanon. The region is cut by numerous normal faults with direction spanning from NE-SW to WSW-ENE. NE-SW faults of Liassic age are well documented at several places (onshore and offshore). They result from the rifting episode of the Levantine basin, a major structuring agent of the area. A second episode of normal faulting occurred in the Early Cretaceous. In Lebanon, the sedimentation was largely controlled by the associated tectonic structures, with considerable thickening of the Neocomian Chouf sandstones within in an E-W basin. Other extensional periods occurred in the Late Cretaceous and in the Eocene and formed NW-SE and E-W tectonic structures. The inversion of the margin and deformation of the Arabian platform led to the development of E-W to NE-SW folds and various faults referred in the literature as the ‘Syrian Arc structures’. Modern interpretations indicate a composite origin of these structures. The Late Cretaceous inversion was very pronounced in the southern margin (Sinai, Negev) whereas Lebanon (onshore) and Syrian coastal range were little deformed at this time. A second compression with a similar WSW-ESE to NW-SE direction occurred in the Early Miocene. Thrusts and folds in NW Syria gentle folds in Lebanon developed whereas southern Israel escapes this deformation phase. The development of the Dead Sea transform plate boundary produced a complex deformation pattern, with a significant degree of diachronism through the Levant region. Recent mechanical investigation suggests that the transform fault initiated simultaneously in the south and in the north and propagated to form a compressive relay in Lebanon. The Neogene period is marked by a rotation of the compression to a NNW-SSW direction all over the region. The pattern of deformation is variable along the plate boundary and includes folds, normal and strike-slip faults, aligned or oblique to the main transform fault.

AAPG Search and Discovery Article #90161©2013 AAPG European Regional Conference, Barcelona, Spain, 8-10 April 2013