Neotectonics of the Offshore Sirte Basin

This study utilizes thirty-four intersecting, multi-channel regional 2D seismic lines from the Offshore Sirte Basin, Libya, to assess the structure and stratigraphy from the Miocene to the Quaternary. The structural regime has been reviewed in relation to regional tectonic events in the Western Mediterranean. The structural style of the study area is characterized by normal faults with a variation in throw direction and fault-related folds. The major structural trend is NW-SE trending, with some Neogene structures inheriting the trend of the pre-existing rift structures. Analysis of the structural and stratigraphic interaction observed in the study indicates that stratigraphic thickness variations were controlled by faulting. Normal faults of Pre-Messinian age lie broadly parallel to the coastline in the South-east of the study area and dip basinward. In the north-eastern part, deformation of Plio-Quaternary sediments is due to differential compaction in underlying incised channels of Messinian age. The South-central part of the study is dominated by Mid-Miocene (?) conjugate fault sets which are bounded by reactivated Pre-Neogene rift faults, while the structures in the North-central margin of the study area are Plio-Quaternary normal faults created by loading of underlying Messinian age evaporites. The extreme western part of the study area in the adjacent Misurata Basin, is marked by transition from purely extensional to transtensional processes. Integrating the evidence obtained from the seismic data, it is proposed that the Neotectonic evolution of the Offshore Sirte Basin is controlled principally by rapid subsidence and re-activation of pre-existing major faults and salt-related thin-skinned tectonics. The transtensional structures, in the Misurata Basin to the west, are interpreted to be related to regional plate reorganization during Neogene times. The reactivated normal faults, conjugate faults and transtensional structures emplaced by