Analysis of structural architecture in western Saudi Neom City area, northwestern Arabian Plate: Field investigation

Abstract

Saudi Neom City is being constructed as an urban mega-project in the northwestern part of the Arabian plate at the southeastern part of the NNE-oriented sinistral Dead Sea continental transform fault that links the NNW-oriented Red Sea Rift to the Zagros collision through the NE-oriented sinistral East Anatolian Fault. The present study aims to detect and analyze the different structural elements in the western Neom city. It also attempts to provide valuable data to help decision-makers for better achievement of such vital projects. From field investigation, the study area mainly comprises Neogene sedimentary sequence and exhibits a complex structural architecture represented by extensional- and wrench-style deformations. Different fault orientations (NNW–SSE striking extensional faults, WNW–ESE and ENE–WSW striking oblique-slip faults, and NNE–SSW and NNW–SSE striking strike-slip faults) dissect the western Neom area. Individual NNW-oriented Red Sea Rift-related extensional faults and fault blocks are antithetically tilted to the northeast. The sinistral movement onset along the Dead Sea Transform Fault postdates the Lower Miocene Burqan Formation deposition. Furthermore, the sinistral strike-slip regime of the western Neom area involves extensional structures, including normal faults, contractional structures (folds and reverse faults), and structures representing horizontal shear on near-vertical planes. NNW-oriented negative flower structures and forced folding occur along a synthetic NNW-oriented sinistral strike-slip fault set. Contractional structures are expressed by sets of NE-oriented left-handed en echelon-arranged folds in the Middle Miocene deposits. A proposed strain ellipse reveals these structures are associated with the NNE-oriented sinistral Dead Sea Transform Fault. The complexity of the structural architecture of the western Neom area can be attributed to its geologic setting under the influence of the Red Sea extensional rifting followed by the tectonic activity along the Dead Sea transform faulting. It is recommended that the structural attributes investigated, especially the geographic distribution of brittle structures (faults and fractures), be considered during the construction of Neom City.