Hormuz Salt Distribution and Influence on Structural Style in Northeast Saudi Arabia

Summary This study uses reflection seismic data and wells to map part of the western margin of the Late Precambrian to Cambrian Hormuz salt basin, and to link Hormuz facies distribution to the evolution of major structures in northeast Saudi Arabia. In the eastern part of the study area, seismically-transparent zones with structural elements provide diagnostics for salt tectonics, which pass laterally into layered seismic facies with local clinoform geometries. The transparent facies are interpreted as mobile salt; and the layered facies as immobile evaporite basin margin strata. The layered facies display onlap and fault-bound relationships with older, basement domains and in map-view the Hormuz seismic facies belts form embayments and promontories on the west margin of the salt basin. Areas of mobile salt underlie domal and periclinal structures such as Karan, Hasbah, Dammam and Khursaniyah. These structures display steeply-dipping reflections at depth that can be interpreted as salt pillow flanks, with base salt locally interpretable, and have plan-view aspect ratios of two or less. Beyond the limits of layered seismic facies, between the embayments and westwards toward the Arabian Shield, seismic and well data indicate that the major structures are not salt-cored, including Berri, Manifa, Safaniya, Juraybi’at and Haba.