Characteristics of Salt-Related Faults in Abu Dhabi, UAE

Abstract

AbstractKinematically salt-related faults and fault linkage in Abu Dhabi were classified based on the faults geometry, linkage patterns, deformed layers, and associated salt bodies. The outcrops observations and subsurface numerical modelling address fault patterns and styles. The study is based on analysis of cored data, well logs, and seismic and potential field data and linked to the exposures from outcrops.Salt updoming in the strike slip regions can be formed in the transtensional and in the transpressional regions of the fault segments. Strike slip faults prevailing Abu Dhabi triggered salt movements; as the inherited basement faults reactivation triggered salt in the transpressional regions due to compressional forces. In the transtentional regions, the pull-apart basins is favouring zones for salt updoming. The faults showing asymmetric arrays of tectonic and salt related faults. The tectonic inherited faults are the master segments evolving transtensional/transpressional zones and the diapirs crestal faults are radial in nature linked to the tectonic faults. These faults dip primarily basinward and sole into a subhorizontal salt layer; ramp faults, that extend upward from the landward margin of mushroom salt stocks. The fault segments found triggering salt movement, principally those showing zone of overlap in both transpressional and transtensional regions. In addition, the salt piercements are usually evolved in the transpressional zones and the diapirs not reached the surface formed in the transtensional regions. Therefore, the salt domes are only updoming in these locations answering the question, why not distributed all over Abu Dhabi. Furthermore, the salt mainly allocated in the offshore relative to the onshore, because of the presence of the NE transtenciona shear zone relative to the master NW-fault trends, creating zones of pula-apart basins. The areas of extension between the fault segments are not favoring salt piercement movement and hence forming deep-seated diapirs. Potential field data revealed that the salt is deep seated in the onshore of Abu Dhabi and most of the anticlines forming the giant hydrocarbon fields are rooted by salt diapirs. Understanding the origin of salt movements and their relation to the fault systems of Abu Dhabi help in exploration of the new ventures and development of those fields related to salt tectonics.