Longitudinal Variations in Rift Architecture and Sedimentation - Case Study from the Eastern Blocks of the Gulf of Suez, Egypt

By

Mohamed Abdel Fattah¹, Mohamed Darwish¹, Adel Sehim¹

(1) Cairo University, Cairo, Egypt

The Gulf of Suez represents unique exposures for studying architecture and sedimentation in rift systems. The central-east rift-blocks are selected for detailed mapping and analysis aiming at reaching a model for rift development and sedimentation in time and space.

The northern rift-border (Baba) fault-system reflects listric-geometry through linkage of several fault-segments. Linkage areas represent deficit-nodes for ruptures. Generally, displacement cessates due south where the northern major displacement exceeded the rate of deposition and shows extensive drags and thrusts. Baba fault-system merges at depth and along-strike with major rift-coastal fault, which forms an intra-basinal ridge separating two different basinal-segments. These two fault-systems cessate southward and synthetic approached with a master Miocene-bounding (Sidri) collateral faults. The linkage area represents low-stand zone onlapped by syn-rifting sediments. Younger channel-clastics charged the rift through this low-stand entry point.

8.5 km wide flexure-zone represents the entrapped block between Sidri fault-system and the basement-border fault. This flexure-zone is crossed by two longitudinal, conjugately dipping fault-systems with intervening transfer zones. Sidri fault-system terminates due south across a hard-linkage transfer fault. South of the latter, the rift is bounded by a master fault showing along-strike displacement variation and transverse folds.

The above represents drastic longitudinal variations in rift-width and blocks architecture reflecting rift development through several rift-centers that propagated and linked during three rift-phases. The linkage areas and differential fault associated subsidence controlled the Miocene basin-morphology and related sedimentation.