Rift Basin Sequence Stratigraphy: Some Examples from the Gulf Of Suez

Abstract

Unconformity-bounded sequences within the Miocene strata of the Suez Rift reflect a complex interplay between tectonism and sea level fluctuations. Analyses of Miocene outcrops along the Sinai margin of the Gulf of Suez provide new insights into the sequence stratigraphy of this basin. The Miocene strata can be subdivided into seven major sequences separated by biostratigraphically defined time breaks. These lacunae represent depositional sequence boundaries, transgressive surfaces and condensed sections. These basinwide time breaks were related to major tectonic events from rift initiation through rift climax, and post-rift stages. These events include regional sag and fault initiation, fault linkage, footwall uplift, shallowing of detachment depths and increased fault block rotations, regional isostatic uplift, and thermal subsidence. Superimposed on this complex structural evolution were Miocene sea level fluctuations of a magnitude of several tens of meters to a hundred meters. The Sinai outcrops expose the four oldest Miocene biostratigraphic sequences which correspond to two depositional sequences. The lower sequence consists of the Nukhul Formation which was deposited during a transgression (with the higher frequency events recorded as local erosional surfaces, flooding surfaces, and ravinements) and the Mheiherrat Formation which was deposited during a relative high stand. The upper sequence includes the Asl Formation which was deposited during a low stand and the Ras Budran Member of the Ayun Musa Formation which was deposited during the ensuing high stand.

Combined stratigraphic-structural play characterization in hydrocarbon exploration: A case study of Middle Miocene sandstones, Gulf of Suez basin, Egypt

“… Integration of structural and stratigraphic analysis, as well as characterization of the petroleum elements of the Middle Miocene Baba sandstones suggests the presence of a unique combined stratigraphic-structural trapping mechanism. Wescott et al, 1996;Bowsorth and McClay, 2001). Sea-level is derived from Haq and Al-Qahtani (2005).…”

Effect of petrography and diagenesis on the sandstone reservoir quality: a case study of the Middle Miocene Kareem Formation in the North Geisum oil field, Gulf of Suez, Egypt

“…The interbedded sands provide excellent reservoirs with porosities ranging from 11 to 24% (Abd El-Naby et al 2010). The palaeo-depositional environments are difficult to interpret because of a lack of faunal content (Wescott et al 1996). The Kareem Formation is subdivided into two members: Shagar Member at the top and Rahmi Member at the bottom.…”

Sequence stratigraphy of the upper Oligocene–middle Miocene succession in west–central Sinai, Egypt

“…The Nukhul/Rudeis formational contact is characterized by abrupt facies and faunal discontinuities, representing the basal sequence boundary (SB2) for the lower Burdigalian depositional sequence (BuM/S‐SQ3). It denotes a hiatus marking the initiation of an accelerated rifting (Evans & Moxon, 1986) and a biostratigraphic break with a duration of about 2 myr (Beleity, 1982; Evans, 1988; Wescot et al, 1996) across the Aquitanian/Burdigalian boundary. This break is indicated by the absence of the planktonic foraminiferal M1b Subzone in the studied sections.…”

“…Sequence stratigraphy may introduce a more accurate and detailed correlation for the Miocene succession of west–central Sinai to enhance the knowledge of the lateral facies variability. Some papers have treated the sequence stratigraphy of the Egyptian upper Oligocene–middle Miocene succession (e.g., Ayyad et al, 2020; El‐Azabi, 2004; Hewaidy et al, 2013; Wescot et al, 1996). Relative sea‐level oscillations are the main driver for environmental fluctuations and, therefore, lead to significant changes in the faunal distribution.…”